PDA

View Full Version : Ampeg reverberocket 2 / tubes?!?!


boot
07-05-2012, 09:50 PM
Hey Everybody! ... my first post! ...got my buddy's amp, been cloistered in his garage- AMPEG REVERBEROCKET 2 --- needs tubes, so i did my search... got ALL kindsa' CRAZY info---" 7199/6U10/7195??? --- hence; WHAT'S THE DEAL???? somebody PLEASE point me in the right direction! SCD

Telefunky
07-05-2012, 10:31 PM
Great sounding amps! Classic vintage tone. Of course you'll need to call a NOS tube supplier, but you really need great tubes anyway, just to get the real tone.

Important- if the amp has been off for a few years, DO NOT plug it in! It will need to be warmed up on a VARIAC for a few days before it can tolerate full voltage from a wall socket.
Plugging it in immediately will completetly fry the amp. Best wishes!

boot
07-05-2012, 10:44 PM
... but WHAT tube designation, EXACTLY, am i looking for??? thanks - boot

Telefunky
07-05-2012, 10:50 PM
Shoot me a PM with your email and I'll have my amp tech call you. He's a tube expert unlike anyone you've ever seen. I'm sure he'd be glad to help you out.

mark norwine
07-06-2012, 05:30 AM
Where's the mystery? Those ARE the tube designations:

- The preamp is a 12AX7A....readily available.

- The 2nd tube is a 3-triode "special", called a 6U10. These can be "touchy" in this amp & you may have to sort through several before you find one that sounds great & behaves well. (They can hum)

- The driver is a 7199. Get a NOS tube....the new EH ones suck

- The power tubes are 7591A, and although the JJ is "ok", your ears will be rewarded most with a pair of NOS tubes. Good news: they sound amazing and they last forever! (in fact, the ones you have in there now *might* be fine). Bad news: a pair will knock you back close to $200 for the pair....but trust me: 100% worth it.

Great amp! The GS12-R is my #1 amp. It will never leave my side.

Give Mike K a call at KCANOS.....he'll help you out.

Drak
07-06-2012, 05:41 AM
What a gorgeous amp you scored!

Follow Mark's advice and retube it, have a tech give it the once over (find a good tech who's worked on them before please), and you will be rewarded with a reverb as sweet and deep as the ocean, and tremolo that will send you into an instant whirly-copter acid-trip.

I had one for several years that was completely beat down cosmetically when I bought it, so I recovered it and in the process opened up the front port and installed a Weber P15N in...Glorious Tone for the ages.

It has it all...sparkly cleans, deep wet reverb, killer tremolo, fantastic overdrive, and not deafeningly loud.

There's one or two areas that a Deluxe Reverb will beat it in, but several other areas where it will eat the DR's lunch and give change back, a really great amp and worth the overhaul.

...And if you can find a way to get a 15" in there...Ooh-La-La!

mark norwine
07-06-2012, 06:49 AM
have a tech give it the once over (find a good tech who's worked on them before please),

Yes, yes, yes....

The can cap might be tired; exact replacements are available from CE Distribution, and your tech should know that, if he has Ampeg experience.

Ampegs are a wee bit quirky inside, and I've seen many of them get messed up by (otherwise well-intentioned) techs who screw them all up making them "try to be like fenders", because that's what they know...

If you're hunting for a new speaker, I'll say that....after years of playing with different speakers...mine now sports a Emi C-Rex, and that speaker is never coming out!

WahmBoomAh
07-06-2012, 08:13 AM
Y

If you're hunting for a new speaker, I'll say that....after years of playing with different speakers...mine now sports a Emi C-Rex, and that speaker is never coming out!
Hi Mark ..
hijack in progress .....sorry .
I have a Gemini VI with the same basic tube chart . It`s got the old original CTS 15 in there famous for low efficiency ...sounds nice though .
What sound were you chasing when you settled on the Emi C-Rex?
I like the old school clean for jazz and R&B with some fullness .
thanks

teleman1
07-06-2012, 08:44 AM
https://www.google.com/search?q=ampeg+reverberocket+2+schematic&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=t_n2T57mB6WU2AX6vt2pAw&ved=0CFQQsAQ&biw=853&bih=484

mark norwine
07-06-2012, 08:58 AM
Hi Mark ..
hijack in progress .....sorry .
I have a Gemini VI with the same basic tube chart . It`s got the old original CTS 15 in there famous for low efficiency ...sounds nice though .
What sound were you chasing when you settled on the Emi C-Rex?
I like the old school clean for jazz and R&B with some fullness .
thanks

I'm mostly a jazz player, but I'm not afraid to push the amp a little & put a little hair on the tone, especially if I'm playing bebop lead lines, like on Dizzy's "Groovin' High", or some such.

