Please check 12xxx build diagrams

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Night Owl
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Re: Please check 12xxx build diagrams

Post by Night Owl » Fri Sep 18, 2009 8:14 pm

I know the feeling. I'm not a whiz at this stuff, either, but I wanted to learn. I spent 2-3 weeks going through the forum, diagrams, wiki, and tons of photos to figure out how to build mine. I wanted to make sure I knew how to do it before I started, and it was clear that the info was kinda scattered. I wrote my entire document before I started and then updated/corrected it as I went. In the end, I was able to build from what I put together, with no other instructions than those that were kindly offered (and gratefully accepted!) in this thread and incorporated into my document. I wouldn't have been able to do it without the instructions written for the basic 100w kit. I recommend keeping those instructions handy if you're looking at my doc. But if I can do it, I'm sure pretty much anyone can.

What I intended to do was take notes on the "why you do this" and "how it works" for each step. I may still do that, but it took a lot of time to get the step-by-step pulled together, build my amp, and debug it. I've been working two jobs and doing this too, so I'm spread a bit thin. One of my jobs ends in about a month, so maybe I'll get back to it then.

If you find errors or have suggestions, send 'em along to me. I'll probably do an update when I add the loop and MV. I know the doc needs a good overhaul, but I'm not sure how much time I'll be able to make for it anytime soon.

I had a great time doing the research and the build. I sense the initial symptoms of a new addiction...

tone chaser
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Re: Please check 12xxx build diagrams

Post by tone chaser » Fri Sep 18, 2009 10:36 pm

Thanks buddy. I also got to wire in the sozo 67 100uf royals to the cap board, kinda confused on that but I will ask for help when I get there. The people on hear are great they are very kind and helpful. This is my first forum and I greatly appriciate all the help........Thanks everyone and thanks for the directions!!!!!!!!! :D :D :D

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Re: Please check 12xxx build diagrams

Post by tone chaser » Sun Sep 27, 2009 12:28 am

thanks for your directions. they where a great basis for my build.
Very cool of you to post all that Thanks :D

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Re: Please check 12xxx build diagrams

Post by Night Owl » Thu Oct 08, 2009 10:00 pm

(there seems to be two versions of this thread, so I'm posting my update on both)

Thanks for the kind words - I hope others find it useful, clunky as it is.

I finally got my LAR/MAR MV installed. It's great, as everyone knows that has tried it. I also tried out some shielding with the copper tape I mentioned in one of these threads a few weeks back. I didn't do "the full job", just part of it. But it worked pretty well. If you don't mind a kinda junky look inside the amp, it did lower the noise level a bit for me. I imagine it could be done prettier, particularly if done during the build, but I was getting a little lazy on the building and more into the playing :)

One of my Mullard power tubes went bad, so I swapped in a quad of JJ KT77's I had while I waited for a replacement (Thanks, Fido!). I like those KT77 tubes. I used them in my 50w 1987x head and they sounded great - better than the winged C's I had in it. Give 'em a try sometime. Makes the sound seem a little bigger, more open to me - and a little louder!

The loop is next, but it'll probably be a while yet.

In the mean time, here's my updated journal. Sections 13, 14, and 15 had notes added about the LAR/MAR MV and shielding. Section 18 has some more info about the LAR/MAR MV installation.

Cheers!
Attachments
Metro 12xxx Build Journal.doc
(401.31 KiB) Downloaded 465 times

mutts
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Re: Please check 12xxx build diagrams

Post by mutts » Tue Jan 01, 2013 12:47 pm

Hey guys, I'm in the process of tackling a 12XXX build and am doing some homework. Night Owl was very kind in posting his build diagrams/instructions and this is a fantastic start. However, I can't seem to download the pictures that he has posted. I think it would be a great help to see the pictures as referenced in his instructions. Can somebody inform me how to download these pictures. Thanks kindly to all!

