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12XXX Build 05/2010

Posted: Mon Apr 19, 2010 8:05 am
by vanhalen5150
Just a few shots of progress to date. Seeing as though nobody lurks in the 12000 build journal, I thought I'd throw these out here. Any suggestions would be appreciated. My main concern right now is how to tie all the wires together for optimal noise reduction. I've looked at all of George's stuff, but its what you cant see under the boards thats eludes me.

Special thanks to ToneChaser for help. 8)

The quality of George's kits and support is second to none. Save some cash fella's and buy one from Metro. Tons of help here if you need it.

Re: 12XXX Build 05/2010

Posted: Mon Apr 19, 2010 9:40 am
by vh junkie
Looks pretty darn tidy to me! You should see some reduction in noise if change the orientation of the Sozos. The stripe should go toward the low impedance side.

I think the two .68ufs are right the way they are.
The four .022uf couplers should have there stripes towards the tube side.
The ones in the tone stack and the PI input caps, I'm not sure about. Someone who knows should chime in.

There is discussion about this on aikenamps.com and also here in metro somewhere.
I was trying to look at the pics of some George's work on plexireplicas.com, and I still can't see the best way to do this tone stack wise.

Re: 12XXX Build 05/2010

Posted: Mon Apr 19, 2010 10:20 am
by vanhalen5150
I was wondering about that with the Sozo's. Are they directional? Some of George's are in different directions.

It's here: http://forum.metroamp.com/viewtopic.php?t=12110" onclick="window.open(this.href);return false;

I'm not sure what to think. :? :lol:

Re: 12XXX Build 05/2010

Posted: Mon Apr 19, 2010 11:51 am
by vh junkie
The pics of the various amplifiers here seem to agree on the direction, except for the one tone stack cap appears in both directions.

http://plexireplicas.com/metropoulos-amplifiers

While the caps aren't polarized, you end up rejecting some noise by having the outer foil towards the low impedance side.

Once the caps have been formed you wouldn't want to switch them (it would require dozens of hours for them to reform), but seeings how yours look like they have never been powered up...

Re: 12XXX Build 05/2010

Posted: Mon Apr 19, 2010 11:55 am
by vanhalen5150
I agree. May as well just switch while I can. After 30 + hours of work/headscratching, whats an extra 20 minutes.
I guess the next question about this would be why are they all not switched that way?

Re: 12XXX Build 05/2010

Posted: Mon Apr 19, 2010 8:29 pm
by vh junkie
vanhalen5150 wrote: I guess the next question about this would be why are they all not switched that way?
Do you mean why are the plexireplicas.com pics different?

I sure you've already done this but, looking at the 100w build guide will help with some hints on lead dress.

Twisting good! Not sure about twist ties though... might want to move wires around a bit to diagnose any oddities.

I wish I had done the 12 series when I went to slaving! I was in a hurry and just got a second 100w kit!

Apparently the way to get those cool looking solder joints is to tap the soldering iron off and on the turret while soldering... but if you gonna be modding the thing endlessly whats the point? :lol:

Re: 12XXX Build 05/2010

Posted: Tue Apr 20, 2010 4:04 am
by Sral68
Hi!

Nice build.

Are you going to use alternate grounding (star grounding/Larrys grounding)? I'm curious to try this myself. My 12.000 has some hum from the transformer (not through the speakers). I've read somewhere that this can be cured by the way the transformers are oriented in the chassis. Might be worth checking into. Sorry that I dont have any reference.

Re: 12XXX Build 05/2010

Posted: Tue Apr 20, 2010 5:16 am
by Roe
vanhalen5150 wrote:Just a few shots of progress to date. ...
I recommend keeping the primaries and secondaries of the OT apart although marshall may not have done so always

Re: 12XXX Build 05/2010

Posted: Tue Apr 20, 2010 1:55 pm
by vanhalen5150
Sral68 wrote:Hi!

Nice build.

Are you going to use alternate grounding (star grounding/Larrys grounding)? I'm curious to try this myself. My 12.000 has some hum from the transformer (not through the speakers). I've read somewhere that this can be cured by the way the transformers are oriented in the chassis. Might be worth checking into. Sorry that I dont have any reference.

I'm just doing the stock/EVH build for now. I do plan to Larry the grounds later.

Re: 12XXX Build 05/2010

Posted: Tue Apr 20, 2010 11:58 pm
by Strat78
Nice! There should be more post like this here, instead of the old lady sewing circle of late. :lol: So this is the 68 build? What OT transformer did you go with? I'm saving up for this kit, should take a couple more months, then I'll be picking your brain.

Re: 12XXX Build 05/2010

Posted: Wed Apr 21, 2010 7:52 am
by vanhalen5150
Strat78 wrote:Nice! There should be more post like this here, instead of the old lady sewing circle of late. :lol: So this is the 68 build? What OT transformer did you go with? I'm saving up for this kit, should take a couple more months, then I'll be picking your brain.
Thanks, I agree. I got the '68 EVH specs kit with Georges original vintage Dagnal OT. I've learned a lot along the way. Help from ToneChaser and a guy named R. Blankenship. :lol:
Lots of little tips that will save you a ton of trouble. I took a lot of picks and wrote a lot of little do's/dont's that are not in the instructions available. Definately get in touch when you start Strat78. :mrgreen:

I'm already saving for a second. "The sickness" continues. :shock:

Re: 12XXX Build 05/2010

Posted: Fri Apr 23, 2010 11:04 pm
by Tone Slinger
I got my 1200 series kit a couple of weeks ago, and havent even had the time to take the chassis out of the headbox to look at the components :o . I got the effects loop (I love digital reverb) and the Lar/Mar ppimv kit. I plan on attenuating and possibly slaving in the future, but I liked having a reasonable way to get at some dirt without all the volume.

I have heard some great things about the Eh el-34's, so I got miy kit with those. I also have a very nice quad of EH 6ca7's. Not sure which I will initially use.

The '69 kit is very easy to decipher/build, but this '68 has the filter caps in different area's. I hope to be using you guy's advice when I get to putting this thing togather.

I also recently got an old 800 series slant 4/12 that has had the grille clothed replaced with the sp basketweave. It as 4 celestion 6402 coned greenbacks :D . Sounds real good.

Re: 12XXX Build 05/2010

Posted: Sat Apr 24, 2010 12:53 am
by vanhalen5150
Lots of help here buddy, when you get to it, ask away.

Re: 12XXX Build 05/2010

Posted: Sun Apr 25, 2010 9:14 am
by Tone Slinger
Thanks man :D

Re: 12XXX Build 05/2010

Posted: Sun Apr 25, 2010 9:38 pm
by Omn
Very nice and tidy!!