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View Full Version : new Marshall DSL 40 and 100 cap "mod"


tmac
12-08-2012, 08:59 AM
not sure if this has been covered yet, so...

the old Marshall DSL heads C12 cap mod (disconnecting the 470pf that is across the OD channel gain pot) is cap C19 in the new DSL 40 combo/100 head. sits right behind the pot on the board. I just left in place but lifted one leg of connection so that it is out of circuit. easy to put back if needed

really makes a big difference in brightness (harshness to me) of the OD (red) channel if like me u run gain pretty low (and crank the volume) for a more vintage type OD tone. and really matches up the tones of red and green (clean) channels in my opinion.

this really depends on your playing style, guitar, speakers, etc. some find this channel too bright but some may like the cut it provides with the cap in place. and if you are cranking up the gain pot it is probably not an issue (because the more the gain pot is turned up the more this capacitor is out of the circuit). this mod also cuts out some hiss noise. a lot of folks hate these DSLs, lot of folks love 'em, but it sounds great to me - with this mod.

I can post pics if anyone needs.

Prattacaster
12-08-2012, 10:32 AM
Those amp really shine on recordings and live. They seem mediocre when used for practicing and jamming; stick a mic in front of them and they are glorious.

tmac
12-08-2012, 11:22 AM
I agree somewhat, these DSL's (& pretty much like any good Marshall) sound best cranked to get those EL-34s workin'. that smooths out the fizz of the cascaded preamp gain, plus you can actually decrease the preamp gain too. this is the way they're meant to be used I think and in live settings they blend beautifully. I prefer my original builds/mods with the vinatge non-cascaded 1987/1959 circuits but they have to be cranked (like we used to in the old daze lol) to get that grind. if I use those I have to bring along a tube screamer for grind at "reasonable" volumes and still usually have to use one of my Prineton Reverbs instead. with the DSL you do have some volume control and still get pretty good Marshall flavor at what is now considered reasonable gig volumes. I like the old days when we didnt mic everything and we cranked it.

Those amp really shine on recordings and live. They seem mediocre when used for practicing and jamming; stick a mic in front of them and they are glorious.

tmac
12-08-2012, 11:33 AM
let me add that the digital reverb in these new DSLs is ok but not as good as I remember the older ones with spring rev. this amp seems to be pretty well built and has beefy iron. punchy 40W too. conservative rating imho. I have not changed tubes or anything, all stock glass, didn't check bias. looks like two trim pots inside chassis for bias adjust.

Kenster
12-10-2012, 12:07 PM
Did you have to remove the board to lift the leg of the cap? I picked up a 40C and it sounds really good to me. But like you I preferred to keep the gain low on the Lead channel which makes it quite bright. I usually used lead 2 since it has a bit more bass even with a low setting which helped quite a bit.

Also I put in a G12-65 which also tamed the overall brightness of the amp compared to the 70/80 it came with.

Pics would be cool if you have them handy.

Thanks for posting this mod.
K

tmac
12-10-2012, 02:11 PM
u r welcome. ok, I'll post some pics I took when I opened her up.

You don't need to lift the board or anything, just make sure caps are discharged and unsolder one leg and lift the cap so that leg pulls out. I did the right cap leg (with rear of chassis facing me) as it was easiest for me and was more room on that side.

Before I bent the leg up and out of the way I plugged in my LP and played while I pressed down the leg (with my plastic non-conductive probe tool!) to make contact again to hear the difference with it in and out of the circuit. Quite a dramatic difference.

I like the idea of a G12-65, might have to try one.

Did you have to remove the board to lift the leg of the cap? I picked up a 40C and it sounds really good to me. But like you I preferred to keep the gain low on the Lead channel which makes it quite bright. I usually used lead 2 since it has a bit more bass even with a low setting which helped quite a bit.

Also I put in a G12-65 which also tamed the overall brightness of the amp compared to the 70/80 it came with.

Pics would be cool if you have them handy.

Thanks for posting this mod.
K

Kenster
12-10-2012, 05:19 PM
Thanks Tmac for the pics in advance. One more question. What wattage soldering are you using on this board. I have the usual 40 or 50Watt for doing wiring to terminals and guitar circuits but that might be too hot. I also have 25 watter which might be the ticket.


Cheers
Ken

tmac
12-10-2012, 05:20 PM
pics are unmodded state

http://img.photobucket.com/albums/v161/tmac1/MarshallDSL40Ca.jpg

http://img.photobucket.com/albums/v161/tmac1/MarshallDSL40Cc.jpg

http://img.photobucket.com/albums/v161/tmac1/MArshallDSL40Cb.jpg

tmac
12-10-2012, 05:24 PM
I used my 40W but used a fairly sharp tip. I like to work hot but get on & off the part quickly and have many years doing so. I'd recommend the 25W, should be just fine because it's a tiny area. Good luck and let us know what you think.

Thanks Tmac for the pics in advance. One more question. What wattage soldering are you using on this board. I have the usual 40 or 50Watt for doing wiring to terminals and guitar circuits but that might be too hot. I also have 25 watter which might be the ticket.


Cheers
Ken

Kenster
12-11-2012, 11:34 AM
I used my 40W but used a fairly sharp tip. I like to work hot but get on & off the part quickly and have many years doing so. I'd recommend the 25W, should be just fine because it's a tiny area. Good luck and let us know what you think.

Excellent. 25 Watt it is. I'm pretty sure I'm going to like this mod. Now I just have to find the time to actually do it :-). Im liking this amp more an more so this will just take it over the top. Only other thing I wished it had was footswitchable modes. I know.. can't have everything.

One other thing I noticed was when checking the bias only the left trim pot as you face the back of the amp actually changed the bias. Tried the right one and it did nothing. I did notice an increase in hum when I moved it from its original position so I moved it back till it was quiet again. Maybe this is a balance control??

Anyway this a very cool sounding amp, especially for its price point.
Thanks again for the info. I'll let you know what I think of the mod when I get around to it.
Ken

tmac
12-11-2012, 12:47 PM
thanks Ken, good info on the bias pot, I agree the other trim pot maybe a tube balance or hum balance on the heaters? Haven't seen a schem for these yet, so if anyone has a schematic please post. btw, what did you bias to? did you check plate voltage on the EL-34's?

When anyone attempts this mod don't force anything and lift the cap lead out carefully, the board traces can be fragile & we don't want any torn or lifted traces. There does seem to be enough of a leg on the cap to cleanly clip & be able to solder back if needed but I don't like doing it that way.

