Another Noob with a tube question.....

[Scooter]

Hey guys, I'm new to doing anything but playing through a tube amp. One of the power tubes in a Peavey VK100 is burnt out, and I've been researching as much as I can about replacing them. So far I've found: replace them all, when one goes, the others are soon to follow. Its also a fixed bias head, so no problem after the swap.
Now my problem. I need to get 4 6L6 tubes, question is, I can't find anyone local store with a matched quad, and they're unsure about mixing brands. Can I run 2 different pairs, ie- 2 matched Groove Tubes, and 2 Electro Harmonics? Or is it a MUST for a quad set? I've read opinions here that 'tubes are tubes' etc, but I'm experimenting with tone, and I don't know if brands can be mixed, I'd rather be safe than sorry, so thanks in advance.

[DonP]

When I first go my DSL100, one of the tubes died (infant death). Since the other three were still new, I just grabbed another Svet tube and went with it. No problems 12 years later still on the same tubes. Still sounding great.

The next time a tube dies on me, or I have sound quality issues, I'll replace the entire set.

[Scooter]

Thank you very much sir!

[MakeAJazzNoiseHere]

You know, when I was looking for a tube amp this is EXACTLY why I passed up the Peaveys... Fixed bias plus NO info about what tubes are recommended replacements in the manual or anywhere I could find...

Call their customer support and tell them you want to know which Groove Tubes would be the best ones to put in there, or, where to get replacement tubes, etc.

Or check with some other owners who have already done the experimentation for you.

They don't HAVE to be matched, and if the bias is off they will just sound crappy (cold) or they will burn up quick (hot) but, you're just throwing away money at that point, which, I'm guessing you don't want to do.

You could probably get a quad of 6L6's from Groove Tubes in a "medium" range (5 or thereabouts) and get decent results.

[Cygnus X1]

"Fixed Bias" does not indicate the bias is not adjustable.

Two historical examples:
Fender Tweed Deluxe: Cathode bias. It "self biases" the power tubes,
similar to how preamp tubes are self biasing.
Except where there is a "grid leak" bias, which is also self biasing.
Can, and should be checked and adjusted upon tube change.

Fender Deluxe Reverb: "Fixed bias". Has a bias potentiometer for changing the bias. It is not "self biasing". Should be checked and adjusted whenever power tubes are changed.

Mesa are the ones that excluded a bias pot. Their claim is you must buy tubes to their specs (exactly) and do not change the bias.
A few others have done that, but not very many.
And a very large number of Mesa's have been fitted with a bias
pot.

[Scooter]

Peavey says Ruby 6L6 tubes come stock. Can't find not one in the area. I'm gonna try an EH 6L6 for now, just to play, see how it works, but I will be putting all new tubes in very soon (I really HATE ebay, but WTH.) Thanks again for the replies.

[warlok]

Some tube places are pretty good about helping you pick the right ones to match the sound you want with the fixed bias the amp has. They have experimented with it and know alot more than me (or you).. I'm gonna put all JJ's in from eurotubes pretty soon in my (new to me) Peavey Ultra Plus. My bro in law called them and they sent a matched set to match the sound he said he wanted and his 5150 sounds amazing now. Whatever rating they use for the tubes will be a close match to run hotter or colder with the fixed bias of the amp. I don't know if I'm saying it right or not. Hope you get the point..

[Cygnus X1]

Try Winged C tubes.
A bit more pricey but well worth it IMO.

[Fender]

When I first go my DSL100, one of the tubes died (infant death). Since the other three were still new, I just grabbed another Svet tube and went with it. No problems 12 years later still on the same tubes. Still sounding great.

The next time a tube dies on me, or I have sound quality issues, I'll replace the entire set.

12 years with the same tubes? How's that working for you? I changed mine 2 years ago and i can already tell il need a new set soon. do you play a lot ? Mine gets about 4-8 hours weekly. When i practice at my friends studio, it climbs up to 10-15 hours.

[charvel750]

You can certainly mix and match brand name tubes as long as they are drawing similar current. So you don't necessarily need Ruby tubes, if you have Sovteks that draw the same current. If you mismatch tubes you not only lose the best tone possible, but you run your transformers irregularly due to the mismatch.

[Spivonious]

Not to hijack the thread but...

Cyg, if I have a schematic for my amp, how can I tell if it's self-biasing or not?

[Scooter]

Spinovious- Hijack all you want bro, I'm learning new things here!
BTW-How can I check to see if they're drawing similar current, what type of tool, setting, reading, and tolerances am I to be looking for?

[Spivonious]

You'd use a multimeter and hook up the leads to the correct pins while the tube was installed and the amp powered up. I wouldn't do it myself though; I don't trust myself not to touch the wrong thing and get electrocuted

[Scooter]

Understood completely, thats why I prefer to ask questions first!
I also saw some things about the VK100 doesn't discharge power either. I promise I'll not blow myself up. Thanks again guys.

[Psh511]

FFIW...I have had good experiences buying tubes from dougstubes.com...they have great customer service and seem to know their tubes