1. Win a Broadcaster or one of 3 Teles! The annual Supporting Member Giveaway is on. To enter Click Here. To see all the prizes and full details Click Here. To view the thread about the giveaway Click Here.

Salvaged vintage organ tube amp...what's next?

Discussion in 'Glowing Bottle Tube Amp Forum' started by Neener, Apr 19, 2021.

  1. Neener

    Neener Tele-Holic

    Posts:
    774
    Joined:
    Apr 19, 2019
    Location:
    Detroit
    This is somewhat a continuation of my previous thread https://www.tdpri.com/threads/salvaged-vintage-organ-tubes-value.1069270/

    For those of you just joining us, I managed to salvage a tube amp out of an old abandoned Baldwin organ. I was able to grab the chassis along with two speakers (one has a tear)

    Just got it home and was able to take a couple pics of the chassis.

    From what I gathered from our last convo, this would make for a decent guitar amp project. This will be my first amp build.

    What next?? :D

    I'd love to hear any thoughts, ideas, musings...

    1.jpg 2.jpg 3.jpg 4.jpg 5.jpg 6.jpg 8.jpg 7.jpg
     
    Last edited: Apr 19, 2021
    Arfage likes this.
  2. Fixcinater

    Fixcinater TDPRI Member

    Posts:
    44
    Joined:
    Mar 29, 2021
    Location:
    San Diego, USA
    You've got the transformers to basically make something like a Fender Twin with the 4x6L6 tube compliment as noted on the chassis. It looks like they were using that as a power amp block, with a remote preamp in another chassis.

    Do you want something in the 80-100W range of power? That would be way too much amp for me to want to end up with so I'd be less interested in going through all the decision making and amp-building time it would require, than if I was building something that I could keep and use.

    Assuming you do want to try and build this into something you can use, I'd still not trust any thing so would try to test out the transformers and then shot-gun out all of the caps and resistors and use what basics are there (pots/jacks/switches, etc) for your own design or steal one from Fender/Traynor/whatever well researched brand is out there and has been built over and over so it'll be easy to trouble-shoot.
     
  3. Mowgli

    Mowgli TDPRI Member

    Posts:
    66
    Joined:
    Feb 18, 2021
    Location:
    Southern Jazzville
    Did this organ hook up to a separate tone cabinet? Some, Baldwin's, even with internal speakers, had jacks to separate tone cabinets.

    IIRC, model 45 (and 45a?) was one of the last Baldwin tube amp models??? My memory is fuzzy right now.

    Many of the older Baldwins had two different outputs for different frequency ranges (a bi-amp scheme). Those amps were often located on the floors of the tone cabinets. I don't think the 45 or 45a employed those types of amps but I could be wrong.

    If there's ever any question about Baldwin organ gear The Organ Forum may help. Baldwin was notorious for poor documentation so finding specific model information and schematics has proven difficult.

    A decade or so ago I ran across a post on some Hi-Fi builder forum who modded an old Baldwin amp(s) into a reported great Hi-Fi stereo amp.

    BTW, I believe that's a Magnavox speaker.
     
  4. Mowgli

    Mowgli TDPRI Member

    Posts:
    66
    Joined:
    Feb 18, 2021
    Location:
    Southern Jazzville
    I just saw your earlier thread. If I had to bet, those are mostly Sylvania 6SN7 octal tubes.

    6SN7s & others like 6SL7s, 6SC7s, etc. are lower gain preamp tubes. They were commonly used in amps prior to the advent of the higher gain 12ax7s and during that transition period.

    I love the commonly described "round" sound of octal preamp tubes. They are found in early Ampeg, Gibson and Fender amps among others. I believe Little Walter amps make models using octal preamp tubes, too.

    They are also used in Hi-Fi amps as are 12au7s. Don't expect high prices for these tubes; they still have utility!
     
  5. ArcticWhite

    ArcticWhite Tele-Afflicted

    Posts:
    1,249
    Joined:
    Apr 14, 2009
    Location:
    Portland Oregon
    If any of those Sylvania 6SN7s have three holes punched on both sides of the plate, they're pretty valuable.
    I sold five of them on the bay for sixty dollars each.

    Sylvania-6sn7GT-Black-T-Plates-3-holes-Bay-Boys.jpg
     
  6. ArcticWhite

    ArcticWhite Tele-Afflicted

    Posts:
    1,249
    Joined:
    Apr 14, 2009
    Location:
    Portland Oregon
    Those transformers are massive, and designed to power a four 6L6GC tube output section.
    As noted above, that's a Fender Twin. That would be an expert only build, and you'd also need chokes, reverb tank, a couple hundred dollars of electrical components.
     
    Neener likes this.
  7. Neener

    Neener Tele-Holic

    Posts:
    774
    Joined:
    Apr 19, 2019
    Location:
    Detroit
    I didn’t see a separate a input but
    There was another transformer I couldn’t pry lose at the time...

    Worth going back to get?
     
  8. Neener

    Neener Tele-Holic

    Posts:
    774
    Joined:
    Apr 19, 2019
    Location:
    Detroit
    Dang was hoping for something a bit lower. Possibly a 1x12 fender-ish deal. I’ll have to do some more research on this configuration. Might be more than I can handle, and worth selling at that point.
     
  9. Neener

    Neener Tele-Holic

    Posts:
    774
    Joined:
    Apr 19, 2019
    Location:
    Detroit
    Nice, I’ll check the stash tomorrow and see what I’ve got.

    Out of curiosity, what makes these so valuable?
     
