My 50W Build! (with pics) - COMPLETE!!!

Get support and show off your MetroAmp 50 Watt kit builds.

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straycat
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Post by straycat » Sat Nov 24, 2007 9:58 am

Ordered the rest of the parts on Wednesday for a 50w Plexi build just have to wait for them to show up now. Did you have any issues with mounting the PPIMV in the extra speaker jack? I thought about just drilling a extra hole where the voltage selector would have gone. The power tube sockets would be right below the pot. Any thoughts or ideas on doing it that way?

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bartak
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Post by bartak » Sat Nov 24, 2007 12:27 pm

Hey Mike,

I just built a 50 and was wondering how they compare. mine starts to break up at around 2, at that volume I get AC/ DC tones but its a bit harsh and really percusive. IT doesn't smooth out till around 7 or 8. but at 8 this is the loudest amp I have ever played. from past experience all the NMV marshalls I've owned and played have had a wonderful clean tone. this amp is harsh and extremely loud on 1. for the last few years I have been using a 68 bassman with a vintage dod250 or a seymour duncan twin tube in front of it and I was planing to do the same thing with the plexi but it overpowers my drummer on 1. I'm just looking for some feedback so I know where to start from to get this amp to work for me. I did try the rich ppimv and didn't like it at all. I ordered the parts for the lar/mar hopefully I'll like that one better. Thanks

Mark

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toner
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Post by toner » Sat Nov 24, 2007 12:59 pm

bartak,
Did you use the stock 500pF bright cap? That will let a lot of treble and gain past the volume pot at low volumes which can seem harsh.

You may want to try lifting one leg of the bright cap and try it at low volumes around "2". It will also change the tone a little at higher volumes so try that too. If the clean tones are too dark or "dull", you can try a smaller bright cap (250pF, 100pF, 47pF) to find a good compromise.

Hopefully, you'll like the Larry/Mark PPIMV. I have one in a 100w and love it.

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mwm523
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Post by mwm523 » Sat Nov 24, 2007 1:23 pm

I second everything toner said. If you've got a 500pf bright cap on vol 1, try something smaller or none at all. I knew the 500 was going to be too much going into the build, so I started with a 250pf. That was still too bright for me at lower volumes, so now I'm down to a 100pf which I like much better.

And yes, mine starts to break up at around 2, and at 3 it settles right into AC/DC-like rhythm crunch (which is still fairly clean, just a little crunchy).

And yes, it is really loud at 8. I'm sure Taco doesn't approve... :lol: 8)

And give the Larry/Mark PPIMV a chance at rehearsal/gigging volumes. These amps really shine best when being overdriven naturally as opposed to setting them clean and using a pedal.
Last edited by mwm523 on Sat Nov 24, 2007 4:44 pm, edited 1 time in total.
-Mike

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mwm523
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Post by mwm523 » Sat Nov 24, 2007 1:26 pm

straycat wrote:Ordered the rest of the parts on Wednesday for a 50w Plexi build just have to wait for them to show up now. Did you have any issues with mounting the PPIMV in the extra speaker jack? I thought about just drilling a extra hole where the voltage selector would have gone. The power tube sockets would be right below the pot. Any thoughts or ideas on doing it that way?
I had no issues mounting the PPIMV in the second speaker jack. That seems to be the standard location for it. I'd rather not drill any extra holes in the chassis if I can help it, and I can't see myself needing the second speaker jack anyway. I won't be playing MSG any time soon... :roll:
-Mike

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bartak
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Post by bartak » Sat Nov 24, 2007 2:16 pm

Thanks for the info, I have the 250pf cap in now but was planning on trying the 100pf. also my cab is an early 80's Carvin with 4 75 watt celestions, wired for 4 ohms, I'm going to rewire it to 16 ohms and see if that takes some of the edge off. it's interesting, in my 25 years of playing I've owned and played through many vintage Marshalls and none of them had such a huge jump in volume. This amp was purchased for the sole purpose of rehearsal and gigs so I wasn't looking for a quiet amp but holy cow this thing is insane. thanks again for the info I'll let you know how the larry/mark ppimv works out.

johnnymenudo
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Post by johnnymenudo » Sat Nov 24, 2007 3:58 pm

mwm523 wrote:
mwm523 wrote:
straycat wrote:How do you like the PPIMV in this amp? How does it sound at lower levels?
Well... My first impression of the PPIMV in this amp at lower volumes is that it is........fizzy.

It works great for bringing the volume down a bit, not much of an effect on the tone. But at bedroom volume the PPIMV in my JTM 45 seems more usable than this one.