Excellent. 25 Watt it is. I'm pretty sure I'm going to like this mod. Now I just have to find the time to actually do it :-). Im liking this amp more an more so this will just take it over the top. Only other thing I wished it had was footswitchable modes. I know.. can't have everything.

One other thing I noticed was when checking the bias only the left trim pot as you face the back of the amp actually changed the bias. Tried the right one and it did nothing. I did notice an increase in hum when I moved it from its original position so I moved it back till it was quiet again. Maybe this is a balance control??

Anyway this a very cool sounding amp, especially for its price point.
Thanks again for the info. I'll let you know what I think of the mod when I get around to it.
Ken

pdf64
12-12-2012, 02:42 AM
Tried the right one and it did nothing.
Were you monitoring the current on the right tube at the time (or did you leave the meter on the left one)?
If hum increased when twiddling the right one, a likely cause of that is an imbalance in the OT primary currents of either leg, ie the trimmer really was changing the current.
Just checking, human error is something we're all qualified for.
Pete

tmac
12-12-2012, 09:28 AM
a little OT but I like your band Pete and the tones you're getting, sounded vintage Marshall-y, what amp you using in those clipz?

Were you monitoring the current on the right tube at the time (or did you leave the meter on the left one)?
If hum increased when twiddling the right one, a likely cause of that is an imbalance in the OT primary currents of either leg, ie the trimmer really was changing the current.
Just checking, human error is something we're all qualified for.
Pete

Kenster
12-12-2012, 05:05 PM
Were you monitoring the current on the right tube at the time (or did you leave the meter on the left one)?
If hum increased when twiddling the right one, a likely cause of that is an imbalance in the OT primary currents of either leg, ie the trimmer really was changing the current.
Just checking, human error is something we're all qualified for.
Pete

Honestly Pete I don't remember since its been a couple months. If I recall I was using one of Eurotubes Bias Probes hooked to the right tube when facing from the back and nothing was changing as I was using the right pot. Just the increase in noise(hum) which was real faint. I then changed the Bias Probe to the left tube and was able to adjust the bias with the left trimmer. Using the right trimmer just increased noise again. Who knows I could have done something wrong initially.

I would like to confirm for sure what the right trimpot does, so we'll have to wait for schemes to come available or someone who knows from their technical prowess.

I ultimately set it to 70% dissipation which again if I recall was around 32 to 36 ma. It was a little colder than that from the factory but not too bad. Sounds bitchin now though :dude.

Ken

Jose Eduardo
12-14-2012, 08:15 PM
Thanks for the tip. I just got a DSL40C. I like the sounds I'm getting so far. Do you know if there are sound clips available anywhere comparing the sounds?

tmac
12-15-2012, 08:30 AM
I'm not aware of any clips at this time, but if you like it now, seems to be no need to mess with it?

Thanks for the tip. I just got a DSL40C. I like the sounds I'm getting so far. Do you know if there are sound clips available anywhere comparing the sounds?

Jose Eduardo
12-15-2012, 08:56 AM
I'm not aware of any clips at this time, but if you like it now, seems to be no need to mess with it?

Absolutely, I don't see myself doing that. I was more curiosity than anything else...

Kenster
12-15-2012, 11:50 AM
I finally got around to doing this mod. Took me all of 10 minutes to do. All I can say is what was Marshall thinking putting that cap in. Removing it made the transition from the Green Channel to the Red Channel very smooth. I had the Lead One Red Channel set for 3 - 5 on the gain knob and there was zero increase in treble frequencies when switching channels. Only change was a thicker sound at whatever volume you want. I don't miss the separate EQ at all now.

I would encourage anyone to try this mod and like TMAC says it's reversable and be mindfull of the precautions when going inside of these amps. I really love the tones this amp can out but now it's a great versatile amp for the money.

Naturally when it come to tone and features YMMV.

Cheers
Ken

Rod
12-15-2012, 02:18 PM
Great info! !!

tmac
12-17-2012, 01:18 PM
my sentiments exactly Kenster. glad mod worked out. did you just lift out one leg or remove cap altogether?

I finally got around to doing this mod. Took me all of 10 minutes to do. All I can say is what was Marshall thinking putting that cap in. Removing it made the transition from the Green Channel to the Red Channel very smooth. I had the Lead One Red Channel set for 3 - 5 on the gain knob and there was zero increase in treble frequencies when switching channels. Only change was a thicker sound at whatever volume you want. I don't miss the separate EQ at all now.

I would encourage anyone to try this mod and like TMAC says it's reversable and be mindfull of the precautions when going inside of these amps. I really love the tones this amp can out but now it's a great versatile amp for the money.

Naturally when it come to tone and features YMMV.

Cheers
Ken

Kenster
12-17-2012, 04:51 PM
my sentiments exactly Kenster. glad mod worked out. did you just lift out one leg or remove cap altogether?

I just lifted one leg. Red channel sure sounds sweet now and as mentioned before the transition when switching channels is so smooth. If anything it seems to add just a little bit of mids and fatten up the tone.

Ken

tmac
12-17-2012, 05:26 PM
definitely lets fatness through and still has plenty of treble response for me & I can actually use the treble knob now! before disconnecting that cap i was immediately turning treble almost off when I went from green to red channel.

I just lifted one leg. Red channel sure sounds sweet now and as mentioned before the transition when switching channels is so smooth. If anything it seems to add just a little bit of mids and fatten up the tone.

Ken

telejammer
12-18-2012, 12:27 PM
I have giged my DSL40C 3 times now and it does sound good, has anyone played the amp at gig volume say 1-2 o'clock withthe mod done? If so did the amp still cut or have still have ample room to adjust the EQ's without getting to muddy or bassy? I'm curious to know before attempting this mod. I do agree the red channel is way more trebley compared to the clean channel.I too have trouble switching between the channels without re-adjusting EQ's.

tmac
12-18-2012, 07:08 PM
was doing just that! I thought it still had plenty of cut and matched up well with green channel. had treble on 6 pres on 6. used my LP and a Srtat. certainly doesnt get muddy but less cut than before. I haven't done a gig with it yet though. next gig is a NYE Stones tribute and I'm using my Princeton Reverb to blend well with other guitar player. it'll be after first of year before I get to use this with a group.

