Oahu Amp by Jester... anyone have one? noise issues.

[axpro]

Hey guys, haven't been to Ampage in a while took me a while to find where you moved to!) I picked up a Jester Oahu amp, really really simple thing, dual el84 power, tube rectifier and 2 12ax7's... haven't looked under the hood much on it, but i know the circuit is dead simple (if anyone has aschematic that might help!) I've heard complaints about noise (crackles and hiss) with these,a nd my new prize is no exception. I have to go over it tomorrow morning (check lead dress, grounding points, try some other tubes and add some ruber mounts so the chassis doesn't rattle itself to death) but was wondering if anyone else has one of these, or had one come across their bench? any tips or tricks? they seem hard as hell to find info on.

Dave McCulloch

[axpro]

After a fun morning of digging through the circuit (gotta map it out and post it here, some weird setups) I switched out the rectifier and blammo, no more noise.

Dunno why, but i guess ithe toob was a little flaky... much quieter now,

I was going to try a 5u4g in it, but was worried about excessive voltage verses the 5y3.

Dave

[Rick Erickson]

The amp was built by Oliver Archut, a former Seattle resident, now living in Kansas. You can find him at: http://www.tab-funkenwerk.com/
They are well built units with metal film (low noise) resistors and decent quality components as I recall.
Oliver brought one of these amps to my shop when he first started building them. I suggested he try a Sovtec 5Y3GT Rectifier instead of the NOS one he had in it. While he was going off in his thick German accent about how much cheaper he could get the tubes he was using, I swapped rectifier tubes and played a single "A" chord, letting it sustain and bloom. He suddenly got a big grin on his face and said "thank you". I see on his website that Keith Richards just bought the last of the available Jester "Oahu" amps. If that means no more will be produced you may have a future collectable on your hands. I'm supposed to be picking up a couple Ampeg SVTs from the Stones when they hit Seattle, (they play this Tuesday) for rush repair service. If I can get close to the stage I'll try to see if Keith is using the Oahu amps on this tour.

RE

[axpro]

GRoovy, A buddy of mine is really digging it (i brought it in to work, i work in a music store) and he is a HUGE Keith Richards fan... if he hears this he's gonna pop!

Component wise, it seems really good (and really simple, which I like in my small amps) it is really sensetive to pick attack... This particular one has gone through a few owners, and the tubes are all new and slick, but i guess nobody thought to change the rectifier tube to eliminate the noise!!! I am using a sovtek 5Y3gt, and like you said, it makes a BIG difference. before i tried that, i had thought about adding another filtering stage, but it did the job with just the tube.

THanks for the info, I'll keep you updated as i try a few new tubes... and maybe rubber mount the chassis!

Dave

[Rick Erickson]

Dave, I just got back from the Stones stage at Qwest Field in Seattle. They had a Jester "Oahu" mic'd up along with a number of what appeared to be original Tweed Twins and I can't remember what else. Three SVT amps on stage. Huge production! Glad I don't have to set it up. Looks like you picked up on a good deal. I'll have to keep a watch for those amps on the used market.

RE

[Chris / CMW amps]

Rick: cool story!

Afaik they're based on old Supro/Valco-amps.
Those circuits can be pretty cool imho, I've used them a couple of times as platform in amps with a few teaks.

EDIT:typo

[caseyblu]

I know this thread has been dead for some time, but I have one of these amps and recently stumbled across this:

AMI TAB-Funkenwerk Oahu guitar amp

I wonder what, if any, differences there are between the "Jester" Oahu and the Tab/Funkenwerk versions...