The old 6v6 in a twin question.

[dragonbat13]

Alright will they work? I havent found nothing but opposite opinions on the subject. I know that the voltage on the plates is gonna be alittle high but I think that they could handle it. Maybe with the use of a zeaner diode?

The impedeance of the OT is always a question that comes up. I run two kt66s and run an 8ohm load. I think I would still be ok with four 6v6s. Is this correct?

What about any tube socket or circut modifications? From What I gather I should just plug them in and rebias.

It is a 100 watt twin, SS rectifier, converted to standard bias, cap job, blackfaced with a dan torres kit.

I really want to run the 6v6 tubes. The 6l6 (and the kt66s and 5881 tubes are all just too clean for me). What brand tubes will handle the higher plate voltages?

I have always read that the 6v6 tubes have a little earlier breakup and are more responsive to the pick attack and volume knob on the guitar.

What do ya think about it folks?

Thanks for all the help.

[mhuss]

The JJ 6V6s will take up to 500 plate volts without burning up.

--mark

[Richie]

if you run 4x 6v6 JJ it will still be loud.. another option is wire the socket for EL34..and just use 2 of them..and cathode bias the EL34s.. makes a cool sounding amp..

[skeezbo]

One of Kevin O'Connor's TUT books has this: in a twin reverb, 4 6v6s operated at about half power (probably the same as 2 6l6s with an 8 ohm load). He also showed another drop to quarter power by usung just 2 6v6s. I sure would use the JJ tubes if I tried it this. He claimed you could try it with the stock 4 ohm load for an even greater reduction in power.

I tried this with 6v6s in a tweed superish clone I built with bassman iron. The tubes were NOS Sylvania (Philips?) blackplates. It sounded really squishy, so I took them right back out. I hadn't changed the speaker load.
Maybe I should have switched to the 4 ohm tap?

Have you thought about wiring the sockets for triode operation? That would sure soften it up.

Good luck!
Skeeper

[dragonbat13]

I have thought of installing a pentode triode switch in the back of the amp.

I am bidding on a pair of 6l6 blackplates and If I dont win those I am gonna get four of the jj 6v6s.

I have all kinds of output tubes and am thinking of doing a ssquare off once I get everything in order.

I liked the twin with 5881 new tung sols the best followed by the tung sol kt 66.

If I never find anything better than the new tung sol 5881 I will get a quad of NOS ones and leave it at that. I will always be using different tubes in diffferent projects anyway.

[LOUDthud]

Hoffman sells EH 6V6's and says he selected them because he tried them in a twin and they worked well.

[bigmik]

I like richie's idea of running 2 el34's I have a twin that get's almost no playing time and this might be the ticket to getting it turned on more often but how would the two el34's affect the output inpedence compared to the four 6l6?

[mhuss]

I like richie's idea of running 2 el34's I have a twin that get's almost no playing time and this might be the ticket to getting it turned on more often but how would the two el34's affect the output inpedence compared to the four 6l6?

It will about double it. However, the factor-of-two impedance mismatch is not a big problem (particularly with only two output tubes) if you want to use the existing speakers, it will just reduce the output power a bit more.

--mark

[Richie]

The guy that has the amp, says its still working fine after about 3 yrs since i last scene it. Hes done some recording with it,and used it alot.
I'm usually a nay sayer for doing things like this, but the fender amps seems to work fine.

[dragonbat13]

My amp is set up for a four ohm load with four 6l6s. I run an eight ohm load to make up for the mismatch in the power section. If I were to run four 6v6s I would still be matched up or so I read.

I am going to try both and see which ones I like. I am only gonna run two 6v6 tubes at first. I think the amp will be ok

[bigmik]

thanks mark and richie ,I thought that the impedence would double but it just makes me fell good to get some reasurance from someone with more experience than myself,i think i'll give it a try and see how i like it.


thanks again
big mik

[dragonbat13]

My amp is set up for a four ohm load with four 6l6s. I run an eight ohm load to make up for the mismatch in the power section. If I were to run four 6v6s I would still be matched up or so I read.

I am going to try both and see which ones I like. I am only gonna run two 6v6 tubes at first. I think the amp will be ok

I never run four tubes in the amp. I wouldn't be able to with the current drawn from the kt66s.

[jaysg]

Richie's suggestion also includes cathode biasing the EL-34's. I believe that affects the primary impedance back in the direction of 2K.

[Richie]

yep thats true.

I don't know how much amp work you have done, but its not too hard to rewire the socket..and remove the neg bias supply..ground the 220k resistors,and cathode bias the amp. Very few parts or changes.. You have to move the 1.5k grid stoppers off pin one to use the EL34s..

[bigmik]

hey richie ,I only got nine amp builds under my belt so far but hopefully that will keep changeing ,I think that I have the steps needed to do the conversion but if I run into problems this will be the first place that i'll run to. thank's again for takeing the time to answer my question

regards
big mik