I have giged my DSL40C 3 times now and it does sound good, has anyone played the amp at gig volume say 1-2 o'clock withthe mod done? If so did the amp still cut or have still have ample room to adjust the EQ's without getting to muddy or bassy? I'm curious to know before attempting this mod. I do agree the red channel is way more trebley compared to the clean channel.I too have trouble switching between the channels without re-adjusting EQ's.

telejammer
12-18-2012, 08:53 PM
I have never worked on amp chassies before,what is the safe way to dicharge the filter caps? Also if I just do the clip instead of de-soldering should I clip closest to the board or leave some of the tail on the board? Any advice would be appreciated. Or should I have a tech do this?

tmac
12-19-2012, 08:02 AM
Since u have no experience i'd recommend a tech, but you can read up on discharging caps and safely working on amps in other posts, too much to cover here. You would want to be very comfortable working on amps before attempting. Just get a tech to do it. should be quick & a minimal bench charge. just show him this post. If you were close I'd do it for u.
Tony

I have never worked on amp chassies before,what is the safe way to dicharge the filter caps? Also if I just do the clip instead of de-soldering should I clip closest to the board or leave some of the tail on the board? Any advice would be appreciated. Or should I have a tech do this?

Jose Eduardo
12-20-2012, 02:20 PM
Absolutely, I don't see myself doing that. I was more curiosity than anything else...

I should never say never! Curiosity killed the cat. I actually did the mod. Now from liking the sounds I was getting, now I absolutely love how balanced both channels are. The ultra gain channel is less trebly, it has now more warmth to it.

Thanks again!!

Kenster
12-21-2012, 11:38 AM
I should never say never! Curiosity killed the cat. I actually did the mod. Now from liking the sounds I was getting, now I absolutely love how balanced both channels are. The ultra gain channel is less trebly, it has now more warmth to it.

Thanks again!!

Cool isn't it? Makes you wonder what they were thinking puttng that cap in. Glad you found it useful.

Big thanks to Tmac for posting this mod. When I bought this amp and opened it up I knew one of those caps was the culprit but I was going to wait for schematics or a player like Tmac to try it and share it with others.

Cheers
Ken

tmac
12-21-2012, 03:21 PM
very welcome guys. would love a schematic if anyone can find . I emailed Marshall & so far nuttin'
maybe they will get one out soon



Cool isn't it? Makes you wonder what they were thinking puttng that cap in. Glad you found it useful.

Big thanks to Tmac for posting this mod. When I bought this amp and opened it up I knew one of those caps was the culprit but I was going to wait for schematics or a player like Tmac to try it and share it with others.

Cheers
Ken

telejammer
12-21-2012, 04:39 PM
I just finished up doing the cap clip mod, wasn't hard at all. The channels seem much more balanced now, the red channel still has plenty of high end to it even though it seemed to increase the bass a little on the red channel. Thanks to Tmac for the great information and for posting the gut shots all marked very clearly. I actually called my amp tech about doing this and he said no need to bring it in that I could do it myself. So now its done, I'll be giging the amp day after XMas so I'll let you know how it performs. Thanks again, Tele

tmac
12-21-2012, 07:03 PM
very cool, glad u did it with no problems and u r right, very simple to do for most anybody. also I think u r correct about letting more bass into signal on red channel. this may be what Marshall designers wanted to do with the cap - reduce low end to keep things 'tight' and keep upper mids cutting. to my ear it just seems a little much and losing that cap evens out the tones . if someone wants to keep some of the original tone but reduce it a bit they could try a 120pf instead of the 470p. I just finished up doing the cap clip mod, wasn't hard at all. The channels seem much more balanced now, the red channel still has plenty of high end to it even though it seemed to increase the bass a little on the red channel. Thanks to Tmac for the great information and for posting the gut shots all marked very clearly. I actually called my amp tech about doing this and he said no need to bring it in that I could do it myself. So now its done, I'll be giging the amp day after XMas so I'll let you know how it performs. Thanks again, Tele

tmac
12-21-2012, 07:07 PM
I also noticed on one of the utoob demos (that sounded good) the guy was running the treble just about off while using a Les Paul

telejammer
12-22-2012, 11:33 AM
I was previously running the treble at about 9:00 o'clock and mids at the same, bass at about 2-3:00 o'clock. Now with the cap clipped I'm now running treble at around noon ,mids at about 10:00 o'clock ,and bass at around 2:00 o'clock. I set my resonence at 2-3:00 0'clock. This gives enough sparkle or cut on the green crunch channel and switches over resonably well to the red lower gain setting. These settings seem to be working well for now, but may change at giging volumes,rooms ,etc. Once again thanks for posting the "mod",now many others can enjoy this amp, Tele.

jeggz
01-11-2013, 03:40 PM
What I'd really like to know is if its possible to change the DSL 15 clean/od2 layout into a crunch/od1 layout.

ibmorjamn
01-15-2013, 12:08 AM
Wow, I need to try this !

guitarbilly74
01-16-2013, 05:57 PM
I don't know about the new DSL but I have the original DSL and I did the C12 mod. At first I was really excited about it but after trying with the band at stage volume (around 1 o'clock on the Master) I noticed the amp became too tubby and wasn't cutting as well as it used to. I ended up reverting it to stock and I am much happier with the results.

I think the mod is great for low to mid volume playing, but at stage volumes the DSL sounds much better stock.

ibmorjamn
01-16-2013, 08:09 PM
u r welcome. ok, I'll post some pics I took when I opened her up.

You don't need to lift the board or anything, just make sure caps are discharged and unsolder one leg and lift the cap so that leg pulls out. I did the right cap leg (with rear of chassis facing me) as it was easiest for me and was more room on that side.

Before I bent the leg up and out of the way I plugged in my LP and played while I pressed down the leg (with my plastic non-conductive probe tool!) to make contact again to hear the difference with it in and out of the circuit. Quite a dramatic difference.

I like the idea of a G12-65, might have to try one.Huge request , could you or anyone with the mod do a sound clip ? Looks like a good mod but the bummer for me is I just payed for the 3 yr. warranty so moding might void that.:brick

teefus
01-16-2013, 08:15 PM
Those amp really shine on recordings and live. They seem mediocre when used for practicing and jamming; stick a mic in front of them and they are glorious.


interesting. i had a musicman 65 watt 1-12" that was the same way. sounded meh in a practice setting but mic it up and it recorded like a monster.

flashtilley
01-17-2013, 05:52 AM
Yeah same here. I just got the 100H but would like to know how it sounds at gig levels before doing the mod. Sound clips would be good too. Thanks!

tmac
01-18-2013, 06:58 AM
can't do clips right now but maybe someone else can?

