| Author |
Message |
    
Foxhunter
Junior Member
Username: Foxhunter
Post Number: 17
Registered: 4-2008
| | Posted on Friday, June 13, 2008 - 3:56 pm: | 
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I was hoping that someone familiar with the GE 8950 tube might know of a suitable replacement tube for this, as they are getting expensive to replace. I have a Palomar 310M Bi-Linear Amplifier that has four GE 8950 tubes and would like to replace them with a "modern" compatible tube.
I've read that the 6LQ6 tube could be used but at the same time the amp would need to be re-wired and the output may not quite be the same either. Is that true? Is there a "direct replacement tube that would work or am I stuck paying a fortune for new-old-stock tubes or to have the amp modified for similarly expensive tubes (what then is the advantage)? Although many of the younger guys dislike the old tube amps as a "relic" of a by-gone era, I have one though and like it. I like old & unusual "antiquated" equipment but am afraid this is one reason why more people don't like them. Can anyone help me with some information regarding compatability/interchangeability for the 8950 tube? Once again the amp is a Palomar 310M Bi-Linear Amplifier. Thanks guys---Foxhunter |
Foxhunter
Junior Member
Username: Foxhunter
Post Number: 21
Registered: 4-2008
| | Posted on Monday, June 16, 2008 - 8:53 pm: |
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Nobody familiar with tube switching/interchanging ? |
Tech291
Moderator
Username: Tech291
Post Number: 508
Registered: 11-2004
| | Posted on Tuesday, June 17, 2008 - 7:49 pm: |
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Foxhunter,
without looking it up,I can tell you the 8950 has a 12 volt filiment whereas the 6lq6 is 6 volt.if you do a websearch for palomar skipper 300 you should find 2 schematics showing both tube types.I have both here somewhere that were gleened from the internet but made very bad copys when I printed them out.What would make more sense to me is to rewire it to use el-519 or something easier and cheaper to procure.with a thirty-something year old amp,keep in mind the electrolytics and the insulation breakdown in the transformer.
tech291
cef291/cvc6
kc8zpj |
Foxhunter
Junior Member
Username: Foxhunter
Post Number: 22
Registered: 4-2008
| | Posted on Wednesday, June 18, 2008 - 1:27 am: |
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Ok I appreciate the comeback I will look at the EL-519 Tube and see how feasible it would be to re-work the amp over to something more modern although I hate to in a way. Really the amp could use a good going-over yet I still have life in the existing tubes as of yet. I'd like to begin doing my homework on what will work and what won't and was hoping someone's had some ideas or to see if anyone's done something similar. Thanks Tech291 I needed something to get me started in the right direction.... |
Monk
Junior Member
Username: Monk
Post Number: 30
Registered: 2-2002
| | Posted on Wednesday, July 30, 2008 - 1:06 pm: |
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The 8950 is a 12 volt tube and the filament pins are 1 and 12, the one with the wide gap between them.
The 310M is a mobile amp that runs off of a 12 volt vehicle system. The 6lq6 tube is a 9 pin tube so not only would you have to rewire it you would have to put in new 9 pin sockets also.
The easiest conversion would be to a 6lf6 which will plug into the current sockets. You would have to rewire the filament pins to be in series for two tubes 6+6=12. You would feed 12 volt + to pin one of the first tube, connect pin 12 of the first tube to pin 1 of the next tube and then ground pin 12 of the second tube. You would wire up both pairs of tubes the same.
Hope this helps
Monk |
Foxhunter
Member
Username: Foxhunter
Post Number: 74
Registered: 4-2008
| | Posted on Thursday, July 31, 2008 - 1:28 am: |
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Yes it does help and thank you. Yes the Palomar 310M is a mobile amplifier and, although maybe similar isn't the amp commonly referred to as "the skipper"---I don't think.
The 8950 tubes still test Ok but looking at getting replacement tubes nearly sent me a "code-blue" type signal. They are expensive and not readily available.
I'd just recently acquired a Kris Big Boomer 300 amplifier that has 3x 6QL6's already (driven by one 6JG6). I haven't checked the prices of the 6QL6 tubes and am hoping they will be more affordable and available both as replacements for the Kri----and justifying the conversion modifications to the Palomar. By any chance did you own a Palomar 310M Bi-Linear amplfier in the past, or do you have one currently? Have you done this modification?
I appreciate the information I probably can't say that enough. I will archive this to my PC to use for a guide. Any reply with additional concerns with this amp or modifying it would certainly be welcome. |
Nickleusa
New member
Username: Nickleusa
Post Number: 3
Registered: 1-2012
| | Posted on Saturday, January 05, 2013 - 11:26 pm: |
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A 2057 is direct replacement, and will give more output |
Kennonotthatone
New member
Username: Kennonotthatone
Post Number: 1
Registered: 12-2013
| | Posted on Sunday, December 08, 2013 - 2:37 pm: |
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My first post here. True, but M2057 is harder to find than 8950 (A 12 volt 6LF6). If you want to use a 6 volt tube (6LF6, 6KD6, etc.) in that 4 tube 310M, just wire the filaments of two tubes in series, and wire each series set in parallel. You can DEFINITELY find 6LF6, and sometimes priced reasonably. |
K2000
New member
Username: K2000
Post Number: 3
Registered: 1-2002
| | Posted on Tuesday, July 29, 2014 - 2:39 am: |
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Yes either the EL519 or convert over to 6LF6 tubes would be better off.. 6LF6 has other tubes that can substitute with:
Tubes with base: 12GW
6KD6 6LF6 6LV6 6MH6 20LF6 30KD6
36KD6 40KD6 |
