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Kurzman
03-08-2008, 09:42 PM
I recently bought an 18 Watt Lite II (Silvatone layout). The way I understood it, was that this was just like an 18 Watt but with only one channel.

(I admit that I've never heard an 18 watt Marshall.)

This thing sounds really anemic through several different speakers**. I had the correct impedance set. Compared to a Princeton Reverb, a Vox AC15, or an Orange AD 15 this thing sounds like a 5 watt practice amp. It's not even in the same universe as a Dr. Z Maz 18.

Dimed with a Les Paul it does sound like a Marshall ('70's R&R crunch) but just not much of it.

Does this sound right? I'd appreciate advice or opinions. Thanks.

** Closed back 8 ohm 15" Showman cab, open back 2X12 4 ohm Pro Reverb cab, 8 ohm open back 1 X 12 Red, White & Blue.

chris_d
03-08-2008, 10:00 PM
That doesn't sound quite right. The amp is definitely voiced to cut through, with a focus on the upper mids, but it should compare favorably to an AC15.

Who built it? What transformers? Any "mods" done to the circuit? Pictures?

I have built three with different transformers. One of those builds with a hammond 125E wasn't all that great(it was also my first build and there were lots of quirks due to the fact that it started out as a zenith hi-fi amp) but even that got quite a bit of distortion and plenty of bass for such a low watt amp. The other two i built with Ceriatone OTs and they sounded pretty great to me, plenty of lower mids.

-chris

Kurzman
03-08-2008, 10:18 PM
http://i199.photobucket.com/albums/aa102/kurzman/turretboard.jpg

http://i199.photobucket.com/albums/aa102/kurzman/chassiswiring.jpg

Here're the pics I got before I bought it. It has GDS trannys. It's supposed to have high quality parts. Sorry, I don't have any other pics of the guts.

chris_d
03-08-2008, 10:35 PM
Yeah, the GDS are Heyboers. They are also some of the most accurate 18w trannies available. Unless one is blown, that should not be the problem.

That actually looks like a pretty nice build with good bits. Is that dual gang knob some sort of master volume?

-chris

Kurzman
03-08-2008, 10:51 PM
Chris, thanks for the help so far. I will check out the pot tomorrow. The amp is at a buddy's place.
I sold it to a guy yesterday (a week after I got it) but I think I'm going to give him his $$ back.
When I got it I thought it was a little weak but didn't know for sure. My buddy said it was EXACTLY what he wanted, tried it out an bought it....now he says it's not cutting it. So I figure if both of us think it's under powered, then something must be wrong.
I suppose the logical step is to go down to the music store and plug into a real Marshall 18 watter so I'll have something to compare it to.
As it is now I'm not even sure you could use it with a drummer.

chris_d
03-08-2008, 11:01 PM
Hmm. After looking at it a bit more, you know, it looks like the Silvatone board layout, but there are a few things done differently, looks like some extra parts, as well. You might want to get in touch with the builder and see where he might have deviated from the silvatone arrangement.

Is it a builder with much experience? Someone who has built more than this one amp? It is hard to tell without more/better pictures, but that looks like some changes were made, and certain parts appear to be wired quite differently from the one on Silvatone's site. Again, it is hard to tell from here, but it looks different to me. The volume and tone pots are swapped, there is that odd cap flying off of the tone control, and neither the volume or tone appear to be attached to the board in the same fashion as Silvatone's.

Possibly some errors, or possibly the builder just wired things in a different fashion, maybe with different under-board wiring that i can't see from here. Who knows? Does the builder live far away from you? Would it be a pain to send it back for sorting out?

Alternately, you might try heading to a local guitar center or someplace that has the reissue 1974x in stock and see if you can't get a point of reference to work from. Once it is sorted, your amp should sound way better than the reissue, but it would give you something to use as reference anyhow, to play through one that wasn't "sick".

-chris

chris_d
03-08-2008, 11:08 PM
As it is now I'm not even sure you could use it with a drummer.

That doesn't sound right either. My 18w builds were all pretty loud. In a small practice space, i had to use dirt pedals(which i really don't like to do) just to get the volume down to play with a medium-heavy hitting drummer.

I think there is probably something wrong with yours. Hopefully it is something simple and easily sorted.

-chris

Unabender
03-09-2008, 01:25 AM
The volume pot definetely looks like a dual gang pot - a 18 watter should NOT have that in place, but a regular pot. Someone has done serious rewiring to it.