Huge request , could you or anyone with the mod do a sound clip ? Looks like a good mod but the bummer for me is I just payed for the 3 yr. warranty so moding might void that.:brick

tmac
01-18-2013, 07:13 AM
with my DSL 40C I'm not perceiving any tubby sounds at stage volumes (or any volume really) with the C15 mod. Just a lack harshness and quieter operation as stated earlier. I am able to run the treble and presence controls in the middle range settings (with room to spare). As I said, it will depend on your ear, speakers, guitars etc. Also, as I recall, there were two "C12" mods on the old DSL amps. Are you sure you're talking about the C12 cap across the gain control or cap on the power amp board?

I don't know about the new DSL but I have the original DSL and I did the C12 mod. At first I was really excited about it but after trying with the band at stage volume (around 1 o'clock on the Master) I noticed the amp became too tubby and wasn't cutting as well as it used to. I ended up reverting it to stock and I am much happier with the results.

I think the mod is great for low to mid volume playing, but at stage volumes the DSL sounds much better stock.

jboyjams
01-29-2013, 11:15 AM
I appreciate this info.

I'm thinking about buying a DSL100H - I tried one at GC and it sounded really good.
I could almost get the shared eq just right, but did seem a little brighter on the lead channel.

Has anyone clipped C19 on the DSL100H?

tmac
01-29-2013, 12:48 PM
The 40C and 100H are very similar - uses the same PCB insde[

QUOTE=jboyjams;14782833]I appreciate this info.

I'm thinking about buying a DSL100H - I tried one at GC and it sounded really good.
I could almost get the shared eq just right, but did seem a little brighter on the lead channel.

Has anyone clipped C19 on the DSL100H?[/QUOTE]

Baileyboy1
02-05-2013, 01:40 PM
Hey folks,

I have the dsl40c as well and am really loving it but, as with other posters here, am finding the imbalance between the channels and the high treble on the lead channel a bit frustrating.

I want to do this c19 mod, as well as swap out the tubes and bias it to see where this takes me. I've got a bias probe kit from eurotubes on the way and have watched their vidoes. This will be my first attempt at biasing an amp, so hope all goes well.

I'm looking for a bit of help before I dive in:

(1) With respect to the c19 mod, would I be okay just clipping off one leg with some wire cutters instead of de-soldering? If so, can someone help me undestand how to discharge the caps before I do this (I assume I will be in for a major shock if I just reach in there with some wire cutters and snip the leg off of the c19 cap without doing this first, correct?).

Telejammer - sounds like you did your homework before doing this...any tips?

(2) For those that have already set the bias on these amps, where is the trim pot located? I assume its internal, but could not see it from the pictures posted.

Thanks in advance for any help.

Baileyboy1
02-06-2013, 06:02 PM
One of the earlier posts by Kenster noted that the right trim pot did not do anything but add hum when adjusting bias. I saw a guts shot of the 110h on another forum, and they appear to be using the same board (40c bring without the two outer power tubes the 100h has. Is it possible that the right trim pot in the 40c is the trim pot that adjusts the bias in the outer tubes on the 100h?

Kenster
02-10-2013, 09:32 PM
Hey folks,

I have the dsl40c as well and am really loving it but, as with other posters here, am finding the imbalance between the channels and the high treble on the lead channel a bit frustrating.

I want to do this c19 mod, as well as swap out the tubes and bias it to see where this takes me. I've got a bias probe kit from eurotubes on the way and have watched their vidoes. This will be my first attempt at biasing an amp, so hope all goes well.

I'm looking for a bit of help before I dive in:

(1) With respect to the c19 mod, would I be okay just clipping off one leg with some wire cutters instead of de-soldering? If so, can someone help me undestand how to discharge the caps before I do this (I assume I will be in for a major shock if I just reach in there with some wire cutters and snip the leg off of the c19 cap without doing this first, correct?).

Telejammer - sounds like you did your homework before doing this...any tips?

(2) For those that have already set the bias on these amps, where is the trim pot located? I assume its internal, but could not see it from the pictures posted.

Thanks in advance for any help.

Hi Baileyboy - With respect to the C19 mod you could just cut one leg of the cap. I wanted to unsolder it in case I didn't like the mod, it makes it easier to solder the leg back in.

The circuit the cap is in won't hurt you with the amp off. Just make sure you don't touch any of the big filter caps or circuitry around them. If you don't feel comfortable doing this then take it to a tech but just snipping one of the leads isn't a big deal.

I do think you will like this mod though. Made this amp so much more usable as a channel switcher.

Good Luck
K

Kenster
02-10-2013, 09:51 PM
One of the earlier posts by Kenster noted that the right trim pot did not do anything but add hum when adjusting bias. I saw a guts shot of the 110h on another forum, and they appear to be using the same board (40c bring without the two outer power tubes the 100h has. Is it possible that the right trim pot in the 40c is the trim pot that adjusts the bias in the outer tubes on the 100h?

Hey Again - You are correct about Marshall using the same board but with using only 2 tubes for 40 watts. You may be onto something about the right one being for the outer tubes. Without having a schematic I don't know what that trimpot does. All I know is when I turned (chassis oriented with trimpots away from you) the right one nothing happened except a bit of hum increased, so I returned it to the original position which was quietest. The left trimmer changed the bias current. Note I was using a bias probe from Eurotubes to bias my amp.

Now you need to realize you are messing with high voltages when biasing, especially with the amp on. So if you are not comfortable in doing this get a tech to do it. Otherwise study up on how to do it correctly and be very careful and not get distracted.

Good Luck
Ken

Baileyboy1
02-11-2013, 07:37 AM
Thanks, Kenster.

I read up quite a bit last week on both discharging the filter caps and on setting the bias. I also ordered a bias kit from Eurotubes...really nice unit.

I did both the cap mod and the bias adjuctment this weekend. Here are my thoughts:

(1) c19 cap mod: huge difference in the amp for the better. Before this mod, I was really enjoying the classic gain channel, both clean and crunch, but not really liking the trebliness of the ultra gain channel. As you and tmac have noted, this c19 mod takes cares of the trebliness on the ultra gain channel and makes it a seemless transition in tone from classic gain to ultra gain channels. So...I now effectively get a seemless switch from clean to moderate break-up to high gain to very high gain as I transition across the four channel settings while keeping the same fundamental tone without any tweaks of the tone knobs. This turned a nice amp into a steal at this price point.

