This isn't for a guitar amp, but rather a tube driven electric organ, but they're still tubes so it's probably the same or very, very similar.
Anyhow, this organ has been dead and sitting in our basement for about a decade without an on switch. I replaced the toggle and it now gets power, however, when I plug it in and look to see if all the tubes glow, two of them don't in what appears to be the amp section. (There are also a group of six tubes next to coils of wire that are marked with the 12 notes. One tube per two note tones.)
I do not get any sound at all out of the organ keys, including the bass pedals. I'm assuming that because two of the tubes (ECC83/12AX) are completely gone that I wouldn't be getting any sound at all? Can I just pull them from the sockets, or is there some kind of special screw or something?
How much does brand matter? These ones are aparently "Telefunken" tubes made in Western Germany.
-Metaellihead
In an organ IMO tube brand generally matters little or not at all, because they're operating in true Class A conditions with very low distortion. The big differences we hear between tubes in guitar amps are because we're driving them out of the normal operating ranges they were designed for, and in these new operating regimes they don't conform to standardized specs. They transition into distortion a little differently. But that's not an issue in an organ, TV or radio where they are operating well within their normal design parameters. Any differences will be subtle. (Exceptions are in some output stages that operate in fixed bias Class AB1 and may need to be biased differently. And some 12AX7 types are naturally more prone to humming than others, due to different heater designs.)
What sort of organ are you working on? If it's a Hammond I can point you to helpful resources, but I don't know much about others. I don't think that's a Hammond, because it's using oscillators as tone references. Most Hammonds of the classic era use notched steel "tone wheels" spinning past magnetic pickups to generate their frequencies. Those coils you see tune the oscillator frequencies for the notes labeled on them. I've tuned a solid state Thomas organ that worked that way by tuning the slugs inside the coils with a plastic diddle stick from a color TV adjustment tool set, while checking the notes with a chromatic tuner. Close enough for my purposes. You'd probably have to redo that whenever you changed the neighboring tubes, and frequencies drift over time.
A 12AX7 pulls straight out of the socket. You may have to wiggle it. To reinsert it, note the wider gap between two pins. Line up the pins with the holes (straighten any bent pins) and gently push it in.
"A cheerful heart is good medicine."
It's an Estey brand organ. It's fairly old, I found a little tag in the cabinet that says:
Robert Nelson Jr.
821 Key
11/30/61
It's wired point to point, no circuit boards. The speaker is an 8 or 10 inch Jensen. I wasn't able to find any pics in Google. Here's a few that I took:
-Metaellihead
That brand's a new one to me.
Nice looking little spinet. Bet you'll have a ton of fun with it if you can get it playing. :D
"A cheerful heart is good medicine."
Yeah, I hadn't heard of it either. I did some google searching and apparently they were the largest pipe and reed organ manufacturer from the late 1800's to around the 1930's. They also made the transistion to fully electric and it seems they went dinosaur around the early 60's.
I think we bought it for 20 bucks 15 years ago.
-Metaellihead
Sounds like a deal to me!
There was a period up till maybe a couple of years ago when it was very common to find fine Hammond organs being given away because no one would buy them. I knew a guy online in Buffalo, New York who had a gorgeous M-3 that his father-in-law had bought new in 1957, that had been in the living room all that time. Said it worked but sounded a little "scratchy," might need tubes. Tried to sell it about three years ago, couldn't, then advertised it for free and couldn't get any takers. Said if anyone wanted it they could come pick it up but had to by Christmas or he'd salvage the amp and bust the rest up. I told him I'd take my Thanksgiving holiday and drive up there with my trailer, 600 miles each way, just to save the thing. He said he'd be gone till that Sunday afternoon, which wouldn't give me time to do it and get back to work Monday. I couldn't get off over Christmas and New Year, and he wouldn't wait till February. So he took out the amp (which has no reasonable use as a guitar amp), busted up the rest and put it out for the garbage truck! Said he "didn't know it'd hurt so bad to do it." Jerk. Now those little things are commonly going on eBay for $500 or so. They've been "discovered." The giveaways still occur, but a lot less commonly. I heard about a guy taking home a C2 console that had been put out for the dump a few days ago. Last spring I spent $250 and a drive to northeast Ohio to rescue an H-182 console from a crumbling house.
Other brands of electronic organs are still by and large valueless on the market right now, but I think they're all cool instruments worth saving and playing.
"A cheerful heart is good medicine."
Yeah, I'm really looking forward to getting my new tubes, but they won't be here till Thursday...
-Metaellihead
Just one more day. Hang in there. :D
"A cheerful heart is good medicine."
