Fryette Sig X and 6550 help.

[bigangryguitar]

I just got a brand new duet of EH 6550's to put in my Sig X. Th problem seems to be that in high power mode I can't get the bias down to the recommended 110 at the test points and one of them gets a very faint dull glow on the inside of one of the plates. I know that is not a good thing! I have the bias at the coldest setting. Is this a bad set of tubes or what? When I put the stock kt88's back in they bias up just fine. Thanks Shane

 

[///MK]

Bet you need different a value for bias resistor.
Do you have another amp to try the tubes in?

 

[bigangryguitar]

Bet you need different a value for bias resistor.
Do you have another amp to try the tubes in?

I didn't even think about that but I bet you are right. I am almost positive the tubes are fine as when I run them with the tube rectifier they are fine. I think I like the kt88 sound better anyway so rather than messing with a different resistor i'll just return them and stick to the kt88's.

 

[LP Freak]

You've got a hot set of tubes. You need to get a set that's not so hot and will work within your bias range.

 

[bigangryguitar]

Thanks for the help guys, i'm going to retun these and just get some more kt88's they sound better anyway to my ears.

 

[LP Freak]

Good luck returning them. Alot of places won't take tubes on return unless they're faulty.

 

[bigangryguitar]

Good luck returning them. Alot of places won't take tubes on return unless they're faulty.

This place will, i've been doing business with them for about twenty years and he said if I didn't like them to bring em' back.

 

[LP Freak]

Good luck returning them. Alot of places won't take tubes on return unless they're faulty.

This place will, i've been doing business with them for about twenty years and he said if I didn't like them to bring em' back.

Nice. Don't tell him you were red plating them though.

 

[stephen sawall]

Make sure you get the KT88's in the right range or you are going to have the same problem you had with the 6550's ....

 

[bigangryguitar]

I only had them on for a couple of minutes in the high power mode and it was just along one of the inner lines of one plate and very, very light so I don't think it would have damaged the tube at all. And thank you Stephen I will make sure the new set of KT88's are at the proper bias level.