Ampeg GV-22 1968 vintage restoration

[Edmund Dantes]

Hey all,

I am in the middle of restoring an old and abused GV-22. I have painstakingly re-drawn the schematic for the amp, as well as split out the schematics for each PCB and devised annotated board layouts with component references. All sources for this info was not available on the web, as far as I know.

I invite all of you to visit my website. It's devoted to technical projects as applied to music. Right now, all I have up is the restoration project, but there will be more soon. I haven't had many visitors yet, and would love some feedback as to the usefulness of the info I have up. There might be something there to enlighten others of a like mind.

http://www.freewebs.com/edmund-dante...estoration.htm

Peace,
ED

[52 Bill]

I invite all of you to visit my website. It's devoted to technical projects as applied to music. Right now, all I have up is the restoration project, but there will be more soon. I haven't had many visitors yet, and would love some feedback as to the usefulness of the info I have up. There might be something there to enlighten others of a like mind.

Man, "woeful disrepair that was nearly Sadean in proportion...and the droppings of various rodentia.", I wish I had said that!

Welcome to the board! I can't wait to find out what happens to your amp in the next installment. Keep up the good work.

[Enzo]

Hi Ed
You have created pretty much an amp rebuild blog.

Just for future reference, many amp schematics are online at places like Schematic Heaven (.com) I think it is wonderful that Joe Piazza redrew lots of old schematics, but it just drives me insane that he never includes the part numbers. SO instead of being able to refer to R35 or R72, we have to refer to "that resistor on the right that connects between the second and third feedback cap in the trem oscillator." ( I see you've called it R67.)

Keep us posted.

[Edmund Dantes]

Hi Ed
You have created pretty much an amp rebuild blog.

Just for future reference, many amp schematics are online at places like Schematic Heaven (.com) I think it is wonderful that Joe Piazza redrew lots of old schematics, but it just drives me insane that he never includes the part numbers. SO instead of being able to refer to R35 or R72, we have to refer to "that resistor on the right that connects between the second and third feedback cap in the trem oscillator." ( I see you've called it R67.)

Keep us posted.

Hi enzo,

Yeah, I guess you're right...I did create a re-build blog as opposed to merely documenting the amp work. It all pretty much snow-balled into a website when I began breaking down the amp schematic into digestible chunks. I figured if it helps me to do all the re-drawing and analysis up front, it might help others, hence the website.

With regards to the component designations, I took them from the in-unit schematic that was pasted down to the inner chassis. I have seen others of a similar look on the web with different designations, but I saw no reason to not use the ones on the Dead Sea Scroll I had on-hand.

Work has been suspended for the moment, due to re-organizing my work area and looking for a job. I project resumption of actual work and a website update to begin this coming weekend. I already know that I am going to have to address the power transformer, in that the chassis had a nasty habit of going live whenever the inner box was moved or flexed. Of course, the charred bits of the main amplifier PCB will have to be repaired as well.

A question for the veterans:

While I want to preserve the classic integrity of the amp as much as possible, can anyone give me a reason not to use mult-strand wire instead of the solid core type that was used back in '68?

I realize that I should keep to copper wire instead of the aluminum stuff widely available, but I am thinking more in terms of flexibility and reduced chance of breakage, not to mention a more robust solder connection.

[Enzo]

Aluminum wire? I have never seen that. I know it used to exist for house wiring, but I thought they had given up on it. In any case, no one would want to use aluminum wiring in an amp, you couldn't solder to it.

I don't care if you make up new numbers as long as some are there to ident the parts. Joe seems not to care about that.

If the amp is not wired original, I doubt there is an issue as to solid or stranded wire - it will be apparent the wires are new and not original. Each has its advantages, use what you prefer.