Ampeg Reverb Rocket? with/6bk11/6u10/7868 tubes

[1ampman]

I have a Reverb Rocket driving me crazy. I can't find a schematic for it.... Joe Pizza had drawn one but its' lacking the voltages ... I can't get the reverb and trem working? I think the B+ voltage is off. Any help is appreciated....

[The Dude]

There are more schematics without voltages than with them. I'd upload the schematic you have, let us know what voltages you have, and go from there. Hard to hazzard a guess otherwise.

[Justin Thomas]

Is this a Reverberocket III? One of the Golden Glo amps? The Reverberocket 2 would be a 12AX7, 6U10, 12AX7 or 7199, and 7591s...
If you have that schematic, can you put it up here? I've never seen a schem of that amp. And good luck finding tubes...

Justin

[g1]

Search for GS-12R, I think you will get more results.

[mozz]

I have a empty Ampeg cabinet here, Model R-12-R, below that it says R-12-R-T. 6bk11 6u10 12ax7 12ax7 7868 7868. I do have the factory schematic glued to the back panel inside. If you want me to scan it(have to fire up the WINXP laptop for flatbed scanner to work) or take pictures let me know.

[Justin Thomas]

Not to inconvenience you, but pictures would be okay... never seen one of those amps, and I bet that'd be the Reverberocket III. The GS-12R is the Reverberocket 2, also the Rocket 2 (which is the same circuit in a different style... whereas the Blue Check Rocket 2 was lacking reverb, the 2nd gen. Rocket 2 had reverb. It's all quite a morass.
My 67 Reverberocket 2 that I sold to my jazzer friend had the heater elevation circuit drawn into the factory schematic by hand, with a date and initials beside the mod, and the amp was wired as such. Too bad it wasn't "KF"...

Justin

[1ampman]

Moss, That's my amp, reverb,trem, 3 inputs, volume/tone. Blue checker cab. I'd love to have a factory schematic. As I found a couple drifted resistors & caps. Still no reverb or trem. I plan on spending the day on this repair. Never knew Ampeg could be such a hassel, this amp didn't have a schematic inside? Tube pin voltages would clear up a lot questions. So far the amp passes a signal fine. The reverb return is working (as I rub the tank springs). O-scope shows no drive signal. And trem I didn't even start on... Could be a long day!

[mozz]

https://www.dropbox.com/s/ke4uolq6er...rtpre.jpg?dl=0
https://www.dropbox.com/s/z9haermces...rtpwr.jpg?dl=0
https://www.dropbox.com/s/onjv4lcnzx...r12rt.jpg?dl=0

[1ampman]

Moss, I'm most grateful! Just what I needed, still working on it..... I spent many hrs searching for it. I'll let you know what I find....Cheers !

[1ampman]

Well, After checking the circuit it seems the 6b11 6u10 are too weak for the trem & reverb. So maybe some day I'll find a pair? I spent a lot of time and don't have much to show for it. At least I have the schematic.....Some one needs to make an adaptor that plugs in the 12 pin socket and alows you to plug in ax7s or at'7s or both....anybody?

[Justin Thomas]

Holy fibsh, that would be cumbersome...

More seriously, what some have done is get a little pedal chassis and mount two or three 9-pin sockets on it, then wire up "umbilical cords" to the main chassis. I haven't done it, but I thought g1 did it at some point? Kind of similar to how both Fender and Ampeg did in their earliest days...

Justin

[Mick Bailey]

Be sure to check the caps. My Reverberocket had no reverb and the trem would sometimes (but not often) work at maximum speed/depth, but was hardly there when it was operating. A tube swap made no difference but changing the caps bought everything back to life. A weak tube may be compounded with leaky or low-capacitance caps. At least one of the trem caps read just a few pf with my amp.

Interesting with these amps - the reverb is always on to some degree due to cabinet vibration rattling the springs (the reverb switch is on the drive side). This threw me at first. Other models are switched on the recovery side. Also, if the reverb is weak you can change the pot from 15k to 25k. It has the side-effect of reducing the recovery corner frequency but can give you a fair bit more output.

[g1]

what some have done is get a little pedal chassis and mount two or three 9-pin sockets on it, then wire up "umbilical cords" to the main chassis. I haven't done it, but I thought g1 did it at some point?

Wasn't me. Maybe Leo G ?

[Justin Thomas]

We need a "tag" feature like Farcebook.
On 2nd thought... nevermind.

Justin

[Leo_Gnardo]

Wasn't me. Maybe Leo G ?

Not for this purpose. I did run that sort of thing to add a ... now I forget . . . well either a reverb or vibrato to an amp that was lacking that feature.

I'm also flummoxed by the Ampegs with compactrons. I had a thought to simply cut a rectangle out of my Jet chassis where the two compactron sockets are, and cover it with a plate that held three 9-pin sockets. Crikeys an awful lot of work to get the old Ampegs working again. Not so bad if you have a regular metal shop or at least some of the tools to do a neat & sturdy job. Around here it would be an all day faff session doubtless involving at least half a dozen Bandaids and a couple aspirins.