Kurzman
03-09-2008, 08:18 AM
I'm going to refund my buddy's $$ and get the amp back. Then I'll take more pics and begin the "sussing out" process.
The guy I bought it from said he A-B ed it with a reissue Marshall 18 watter and said it sounded better. So either he's a liar or something got josstled in shipping. There's no hisssing or crackling or weird noises...dead quiet.
I just find it hard to believe this is the amp so many people love. Like I said, Les Paul in, Vol and tone dimed...sounds crunchy but at loud living room volume. With a Strat plugged in it's really weak.
I appreciate the help. More later.

5E3
03-09-2008, 08:26 AM
If you could find a wiring diagram for the original circuit layout, it wouldn't be too much trouble to verify the correct values and paths are used.

Kurzman
03-15-2008, 10:41 AM
Well, I got the amp back. I borrowed a friends handwired Marshall 1974X and ran them A-B through the speaker in the 1974 (15 ohm Celestion-the Lite II has a 16 ohm output).

The 1974 is a nice sounding amp. The Lite II seems to have about 60-75% of what the Marshall has. The Lite II sounds ALMOST as good as the Marshall if the Lite II is dimed and the Marshall is on about 60%.

The Lite II just lacks...I don't know, balls, bottom...something. Both vol. and tone have to be dimed to get a halfway decent sound.

I installed ANOS Mullard 12ax7's, a NOS Sylvania EZ 81 and a NOS pair of TESLA EL84's (from KCA). Didn't hear much of a difference over the JJ's.

Who would you recommend I send this to to be "adjusted"? To be honest I really don't want to put more than another $100 in this thing.
Thanks in advance for tips or opinions.

I'm not a member of 18watt.com.

mockoman
03-15-2008, 11:02 AM
Are you in the U.S.? S2amps (Steven Scott) built a killer 18w Lite for me,in a Pro Jr chassis. He could probably tell you what's up...
I see in another post that he is going on vacation,till the end of March,I think.

www.s2amps.com (http://www.s2amps.com)

Kurzman
03-15-2008, 11:15 AM
Yes, I'm in Va.

chris_d
03-15-2008, 11:21 AM
I'm not a member of 18watt.com.

Why not sign up? That's the place for this kind of stuff.

Without lots more detailed photos to make clear what is or isn't hooked up and how, i personally can't say where you should go next.

I would say snap some pictures showing the wiring to the tubes and the controls, and as much of the board connections as possible, sign up at 18watt, and see what folks tell you.

Like i said, at the very least it looks like there is some deviation from the Silvatone layout. It also looks like you have a master volume in there maybe. The 18watt is NOT an amp that works well with a master volume at all. Much of the characteristic sound is distortion from the el84 output tubes, if you lower the input to them with a master, that, in and of itself will make the amp sound weak and crappy.

I suspect that much of the work needed to get your amp happy will consist of removing things and making sure that it is wired up in the correct, standard 18 watt way.

-chris

Kurzman
03-15-2008, 11:52 AM
I've got it taken apart and I've snapped and uploaded ten good pics. Should I just list links or have the 10 pics post here (one is pretty large).
I just don't want to break any rules.

BTW, the work looks incredibly neat.

guitarsnguns04
03-15-2008, 12:03 PM
If you dont want to mess with it and decide to sell it or whatever let me know. I am looking for a new little project to tweak on. Just shoot me a pm and a price and I will take your headache away. Or I will try to help you when I see the pics and the circuit layout.

Kurzman
03-15-2008, 12:09 PM
I hope it's OK to post all of these pics:

http://i199.photobucket.com/albums/aa102/kurzman/amp10.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp9.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp8.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp7.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp6.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp5.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp4.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp3.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp2.jpg

http://i199.photobucket.com/albums/aa102/kurzman/amp1.jpg

Kurzman
03-15-2008, 12:14 PM
BTW, this is what the amp looks like. I've got $460 in it.

http://i199.photobucket.com/albums/aa102/kurzman/DSCN2542.jpg

Scott Auld
03-15-2008, 12:46 PM
Kurzman, thanks for posting those pics. That is a SWEET amp.

Hope you get it fixed and making you happy.

S

Kurzman
03-15-2008, 01:15 PM
I had big plans for this. I've got a 2 X 12 Truetone cab ordered for it. Black tolex, white piping, red valence panel. I've got two Celestion Blues ready for the cabinet.
But the amp just ain't cookin' and I'm not a tech guy. Pretty frustrating.

Scott Auld
03-16-2008, 12:35 PM
Sell it to guitarsnguns04 and move on to something else :)

VanR
03-16-2008, 02:49 PM
Where did you buy that I've been thinking of an 18 watter myself?

Kurzman
03-17-2008, 07:35 AM
Scott, since I've got $460 in it I doubt if I could recover the money spent. Also I've got a matching cab coming so I've decided not to give up.