If I'm doing chord melody work, the amp's cleans are great.

I think you said it best: "old school clean for jazz and R&B with some fullness". That's what I like, too.

The C-Rex came after a long line of speakers.....old CTS, old Oxford [flabby & tired], newer Jensen P12N reissue [lackluster], a weber P12N [all wrong in every department], an Emi RW&B [awesome in a twin reverb, but too bright here], Emi Swamp Thing [close! very close!]......then the C-Rex. It's "smoky" without being dark, but has no problems sounding clear & articulate.

Of course, your amp has a 15", so all of this is most likely useless info...

boot
07-06-2012, 04:49 PM
THANK YOU! THANK YOU! THANK YOU, one and all! ... I've got some work to do! boot

mark norwine
07-06-2012, 05:01 PM
I did amp repairs professionally for 15+ years, and I know the inside of this amp better than I know my kids.

If you get into the soup, PM me and I'll guide you if I can.

(that said, if you don't know about the innerworkings of amps, best to leave it alone & seek out a tech)

Drak
07-06-2012, 10:14 PM
Well we all have our preferences...one thing I remember about that amp and the P15N was that when played clean, it sounded exactly like a robust alnico 15" speaker should, but when driven (maybe due to compression?), it seemed (aurally) like the 15" shrunk to a 12", it was the coolest kind of phenomenon that I've never heard in any other amp before or since, one thing I always remember about that amp in particular.

pete kanaras
07-07-2012, 07:00 AM
right on to everything mark norwine said about these amps. my rr2 is my main gigging amp as well, along with a heavily modded (and very tired) deluxe reverb. his speaker trials almost mirror mine, with the same results. i too had a c-rex that sounded unreal in my rr22 at first, man it was like the most perfect c12n i ever heard. but after it broke in it got way too dark for me so i sold it. pity because i thought i hit paydirt forever! for now i've settled on a newer jensen c12k, and that sounded horrid at first. but after being thrust into shop amp duty for 6 months (i do guitar/bass repair full time) it has broken in Beautifully. think of a c12k as a c12n that does'nt fart out when you push it, with not quite the same magical top end that an original has. an acceptable compromise in my book. imo these amps need a speaker with a slightly relaxed top end, because they have tons of treble on tap. it's quite a dance finding the right speaker for them that fits your tastes. a fresh & strong 6u10 is essential in these amps. they're an oddball tube but are very cheap (i got mine for $10 from some tube vendor) and you will definitely notice the improvement. the accordian input is where it's at with single coils, the guitar input for humbuckers. mullard 7591's are the best, the jj's are ok (i have a pair for spares, but the mullards have the magic). my tube chart calls for a 7199 but it actually has a 12ax7 in that slot, so my amp must be from the 2nd period of production when they switched to an ax7, but with the older tube chart. oh, and if you hear what sounds like reverb feedback when you wind the 'herb up it is not a bad tube, it's the reverb pan oscillating against the cabinet's sidewall. simply put some foam on the underside of the pan, reattach it and problem solved. congrats on scoring one of my alltime favorite amps. the 18watt King Of Kleen, with the best onboard 'verb and trem ever. and if you want some hair in your tone grab a tele, bridge pickup. pin the bass, dial the treble down to 3 and pin the amp. those who know, know

Irreverent
07-07-2012, 07:06 AM
right on to everything mark norwine said about these amps. my rr2 is my main gigging amp as well, along with a heavily modded (and very tired) deluxe reverb. his speaker trials almost mirror mine, with the same results. i too had a c-rex that sounded unreal in my rr22 at first, man it was like the most perfect c12n i ever heard. but after it broke in it got way too dark for me so i sold it. pity because i thought i hit paydirt forever! for now i've settled on a newer jensen c12k, and that sounded horrid at first. but after being thrust into shop amp duty for 6 months (i do guitar/bass repair full time) it has broken in Beautifully. think of a c12k as a c12n that does'nt fart out when you push it, with not quite the same magical top end that an original has. an acceptable compromise in my book. imo these amps need a speaker with a slightly relaxed top end, because they have tons of treble on tap. but it's quite a dance finding the right speaker for them that fits your tastes. a fresh & strong 6u10 is essential in these amps. they're an oddball tube but are very cheap (i got mine for $10 from some tube vendor) and you will definitely notice the improvement. the accordian input is where it's at with single coils, the guitar input for humbuckers. mullard 5791's are the best, the jj's are ok (i have a pair for spares, but the mullards have the magic). my tube chart calls for a 7199 but it actually has a 12ax7 in that slot, so my amp must be from the 2nd period of production when they switched to an ax7, but with the older tube chart. oh, and if you hear what sounds like reverb feedback when you wind the 'herb up it is not a bad tube, it's the reverb pan oscillating against the cabinet's sidewall. simply put some foam on the underside of the pan, reattach it and problem solved. congrats on scoring one of my alltime favorite amps. those who know, know