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Strat78
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Re: Please check 12xxx build diagrams

Post by Strat78 » Tue Jan 01, 2013 1:11 pm

Looks like there are allot more graphics from the last time I checked out this journal doc. Pics seem to work for me. His journal is very helpful, but I would use other picture sources for cleaner lead dress and wire routing. Also, think about incorporating the Larry ground schematic. Are you using a 69 chassis or a 67/68?

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Re: Please check 12xxx build diagrams

Post by mutts » Tue Jan 01, 2013 3:28 pm

Strat78,
I have no trouble opening the Night Owl's instructions - all is good there. I am referring to the photographs posted on the first page of this thread. They are zipped files with a php file extension that for the life of me I just can't open. I anyone can open these files what program are you using??

As to the question what chassis I'm using I will use George's chassis - see the 12xxx checklist on Valvestorm's website. I recently, built a JTM45 and got a lot of my stuff here - it's like one stop shopping!!

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Re: Please check 12xxx build diagrams

Post by Night Owl » Tue Jan 01, 2013 10:31 pm

That's odd about the photos. They should be compressed .zip folders full of .jpg files (and maybe some thumbnails and other stuff you can ignore). I just tried downloading some and that's what I got. I thought maybe they had been moved or something since my posting, but they seem to be working OK for me. If you still have problems I should still have the originals somewhere and might be able to email them or something. The folders are in the 1-2MB range, so might be too large for email. When you download them, make sure that the weird php file type thing isn't getting added on in your download process as some default file type or something like that. If the folders are showing you the files inside with the wrong type, try changing the file types to .jpg and see if that works.

mutts
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Re: Please check 12xxx build diagrams

Post by mutts » Wed Jan 02, 2013 12:03 pm

Thanks Night Owl, I have a computer issue at home because I was able to open the files from another computer without a problem.

On another note, what OT, PT and choke did you use in your build?

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Strat78
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Re: Please check 12xxx build diagrams

Post by Strat78 » Wed Jan 02, 2013 12:35 pm

George's 68 kit came with a dual tap 1203-80 PT and the Metro Dognall OT clone, at least that is what mine came with. Here is the parts list:
http://forum.metroamp.com/viewtopic.php?f=29&t=2978" onclick="window.open(this.href);return false;
I had forgotten about the 20H choke being popular in these amps back then, I have a NOS Radiospares 20H I think I'll utilize in the near future. :scratch:

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Re: Please check 12xxx build diagrams

Post by Night Owl » Wed Jan 02, 2013 4:22 pm

Glad you got it going. My journal and pics are OK for figuring what to connect to what and what order to do it in, but I'm a complete electronics neophyte, so my actual build/dress technique (or lack thereof) is probably far from pretty. Lucky for me, the end product seems to be pretty forgiving about some of that, as long as you get the basics right. So while my eyes may not be pleased, my ears are. I don't find myself looking inside my amp near as much as I listen to it. And outside this forum, I don't personally know anyone that would know what they were seeing if they looked inside - they just want to hear it :D But my daughter is becoming an electrical engineer, so I may get busted on all this in another year or two when she takes a look :lol:

I used the OT, PT, and choke from George's kit (parts list is somewhere here in the forum). It included these part numbers:
PT: Metro/Heyboer stand-up 1203-80-MS (has second tap for "variac" power level)
OT: Metro C1998
choke: MM MAR100

As an aside, I'll mention something else just from my personal experience with building this amp and trying to get different types of tone out of it. Not trying to start an argument or anything, just relating my experience based on my lack of technical understanding and over-eagerness to "try stuff" to find that magic tweak...

