Other Amps

1962 Ampeg R-12-R caps

1

1962 R-12-R on the way. It's gonna' need a lot of restoration work, but the bones look good. I'll post pics when I have it. Question: It has a lot of the original Black Cat coupling and tone caps. (or are they the same thing?) Makes sense because the company that made them, Cornell Dubillier, were in New Jersey as well as Ampeg. What's the general opinion of these? If they are within spec, keep em?

2

Depends who you talk to.

3

Big vintage Ampeg group on FB... lots of opinions and advice there also.

4

Ampeg, like a lot of East coast manufacturers (and unlike FEI Fender) swapped resistor/capacitor suppliers often probably depending on who gave them the best deal. Canal St was the place for cheap components, and I'm sure Everett was well known there.

I've had early 60's Ampegs where every single non-electrolytic cap was fine, and others where every single one was leaky.

Black Cats were fairly high end in their day, and I've not seen many bad ones, unlike the waxy ones like regular C-D's or Astrons.

As an aside - Leo Fender was nothing like the cheapskate people often make him out to be. Frugal, maybe, but it's no coincidence that such a high percentage of amps made under his watch are not only functioning, but highly sought after.

5

BTW, this is a what a real "Black Cat" looks like.

It's not black and striped. That's a bumble bee, which are valued for other reasons, but definitely not in a high voltage circuit.

6

I had heard that the Fender swtich from Jensen to Oxford had to do with what as termed a 'purchasing dispute/ with Jensen

7

BTW, this is a what a real "Black Cat" looks like.

It's not black and striped. That's a bumble bee, which are valued for other reasons, but definitely not in a high voltage circuit.

– Kap'n

Yessir, the one pictured. Glad they are held in high regard; I want to keep as many original parts as possible, as long as they are still good, and not inferior to begin with. The original speaker is a Jensen P12R; very low wattage and reportedly can't handle the output from the R-12-R, but I happen to have an old Rola with a 1 1/4" voice coil that I will drop in. It should handle the 18 or so watts that these amps put out and I read somewhere that is is very close to a Jenses P12Q.

8

I had heard that the Fender swtich from Jensen to Oxford had to do with what as termed a 'purchasing dispute/ with Jensen

– DCBirdMan

Fender had a lot of changes c. 1960-61. "Rock and Roll" was on the wane, they had just designed a whole new line of amps and the Jazzmaster, and surf hadn't taken off yet. Probably some cash flow issues at the time. That was also the time they changed over from Triad to Schumacher for transformers too. They pretty much stuck with Oxford and Schumacher through the rest of the Leo years. The early Oxfords were great, the later ones less so.

9

Yessir, the one pictured. Glad they are held in high regard; I want to keep as many original parts as possible, as long as they are still good, and not inferior to begin with. The original speaker is a Jensen P12R; very low wattage and reportedly can't handle the output from the R-12-R, but I happen to have an old Rola with a 1 1/4" voice coil that I will drop in. It should handle the 18 or so watts that these amps put out and I read somewhere that is is very close to a Jenses P12Q.

– Journeyman

FYI, if the cone on your P12R looks like this, Weber has the right cone. As far as I know they're the only ones who tooled up for a replacement.

10

The Weber W66 cone (ask for it on the recone form). It sounds very close to the original.

11

The Weber W66 cone (ask for it on the recone form). It sounds very close to the original.

– Kap'n

So, would the P12R handle more power after the Weber recone?

12

The voice coil is a far more important factor in power handling than the cone. A doped surround would help to keep the bass from getting flubby at higher volumes, though.

13

OTOH, if the cone is old and brittle, a to-spec recone will give you a bit more volume and headroom, all other things being equal (which they seldom are, but Weber stuff is pretty dialed-in).

14

You can email CJ at Weber and pick his brain for ideas. He’s pretty good at pointing you in a direction based on the sound you’re looking for. If you prefer loud and clean, the P12R may not be the perfect match for your Ampeg. They do sound great overdriven. I’d definitely give that Rola a whirl.

15

So, would the P12R handle more power after the Weber recone?

– Journeyman

It would make it capable of handling about 20W RMS, and all of the fatigued, wearing, brittle parts would be replaced.

I'm not saying "premptive recone" but if you blow it up, know that it can be redone close to stock.

That cone is fairly bright, and is a good complement for the amp, but if you're interested, why not try others? It's not an irreversable mod even if it does require soldering/resoldering the speaker wires.

16

It would make it capable of handling about 20W RMS, and all of the fatigued, wearing, brittle parts would be replaced.

I'm not saying "premptive recone" but if you blow it up, know that it can be redone close to stock.

That cone is fairly bright, and is a good complement for the amp, but if you're interested, why not try others? It's not an irreversable mod even if it does require soldering/resoldering the speaker wires.

– Kap'n

I also have Weber 12A125 that I can drop in. The old Rola, an organ pull, was in my Princeton Reverb for a while; it has the nicest dark, warm jazz tone of any speaker I've ever used. Cranked up though, it becomes thin, with very little bass response. It also broke up a bit too early, but at low volume it was beautiful.

17

Hmm. This Ampeg speaker talk reminds me of one of the most cost-effective items from my own hacks-for-musical-satisfaction thread - to wit, a speaker change - which I’ve unaccountably not considered for my own Reverberocket.

Which is mid-60s, gloriously pristine, all original, and sounds heavenly - if heaven places a limitation on (presumably infernal) bass response. Yes, great as it sounds, it must be admitted it’s a touch thinnish in sonic profile. Fine for combo and mixed purposes, but the struggling fingerpicker/solo player in me cranks the bass knob to the stop and still wishes for more booty.

The amp has the original speaker (and when I get next to the amp I’ll report what that is) - but meantime, can one of you more experienced speaker-speccers recommend a replacement that might boost the bottom (while retaining the amp’s otherwise divine tone)?

18

You can never go wrong with a real Jensen C12N. Or, give that 100 watt Jensen Neo a spin.

19

Hmm. This Ampeg speaker talk reminds me of one of the most cost-effective items from my own hacks-for-musical-satisfaction thread - to wit, a speaker change - which I’ve unaccountably not considered for my own Reverberocket.

Which is mid-60s, gloriously pristine, all original, and sounds heavenly - if heaven places a limitation on (presumably infernal) bass response. Yes, great as it sounds, it must be admitted it’s a touch thinnish in sonic profile. Fine for combo and mixed purposes, but the struggling fingerpicker/solo player in me cranks the bass knob to the stop and still wishes for more booty.

The amp has the original speaker (and when I get next to the amp I’ll report what that is) - but meantime, can one of you more experienced speaker-speccers recommend a replacement that might boost the bottom (while retaining the amp’s otherwise divine tone)?

– Proteus

When I called Weber, they recommended their 12A125 for that amp. (or was it the 12A125A? I''ll check) All of their versions of Jensens are really good. An old C12N in good condition or reconed, or Weber's equivalent, the 12F150, would certainly give you more bass response and LOTS more volume, but my own sense is that it would be a little more than what's needed. Their 12F125 might do just as well. When I get the R-12-R I'll pop the 12A125 in and run 'er up the flagpole.

If you have one of the older Jensen Neo-12-100 speakers, that might be just dandy. Also more than what is needed, but you would have the advantage of less weight, and they are really good sounding speakers; better than their reengineered current issue. They got it right the first time, whereas Celestion, Eminence, et al had to go back and redesign their neodymium speakers. Maybe Jensen second guessed themselves; only the Shadow knows.


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