For those that don't yet have this amp, here are my opinions on it. The Classic gain channel goes from a Marshall clean to light gain/break-up. The gain on the side reminds me of the jtm45 type of gain. This channel with a bit of dirt loves my strat in the two and four positions...very blues and SRV-like tones. My LP on this channel gets some very convincing early ACDC tones (pre- Back in Black era stuff). The ultra gain channel gets more into JCM800 territory and covers modern ACDC tones well. Hard to get one amp to cover the entire ACDC tones...this one does it well, or at least close enough for my ears :)

The ultra high gain wtih the mids cut get a very good scooped mid heavy metal sound. I don't spend much time here, but it's nice to know it is readily available when the mood suits me.

(2) bias adjustment: The plate voltage on my amp was running about 460-465, and the stock tubes were biased at about 75%. I swapped these out for SED winged C's and set the bias to about 69-70% (plate ran at about 462 with bias on these at about 37mA if I recall correctly). The amp sounds great to me at these settings. Decent headroom. Great break-up. Not muddy. I've got some Tung-sol preamp tubes coming and will see what affect these have on the tone, but I am pretty happy with the current set-up.

Regarding the two trim pots, here is what I noticed. When I first installed the Sed tubes, they were running at about 58! I tried to adjust one trim pot, which made only very slight difference (+/- about 4 mA). The other trim pot allowed me to really bring down the readings with even a very slight turn of the trim pot. I set the first trim pot that I messed with back to its center position and then made my bias adjustments solely with the other pot. So..it appears that the trim pot does have some effect, just not sure exactly what. Perhaps a balance pot of some sort as others have suggested?

Anyway...I am now really loving this amp. Great and easy adjustments led to significant improvements! As others have noted, one really nice feature would have been to be able to use the footswitch to control the two different gain settings within each channel. Maybe someone clever enough to figure out a way to do this will come up with a solution. Other than that, I have no complaints about this amp.

The speaker sounds fine to me. I have a Peavey Classic 30 with a Celestion V30 in it. I've thought about taking the V30 out and trying it in this amp...not sure...I'll report back if I get around to doing this.

Kenster
02-11-2013, 09:19 AM
Baileyboy - You nailed with your review. The only other thing I did was try a few different speakers (V30, G12-65, Greenback). I usually don't care for V30's but it sounded really good in this amp. However I preferred the G12-65 and Greenback better so I ended up using the G12-65. I like how it attenuates highs and any spikiness. The Greenback doesn't have the right power rating. I am curious about the new Creamback but I can't get a hold of a 16 Ohm from my favorite dealer, but he is working to fix that.

For tubes I switched out V1 and V2 respectively with EH and Mullard re-issue. All in all a killer deal for a small protable rig that sounds great for getting classic and modern Marshall tones. I'm tempted to get a hold of the 100 watt head but my back reminds otherwise.

Enjoy your new amp
Ken

flashtilley
02-13-2013, 06:02 PM
Would still love to hear sound clips after the C19 mod before I do it with my 100H. I installed JJ preamp tubes in mine and it tamed the highs quite a bit. Not sure about doing the mod yet.

Baileyboy1
02-14-2013, 08:18 AM
I will try to post some clips this weekend.

The best way that I can describe the change is this:

Play through the classic gain channel, first clean and then with crunch. The basic tone stays the same when you switch between clean and crunch, you just get more gain.

Now switch over to the ultra gain channel. In stock form, the switch from classic gain channel to ultra lead channel results in a dramatic change in the basic tone, adding a lot of high end treble when switching to ultra channel. I actually found that I could not tweak the tone knobs in a way that would get me back to the basic tone of the classic channel.

After the cap mod, when I switch from classic gain channel to ultra gain channel, the basic tone now stays the same, I just get more gain.

So here is what I get now when going from clean, crunch, ultra gain 1, and ultra gain 2:

clean: nice Marshally clean sound
crunch: same basic tone as clean, with 60's-70's type gain response (JTM45 type gain)
ultra 1: tone now stays the same as the classic channel, but adds JCM800 type gain to the sound.
ultra 2: again...same basic tone, but now with very high gain added in (more compressed than ultra 1 with a tighter low end)

So..the response to me now feels like having a four channel amp with progressively more gain with each "channel" without changing the basic tone and, hence, no need to change tone settings when going from green side to red side.

The treble is still there on tap, but you can dial it out better now.

Baileyboy1
02-14-2013, 08:38 AM
I'll add a couple of more thoughts:
Before the mod, I really liked the green channel, but was struggling with the red channel in terms of taming the treble reponse.
Now...I am very happy with both channels and think the basic tone there now with stock tubes and speaker is great. So...I feel like it's a great platform: very good with the stock tubes and speaker; any tweaks I do in experimenting with tube and speaker swaps are just an attempt to fine-tune an already great sound to my taste :)

flashtilley
02-14-2013, 07:11 PM
Awesome! Thanks for the info. I will definitely try that mod.

tmac
02-15-2013, 08:05 AM
I wholeheartedly agree with Kenster & Baileyboy's findings. I tried my DSL40 through my Mesa cab with C90 and it sounds very good through that, definitely a more efficient speaker. The stock speaker in the combo is good but I may go ahead and get a G12-65 for a more vintage twinge.

If anyone is thinking that they cannot live with the tonal difference between the green & red channels, this simple mod really lines them up and just gets the red channel sounding better for my ear. I'm sure there are more extensive mods that can be done to really dial in the amp to a particular taste -you could go as far as you want; but for me no other electronic mods are needed. I may change speakers around and tubes/bias a bit in the future but it's a great sounding amp and does a lot of things very well for the coin.

