Harmony

[Slowy]

Just got the old Harmony back from Clarry. The caps were bubbling nicely and retired. Less expected was my prized vintage Telefunken 12AX7 which had suicided in the amp

I asked for a full conservation overhaul; you're not going to find one of these in Andertons so there's a responsibility to care for them. He did as asked- Clarry doesn't modify, but I got the impression he was hesitant about the results.

I see what he means. The distortion is harsh and raspy, and not in a goodly Marshall way. Playing with a light touch, it's fine but pushing it isn't pretty; especially with a Telecaster.

So I think we may delve a little deeper and see what can be done. It's worth it. I love the idea of a featherweight, 12 watt combo that's older than any of you lot.

IMG_4638.JPG (2.64 MiB) Viewed 1602 times

[clubhouse]

Dude...what's the story with the Telefunken? I assume it's an ECC83 with the diamond on the bottom between the pins? Is it a white-out or noisy/microphonic? May be able to help is all...

[Slowy]

Dude...what's the story with the Telefunken? I assume it's an ECC83 with the diamond on the bottom between the pins? Is it a white-out or noisy/microphonic? May be able to help is all...

I have a bunch of great old pre and power valves I spent a couple of years scoring off TM from the vintage radio guys before they heard of guitar players.

One side of the Telefunken has shorted and glows red apparently. A rare event in preamp tubes. Shit happens, I doubt it cost me $5 and I have plenty more so I'll bin it and then it never happened.

And this is what being rich feels like.

[k1w1]

What model is that Slowy? I have 2 X 5 watts a mid sixties H400A and a 1954 H8148. I may be able to get some info for you depending on what you are looking to achieve.

[GrantB]

Is that the sum of the parts he changed?

[Slowy]

Is that the sum of the parts he changed?

I wasn't expecting the Existential inquiry

[Slowy]

What model is that Slowy? I have 2 X 5 watts a mid sixties H400A and a 1954 H8148. I may be able to get some info for you depending on what you are looking to achieve.

It's an H307X

The X, as I understand it denotes Export, ie. not American. The export models were fitted with EL84s rather than the domestic version's 6V6.

Try as I might, I have so much trouble ending up with 6V6 amps; they seem to avoid me.

[GrantB]

Is that the sum of the parts he changed?

I wasn't expecting the Existential inquiry

Bear with me. So did it sound ok before when pushed to od, but now it doesn’t !

[Slowy]

Is that the sum of the parts he changed?

I wasn't expecting the Existential inquiry

Bear with me. So did it sound ok before when pushed to od, but now it doesn’t !

Its od was never its strong point but now it has a harshness that wasn't apparent before. I'm going to start with a 12AT7 or 6550 and see what happens, then talk to Clarry. Could probably look at the original ceramic Jensen but I don't want to turn it into something it's not.

It always liked a bit of Klon. I'm about to fire it up and have a play.

But bottom line, this is an old cheap Sears Roebuck amp. It was never a Supro or Magnatone and it would be a mistake to think it could be.

[jeremyb]

Maybe a 5751? Not sure how its gain level stacks up against the 12AT7 but they’re a sweet sounding 12AX7 replacement, really dig it in the AC10

[Slowy]

Maybe a 5751? Not sure how its gain level stacks up against the 12AT7 but they’re a sweet sounding 12AX7 replacement, really dig it in the AC10

I meant 5751 not 6550.
Too much blood in the caffiene stream.

[clubhouse]

I wasn't expecting the Existential inquiry

Bear with me. So did it sound ok before when pushed to od, but now it doesn’t !

Its od was never its strong point but now it has a harshness that wasn't apparent before. I'm going to start with a 12AT7 or 6550 and see what happens, then talk to Clarry. Could probably look at the original ceramic Jensen but I don't want to turn it into something it's not.

It always liked a bit of Klon. I'm about to fire it up and have a play.

But bottom line, this is an old cheap Sears Roebuck amp. It was never a Supro or Magnatone and it would be a mistake to think it could be.

Potentially, the sum of the parts was the sound of an instrument operating outside its electrical spec as various components drifted in various amounts over time toward self destruction creating a special sauce along the way. If the remaining components (original speaker) were capable of producing the special sauce, I’d leave them alone and focus on finding replacement caps, resistors and a valve that can replicate individually/collectively the similar electrical drift from original design spec but in a stable way. May take a bit of faffing and Clarry’s time but a bit of input from the filament heads on the forum might speed it up. Just a methodology…but you probably got it sussed anyhoo

[Slowy]

Is that the sum of the parts he changed?

I wasn't expecting the Existential inquiry

Bear with me. So did it sound ok before when pushed to od, but now it doesn’t !

Interesting. Just spent half an hour with it. There's a sweet spot; the channel volumes and the guitar tone backed off a bit. Volume wise, it's maximum comfortable home use. Tonally, it has the character of a Marshall presence control on full combined with a very old, well worn 12" speaker that can't produce much bottom end. I think it will play very nicely in a quiet band situation. It still likes the Klon and a touch of reverb sweetens the package.

Haven't tried it yet, but the boost side of the KOT may be interesting too.

I'm inclined to leave it alone for now and learn to play the best out of it.

And to borrow Oleg's golden ears for a second opinion.

[Slowy]

Potentially, the sum of the parts was the sound of an instrument operating outside its electrical spec as various components drifted in various amounts over time toward self destruction creating a special sauce along the way. If the remaining components (original speaker) were capable of producing the special sauce, I’d leave them alone and focus on finding replacement caps, resistors and a valve that can replicate individually/collectively the similar electrical drift from original design spec but in a stable way. May take a bit of faffing and Clarry’s time but a bit of input from the filament heads on the forum might speed it up. Just a methodology…but you probably got it sussed anyhoo

I wouldn't say it had a special sauce. It's a cool, funky old amp that I enjoyed in my study and worked very well in a studio/ small space band situation where volume was a problem.

But it was scary; it gave the impression if you turned your back, it would burn the place down. So it needed an overhaul. Now it's a bit more vigorous and strident than it was but that's OK. Tone after all, is in the fingers.

[clubhouse]

Potentially, the sum of the parts was the sound of an instrument operating outside its electrical spec as various components drifted in various amounts over time toward self destruction creating a special sauce along the way. If the remaining components (original speaker) were capable of producing the special sauce, I’d leave them alone and focus on finding replacement caps, resistors and a valve that can replicate individually/collectively the similar electrical drift from original design spec but in a stable way. May take a bit of faffing and Clarry’s time but a bit of input from the filament heads on the forum might speed it up. Just a methodology…but you probably got it sussed anyhoo

It's a cool, funky old amp that I enjoyed in my study and worked very well in a studio/ small space band situation where volume was a problem.

I, sir, would call that...special sauce That's the sound-in-the-head stuff that has driven many a boutique builder to make their idea of a tweed, BF, Lead, etc. It's the few amps, out of the many, that drift in a certain way over time that inspire as much as they function.