Old no-name amp info

[CasinoShanty]

Hey guys, my name is Andrew. I was wondering if you could lend some expertise. I have been interested in building an amp for quite a while, and have managed to procure an old hammond tube organ that I am planning on re-purposing. I've since started cutting my teeth on a couple stomp boxes, and I think I'm ready to tackle the amp soon.

However, this little guy happened to pop up on the old kijiji recently. I was wondering if anyone could tell me what they think of it, and what sorts of pitfalls there may be in buying it. I have a few questions myself for the seller. He said he was going to give me a call later today. I'm not entirely sure he even plugged it into a speaker or knows what he's talking about. Anyways, I'll post again when or if he provides some more information.

Thanks guys.

http://lethbridge.kijiji.ca/c-buy-and-s ... Z403645010

[M Fowler]

Which model of old Hammond organ amp do you have? I would just stick to the Hammond to make into a guitar amp.

The other amp is kool looking but with the Hammond you could put it into a home built combo amp.

I've done several organ to guitar amp rebuilds and so have many on this forum so we can answer questions.

Mark

[Structo]

Welcome to the Amp Garage Andrew.

Cool amp but seems a bit over priced for what it is.
But these things have gained popularity so perhaps that is the reason for the price.

It's probably a phono and public address amp.

What are the controls labeled as?

See if there is anything printed on the transformers.

As for the age, check out pot codes, etc.

The filter caps (electrolytic capacitors) will need replaced.
These are the big paper wrapped capacitors with the value and voltage printed on them.

Do you have the amp yet?
If and when you get it, post some gut shots and we can advise you better.

Looks like it has three output transformers.

Definitely worth it to repurpose it for guitar amplification.

Try to find a name or model number on it, there is probably a schematic online somewhere.

[CasinoShanty]

The organ is an L-122, with an AO-43-1 amp in it. I was still planning on doing a build with it, but I like the chassis and look of the old kijiji one in question. I figured it might not hurt for the price to clean it up and put in a three prong cord and switch the tubes out. Do amps tend to break down with age? should I be worried about the transformers simply dying?

[Structo]

I have converted an old Hammond organ amp before.
I believe mine was a AO-29 from a Hammond M3 organ.

Initially I was going to use everything I could but due to the nature of it's contruction, point to point using terminal strips I ended my frustration and gutted it.

So I only really used the chassis (which I shortened), power transformer and rectifier socket.
Those old PT's put out a lot of voltage and I ened up having to drop about 30v from the B+ using a zener power diode.

The Kijiji would make a much better choice for converting it to guitar amp.

Don't judge those old tubes until you have determined if they are good or bad.
The 6V6 power tubes on my organ amp (Sylvania 6V6GT) were still good and are still good.
The rectifier tube, a RCA 5U4GB, was also good.

Vintage tubes last much longer than current production tubes.

[CasinoShanty]

http://www.solorb.com/elect/musiccirc/l ... index.html

I have been planning on using this site to sort of guide my organ conversion since he started with the same chassis. I would make my circuit a little simpler though, and keep the original spring reverb.

[CasinoShanty]

But getting back on the topic of the kijiji ad, as far as I can tell, the last three pots are volume, gain, and tone. I wonder if it wasn't already built as a guitar amp originally.

[M Fowler]

So it's an 18w amp so you have exactly enough tube sockets to build a Matchless Lightning or my favorite an 18w Marshall with treble, mid, bass (TMB) and use the octal socket as the rectifier tube 5y3, 5U4 or 5AR4.

Mark

[Structo]

http://www.solorb.com/elect/musiccirc/l ... index.html

I have been planning on using this site to sort of guide my organ conversion since he started with the same chassis. I would make my circuit a little simpler though, and keep the original spring reverb.

Yeah I think I saw that site when I was building mine.

This is what my amp looked like when I got it.

[gar13]

Don't mean to hijack but....

Structo, I have one of those exact chassis sitting in my shop. Can I ask how you shorten the chassis and what did you end up building with it?