I'll add a couple of more thoughts:
Before the mod, I really liked the green channel, but was struggling with the red channel in terms of taming the treble reponse.
Now...I am very happy with both channels and think the basic tone there now with stock tubes and speaker is great. So...I feel like it's a great platform: very good with the stock tubes and speaker; any tweaks I do in experimenting with tube and speaker swaps are just an attempt to fine-tune an already great sound to my taste :)

diamonded
02-15-2013, 04:14 PM
I just did this mod myself. I managed to break one of the legs on c19 instead of merely pulling it away from the board, so i'll have to buy another one if I ever want to put it back, but I can't imagine ever wanting to.
What a difference one little cap out of the circuit makes! There is still plenty of treble but none of the harshness and fizz at low volumes at all. The fizz always lessened at higher volumes anyway, but at the volumes I usually play at it was not to my liking.
I could swear the one I played at GC didn't sound this trebly, but it's all good now.
I now can run the treble at 12:00-3:00 whereas pre-mod I kept it almost all the way off.
ACDC, GnR, Zep, VH, tunes all sound great through this thing now. If I ever graduate form bedroom to stage maybe I would need to hook the cap back up, but it sure sounds great at the volumes I play at now.

flashtilley
02-15-2013, 04:42 PM
I just did this mod myself. I managed to break one of the legs on c19 instead of merely pulling it away from the board, so i'll have to buy another one if I ever want to put it back, but I can't imagine ever wanting to.
What a difference one little cap out of the circuit makes! There is still plenty of treble but none of the harshness and fizz at low volumes at all. The fizz always lessened at higher volumes anyway, but at the volumes I usually play at it was not to my liking.
I could swear the one I played at GC didn't sound this trebly, but it's all good now.
I now can run the treble at 12:00-3:00 whereas pre-mod I kept it almost all the way off.
ACDC, GnR, Zep, VH, tunes all sound great through this thing now. If I ever graduate form bedroom to stage maybe I would need to hook the cap back up, but it sure sounds great at the volumes I play at now.


That's kind of what I'm afraid of. I do play at louder stage volumes and gig with my band. I'm wondering how this will sound at those volumes. There must have been a reason why Marshall put that cap in there in the first place. I guess I could try it and hook it back up if I didn't like it.

INSEARCHOFTONE
02-22-2013, 08:08 AM
with the dsl40 cap mod on the od channel sound like i mite give it a try can this also be done on the classic channel if so what cap is it and is the location behing the gain pot on that channel as well i feel both channels are to bright

INSEARCHOFTONE
02-22-2013, 08:09 AM
meant 2 say cap mod

tmac
02-22-2013, 11:49 AM
seems it was C4 on the old DSL's. It would help to have a current schem for these DSL amps. But should be right behind the gain control for the clean side V1r I believe, 100pf cap, probably small/yellow like C19 (but 100 pf instead of 470p). Just a guess, don't hold me to it! :aok:wave

with the dsl40 cap mod on the od channel sound like i mite give it a try can this also be done on the classic channel if so what cap is it and is the location behing the gain pot on that channel as well i feel both channels are to bright

Goldstrat
03-03-2013, 01:38 PM
I got one of these amps last weekend and noticed the same thing as everyone else. I did the mod and just clipped one side of the cap so I can put it back later if I want. I agree with all of you much better mix between channels and now I can kick on the higher gain side and it works great. The only other thing I have done is put an old Amperex Bugle Boy in V1. This amp is great for how much it cost and I might be getting rid of other gear because this sounds better than some of my vintage amps with pedals. I will probably get a different speaker later and some power tubes. Does anyone know what power tubes are in it? The 12ax7's are definitely cheap tubes. Thanks for posting this mod!

Seven14
03-09-2013, 01:54 AM
One of the most helpful threads I've seen on TGP. Thanks, ALL!!!!

Maybe I'll try this in a month or so; only change for me in the DSL40c is replacing the stock speaker with a Veteran 30.

Thanks much for the really, really useful contributions.

Random Hero
03-11-2013, 01:39 PM
Can someone offer up a link to the C12 mod? I wanna see exactly where it is to do it to mine!

tmac
03-13-2013, 07:35 AM
some pics and links here I think: http://www.seymourduncan.com/forum/showthread.php?157240-I-hate-to-admit-it-but-Im-hating-my-Marshall-DSL!/page3

Can someone offer up a link to the C12 mod? I wanna see exactly where it is to do it to mine!

Seven14
03-18-2013, 10:59 PM
tmac: thanks again for this suggestion.

I just dove into the deep end. One snip and it was done.

It is an easy and great mod!



not sure if this has been covered yet, so...

the old Marshall DSL heads C12 cap mod (disconnecting the 470pf that is across the OD channel gain pot) is cap C19 in the new DSL 40 combo/100 head. sits right behind the pot on the board. I just left in place but lifted one leg of connection so that it is out of circuit. easy to put back if needed

really makes a big difference in brightness (harshness to me) of the OD (red) channel if like me u run gain pretty low (and crank the volume) for a more vintage type OD tone. and really matches up the tones of red and green (clean) channels in my opinion.

this really depends on your playing style, guitar, speakers, etc. some find this channel too bright but some may like the cut it provides with the cap in place. and if you are cranking up the gain pot it is probably not an issue (because the more the gain pot is turned up the more this capacitor is out of the circuit). this mod also cuts out some hiss noise. a lot of folks hate these DSLs, lot of folks love 'em, but it sounds great to me - with this mod.

I can post pics if anyone needs.

tmac
03-19-2013, 01:54 PM
my pleasure, cool that some folks are getting some use outta this.

tmac: thanks again for this suggestion.

I just dove into the deep end. One snip and it was done.

It is an easy and great mod!

iec950cb
03-20-2013, 05:08 AM
I was messing with my DSL40C and the bias works the same for me as the older dsl. You have two trim pots and a 3 pin connector to probe and set the mVolts. One side out of the box factory was 36 mV and the other side was set to 43 mV. Remember the middle pin is ground or connect your negative probe to chassis when checking. Rember each oposite pin on the
ouside of the connector is for each pot setting. I know marshall likes to set the around 45 mv per side. I set mine to 39 mV per side. Once you get the number you like, put a little dab of hot glue on the trimmer portion to the body of the pot. These pots are chinsey and can move though vibrations. When you want to rebias, the hot glue dob / blop will come off real easy with a pair of needle nose pliers. Worked perfect for me. oh well. Regards, Paul

Seven14
03-29-2013, 09:47 AM
I was messing with my DSL40C and the bias works the same for me as the older dsl. You have two trim pots and a 3 pin connector to probe and set the mVolts. One side out of the box factory was 36 mV and the other side was set to 43 mV. Remember the middle pin is ground or connect your negative probe to chassis when checking. Rember each oposite pin on the ouside of the connector is for each pot setting. I know marshall likes to set the around 45 mv per side. I set mine to 39 mV per side. Once you get the number you like, put a little dab of hot glue on the trimmer portion to the body of the pot. These pots are chinsey and can move though vibrations. When you want to rebias, the hot glue dob / blop will come off real easy with a pair of needle nose pliers. Worked perfect for me. oh well. Regards, Paul

Thanks, Paul. Do you know which trim pot I should attack? Is Trim 1 or is Trim 2 the bias for the DSL40C? I'm using the Eurotubes "Pro One" Bias Probe.

iec950cb
04-01-2013, 04:56 AM
It is the same as the earlier DSL's One pot for each tube. one outside pin is for one tube and the other outside pin is for the other. my range to play with with would be 35-45 mV on each. I have mine set to 39mV on ech tube. good luck.