  10. bebopbrain

    bebopbrain TDPRI Member

    Posts:
    18
    Joined:
    Feb 5, 2021
    Location:
    New York City
    Neener likes this.
  11. Mowgli

    Mowgli TDPRI Member

    Posts:
    66
    Joined:
    Feb 18, 2021
    Location:
    Southern Jazzville
    If I had to guess regarding an old Baldwin transformer I would say Yes. I read on a hifi forum that the iron on those tranny's are good.
     
    Neener likes this.
  12. BobbyZ

    BobbyZ Doctor of Teleocity

    Posts:
    13,625
    Joined:
    Jan 12, 2011
    Location:
    Snellman MN
    Did I read the chassis right?
    Four 6L6s and TWO 5U4s?
    Plus it says 6L6-G so I'm guessing it's the old low voltage 6L6 !
    I'd be building me a high powered Tweed Twin with that iron !
    The original 5F8-A only ran one rectifier tube, first Twin that only ran one, last Twin with a tube rectifier at all. It used a GZ34 pushed to its breaking point! The best GZ34s are British Mullards and cost 200 bucks now. Not a problem with this PT!
    So with that PT you can run two rectifier tubes and since its made for two 3 amp 5u4s (which are still cheap NOS) you can also try 2 amp rectifiers. PERFECT.
    It gets better. The 5F8-a used a 600 volt PT 300+300 and this one is probably pretty close to that if made for the early glass 6L6s.
    Only problem is you'd have to make your own chassis. Not exactly that difficult if you took shop class instead of something useless like math, English or information technology.
    If you did waste your time in those other classes you can probably afford to have someone build you a chassis. Us shop class geniuses are always looking for a way to pay the rent.
    Oh and don't be scared of an 80 watt amp. You don't have to crank them to make them sound good. Some people don't get that.

    I gotta get back into organ hunting !
     
    Antoon, JKjr, monkeybanana and 2 others like this.
  13. Neener

    Neener Tele-Holic

    Posts:
    774
    Joined:
    Apr 19, 2019
    Location:
    Detroit
    I ain’t scared! Haha I have a twin that I play at home. Neighbors love it :D

    I didn’t take shop class in high school unfortunately...But oddly enough my i work at a machine shop, so could whip something up if I decided to go that route
     
    Last edited: Apr 20, 2021
    BobbyZ likes this.
  14. Neener

    Neener Tele-Holic

    Posts:
    774
    Joined:
    Apr 19, 2019
    Location:
    Detroit
    Went back for the last transformer and decided to grab the entire organ chassis...o_O

    7E48C584-378C-47AE-BD41-EC2661D947D9.jpeg BF9CAA1B-420B-4D52-AD75-4FC3E70AA567.jpeg 256EE448-F61A-44E5-9C90-5138C8497AA1.jpeg
    FE7C847A-CA0C-4DAC-89DB-6BDB291861E4.jpeg
    44CB5671-6331-4FAF-AD7C-00CA7427A583.jpeg
     
    Last edited: Apr 20, 2021
    Telekarster, BobbyZ and DADGAD like this.
  15. Wally

    Wally Telefied Ad Free Member

    Posts:
    39,083
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    Neener, what you show in the first post is a power amp...including the phase inverter. You would need to fashion a preamp. You could use only two of the power tubes thereby freeing up two octal sockets for octal preamp tubes to be used. Big project.
     
    Cosmic Cowboy likes this.
  16. Neener

    Neener Tele-Holic

    Posts:
    774
    Joined:
    Apr 19, 2019
    Location:
    Detroit
    Thanks Wally. I’m going to part it out most likely.
     
  17. jmp81sc

    jmp81sc Tele-Meister

    Posts:
    432
    Joined:
    Feb 6, 2015
    Location:
    Orange County
    If it was me I would use that power amp basically as is. I would trace out the power circuit and do a schematic to see how it stacks up against a guitar amp power section. Add a fuse and 3 prong power chord. You will also need to measure the output of the PT. You are probably stuck with a 2 speaker configuration, probably a 4ohm output transformer.

    I would build a combo cabinet and put the power amp section in the bottom of the amp and build a separate preamp chassis and put it on top with an umbilical wire harness. Some older amps did it this way and the modern Excelsior did also.

    I did two amps this way that were taken out of Hammond S6 chord organs.
     
    Cosmic Cowboy and Neener like this.
  18. Cosmic Cowboy

    Cosmic Cowboy Tele-Meister

    Posts:
    485
    Joined:
    Dec 10, 2020
    Location:
    New Mexico
    I am not an amp tech, but I am fairly certain you don't NEED to run all 4 6L6's.

    You could probably figure a way to pair it down to two 5881's and make a killer tweed Bassman 40-50 watt chassis.

    I would look at some schematics based around tweed bassman and twin amps.

    There is no tone stack (preamp) in your circuit. It would be cool to at least add a hi cut and low cut. Maybe you could even bias the plate voltage for 6v6s.
     
    Neener likes this.
  19. printer2

    printer2 Poster Extraordinaire

    Posts:
    7,314
    Joined:
    May 24, 2010
    Location:
    Canada
    It depends on what you want to build. The 6SN7's can make a 5W bedroom amp. Of course you need to buy all the parts for the amp other than the 6SN7, but you will be set for life for a supply of them. Use them for a reverb driver also. The output transformer can be run with one set of tubes, measure the impedance of the speakers. Drop one set of tubes and use one of the speakers. Now comes the boat anchor. The output transformer was used to power a 4-6L6 amp but also a ton of heaters. Unless you did not plan on hauling it around a lot I would get a different one if possible.
     
    Wally and Neener like this.
  20. Neener

    Neener Tele-Holic

    Posts:
    774
    Joined:
    Apr 19, 2019
    Location:
    Detroit
    I'll most likely part out to those with more experience than I.
     
    Last edited: Apr 20, 2021
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.