Other Amps

Red VS Yellow Jupiter Capacitors

1

Just picked up an old Ampeg Reverberocket from 1962 and will be replacing most of the innards. My Ampeg Mercury has yellow Jupiter capacitors and I'm tempted to put their red ones in this Reverberocket. Anyone have any experience with these?

2

I could be wrong, but I believe the Jupiter Reds are intended to replicate the paper/foil caps found in the early 50s Fender tweeds and the Jupiter Yellows are more like the later yellow Astrons.

Although my experience is limited, I found the Reds to have a rougher and slightly grainy quality. The Yellows are smoother sounding.

I suspect that the caps originally fitted in your Reverberocket might have been closer to the Yellows.

3

When I was prototyping my Spooktator amp which is a 50’s Supro circuit, I tried a lot of different capacitors. The red Jupiter’s sounded most like the wax dipped caps found in old 50’s Valcos. Kinda dark and greasy. The yellow caps sound more like the Astrons and blue/brown molded caps found in 60/70’s Fenders and Ampegs. Brighter, more precise.

For what it’s worth, I tried some of the Russian military surplus PIOs and they sounded terrible in everything.

4

This came up during my on-line search; a guy built two identical amps and used red Jupiters in one and yellow in the other. There is a difference for sure, noticible even on a laptop.

5

Great pickup! I have a 61, Does the 62 still have 6v6s?

6

Great pickup! I have a 61, Does the 62 still have 6v6s?

– eCastro

Yes, this one has 6V6s, 6SL7s and 6SN7s with a 5Y3 rectifier. We're treating it as version 1, even though there was some strangeness in cap values in the can. The schematic on the inside of the back panel corresponds to V.1 and all the rest of the circuity in the chassis. Does yours have the original Jensen C12R labeled Syntox-6? I'm thinking of sending this one to Weber for a recone; it's real tired and the paper cone is cracked in a few spots around the rim; very brittle.

7

Does yours have the original Jensen C12R labeled Syntox-6? I'm thinking of sending this one to Weber for a recone; it's real tired and the paper cone is cracked in a few spots around the rim; very brittle.

Does the C12R have the 12-rib cone? I just (as in today) got back a C12R recone from Weber. I think they did a great job, and have the proper cone for the task. Ask for the "W66."

That's a great sounding speaker for Jets, Rockets, and the 5E3 tweed deluxe, BTW.

8

Mine doesn’t have the original speaker. I’m not sure what has been changed but with treble up full it is unpleasant at low volume. But up full it sounds amazing. Especially with a plank

9

Mine doesn’t have the original speaker. I’m not sure what has been changed but with treble up full it is unpleasant at low volume. But up full it sounds amazing. Especially with a plank

– eCastro

My 1960 Mercury (similar circuit) had a harsh treble and my amp tech found that the guitar input had a bright cap. He removed it and the amp is much warmer now, although I do find that the treble on these old Ampegs is to me, upper mids. I don't know if these Reverberockets have the bright cap or not, but I'll find out when my tech starts working on it.

10

That would make sense. It’s natural quiet dark but the Neil youngish gain and grinds is amazing. I love the verb too, it is super dead but is a lil closer to an external tank then the fender amp verb. It never drowns the note. Mine may have been modded cause it had an sl7 where an sn7 should have been for verb. I’ve changed it back

11

I love the way the circuit is in the back panel

12

Yea, its the gain that I'm hoping to get from this R12R; the M12 is clean all the way up. I have a Reverberocket 2 that breaks up nicely, but not until it is really cranked and loud. Love the Ampeg reverb. I want one of those Echojets. they can be used as a stand-alone amp without reverb or a satelite reverb unit with its own speaker. Can be separated from the other amp for up to eight feet. Totally analogue maaaan.....

13

That's a really cool shootout/comparison. Thanks for finding/posting that.

14

Does yours have the original Jensen C12R labeled Syntox-6? I'm thinking of sending this one to Weber for a recone; it's real tired and the paper cone is cracked in a few spots around the rim; very brittle.

