Rocketus Addus Reverbus

[RJ Guitars]

Well I got the new reverb tank in today and it made a world of difference... It sounds like Accutronics USA is no more or at least AES is not stocking new ones from them. This was an Accutronics made in Korea unit. It sounds pretty awesome.

I am calling it done but I'm not ready to live with it yet. I get a little bit of extra hum as I turn up the gain on the reverb. Not enough to call it a failure but enough to annoy me and prevent me from really being able to feel done. I'll look at power supply filtering and layout issues. I did this pretty quick and dirty so I'm sure I am paying the price for that...

Post submission edit... when I got it indoors and out from under the fluorescent lights in the garage most of the hum went away. So the jury is still out.

Here is a look at things as they are now. The short 3-spring reverb tank fit nicely inside the cabinet. I need some short cables with right angle plugs and a replace the knob I stole off of the impedance switch... funny things happen to amps that set on the workbench too long.

rj

[M Fowler]

Nice job rj, I love these Rocket reverb amps better sounding verb than any Fender I have ever owned.

I ended up not using a bag but do have the rubber feet in the mounting slots and the pan is mouted over the preamp tubes like you have without any noise so rj I am thinking its just the lights your having trouble with as you stated.

Mark

[jhaas]

Is that the Accutronics tank in the pic? Are the Korean made tanks black?

[RJ Guitars]

Is that the Accutronics tank in the pic? Are the Korean made tanks black?

O.K. I had to look at all a bit closer to answer your question. The tank I used is built by MOD but I can't see a label of origin now that I've mounted it but I suspect it says somewhere. I bought it from my dealer catalog associated with Antique Electronics but I don't see that model number on their web site. It's a medium reverb - 9 inch - 3 spring. I remember now that they didn't have what I wanted in an Acuutronics tank so I went with the MOD.

In that same catalog they introduce both the MOD reverb tanks and a new line of Accutronics reverb Tanks that are made in Korea. The Accutronics tanks are in a black anodized housing that appears to be identical to the MOD unit... so it's probably all the same beast.

I originally tried to mount it in a bag but found that as a hanging unit I didn't care much for the look of it. I'll have to think about some way to clean that up.

I do still have a small but audible hum that goes up with the reverb level. It's small but worth going after & nip it off if I can. I get it whether I have the tank plugged in or not so I think it's on the return gain stage... worth tracking down but the amp is really fun to play. Nice rich deep reverb sound...

rj

[jhaas]

Oh yeah, I see what you mean. I just looked at the CEDist site and all the "Made in Korea" Accutronics tanks are "Out of Stock" and the made in USA tanks are listed as "While Supplies Last".

It's nice that the MOD sounds good, I think they're quite a bit less expensive than the Accutronics.

I have a Accutronics 4AB3C1B connected to my very recently completed 4x6V6 rocket (still not in a cab). That's a two-spring, long decay, long tank, but also listed as "open side down" so it wouldn't work in your head. Mines going on the floor of a combo. I didn't put a lot of thought into my choice of tank. It's just what I had, but sounds good to me so far. I haven't been able to spend much time with the amp yet.

[angelodp]

rj, & co will my Rocket which has both the 1/2 power switch and the VVR be a candidate for the reverb mod and keep those two features. Looking forward to the kit rj.

Ange

[RJ Guitars]

Ange,

you'll need some real estate to add the extra tube, look at my pictures and see if you have that same space available. If you've got that space free then it should work very well. They really don't require a lot of components once you get that tube mounted.

thanks

rj

[RJ Guitars]

Hey guys (and Jana),

Would you mind taking a look at these drawings and see if there is anything that will cause someone an extreme problem in building this amp? I have looked at it far too many times in the recent past and if there is a problem I have my eyes trained to look right past it.

thanks,

rj

Edit August 2011 - I moved the schematic and layout to the original post on page 1. After going through a few group builds it seems the best place to put those documents. I will edit in the latest and greatest as we go.

[statorvane]

Well, the schematic shows three triodes from V2, and one triode from V6. I am guessing you meant to indicate that the 12AT7 (V6) drives the tank, and the second triode of V2 is for for recovery of the reverb (wet) signal.

[RJ Guitars]

Well, the schematic shows three triodes from V2, and one triode from V6. I am guessing you meant to indicate that the 12AT7 (V6) drives the tank, and the second triode of V2 is for for recovery of the reverb (wet) signal.

Exactly right you are... I'll fix it and repost that schematic. thanks rj

[rawnster]

Hey RJ or Mark, got a schem for this one tube reverb your adding?
I might add some verb to this 15W, Rocket/Vox/DC-30 amp I thinking about building.

Chris, this is from Rawnsters earlier post on this topic... https://tubeamparchive.com/download/file.php?id=10313

thanks,

rj

Hey that looks vaguely familiar.

Hey RJ, I've been building several bassman-ish amps lately /w reverb. I'm using the MOD 3 spring tank from cedist too. They sound cool enough. Yet they appear to bit a more picky on it's proximity to the PT. Lots of hum if it's not oriented correctly in the head cab.

[M Fowler]

Yeah the head cab needs to be taller to keep that reverb pan away from the transformers.

Shield the reverb wiring as well this will cut down on noise too. (From the triode to the RCA jack).

Mark

[rawnster]

Yeah the head cab needs to be taller to keep that reverb pan away from the transformers.

Shield the reverb wiring as well this will cut down on noise too. (From the triode to the RCA jack).

Mark

For sure! I've got a new build on the bench right now where I'm using shielded wire in that very place. What about isolating the RCA jacks too? Don't know if it's necessary, but I'm doing it on this build to see if it's quiet. Also, grouping all of the reverb-related ground connections to a single star ground. (i.e., driver and return cathodes, 220k grid resistor recovery triode, RCA grounds, filter stage for reverb tube...both triodes)

[RJ Guitars]

This is excellent info guys. My only complaint about my Rockster Reverb was that I had some hum that tracks with the reverb level. I had plans to track it down but hadn't started yet... maybe you have the answer for me already?
This last bunch of cabinets I had made up are just a bit taller just to accommodate the tank so that should be a good help right there.

good stuff - thanks!

rj

[PlinytheWelder]

I like these mounts. I even use them for circuits boards... 8-32

Should work for a reverb pan...
http://www.mcmaster.com/#catalog/116/1368/=8ajr5a