Ow. That made my brain hurt.

pete kanaras
07-07-2012, 07:19 AM
troll

Masco
07-07-2012, 09:32 AM
my tube chart calls for a 7199 but it actually has a 12ax7 in that slot, so my amp must be from the 2nd period of production when they switched to an ax7, but with the older tube chart. oh, and if you hear what sounds like reverb feedback when you wind the 'herb up it is not a bad tube, it's the reverb pan oscillating against the cabinet's sidewall. simply put some foam on the underside of the pan, reattach it and problem solved. congrats on scoring one of my alltime favorite amps.

Pete, I have a ~'67 RR2 that uses the 12ax7 driver instead pf 7199. My tube chart has the 12ax7 listed though.
I re-wired the output tube sockets for 6V6's about 10 years ago because I didn't want to pay big bucks for vintage 7591s at the time. I lost some volume due to this and have been wanting to convert back to 7591s for a while now, just haven't got around to it. Regardless, I love the cleans from this amp and REALLY dig the lush reverb.
The oscillations from your pan were probably a loose winding in one of the transducers inside the pan. You can also shove a small wedge or shim of wood between the windings and laminations to keep them from vibrating and howling. When I find the time, I'm going to go through this amp again and put her back to stock. I'll probably go with your speaker recommendation as well.
BTW, it was great seeing you play on the 4th and talking gear.

mark norwine
07-07-2012, 10:57 AM
Hey Pete! Long time! I hope all is well with you....

The 7199 tube is a fickle lady, and I can see why Ampeg went to the 12AX7A. I've had to comb through quite a few to find one that sounded great & didn't feed back, but now that I have one, I'm happy. I considered rewiring for a 12AX7A, but decided against.

Changing to 6V6 tubes is something that a lot of folks did, but to my ears, the 7591A is part of the magic. The pricetag is enough to stop a rhino in its tracks, but still: I have no regrets about springing for a NOS pair last year. (Thanks, Mike K!!)

The pans can get wonky, just like the can / do on Fenders....but let it be known: the replacement tanks won't work "stock".

Ampeg....quite smartly...only connected the ground on the send side so as to eliminate loops, however the "correct" replacement tank has isolated connectors, so the circuit is incomplete, causing one to think they've received a defective pan. You need to connect the sleeves of the RCA connectors together inside the tank. Once done, the reverb will work with a replacement pan.

Another thing I did to mine.....and I don't suggest you do this unless you really understand circuit topology....was to re-do 100% of the grounds in the amp. Mine was never noisy to begin with, but it wasn't silent, either. By running new ground wires, connecting only logical, same-circuit nodes to one another, I pushed my noisefloor to zero. Were it not for the pilot light, you wouldn't know my amp was even on!

The RR2 is an amazing amp. I'm very glad I found mine (2003, on ebay, not working, for $125) and if I find another for a good priced, I won't mind owning two of them!

Masco
07-07-2012, 01:15 PM
Changing to 6V6 tubes is something that a lot of folks did, but to my ears, the 7591A is part of the magic. The pricetag is enough to stop a rhino in its tracks, but still: I have no regrets about springing for a NOS pair last year. (Thanks, Mike K!!)

The pans can get wonky, just like the can / do on Fenders....but let it be known: the replacement tanks won't work "stock".

Ampeg....quite smartly...only connected the ground on the send side so as to eliminate loops, however the "correct" replacement tank has isolated connectors, so the circuit is incomplete, causing one to think they've received a defective pan. You need to connect the sleeves of the RCA connectors together inside the tank. Once done, the reverb will work with a replacement pan.

Another thing I did to mine.....and I don't suggest you do this unless you really understand circuit topology....was to re-do 100% of the grounds in the amp. Mine was never noisy to begin with, but it wasn't silent, either. By running new ground wires, connecting only logical, same-circuit nodes to one another, I pushed my noisefloor to zero. Were it not for the pilot light, you wouldn't know my amp was even on!

The RR2 is an amazing amp. I'm very glad I found mine (2003, on ebay, not working, for $125) and if I find another for a good priced, I won't mind owning two of them!