Seven14
04-01-2013, 09:55 PM
Thanks, Paul! New tubes are now installed and biased.

And, back to the OP: the c19 mod has made this amp a real sleeper at any price. The transition from green to red is now seamless.

Thanks again for sharing.

edwinhong
04-06-2013, 01:03 AM
Hey thanks Tmac and everyone else,
but can we think of put a switch between c19 cap, so we can go on and off, maybe install a pull switch in the gain control for those of us worry about tone being too bassy when cranked up ?

edwinhong
04-06-2013, 01:15 AM
Hope this will help for those of you want to bias the amp.
Found on http://www.marshallforum.com/marshall-amps/53780-official-marshall-dsl40c-information-thread.html
and lot more there also.


Here are some gut shots of my DSL40c.
Again, if anyone has any requests for specific photos let me know.
Here is a shot of the bias trimpots:
http://k1xh.smugmug.com/Photography/New-Guitar-Day/i-GW7vqMf/0/L/DSCN4005-L.jpg

Here is a shot of the bias test connector.
Remember, when checking/setting the bias, the left trimpot adjusts the right test point...
http://k1xh.smugmug.com/Photography/New-Guitar-Day/i-hGrBkD4/0/L/DSCN4182-L.jpg

I finally got the bias evened out at 38.xx and all seems very stable:
http://k1xh.smugmug.com/Photography/New-Guitar-Day/i-d3TpDHS/0/L/DSCN4180-L.jpg

tmac
04-06-2013, 08:37 PM
thanks for the info on biasing edwinhong, thought that's the way it was configured but wasn't sure and I hadn't messed with bias yet but I should check it at least. I was cranking this amp earlier and I just love it. I have a Germino that I love but this DSL is awesome too and a lot more versatile, especially volume wise. love the 20w setting. loud enough for most any indoor gigs. gentleman above asked about putting the bright cap on a switch. very easy to do to drill a small hole by the pot and mount a mini-switch to bring in/out the cap. I don't like the cap being there at all so I won't be doing the switch but others may like it. Doug Hoffman sells the perfect little Dpdt switches

Axeplyr
04-23-2013, 06:35 PM
Bumping a slightly older thread with newer info...

I did the C19 mod and speaker swap today with great results. I replaced the speaker with an Eminence GB128 and then replaced C19 (470pF) with a 68pF. Sounds KILLER. This speaker is just about perfect in this amp. Smooths the piercing highs without adding a bunch of mud, just really well-balanced, killer tone.

About C19... I removed it first and, while it sounded much better, made the drive channel a little too dark and bassy. I knew I wasn't going to be able to leave it that way. I read that some DSL50 owners were very happy with a 150pF cap in C12 (same cap), so I tried that. With the 150pF, it was still just a little too bright and not quite enough bass. Tried the 68pF next, and it seems dead PERFECT... it really does seem like a high-gain boost of the clean/crunch channel now!

I am absolutely thrilled with both the speaker and cap changes. :dude

Kenster
04-24-2013, 09:17 PM
Bumping a slightly older thread with newer info...

I did the C19 mod and speaker swap today with great results. I replaced the speaker with an Eminence GB128 and then replaced C19 (470pF) with a 68pF. Sounds KILLER. This speaker is just about perfect in this amp. Smooths the piercing highs without adding a bunch of mud, just really well-balanced, killer tone.

About C19... I removed it first and, while it sounded much better, made the drive channel a little too dark and bassy. I knew I wasn't going to be able to leave it that way. I read that some DSL50 owners were very happy with a 150pF cap in C12 (same cap), so I tried that. With the 150pF, it was still just a little too bright and not quite enough bass. Tried the 68pF next, and it seems dead PERFECT... it really does seem like a high-gain boost of the clean/crunch channel now!

I am absolutely thrilled with both the speaker and cap changes. :dude

Very cool. I've been waiting for someone to blaze the trail on subbing a cap for C19. Having it removed there are times I wished it had a little more bite, but then there are times I like the thickness Channel 2 adds without the cap. Almost like an EJ tone. Be nice to rig a switch to switch a cap in or out. I was going to try a 120pf next time I was inside the chassis but I'll try the 68pf first. Thanks for posting your experience. Either way I am really digging this amp for the many tones I can get out of it.

Cheers
Ken

Axeplyr
04-25-2013, 05:22 PM
Very cool. I've been waiting for someone to blaze the trail on subbing a cap for C19. Having it removed there are times I wished it had a little more bite, but then there are times I like the thickness Channel 2 adds without the cap. Almost like an EJ tone. Be nice to rig a switch to switch a cap in or out. I was going to try a 120pf next time I was inside the chassis but I'll try the 68pf first. Thanks for posting your experience. Either way I am really digging this amp for the many tones I can get out of it.

Cheers
Ken

You might be onto something with the 120pf. I am thinking of going up to 100pf, the 68pf, though pretty darned close, might still be a teeny bit too low. :)

I'm actually thinking of adding 10pf (or two) in parallel to the 68pf just to see what happens. Adding caps in parallel increases the overall capacitance.

I think it would be very cool to have a five position rotary with these different cap values on it.

I love this stuff. :)

mattrayetta
05-12-2013, 07:54 AM
Just a question for Axeplr and Kenster. I know the original Dsl's used a 63v cap for the C12. It seemed that 100pf was the popular choice for most. What voltage value are you guys using for the swap?
Thanks

Axeplyr
05-12-2013, 06:39 PM
Just a question for Axeplr and Kenster. I know the original Dsl's used a 63v cap for the C12. It seemed that 100pf was the popular choice for most. What voltage value are you guys using for the swap?
Thanks

50v.

http://www.radioshack.com/product/index.jsp?productId=2062361

mattrayetta
05-13-2013, 07:44 AM
Thanks for the link Axeplyr. Is 50v the original value? Now if I can only bring myself to solder on my brand new amp :o. Have you tried adding a couple of 10pfs on your yet?

tmac
05-13-2013, 08:58 AM
my opinion is that you're starting to split hairs a bit at this point, seems like 100 pf would be plenty for that cap (if you want it there to begin with), but 47 or 68 may be plenty too. But interpretation depends on your ears that particular day, your mood, the relative humidity, your strings, speaker, volume, etc. so what seems just right one day may be a bit off the next, or next week. YMMV.
...but Marshall played around with volume cap values a lot too in the early days. Not sure if it was what they determined was "good" at the time or just what part was available & cheap? sometimes none (depending on the circuit and who was working that day), to 100 pf (tweed Bassman spec) to 500pf to 5000 pf, so who knows? but as time went on generally Marshall's got more aggressive and tighter/louder, plate voltage increased, as did power supply filtering, split cathode, etc....
also yes, agree that 50V cap is plenty here.

