Welcome To the Hoffman Amplifiers Forum

September 07, 2025, 05:30:42 am
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: 7591 - what to do with them  (Read 3032 times)

0 Members and 1 Guest are viewing this topic.

Offline SoundCity85

  • Level 1
  • *
  • Posts: 60
  • I love Tube amps
Hoffman Amps Forum image
7591 - what to do with them
« on: February 11, 2021, 05:16:35 am »
Any good ideas? I just found a quad of NIB branded ITT 7591 in a large tube collection I bought for next to nothing. Can they be used as replacements for EL34 where plate voltage isn't too high? Cheers

Offline HotBluePlates

  • Global Moderator
  • Level 5
  • ******
  • Posts: 13127
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #1 on: February 11, 2021, 07:36:27 am »
... 7591 ... Can they be used as replacements for EL34 where plate voltage isn't too high? ...

Not really, as the 7591 is a 19w tube and the EL34 is a 25w tube.  You'd expect the power supply & loading of the EL34-circuit to attempt to pull more current than the 7591 can deliver without overheating.

It's kind of a very-early (19w) 6L6, that only needs about as much drive voltage as an EL34, in a 6V6-sized package.  It's a bit of its own animal.

Any good ideas? ...

Ampeg (and maybe others) made lots of 7591 amplifiers.

Offline J Fletcher

  • Level 1
  • *
  • Posts: 15
  • I love Tube amps
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #2 on: February 11, 2021, 11:18:06 am »
 If it was me , I would sell the quad to a hifi buff who can use them . They go for big $$$ , and a quad would be very desirable for a tube stereo amp . Fishers I believe , amongst others .

Offline TitaniumValhalla

  • Level 1
  • *
  • Posts: 67
  • I love Tube amps
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #3 on: February 11, 2021, 11:20:36 am »
Gibson used them in a couple of different amps in the mid-60's. I really like the way they sound when overdriven in the '64-'65 GA-25RVT, after a few circuit mods.

NOS 7591's seem to be relatively expensive, probably because of the hi-fi crowd who are its primary user these days, though JJ and New Sensor make new production tubes that sound fine.

Offline jordan86

  • Level 3
  • ***
  • Posts: 562
  • I love Tube amps
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #4 on: February 11, 2021, 11:25:55 am »
I have a buddy on here who may be interested, @DBork. He just picked up an old univox amp that uses 7591's.

Offline mmrxcsr01

  • Level 1
  • *
  • Posts: 21
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #5 on: February 11, 2021, 05:58:17 pm »
How about a Premier Twin 8 build?

Offline SoundCity85

  • Level 1
  • *
  • Posts: 60
  • I love Tube amps
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #6 on: February 12, 2021, 02:07:34 am »
1 getter flash was white, so a leaky tube for the bin. So only 3 tubes instead of 4 :(

Offline DummyLoad

  • SMG
  • Level 5
  • *****
  • Posts: 5791
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #7 on: February 13, 2021, 02:30:24 am »
1 getter flash was white, so a leaky tube for the bin. So only 3 tubes instead of 4 :(

reverbrocket clone and a SE of some sorts?  :icon_biggrin: 

consider sale to a Hi-Fi guy to keep an Eico chugging along.

--pete

Offline dude

  • Level 3
  • ***
  • Posts: 1875
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #8 on: February 13, 2021, 01:12:10 pm »
I fixed an old oddball SE running a 7591, sounded great, maybe sell one pair, SE for the other  :icon_biggrin: .
If it ain't broke, don't fix it.

Offline SoundCity85

  • Level 1
  • *
  • Posts: 60
  • I love Tube amps
Hoffman Amps Forum image
Re: 7591 - what to do with them
« Reply #9 on: February 15, 2021, 02:06:29 am »
yeah I agree, too many things on my plate to mess around with these

 


Choose a link from the
Hoffman Amplifiers parts catalog
Mobile Device
Catalog Link
Yard Sale
Discontinued
Misc. Hardware
What's New Board Building
 Parts
Amp trim
Handles
Lamps
Diodes
Hoffman Turret
 Boards
Channel
Switching
Resistors Fender Eyelet
 Boards
Screws/Nuts
Washers
Jacks/Plugs
Connectors
Misc Eyelet
Boards
Tools
Capacitors Custom Boards
Tubes
Valves
Pots
Knobs
Fuses/Cords Chassis
Tube
Sockets
Switches Wire
Cable


Handy Links
Tube Amp Library
Tube Amp
Schematics library
Design a custom Eyelet or
Turret Board
DIY Layout Creator
File analyzer program
DIY Layout Creator
File library
Transformer Wiring
Diagrams
Hoffmanamps
Facebook page
Hoffman Amplifiers
Discount Program


password