Alright amp modder dudes...

  • Thread starter Thread starter tweed
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tweed

tweed

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If I wanted to turn this old PA amp into a fire breathing dragon of an amp, what should I do?

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Thanks for the link Ralph!! Not sure about posting at Metro. I'll wait a while so as not to get shot over there.
 
tweed":ff9da said:
Thanks for the link Ralph!! Not sure about posting at Metro. I'll wait a while so as not to get shot over there.
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Nah, those guys are extremely cool with giving out information!! Just hit them up and Im sure you'll get lots of ideas!
 
Eat a box of Hot tamales and then plug in a mic and breath into it! :clap:
 
I really should have said,,,,eat box of hot tamales, plug in mic and fart into it! :doh:
 
Hot Tomales RULE!!! :thumbsup:

I would love to turn this thing into a single channel monster. There are a lot of things Im sure I could do but have no clue where to start. I do know that the amp was working at one time and it sounded great. All I did was put a 1/4" jack on it and presto, nice tone. Are there simple things I can do like identify the trannies? They don't really have any markings on them and im not even sure if they are 50w or 100w or somewhere inbetween.

Maybe I can just buy a prewired board to drop in, change the tube slots out, add different tubes and go from there?
 
tweed":eff59 said:
Hot Tomales RULE!!! :thumbsup:

I would love to turn this thing into a single channel monster. There are a lot of things Im sure I could do but have no clue where to start. I do know that the amp was working at one time and it sounded great. All I did was put a 1/4" jack on it and presto, nice tone. Are there simple things I can do like identify the trannies? They don't really have any markings on them and im not even sure if they are 50w or 100w or somewhere inbetween.

Maybe I can just buy a prewired board to drop in, change the tube slots out, add different tubes and go from there?
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Doing that would save you trouble shooting time but if the amp works already a few tweaks will be easier.
 
Gainfreak":a6190 said:
tweed":a6190 said:
Hot Tomales RULE!!! :thumbsup:

I would love to turn this thing into a single channel monster. There are a lot of things Im sure I could do but have no clue where to start. I do know that the amp was working at one time and it sounded great. All I did was put a 1/4" jack on it and presto, nice tone. Are there simple things I can do like identify the trannies? They don't really have any markings on them and im not even sure if they are 50w or 100w or somewhere inbetween.

Maybe I can just buy a prewired board to drop in, change the tube slots out, add different tubes and go from there?
Click to expand...

Doing that would save you trouble shooting time but if the amp works already a few tweaks will be easier.
Click to expand...

If you look closely in the guts pic, you'll see that one of the resistors has since "left the building". Left a lot of nice white residue on the chassis. I would love to troubleshoot and mod this thing to taste, but would need a lot of help to get there.
 
tweed":b51cd said:
If you look closely in the guts pic, you'll see that one of the resistors has since "left the building". Left a lot of nice white residue on the chassis. I would love to troubleshoot and mod this thing to taste, but would need a lot of help to get there.
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troubleshooting is the biggest pain in the butt. Starting from scratch might be the way to go but methinks either path is going to take some help. Im pretty sure you can get all the help you need between here and the Metro board. Trace is also a great guy who shares much information as well as Olaf and many others!!
 
Man there is tons of good reading at Metro. Where the hell do you start and how do you stay on track? To much info to soak up there Ralph!
 
You're not only going to have to rewire the entire amp (or almost the entire amp), but also create a circuit layout that suits the chassis layout (of the tubes, transformers, and so on).

Unless you've built amps before, this is not a good place to start, especially if you want it to be a high gain amp. A clean amp, you can get away with some little mistakes; a high gain amp will cause you headaches though, if you don't know what you're doing.

A "drop-in replacement board" isn't going to help unless that board is designed with your amp's particular layout in mind (and I'm betting there are no such boards). Even so, without good layout diagrams and instructions you're going to be fighting an uphill battle.
 
These guys are making it too complicated. Just drop some resistors, caps, a few wires and a tube or something in there and you should be good to go.
 
JamesPeters":07b4c said:
You're not only going to have to rewire the entire amp (or almost the entire amp), but also create a circuit layout that suits the chassis layout (of the tubes, transformers, and so on).

Unless you've built amps before, this is not a good place to start, especially if you want it to be a high gain amp. A clean amp, you can get away with some little mistakes; a high gain amp will cause you headaches though, if you don't know what you're doing.

A "drop-in replacement board" isn't going to help unless that board is designed with your amp's particular layout in mind (and I'm betting there are no such boards). Even so, without good layout diagrams and instructions you're going to be fighting an uphill battle.
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Thanks James. Is there any way to tell what the trannies are with a DMM maybe? Maybe I can use them for another project.
 
It's a pair of 6L6s, so probably 30-50 watt output transformer. If it still works, you can get out your multimeter and measure the voltage for the power transformer. Then look at some different amps that kinda fit in that range, and that's what you're going to be able to build around the transformers.

You can also use solid state rectification to get more voltage from the power transformer, or change to a different rectifier tube to change voltage also.

I would advise going to AX84.com and reading up - most of those are simple projects, and would be good to think about building before you turn this into the firebreathing monster amp from hell. You're also going to have to replace the sockets for the 6SN7 preamp tubes if you want to run 12ax7s. They are totally different regarding physical size and pin layout.

Pete
 
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