You might be onto something with the 120pf. I am thinking of going up to 100pf, the 68pf, though pretty darned close, might still be a teeny bit too low. :)

I'm actually thinking of adding 10pf (or two) in parallel to the 68pf just to see what happens. Adding caps in parallel increases the overall capacitance.

I think it would be very cool to have a five position rotary with these different cap values on it.

I love this stuff. :)

Axeplyr
05-15-2013, 07:30 PM
Thanks for the link Axeplyr. Is 50v the original value? Now if I can only bring myself to solder on my brand new amp :o. Have you tried adding a couple of 10pfs on your yet?

I don't know what the original value was. To be honest, I just bought the only available 100pf cap Radio Shack sells at their stores. Luckily it is a good approximation to the original and seems to work just fine.

my opinion is that you're starting to split hairs a bit at this point, seems like 100 pf would be plenty for that cap (if you want it there to begin with), but 47 or 68 may be plenty too. But interpretation depends on your ears that particular day, your mood, the relative humidity, your strings, speaker, volume, etc. so what seems just right one day may be a bit off the next, or next week. YMMV.
...but Marshall played around with volume cap values a lot too in the early days. Not sure if it was what they determined was "good" at the time or just what part was available & cheap? sometimes none (depending on the circuit and who was working that day), to 100 pf (tweed Bassman spec) to 500pf to 5000 pf, so who knows? but as time went on generally Marshall's got more aggressive and tighter/louder, plate voltage increased, as did power supply filtering, split cathode, etc....
also yes, agree that 50V cap is plenty here.

Agree... it really is up to personal choice in the end. I really just want the Lead channel to sound like an overdriven boost of channel 1. That brought me to 100pf after trying 67pf and 150pf.

michael razor
07-30-2013, 12:41 AM
Great Thread.
10/10
I'm going to get a DSL 40 c this week!!

hdspringer98
10-24-2013, 03:38 PM
I picked up a DSL40c via CL for only 350 clams. It has killer sveltlana winged-c power tubes and the dude gave me 4 tung-sol 12ax7's along with it. Smoking deal.

I too found the tone a bit harsh so I clipped C19 and, while the tone was improved, it lost something.

Reading through this topic I decided to try the radioshack 100pF capacitor. Popped it earlier today and WOW, what a difference. Was thinking of changing the speaker but now not so sure, will give the 70/80 a chance as its not even broken in.

RED1 is amazing and green is full.

guitarman3001
10-24-2013, 05:30 PM
I picked up a DSL40c via CL for only 350 clams. It has killer sveltlana winged-c power tubes and the dude gave me 4 tung-sol 12ax7's along with it. Smoking deal.

I too found the tone a bit harsh so I clipped C19 and, while the tone was improved, it lost something.

Reading through this topic I decided to try the radioshack 100pF capacitor. Popped it earlier today and WOW, what a difference. Was thinking of changing the speaker but now not so sure, will give the 70/80 a chance as its not even broken in.

RED1 is amazing and green is full.

Cool. I ordered some 100pF capacitors just in case.

Here's another angle - what I noticed is kind of the opposite everyone else seems to hear. To me, Ch2 was not too bright and with the settings I use on most amps, which is the treble way down, the mids way up, and the bass very low, it sounded great. But, when I had the tone controls set like that, Ch1 was too dark and too bassy.

I was wondering if instead of making Ch2 darker with the C19 mod there might be a way to make Ch1 a little brighter so with the tone knobs set for Ch2, Ch1 matches it better.

Looking at the schematic, it looks like there's a capacitor for Ch1 that's comparable to C19 for Ch2. It's at C4 and has a 100pF cap. So, I am wondering if anyone knows if replacing that capacitor with a higher value like the 470pF one that's in C19 would make Ch1 brighter, which to me would be preferable than making Ch2 darker.

Make sense?

Any thoughts on this?

TJN
04-01-2014, 09:40 PM
I just got my 40c and would like to upgrade the speaker. I play on the clean/crunch channel mostly, but I do use the drive channel. I tried a WGS Reaper 30 in it, which is better, but I am still thinking there is a more suitable speaker. I go for a great clean tone on the vintage side. I have seen that there are some people putting in the WGS ET65 in it. Any feedback on that speaker?

I also read on the the WGS board that people are using Veteran 30's.

I like to use pedals for controlled dirt, not sure if that is relevant or not.

Thanks,

TJ

PS. TubeDepot recommends either TungSol or JJ preamp and power tubes. They like JJ because they are creamy and articulate, and they are cheap. They love the TungSol, but that is their second choice due to them being way more expensive. Thoughts?

Rod
04-02-2014, 08:33 AM
I really like the Celestion Cremeback M series in my Marshall Haze, which is a similar amp to your DSL... That was after trying 5 different WGS speakers. I'm also a big fan of JJ tubes in Marshalls.. The Tung Sol 12AX7's are very bright, which in a DSL, you don't need..

harrisondj
08-24-2014, 09:12 PM
The *VERY* reason I am not using this amp while gigging is because the *LOUD* hiss is unbearable! I'm using an NS-2 Noise Suppressor, tried different cable/guitar setups, checked the tubes, etc. So sad since it has done this right out of the box.

(BTW this in reference to a Marshall DSL40C on the Ultra Gain Lead1/Lead 2 channel)

Thanx for your response!

Don Harrison

Rod
08-24-2014, 11:33 PM
The *VERY* reason I am not using this amp while gigging is because the *LOUD* hiss is unbearable! I'm using an NS-2 Noise Suppressor, tried different cable/guitar setups, checked the tubes, etc. So sad since it has done this right out of the box.

(BTW this in reference to a Marshall DSL40C on the Ultra Gain Lead1/Lead 2 channel)

Thanx for your response!

Don Harrison

How high were you running the gain on the ultra channel?