I got caught up in trying lots of tweaks to the 12xxx build right away - cascade, bright caps, different values of components, different wiring on v1, different types/brands of components, vintage vs new components, different NFB setups, grounding, shielding, etc, etc. It's mostly cheap and easy to do, although a little tedious. In the end, I've removed almost all of the changes. I do have the LAR/MAR MV and the zero-loss FX loop to give me some options and I use them. Those will probably stay, even if they aren't always used. I have a switch that lets me select different bright cap values, including no bright cap. It will probably stay. I have another switch that lets me select different combinations of taps and resistors for NFB. I almost never touch it and it will probably come out eventually. I haven't toyed with slaving/re-amping much yet (was using a Fender Twin instead of my other plexi and greenback 4x12), but that is the top of the to-do list. If that goes as planned, then even the LAR/MAR MV and loop may not be necessary for me. That 12xxx build, once broken in, is probably what I should have stuck with the whole time, particularly if I had tried feeding from it to another amp earlier. I like it as a base tone machine. I think I can fiddle with tubes and knob settings on that stock build (including using low power tap on PT) and by just changing other stuff and how it is connected in the overall setup (pups, FX, placement, loop, MV, speakers/cab, load/line out/second amp, etc) get pretty much everywhere I need to be without touching a soldering iron. At least that is where I am in my journey now.

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Strat78
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Re: Please check 12xxx build diagrams

Post by Strat78 » Wed Jan 02, 2013 9:10 pm

Wow, those were the days, when the 68 kit was for sale in George's store with NO instructions. Night Owl's step by step instructions made allot of our first time builds possible back then, THANK YOU!!! I still have a pile of print outs of his jpgs and of course the instructions to go with it. I can build these things from memory now but I will always be greatful to Night Owls hard work. On another note, if you want to see lead dress that is natural as nature itself, check out emmjaydubyas thread:
http://forum.metroamp.com/viewtopic.php?f=44&t=39823" onclick="window.open(this.href);return false;
It's truly a group effort here.

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Re: Please check 12xxx build diagrams

Post by Night Owl » Wed Jan 02, 2013 10:11 pm

This is a bit of a digression that might be better in one of the *lengthy* discussions about slaving/re-amping for EVH tone, but since it is also related to my build, I'll just mention it here...

Diming the tone stack on a plexi is part of the slaving/re-amping approach to getting the early VH sound. I also saw some concerns that very small amounts of gain might be coming in from pedals that EVH used, but may not be present in substitutes for those pedals. If you are concerned about that possible gain loss, or just want a little bit more gain from the amp, there is a simple mod that may be of interest. You switch your midrange pot for a switched pot as part of that mod (looks identical from outside). When the pot is switched off, the tonestack is bypassed. That should give you just a touch more gain, but is otherwise like diming the treble, mid, and bass. Search the forum for "one wire mod" or "tone stack bypass" and I think you'll find the details. When the pot is not off, the tone stack behaves as normal.

I have this mod in my amp. I haven't yet built a load/line-out box to try it with slaving/re-amping, though. I did it at a point when I was trying to get every drop of plexi gain I could find.

There is another side effect of this mod that might be appreciated by a certain devious tone master. When the bypass is engaged, it would look like your midrange is turned all the way down. And you can set your treble and bass knobs to random (unused) positions!

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Re: Please check 12xxx build diagrams

Post by emmjaydubya » Thu Jan 03, 2013 2:34 pm

Strat78 wrote:Wow, those were the days, when the 68 kit was for sale in George's store with NO instructions. Night Owl's step by step instructions made allot of our first time builds possible back then, THANK YOU!!! I still have a pile of print outs of his jpgs and of course the instructions to go with it. I can build these things from memory now but I will always be greatful to Night Owls hard work. On another note, if you want to see lead dress that is natural as nature itself, check out emmjaydubyas thread:
http://forum.metroamp.com/viewtopic.php?f=44&t=39823" onclick="window.open(this.href);return false;
It's truly a group effort here.
Thanks for saying that Strat but in all fairness, I ripped off a ton from the pics on your thread. Now THAT is a useful thread! Between yours, the 12,000 Larry ground thread and the Billy Batz layout, that got me about 90% there. It truly is a group effort, one of the best on the web. Wish there was more activity here but I guess I understand why there isn't.

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Re: Please check 12xxx build diagrams

Post by vanhalen5150 » Thu Jan 03, 2013 4:33 pm

Nightowl instructions and the Metro Kit 12000, I wouldnt have even attempted anything.
12000 Metro Kit

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