ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

WTB: 7591A's USED, tested and cheap

:

12/23/1999 8:02 AM
bill	WTB: 7591A's USED, tested and cheap WTB: 7591A's USED, tested and cheap. there ya go-- hope someone has a functioning pair of used, tested 7591A's, preferably of same brand. this is for a fix-up project that i can't sink much money into. although i'm an ampeg-fender guy, i have this 2x10 gibson hawk with messed up electronics that i want to get running. thanks, rise

12/23/1999 2:53 PM
Farrow	Bill, I'm generally against this, but I'd suggest rewiring the tube sockets for 6V6s. That's a MUCH cheaper alternative than trying to find some 7591As. Email me. Farrow http://www.skybolt6.com

12/23/1999 3:28 PM

Bill:

What is Cheap in your estimation? You could look for an old HIFI to scrounge from, that's where I got mine. Or you could get radical and rewire for 7868's which can be easier to find, or you could take Farrow's suggestion. There's always Ebay, but they usually aren't cheap. I sold a pair, used for $48.... if you do go with 7591's they will last a long time so tunes for the buck ratio is pretty good.

good luck.
Marc

12/24/1999 5:38 AM

Has anyone had any experience with the Sovtek 7591. I get the impression that it may be a rewired 5881 or something makeshift, since they recommend installing a resistor in the cathode circuit and it looks like a wafer-based Sovtec 5881 in appearance. I wonder if Tesla or Svetlana has any plans to produce this tube? It seems strange in that as often as this tube was used by Ampeg,Gibson, hi-fi mfgrs,etc that it has taken so long for a suitable replacement to come on the market.

12/24/1999 3:43 PM

The Sovtek 7591XYZ is in fact a re-based 5881. I would use thm in my amp, but 1) the 7591 sounds better, 2) my amp is fixed-bias so I'd have to re-do that circuit instead of simply installing new Rks, 3) I'd lose output in the end since the 5881 / 7591XYZ has a lower transconductance. So that means re-doing the driver (s) as well (my amp is stereo.)

In an old Ampeg or Gibson, I recommend leaving the old tubes since they're usually good, getting the adaptor for the 6GM5 from AES, or converting to 6V6. Since a lot of people seem to want nice overdriven sounds from their Reverborockets or what have you, most people go with the 6V6. I put a little laminated card in there with instructions on how to reverse the mod and my name and phone#. It takes about 30 minutes.

Farrow
http://www.skybolt6.com

PS compared to the 6L6 or 6CA7, there are very few amps out there that use 7591s. I LOVE the tube myself. I'd like to see Svetlana make a 7591 as good as their EL34.

12/23/1999 3:46 PM
bill	thanks for all suggestions. just a shot in the dark.... bill

12/23/1999 4:26 PM
DavidB	Keep lookin,the RCA "best" in my 1960 Heathkit are still going strong,ok one hade to be replace.7868 sound very good also but you need to repin,good luck

Page 1 of 2