It's packed up and will be going out to Dave Allen for "beefing up" today. The guy that sold it to me said he had compared it to a re-ish 1974X which I did a couple of days ago. The Marshall was nice sounding amp. My amp seemed like 50%-75% of the 1974X. Basically this head sounds like a Marshall 8 watter.

Van, I bought it from a guy on the Weber Buy & Sell page.

I'll update after I hear from Dave Allen.

Unabender
03-17-2008, 10:43 AM
Like i said, at the very least it looks like there is some deviation from the Silvatone layout. It also looks like you have a master volume in there maybe. The 18watt is NOT an amp that works well with a master volume at all. Much of the characteristic sound is distortion from the el84 output tubes, if you lower the input to them with a master, that, in and of itself will make the amp sound weak and crappy.

Well technically, if an amp has only a single volume/gain knob, and it's right after the preamp and before the PI, it IS pretty much a traditional master volume :)

chris_d
03-17-2008, 11:30 AM
Well technically, if an amp has only a single volume/gain knob, and it's right after the preamp and before the PI, it IS pretty much a traditional master volume :)

Sure, but this one seems to have something else going on as well with the volume controls, MV or otherwise. What is with the dual-gang pot? Are both sides wired up?

What is with the two shrink-wrapped resistors that have been inserted between the pots and the P.I. input cap? I haven't seen either on a standard 18watt schematic, as far as i can remember. It would seem like adding resistance there in series with the pots would make it so that the amp would never reach full volume, right? There would always be the resistance of the two resistors in the circuit regardless of whether the volume and tone were maxxed? Again the pictures don't quite show how those resistors are connected and i am assuming that they are off of the wipers of both pots. Also i can't make out the resistor's values either, to see how bad an effect they might have on strapping the amp for gain/volume.

If it is possible to contact the builder, it might be a good idea to see what his thoughts are on those resistors? My relatively uninformed thought is that they are unneeded in this amp, and they certainly appear to be "extra" compared to the Silvatone layout.

But what do i know, right? Maybe they have a purpose and don't get in the way. Ask the builder if you can.

-chris

chris_d
03-17-2008, 11:38 AM
By the way, although it doesn't sound right to you now, that is a pretty nice looking build. Definitely worth the further effort to sort out, i would say. Stick with it as long as you have the patience to, and you should get a sweet amp out of it.

-chris

mockoman
03-17-2008, 05:09 PM
By the way, although it doesn't sound right to you now, that is a pretty nice looking build. Definitely worth the further effort to sort out, i would say. Stick with it as long as you have the patience to, and you should get a sweet amp out of it.

-chris


I agree.It's filled with good parts,& Dave Allen knows his stuff.
I'll bet it will be something simple,like a cap or resistor value.
Good luck,& let us know what you find out...

Kurzman
04-03-2008, 08:34 AM
Just in case anybody was curious:

I got the amp back from Dave Allen last week. He's astonishing. It's like I sent in half an amp and got back two amps. Now I see what the fuss is about these 18 watt Marshall circuits.

As far as I know Dave found that the pots were incorrectly wired. There was a resistor on the vol. pot (?) that shouldn't have been there. He also changed a couple of caps to increase the bottom. I've been playing it through an Eminence R, W & B. It's really, really loud with the vol. pot up at 50-60%.
Lots of gain and crunch.

I'm waiting on a Trutone 2 X 12 cab which I'll load with two Celestion Blues. As the amp has outputs for 4, 8 and 16 ohms, do you think I'll get the best sound from wiring the two 8 ohm Blues as 16 or 4 ohms or is it a wash?

Thanks in advance.

Kurzman
04-15-2008, 05:35 PM
I doubt if anyone is interested but my 18 watt story ended today with the receipt of a Trutone 2 X 12 cab. I loaded it with two Blues, plugged in and BOOM!. Absolutely great sounding set up. Completely different from the Fender sound I'm used to but very nice and very rock and rolly.

I appreciate the encouragement and advice. Signing off with a pic of the rig.

http://i199.photobucket.com/albums/aa102/kurzman/stack.jpg

http://i199.photobucket.com/albums/aa102/kurzman/stack2.jpg

59Vampire
04-15-2008, 05:51 PM
i have an 18 watt clone in a 2 x12 cab AWESOME im happy yours ended up good. mine started out as a build froma diy'er and i had it rebuilt by Plexi at the 18wattcommuntiy center. its awesome/!!

guitarsnguns04
04-15-2008, 06:28 PM
congrats...I am glad to hear you got the issues resolved and are happy. :RoCkIn

mockoman
04-15-2008, 06:41 PM
Good for you. I had a feeling it would be simple to fix.
Enjoy that sucker!