Guitar Gear Forum

i just got this fryette power station ps100 and tubes looks like redplaating. is?

That doesn't look great.

Yes. Definitely redplating.

thx. ugh, just my luck. so just get new tubes? i dont think you can adjust the bias on these things. they are the stock fryette label tubes

i just noticed this too and had been playing it for many hours the last few days. thankfully nothing happened.

I don't know about this particular model, but the Fryette stuff I've seen has a bias adjust on it. That said, if it's been red plating a while then the tube is toast. It may be worth swapping the tube with the other in it's pair to see if the red plating stays with the tube or the socket. If it's the tube then it's just a dying/dead tube; if it's the socket then something a bit more fucky is going on.

Where did you get the amp from?

Zozobra wrote:I don't know about this particular model, but the Fryette stuff I've seen has a bias adjust on it. That said, if it's been red plating a while then the tube is toast. It may be worth swapping the tube with the other in it's pair to see if the red plating stays with the tube or the socket. If it's the tube then it's just a dying/dead tube; if it's the socket then something a bit more fucky is going on.

Where did you get the amp from?

This is what it says in the manual regarding bias:

Power and phase inverter tubes are mounted horizontally near the back of the unit. The power tubes are
factory biased for optimum performance. No provision for internal or external biasing is provided. To insure
that the Power Station will remain within safe temperature operating limits, the bias must not be modified
or tampered with. Doing so will immediately void the warranty. Tube types are factory selected for superior
performance, consistent tone quality and reliability. Power tubes are factory tested and matched. For best
performance, replace only with factory recommended tubes.

The other tube seens to be redplating slightly as well however. I bought it used aon another forum. My first PS100 had a bad PI tube, now i get this one and its redplating

Ah fair enough. When one tube in a pair starts to go it can pull the other one with it as the current becomes imbalanced in the pair.

Zozobra wrote:Ah fair enough. When one tube in a pair starts to go it can pull the other one with it as the current becomes imbalanced in the pair.

oh ok good to know. I'll order a new set of 6550's and see if that fixes the problem. hopefully it does.

Oh it just has two power tubes! I'd swap em over just to see if it's the tube or the socket though. It would suck to immediately red plate a fresh set of big bulbs if it was an amp issue.

Zozobra wrote:Oh it just has two power tubes! I'd swap em over just to see if it's the tube or the socket though. It would suck to immediately red plate a fresh set of big bulbs if it was an amp issue.

yeah only 2 6550's. ok ill try that. now to get to the tubes, so many screws to remove lol

Swapped the tubes around, and the one tube is still redplating.

That's good news as far as having dead tubes go. If it followed the socket then that would indicate either something screwy with the bias supply to the socket/bad solder joint or a leaky coupling cap. The other tube is probably ok enough to keep as a spare.

Zozobra wrote:That's good news as far as having dead tubes go. If it followed the socket then that would indicate either something screwy with the bias supply to the socket/bad solder joint or a leaky coupling cap. The other tube is probably ok enough to keep as a spare.

Tubes replaced. All is good now! No redplating at all~!

Fryette not allowing bias adjustments. Typical.

Good luck! You will probably have to ship it to steve himself.

boris the blade wrote:

Zozobra wrote:That's good news as far as having dead tubes go. If it followed the socket then that would indicate either something screwy with the bias supply to the socket/bad solder joint or a leaky coupling cap. The other tube is probably ok enough to keep as a spare.

Tubes replaced. All is good now! No redplating at all~!