Marshall 6100 30th Anniversary EL-34 Version

ProfRhino

Member
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10,433
thanks for the link, that's the one I was talking about.
you'll still have to find a tech willing and capable to diagnose, repair and improve (power supply) the monstrosity ...
if they'd only done it like e.g. the Quad, which also has a proprietary footswitch (for better reasons, as it does way more), but it also has individual connectors for standard switches in the back, so it still works perfectly without its native system.

a few miscellaneous replies :
- afaik Johnny A (great musician, great tone !) only ever used the clean channel on his combos, these days he's touring with a small JMP1 based rack afaik. If you're after his kind of tone, simply get a JTM45 and a handful of choice pedals, perfection.
- re the NOS tube suggestion, unlike most other amps, V1 serves the clean channel exclusively, V2 & V6 are for crunch and V3 - V5 for that constipated lead channel, V7 is PI, obviously.
Without the messy PCB- & switching construction this would actually be a pretty cool concept ...
- the LM was 5881 based with an even higher gained lead channel, both changes are relatively easy to mod back and forth.

ymmv,
Rhino
 

/13guitarman

Member
Messages
1,128
I have the 6101 1x12 combo. The tubes are blown and what else I don't know. The tubes glow red and no sound. I just put it in the attic and havn't decided to get it looked at. I already had it repaired 3 times for tubes and the midi switching. I do have the 3 channel foot switch laying around somewhere.


I had an old ART midi pedal that worked with mine. It can be used as well as the foot switch to change the channels. If the midi is working.
 

drbob1

Gold Supporting Member
Messages
30,125
Back to the OP: you don't need a footswitch. Any $75 midi switch from Music Go Round will work. You press the learn switch for each midi preset and the amp will go to that channel when you go to that preset. So set up preset 1 as channel 1... and you've got a 3 channel footswitch. At least that's how I remember it.

$500 for an EL34 version that's working is a killer deal. If you don't buy it, PM me the location and I likely will. I remember it fondly! The clean and crunch channels are truly great. I don't really use high gain so I can't comment on channel 3. But the clean channel may be the best Marshall ever built!

There is really only one achilles heal to these amps: the switching system is ONLY midi based. There's no work around, if the midi section dies, the amp is stuck on one channel. And there's too much heat and not enough reliable voltage to protect the midi switching chips, so they DO die. It's not hard to find someone to fix that section, since it's a chip problem and things are thru-hole mounted not SMD-pull all the chips and replace, $75 and done. If you want more reliability then cooling (especially for the combo) and more robust power supply for the chips would be a good idea.
 

andyk

Silver Supporting Member
Messages
2,145
I had a later 6100B - same as the original, but with 5881 tubes. I got the idea that EL34's would sound way better, so I asked Marshall what needed to be changed to get EL34's running. They sent me a list of like 50 resistors that had to be changed all throughout the power section! So took it to a tech, and when I got the amp back - you guessed it - sounded better with the 5881's! D'oh!
 

mbetter

Member
Messages
801
One of my first real amps, could never bond with it. Lead channel was pretty crap, but it sounded massive with an MT-2 into the clean channel.
 

Hamer95USA

Member
Messages
3,227
I have the old Guitar Player magazine (Keith Richards cover IIRC?) where they did reviews of a bunch of 100w tube combos including this one. I've been wanting one since. I read the combos came loaded with JBL's or something, not Celestions. I've read a number of slightly negative comments from owners saying the lead channel isn't very good.

That Guitar Player magazine 100 watt combo shootout was what inspired me to buy my Marshall 6101 out of the blue. The Marshall 6101 combo distributed in the U.S. has the EV12L speaker. The 6101 amps that I've seen from Europe came stock with a 200 watt gold Celestion G12-Gold S303 (which was made by Electro Voice). I have no problem with getting a good tone from the lead channel. I don't dial up the treble as much on that channel.

Guitar George
 

Hamer95USA

Member
Messages
3,227
I had a later 6100B - same as the original, but with 5881 tubes. I got the idea that EL34's would sound way better, so I asked Marshall what needed to be changed to get EL34's running. They sent me a list of like 50 resistors that had to be changed all throughout the power section! So took it to a tech, and when I got the amp back - you guessed it - sounded better with the 5881's! D'oh!

I'm glad to hear that worked out with getting your Marshall 6100B amp head rebiased for EL-34 power tubes. It's the best sounding power tubes for that amp.

Guitar George
 

Hamer95USA

Member
Messages
3,227
There is really only one achilles heal to these amps: the switching system is ONLY midi based. There's no work around, if the midi section dies, the amp is stuck on one channel. And there's too much heat and not enough reliable voltage to protect the midi switching chips, so they DO die. It's not hard to find someone to fix that section, since it's a chip problem and things are thru-hole mounted not SMD-pull all the chips and replace, $75 and done. If you want more reliability then cooling (especially for the combo) and more robust power supply for the chips would be a good idea.

I agree with you, drbob1. I had a component on the MIDI board die from heat coming from the amp, which resulted in my amp staying on Channel 1 and not being able to switch channels.. The best solution to this problem is to run a fan on the back of the Marshall 6101 combo to cool it down. It doesn't have the ventilation vents like the 6100 amp heads have.

