6550 tubes. What are these worth.

[Tone Junkie]

My brother in law has a late 70’s early 80’s marshall he put groove tubes in back in the day. He has some old tubes from the amp that are fine.
He was asking what they are worth - ballpark. I think some were out of the JCM 800 the others out of a JMP.

I think he has three of the tung sol and 4 of the GE

 

[Racerxrated]

I'd say 60-100 per tube. Put em on eBay; let them go to bid for 7 days. That's if they test strong; no leaks etc.

 

[Tone Junkie]

No they were taken out when working. Back then all the rave was groove tube matched sets.

 

[glpg80]

I'd say 60-100 per tube. Put em on eBay; let them go to bid for 7 days. That's if they test strong; no leaks etc.

Yeah I agree with this. In my head I was thinking $100 for the GE/ea and less for the tung Sol, $60 or so if they all test average. If they test strong/like new then add as much as $50/ea.

Now here’s where it gets interesting. If the quad of GE all test to be close in tolerance to one another as a matched quad, then you could easily charge $600-$800 for that quad alone. Original NOS matched quads in like new working order are unobtainium.

 

[Tone Junkie]

Thanks. Are they interchangeable with EL34s.

 

[glpg80]

Thanks. Are they interchangeable with EL34s.

Yes and No. The heater filaments of 6550s require much more current than EL34s.

The Yes part is because the pinouts are roughly equivalent on an octal socket.

 

[LPMojoGL]

I'd say 60-100 per tube. Put em on eBay; let them go to bid for 7 days. That's if they test strong; no leaks etc.

I'd be interested if they're matched. Got some great GEs, but they measure 20ma out from each other. I installed em anyway, and haven't noticed any bad hum, noise or other ill effects.

 

[baron55]

Yes and No. The heater filaments of 6550s require much more current than EL34s.

The Yes part is because the pinouts are roughly equivalent on an octal socket.

EL34 and 6550 average 1.6 amps per tube heater current.

 

[Tone Junkie]

I don’t know if he will sell them. He’s got an early Marshall JCM800 4 input. Maybe 1983
We just happened to be discussing guitars etc and he brought them out. He was just curious as to if they were worth anything.

Thanks guys

 

[glpg80]

EL34 and 6550 average 1.6 amps per tube heater current.

6550 average higher in my experience, the difference of a quad could be +/- 0.4A.

 

[glpg80]

I don’t know if he will sell them. He’s got an early Marshall JCM800 4 input. Maybe 1983
We just happened to be discussing guitars etc and he brought them out. He was just curious as to if they were worth anything.

Thanks guys

You’re welcome - in summary they’re worth something as long as they work and how well determines the price. Bonuses go for matches as a pair or quad

 

[Racerxrated]

You’re welcome - in summary they’re worth something as long as they work and how well determines the price. Bonuses go for matches as a pair or quad

NOS Matched quads of GE 6550s are 5-600 from what I've seen on eBay. Hard to find, and prove NOS these days though.

 

[glpg80]

NOS Matched quads of GE 6550s are 5-600 from what I've seen on eBay. Hard to find, and prove NOS these days though.

It does prove the OP’s point that there’s definitely money behind them if they’re cream of the crop. Worst case $400 if nothing matches, as much as $600-800 if they all match and are in excellent working order.

The sad part? If they were like new they’d probably outlast the newer stuff by a factor of two.