Welcome To the Hoffman Amplifiers Forum

September 06, 2025, 01:04:29 pm
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: what kind of amps are these?  (Read 6224 times)

0 Members and 1 Guest are viewing this topic.

Offline strangedisc

  • Level 1
  • *
  • Posts: 7
Hoffman Amps Forum image
what kind of amps are these?
« on: January 16, 2013, 08:53:34 pm »
have had these for quite awhile.  just now got around to checking them out.  what exactly are they?    thanks

Offline eleventeen

  • Level 4
  • *****
  • Posts: 2229
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #1 on: January 17, 2013, 10:28:20 am »
Can't tell you *exactly* what they are. Sometimes this determination is better made looking at the ends (in this case) of the chassis which you pix do not show. Is there, for example, an octal plug, esp labelled "preamp" or "accessory"? Most hi-fi setups of that era used a separate preamp and power amp, and the tendency was to use an octal plug and interconnect cable to power up the preamp. Or, it could be more of an industrial item. Or, it could be an organ power amp. If it's an organ power amp, it would be a bit rare to see, for example, an impedance select switch or barrier strip...because there's (in most cases) only one speaker arrangement. If it was an organ amp, then maybe the volume control is not especially in a "user-friendly" spot, as it is pretty much set once and forgotten about. These kinds of clues can help identify.

They certainly look like that have entirely adequate iron for what would appear to be a dual 6L6 amp. What is that metal-tube rectifier, a 5Z3?

At first they sure look like great chassis to warp into a geetar amps, but at the same time you'll be seriously space limited trying to get any kind of preamp circuitry in there. Long, narrow chassis are good to a point---once they are narrow like these, it's hard to see how you could get a row of preamp tubes in there while placing a row of controls along one long side of the chassis. Working with this typically forces the builder to put stuff next other stuff that one would ordinarily like to avoid.

You realize there is essentially no circuitry at all in those...you don't even have a phase splitter tube!

« Last Edit: January 17, 2013, 10:33:40 am by eleventeen »

Offline Tom_Hull

  • Level 2
  • **
  • Posts: 189
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #2 on: January 17, 2013, 10:42:00 am »
5z3 or what ever rectifiers link.since you mentioned that tube

it has a lot about rectifiers .if you like a nice download .

http://www.fourwater.com/files/fullrect.txt



tom
« Last Edit: January 17, 2013, 10:45:27 am by Tom_Hull »

Offline kagliostro

  • Level 5
  • *******
  • Posts: 7739
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #3 on: January 17, 2013, 01:34:43 pm »
Hi Tom

Very useful file

Many thanks for sharing

K
The world is a nice place if there is health and there are friends

Offline DummyLoad

  • SMG
  • Level 5
  • *****
  • Posts: 5791
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #4 on: January 17, 2013, 10:04:15 pm »
5T4 recto; sweetness. - it's_kind_of_like_a_5AR4_in_a_can. metalmania!! - probably designed for either 6L6 metal or 6L6G. the exposed resistors are dangerous. maybe military? do you have the pre-amps? looks like just the PS and output stage, no PI or pre.
hefty iron. revive them as is with a cap job. caps do seem fried is that rust or electrolyte on the cap cans?

--DL 

Offline strangedisc

  • Level 1
  • *
  • Posts: 7
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #5 on: January 18, 2013, 07:43:07 pm »
I don't see anything else that was in the box, except these.  that is somekind of build up on the one can.  I don't
really think I'm gonna mess around with these anyways.  And I don't have enough experience, to even know what
I'm doing!   :icon_biggrin:

Offline DummyLoad

  • SMG
  • Level 5
  • *****
  • Posts: 5791
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #6 on: January 19, 2013, 09:02:06 am »
I don't see anything else that was in the box, except these.  that is somekind of build up on the one can.  I don't
really think I'm gonna mess around with these anyways.  And I don't have enough experience, to even know what
I'm doing!   :icon_biggrin:

no manufacturer markings at all? on the transformers? chassis?

salvage those 6L6GC GE tubes in the one - the gettering looks nearly new on both tubes.

--DL

edit: ...they may be salvage from a theater.
« Last Edit: January 19, 2013, 09:05:12 am by DummyLoad »

Offline eleventeen

  • Level 4
  • *****
  • Posts: 2229
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #7 on: January 19, 2013, 02:14:18 pm »
Those will sell for decent money on fleabay as matched, industrial type dual-6L6 amps. Probably $80-$120 each.

Offline strangedisc

  • Level 1
  • *
  • Posts: 7
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #8 on: January 20, 2013, 09:35:40 pm »
hey,  ok,  thanks for all the info.        I'll go ahead and remove all the tubes, and ditch the chasis.                 

Offline Ritchie200

  • Level 4
  • *****
  • Posts: 3485
  • Smokin' 88's!
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #9 on: January 20, 2013, 11:17:49 pm »
Maybe old juke box amps? :dontknow:

Jim

My religion? I'm a Cathode Follower!
Can we have everything louder than everything else?

Offline Jack1962

  • Level 2
  • **
  • Posts: 376
  • I love AMPS, Tube or SS
    • Latham Electronic Systems
Hoffman Amps Forum image
Re: what kind of amps are these?
« Reply #10 on: January 30, 2013, 07:07:46 am »
Yeah I'm with Ritchie the look like either old jukebox amps
Any tube unit can be brought back to life.
I never meet a tube I didn't like.

 


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