Time to change the tubes/valves?

[PeterUK]

I've been using my PTP re-wired Deluxe Reverb for quite some time now and I'm still using the original tubes/valves it was supplied with. All JJ Telsa tubes/valves.

It's started to become quite noisey at louder volumes - a strong hiss - but plays fine and sounds pretty good.

Mike who built the amp supplied me with a pair of JJ6V6s and a pair of JJ6L6s. He also a SS rectifier plug.

I'm going to switch out the 6V6s for the 6L6s and try the SS rectifier too. Should I wait until I get my preamp tubes/valves or will I be OK to just change the power amp side for now?

Any advice welcome.

Peter

[PeterUK]

Anyone?

[Tim Armstrong]

Go for it, Peter! Do you have any way of checking the bias? Because you will want to be able to adjust it, particularly with those 6L6s and the new rectifier...

Cheers, Tim

[PeterUK]

Originally Posted by Tim Armstrong

Go for it, Peter! Do you have any way of checking the bias? Because you will want to be able to adjust it, particularly with those 6L6s and the new rectifier...

Cheers, Tim

Tim, I had Mikey add me a bias pot so I can stick in the new valves and bias it with my multimeter.

I'm going to go for.

Thanks

Peter

[marshman]

Bias issues aside, it will cause no damage/problems whatsoever if you switch power tubes w/o switching preamp tubes, and vice versa. I think there might be an issue switching the rectifier in that it could affect the bias, so check the bias whenever you do the recto, as well. If you've got a bias point, it should be pretty painless.

[Tim Armstrong]

Yeah, the preamp tubes are self-biasing, so they can be switched whenever...

Cheers, Tim

[jefrs]

Originally Posted by PeterUK

It's started to become quite noisey at louder volumes
Peter

They usually do, Peter, they usually do.

Amp having hissy fit might also be traced to a duff capacitor around the output section, prolly not the big smoothing caps... Was an RF suppressor added across the output anodes?

Otherwise first guess of ailing valve porbably right. Don't go with the shotgun fix, swap one at a time until you find the problem.

Then there's Murphy's law...

[PeterUK]

Originally Posted by jefrs

Don't go with the shotgun fix, swap one at a time until you find the problem.

Oops. Maybe I should read this before I changed all the valves this afternoon.

Anyway, all the preamp and poweramp valves have been changed and a solid state rectificier too. I've also gone from 6V6s to 6L6s and WOW!, what a difference.

Seems to have tons of clean headroom and and a much fatter sound.

I'm one happy boy and once these valves have bedded in, I know I'm going to be very, very happy.

BTW, I got my preamp valves from bnb_tubes in NY, USA. Very fast shipping and saved myself about 40% on the best UK prices.

Peter