I have to play around with it some more, maybe try some different tubes in the PI to see if it makes a difference.
Update on the PPIMV... The more I play the amp, the less fizzy it is with the PPIMV down to bedroom volume. It's really smoothing out nicely now. My guess is that the Sozos are breaking in, and the fizz I was hearing at low volume was because they were brand new. I've got about 8 hours in them now.
Good to hear the PPIMV is working well. I am going to put one in myself during the build process. I am about 30% through the build. Did you order George's PPIMV kit? What version of the PPIMV did you end up using?

JM

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mwm523
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Post by mwm523 » Sat Nov 24, 2007 5:45 pm

No I didn't specifically order George's PPIMV kit, because I believe that kit is for the "Rich Mod".

I ordered an Alpha dual 250K pot:
http://store.metroamp.com/product_info. ... cts_id=480

a length of two-conductor shielded wire:
http://store.metroamp.com/product_info. ... cts_id=286

a Marshall set screw knob:
http://store.metroamp.com/product_info. ... ucts_id=41

and some 2.2M resistors from Radio Shack to make the Larry/Mark PPIMV described here:
http://forum.metroamp.com/viewtopic.php?p=81331#81331
-Mike

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Post by johnnymenudo » Thu Nov 29, 2007 11:46 am

MWM (or anyone for that matter)

Question about the orange green twisted pair you omitted from the board because of the PPIMV. I was thinking that I would go ahead and solder up these two wires and heat shrink the ends and leave them in the chassis in case I decide to get rid of the PPIMV and return the amp to stock. I thought this would be easier than trying to solder them in later if I don't like the PPIMV. This is my first amp so not sure if this is a good idea or not. Thoughts?

JM

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neikeel
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Post by neikeel » Thu Nov 29, 2007 1:28 pm

Probably a good idea.

I was a rowdy rebel and used my green/oramge wires. ie I went to the pot with shielded wire and then took the wires back to the board on a stand off (like the ones used in Georges Rich mod). I have had no increased noise at all and I can easily go back to stock without lifting the board.

If you are paranoid about noise you could use shielded wire instead of the orange/green as well, but if you are going to do that you will need to do it for your input wires in the preamp etc, etc.
Neil

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mwm523
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Post by mwm523 » Tue Dec 04, 2007 10:47 pm

Ok, I put up a few clips of this amp in the Sound Clips forum. Check it out:

http://forum.metroamp.com/viewtopic.php?t=15432

Keep in mind, these are my first attempt at clips of any kind, so the recordings need a little improvement.
-Mike

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Post by JimmyR » Tue Mar 18, 2008 11:03 am

Great post! I should try one of George's kits. I always seem to have some of the bits already so end up buying parts and not kits. But I have built a few 50watters with George's parts. I really like the steel chassis - fantastic and a big improvement over the aluminium chassis I've used in the past.

I built a '68 spec 1987 with lots of reference to the Marstran site and it is one of the best amps I have ever heard. I link channels with both vols at 12.00 and my 335 sounds like god through it. I find that by using the normal channel for extra bass or bright channel for clarity works really well. The amp set up like this isn't too deafening and works incredibly well with the guitar's stock vol pots. BTW I ended up with a 100pF bright cap, split cathodes and .1uF PS coupling caps. The PS caps are the only major deviation from '68 spec. I can get some JTM45-ish tones as well as killer plexi tones, and all out of an open-back 2x12 cab. The cleans are amazing too.

I think George deserves a helluva lot of kudos for making all this stuff available and so easy to use. For what I've spent on parts I have ended up with a LOT of amp! Thanks George!

bravedude
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Post by bravedude » Mon Apr 14, 2008 5:06 pm

this is my first post , let me say you did some nice work .
when i get the guts and cash i will try. until then i will just learn from these great pics and suggestions. :D

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NY Chief
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Post by NY Chief » Tue Apr 29, 2008 11:26 pm

johnnymenudo wrote:MWM (or anyone for that matter)

Question about the orange green twisted pair you omitted from the board because of the PPIMV. I was thinking that I would go ahead and solder up these two wires and heat shrink the ends and leave them in the chassis in case I decide to get rid of the PPIMV and return the amp to stock. I thought this would be easier than trying to solder them in later if I don't like the PPIMV. This is my first amp so not sure if this is a good idea or not. Thoughts?

JM
Interesting thought. How would it be done if the amp was already built? Pull the board and unsolder the org/green pair form the turrets?
NY Chief 5-0, transplanted in SoCal

"Book 'em, Dan-o!"

myfoot

Post by myfoot » Wed Apr 30, 2008 7:21 am

I left the wires on with the ends heat-shrinked . It's tucked under the board. I left the resistors off. Figured it would be easier to change somewhere down the road that way. I don't have any noise or anything from the wires being under the board.

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