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0ne 6l6 and one el34 in PP?

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9/6/1999 5:50 AM
FRANK	0ne 6l6 and one el34 in PP? I have a BF bassman.I have a bias control for each tube.Can I put one 6l6 and one el34 in it, if I set the bias for each tube?Thanks!

9/6/1999 7:22 AM

Yes you can, but don't expect it to sound great though

since you'll be producing a non symetrical component thereby increasing the amount of dissonent harmonics generated when driven to the rails. In other words as long as the amp is at low volumes the negative feedback will linearize the signal and you probably won't hear any difference. But if you crank the amp, the sound of the

output section overdriven probably won't sound as good as it would with a pair of matched tubes. =^^= DM

9/7/1999 8:07 PM
dave r.	Re: How about mixing tubes types in a 4 tube design? Assuming that it symetrically done, has anyone tried mixing tube types in a 4-output tube design? For example, one 6L6 and one EL34 on each side of ther PI? I guess getting the bias supply to supply the correct voltage to each tube type would be the drawback?

9/7/1999 8:25 PM
MJ Harnish	Mesa has the blue angel which uses El84's an/or 6V6's, though not set-up the way you describe (one type on one side of PI, one type on other). MJ

9/7/1999 9:08 PM
Farrow	Remember the Simul/Class? Mesa's Simul-Class amps did exactly what dave r. is asking. 6L6s in the middle and EL34s on the outside. Pretty good sound for a Boogie Might sound better with a simpler, lower gain preamp. Farrow http://surf.to/pharaohamps

9/8/1999 1:18 PM
MJ Harnish	[smacks self in head] I mentioned the BA and forgot the simul-class amps like the Mark II...

9/8/1999 5:22 AM

Re: How about mixing tubes types in a 4 tube design?

Although hardly a horrible mismatch, I had a gent come in to the shop with a well worn(out) ugly as a bucket of smashed donkey butts... tweed Deluxe this weekend.

One power tube was an 80% 6K6 and the other a near shot RCA 6V6GTA.

The 12AY6 was fair while the 12AX7 was about 50% gone on both triodes.

Max power out was a whopping 4.5 watts and it actually sounded pretty good! How amazing was that!?

I completely retubed it (NOS), replaced all the jacks, and found a leaky driver coupling cap so I used some .1uF O'drops and also replaced the bypass E-caps with some new ones. Atom power supply caps filled in the rest.

Great sounding tweed now! A most satisfying tone to me.

Max power was about 14 watts and..... he didn't really like the sound of it, but, reluctantly said he'd take it for awhile and see if he could get used to it, if not, I'll be putting all the broken parts back in (one at a time while tone testing no doubt) and then call it a day.

Live and learn...

What's that got to do with anything?

Just goes to show you that what ever sounds good to you and

inspires you or makes you feel great while playing,...

is the RIGHT thing.

Bruce

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