Guitar George
 

DiPa

Constant GAS
Silver Supporting Member
Messages
17,264
The 6100 amp has some interesting life to it and I found some good stuff online that I will place here for your enjoyment:
30th Anniversary 6100 series
1992 marked 30 years in the amplifier business. To commemorate this milestone, Marshall released the 30th Anniversary series of amplifiers, the EL34 powered 6100LE with commemorative blue covering and gold faceplate, which was followed by the 6100 (in standard Marshall livery and still EL34 powered) and then in 1994 the 6100LM (in standard Marshall livery but now 5881 powered like the JCM900s of the time). All versions of the 6100 had three channels; clean, crunch and lead. The clean channel featured a mid shift, which gave the option of a more "Fender-like" voicing, and the crunch channel featured three modes recreating all the classic Marshall crunch tones of the past three decades. The lead channel featured a switchable gain boost and a mid-range contour switch, which gave it the tone and gain levels, which Marshall's engineers hoped would keep it competitive in the high-gain world in the early to mid-1990s. In fact some players felt the lead channel was perhaps the weaker link in the amplifier's arsenal, and it came in for revisions in the third year of production (the LM standing for "Lead Mod"). This revision featured even higher gain.

The Anniversary series found prominence with Joe Satriani in particular, who favoured the early EL34 powered versions and used only the clean channel live along with his signature Vox Satchurator distortion pedal which is based on his old modded Boss DS-1. Satriani used these older Boss pedals almost exclusively for live work and on a number of studio albums including The Extremist (1992) until the early 2000s. The Anniversary models were probably the most complicated Marshall ever (other than perhaps the later JVM), with full MIDI control built in, half power switching, pentode/triode switching, adjustable speaker excursion, and a low volume compensation switch. Despite all this complication the amps had a pure signal path that did not share preamp tubes between channels (unlike later Marshall designs like the TSL and JVM). Other famous 6100 users included Alex Lifeson on Rush's album Test for Echo(1996) and Ocean Colour Scene (OCS) guitarist Steve Cradock
 

Hamer95USA

Member
Messages
3,227
I have the 6101 1x12 combo. The tubes are blown and what else I don't know. The tubes glow red and no sound. I just put it in the attic and havn't decided to get it looked at. I already had it repaired 3 times for tubes and the midi switching. I do have the 3 channel foot switch laying around somewhere.


I had an old ART midi pedal that worked with mine. It can be used as well as the foot switch to change the channels. If the midi is working.

Get it fixed by an authorized Marshall repair shop that knows how to fix the 6100/6101 MIDI boards, have the power tubes rebiased, and any worn out 12AX7 preamp tubes replaced. I had similiar issues like yours with my 6101 combo amp years ago. Unforutnately, the amp generates a lot of heat, has no ventilation vents like the 6100 amp heads, and needs to have a fan blowing on the back of the amp, especially in the summer. Getting the MIDI board repaired and rebiasing the power tubes resolved my issues. The only thing I have to replace now is just the 12AX7 preamp tubes when they wear out.

Guitar George
 

ericb

Gold Supporting Member
Messages
11,016
I have the el34 6101. Have no issues with mine. .I haven't used the midi channel switching but . I've used the regular footswitch. I don't really like the clean channel that much (Joe Satriani used that as did Johnny A) . . I'm surprised but hey whatever works! lol.. .Channel 2 is KILLER KILLER and Channel 3 is good (not KILLER KILLER but very good) . . . The amp is very versatile at ALL volume levels and I like it a lot. Haven't used it in awhile as I'm an amp-addict and have been using other modded Marshalls and Splawns predominantly recently but am gonna dig it back out.. The original speaker btw wasn't a JBL but an EV/Marshall speaker and I still have that. Eric
 

/13guitarman

Member
Messages
1,128
Yes I still have the original EV speaker. That amp did sound killer. I think I will search someone who has experienced and are qualified to work on this as suggested.
 

thelionsden

Member
Messages
918
Yes I still have the original EV speaker. That amp did sound killer. I think I will search someone who has experienced and are qualified to work on this as suggested.

Don't know where you are located but my friend in Cleveland is an electronics tech that knows the flaw in the midi board and knows how to upgrade it. He dialed mine in. I have the combo with the footswitch.
 

thelionsden

Member
Messages
918
That amp has been on my radar since I got turned onto Johnny A.
I'd love to score the brass 112 combo!

S.
j

Hi Steve... I don't have the brass one but I have a nice black combo in great shape with the midi board flaw corrected, footswitch, new tubes and bias and the 1x12 extension cab. I only use it to work on tunes in front of my computer, but I would play the gig with it any time, it is very capable. I just stick with my 76 JMP which remains set up all the time. Maybe we can make a trade like the old days! :p
 

TNJ

Gold Supporting Member
Messages
28,912
Hey Dennis,
Will shoot you a line.
Hope all is well!

S.
j
 

DiPa

Constant GAS
Silver Supporting Member
Messages
17,264
Played my 6100LM today and all 3 channels were singing beautifully.
I am going to add a NOS in v1 per suggestion from a fellow TGP as I have the amp out. Will try to post some new pics next week.
 

TNJ

Gold Supporting Member
Messages
28,912
Really digging my newly acquired 6101 EL34 combo!
Chs 1 and 2 are just fantastic!

Will gig with this amp later in the month and report back in.


S.
j
 
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/13guitarman

Member
Messages
1,128
Don't know where you are located but my friend in Cleveland is an electronics tech that knows the flaw in the midi board and knows how to upgrade it. He dialed mine in. I have the combo with the footswitch.

I'm only an hour away. pm me your buddies info, Thanks!
 

ProfRhino

Member
Messages
10,433
got mine back today, after a quick 3 year pit stop at my tech's. :dunno
as I only need it for recording and never had a FS anyway, we decided to show the finger to all the monkey business and he replaced it completely with two mini toggles in the holes where the channel LEDs used to sit.
Not exactly trivial when done correctly, there's a lot of switching going on under the hood, but now it should be way more robust. :aok
I had almost forgotten how great and unique ch1, ch2A & ch2B can sound ...
A nice bonus - it is whisper quiet now.
quite impressed again,
Rhino
 




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