Just threw in some 6L6s in there instead of the 6V's, it's a bit better. Another 100mA Ih than 7591As, but I'm sure no extra stress on the PT. I'll still put her back to stock when I get the chance.
Good point about the isolated grounds in the reverb tank, I had to replace mine when I bought it many years ago and modified the connections. I don't know, maybe not a good idea/design to have a vertical mounted tank?? The shock mounted chassis is brilliant.
Mine didn't seem noisy enough to mess w/ the grounding.
Love this amp. Paid $140 for it at an auction, just another reason to spring for the vintage 7591's.

pete kanaras
07-07-2012, 01:57 PM
masco right back atcha. i enjoyed hanging with you again, sure wish we lived closer. and boy howdy mark, been forever indeed! all is well thanks, just doing the do. and thanks for the tip on the rca's, you saved me a ton of head scratching if i ever need a replacement because i woulda Never figured that one out. my amp is essentially bone stock, the cap can Seems to be fine but i'll do a cap job at some point. the bias resistor had to be replaced when i got it and i had my guy check the can while he was at it, he said it spec'd up fine. it's quiet too, save for a semi loud turn-off thump which dennis kager said was normal last time i was in his shop. i got mine for $200 four years ago (c'list ad) and it was right down the street too boot. best $200 i ever spent for sure

MKB
07-07-2012, 02:44 PM
Ah, the 7591A; I got a set for an old Ampeg I used to have for about $40 right before the price skyrocketed. Rumor is back in the 80's some fellow from Asia bought up every 7591A available, and overnight the prices went crazy.

The 7591A is a bit of a unique tube. Back then in the waning days of mass market tube power amps, the tube makers tried to come up with a tube set that would give 30-50W with the least number of tubes. The 7199/2X7591A tube set would give 30-40watts with only 3 tubes. The 7199 is a combination pentode/triode in a 9 pin envelope, and the 7591A is a true pentode with a significant amount of voltage gain as compared to a 6L6. So the 7199 pentode section gave the voltage gain for the power amp, the 7199 triode acted as the phase inverter, and the 7591A's were the push/pull outputs. The 7591A was actually somewhat common back then in US made stereos. If you look carefully at a hamfest, you should be able to find NOS 7591A's or used equipment with them installed. Other than their current rarity, I'm not aware of their having any magical qualities.

This arrangement is very similar to what was used in the Dynaco ST70 stereo amp, maybe the most widely used stereo tube amp of all time. However Dynaco decided to use EL34's in place of 7591A's; maybe the 7591A wasn't available when the ST70 was designed.

I've always been curious why you couldn't use a EL34 in place of a 7591A other than the higher filament current of the EL34 (and the different pinout). A 6V6 should work, but it would need to be a beefy one as the 7591A can handle higher voltages and plate dissipation. A 6L6 would not have the same amount of voltage gain and you would most likely need to change the bias circuit to get the higher bias voltages needed.

In any case, that guy with the stash of 7591A's really put Ampeg owners in a difficult place.

BTW, if your amp has the original tubes, try to get them tested before you replace them. If the amp was of a conservative design, your tubes might be just fine and have a lot of life left in them. Most of those sixties tubes were very well made and quite sturdy; perhaps Ampeg didn't drive the heck out of them like Marshall and Fender did.

Masco
07-07-2012, 03:29 PM
A 6L6 would not have the same amount of voltage gain and you would most likely need to change the bias circuit to get the higher bias voltages needed.



FYI, the RR2 output has shared cathode R.

pete kanaras
07-07-2012, 04:56 PM
Other than their current rarity, I'm not aware of their having any magical qualities.

well tone is in the ear of the behearer i guess! the 7591 is my 2nd favorite output tube ever, after 6L6's. to me they sound like the best 6v6 ever made; they have a beautifully sweet top end, neutral but not sterile mids and a very full bass. you can push the living bejesus out of them and they won't cave in like say a 6v6 does. they stay very composed and together under stress. in the right circuit you can get 35 watts/pair out of them. so in a reverberocket2 they're just coasting along at 18watts and should last damn near forever. they sound glorious in 60's tube hifi gear too; the Fisher 500b, maybe the greatest tube receiver ever built by anyone, used a quad of them. simply awesome sounding output tubes, and nothing else sounds remotely like them

beanbass
07-10-2012, 11:06 AM
Boot, I still have a few 7591's left over from when I had a Reverborocket II. I wish I kept that amp - I sold it back to the guy I bought it from, after owning it a few years. I need to make some room in my tube box, so you can have these cheap - PM me if you're interested.