Does the C12R have the 12-rib cone? I just (as in today) got back a C12R recone from Weber. I think they did a great job, and have the proper cone for the task. Ask for the "W66."

That's a great sounding speaker for Jets, Rockets, and the 5E3 tweed deluxe, BTW.

– Kap'n

I'll check to see if it has the ribbed cone. Thanks for the tip; W66 it is. I spoke with CJ at Weber and he said that if I was going to run the amp wide open with distortion the C12R would not hold up, but otherwise it should be fine. There are a couple of spare Webers here so I'll have options; we'll see how this amp is after restoration and then decide on speaker. I'll still get the Jensen reconed though; just too cool a piece of vintage not to, what with the silverish-greenish anodized frame, bell cover over the ceramic magnet and Syntox-6 on the label; now that's some space age shtuff.

15

I'll check to see if it has the ribbed cone. Thanks for the tip; W66 it is. I spoke with CJ at Weber and he said that if I was going to run the amp wide open with distortion the C12R would not hold up, but otherwise it should be fine. There are a couple of spare Webers here so I'll have options; we'll see how this amp is after restoration and then decide on speaker. I'll still get the Jensen reconed though; just too cool a piece of vintage not to, what with the silverish-greenish anodized frame, bell cover over the ceramic magnet and Syntox-6 on the label; now that's some space age shtuff.

– Journeyman

A top-panel Reverberocket (not the Reverberocket II) should be fine with the reconed Jensen. It's really about 12-15 watts or so, both the 6V6 and 7591 versions, and the recone is conservatively rated at 20.

And if you really beat it hard, and blow it, what's another recone?

16

Yea, its the gain that I'm hoping to get from this R12R; the M12 is clean all the way up. I have a Reverberocket 2 that breaks up nicely, but not until it is really cranked and loud. Love the Ampeg reverb. I want one of those Echojets. they can be used as a stand-alone amp without reverb or a satelite reverb unit with its own speaker. Can be separated from the other amp for up to eight feet. Totally analogue maaaan.....

– Journeyman

Thats good...cause you won't get any nice cleans out o it (at least i can't with mine) But verb and trem are delicious. doesn't sound great at low vol . though that may be the bright cap you spoke of

17

I got the Ampeg R12R back today and it sounds very good; similar to my Mercury M-12, but with reverb. We tried increasing the gain for some nice breakup, but decided to leave it as is because that's where it has the warmest tone. It is pretty clean all the way up. Maybe some slight overdrive with the volume wide open, but not much. We did open it up just a tiny bit at the front end for some added presence, but that was the only change. I'll use it as a low volume jazz amp. It's nice to have the on-board reverb, but it is a tad weak so we're going to revisit that down the road. Oh yea, and the tone pot is totally interactive; when all the way up it is gainy with lots of upper mids and when all the way down, there is hardly any volume. It sounds nice around 3ish on the dial. The M-12 is similar in that regard.

I'm going to take Kap'n's (that doesn't look right: Kapin's) advice and get the original Jensen C12R reconed by Weber. I wound up putting their budget Signature 12 in the Mercury and really like it. This one will get the original Jensen though.

For gain and grit, the Reverberocket 2 has it. A bit loud, but after 6 on the volume dial it starts to saturate and compress in a way that is a bit 'o the alright. These Ampegs seem to be all about the midrange, so it's new sonic territory for me, being a long time black & silver Fender guy. I have to say, these old Ampegs really are cool and one of the very few well built under-the-radar vintage amps left floating around. Although, I notice that prices are higher now than even a year or so ago. Best deals in non-Fender amps right now, IMHO, are the Reverberocket 2 and the Gemini I with the 12" speaker. I guess the ones with the 15 are probably good too, but weight becomes an issue. I'll get an mp3 posted soon; maybe use the 1960 Anniversary with the T-Armond into the 1960 M-12; it was a very good year.


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