Univalve--what tubes do you suggest?

[T.B.A.]

I picked up a THD Univalve the otherday and after experimenting with the EL34 it came with (and a yellow jacket with EL84 coversion), I'm ready for more.

It runs electro harmonix 12AX7EH's in the pre amp (imput & driver).

Just for kicks, I'm looking to see how much overdrive, or heavy gain/distortion I can get out of this at low-ish volumes.

My problem is I know very little about tubes, so I'm not sure which direction to go with pre or power tubes to get me that sound.

Thanks for any help

[markyperfection]

sweet score! they are awesomely fun lil amps!

the el34 is going to give you the most overdriven sound IMHO, as el34's are more prone to early break up. other than that, i'd say maybe a pair of 12ax7a's spec'd for higher gain (i prefer JJ myself, but there is a VAST array of good-sounding tubes out there) to give you a little bit more heat from the pre-amp section. being that it's a class-a amplifier, it's not going to saturate quite the same way as a class-ab amp and the best way to get a nice screaming tone out of it is to crank it and use the built-in hotplate attenuator thingamajig to bring the volume down to a lower level.

[Lefty Robb]

http://www.jemsite.com/forums/showthread.php?t=74859

[losgatosrg350dx]

tung sol 12ax7 is the highest driving tube u can use preamp and svetlana 6550 power section with a high output distortion will make ur and scream like nobodys buissness

[markyperfection]

Originally Posted by losgatosrg350dx

tung sol 12ax7 is the highest driving tube u can use preamp and svetlana 6550 power section with a high output distortion will make ur and scream like nobodys buissness

[sarcasm]
yeah man, +1. great ideas. all fantastic advice. because brand name has everything to do with gain characteristics, and 6550/KT88's definitely aren't more or less the loudest and cleanest power tube you can get. you will definitely not find 6550's 9 times out of 10 in audiophile-quality home stereo equipment because of their high headroom and low saturation characteristics. again, killer advice.
[/sarcasm]

btw, you left one of your shoes in another thread; thought i'd grab it for you.

[microdmitry]

Originally Posted by T.B.A.

I picked up a THD Univalve the otherday and after experimenting with the EL34 it came with (and a yellow jacket with EL84 coversion), I'm ready for more.

It runs electro harmonix 12AX7EH's in the pre amp (imput & driver).

Just for kicks, I'm looking to see how much overdrive, or heavy gain/distortion I can get out of this at low-ish volumes.

My problem is I know very little about tubes, so I'm not sure which direction to go with pre or power tubes to get me that sound.

Thanks for any help

If you want distortion, you'll be much better off running an overdrive or clean boost pedal in front of it. If tubes are good (no hum/pop/crackle) I wouldn't waste my money swapping them, except for maybe buying a JJ 6V6 for the output (because it's cheap and it's lower power).

[T.B.A.]

Thank's for the replies guys.
I read your whole thread Micro', re valves from a while back and thanks to Lefty, I've spent waaaay to much time on the Bob's "Eurotube" site this afternoon.
(I'll have to see if he'll ship O/S)

losgatosrg350dx, thanks for your input, and the fun, cryptic puzzle that only requires spellcheck to decipher what you're refering to. ;-) I'll check 'em out!

Marky', the built in "hot plate" really does completely change the tone and Micro', I've got one of the best drive tones I've ever heard by running my Tone bone Hot British and Boss EQ in that order. It's just that I'd love to get somewhere remotely near this ,without any effects. This is residing in our lounge room and cables and crap everywhere isn't an option.
EG: ( Well darling, if you dont like the way my JCM 900 dual reverb with 1960A/B cab's, pedal board, etc, doesn't match the new decor, I can always get a Little amp'.)
'You see my problem?

[losgatosrg350dx]

i suggested those tunbes becasue u can drive them soo much harder with any pedal input before gettign sqeals or whatever from high input

i like them and the amp loves to scream with svetlanas in the power section