Pre Tube Choices

[brewdude]

Hello,
I am preparing for my first D'Lite build.
I want to solicit a quick survey.

What are your favorite tube choices for V1 (Clean), V2 (O.D.) and V3 (P.I.).
Does anyone like using any of the other 12a_7 tubes?
If so, which ones are worth trying and where do they work best.
Which tubes should I avoid? Where?

Thanks

[pedro]

Hi brewdude,

keep your life simple and stick with the 12ax7's - the circuit is designed around those tubes and their operating points, and you want to be shooting for the *umble sound I take it ?

Other tubes in the 12A_7 family will have different gain and tube characteristics. Not worth the bother - unless you want to go hunting through tube data books to work out suitable alternative circuit solutions.
you could try using the older Octal equivalent of the 12Ax7 - the 6SL7 i think - but thats a lot of work and bigger tubes to fit in a chassis. Though the octals do sound great in some amps ( I miss my Reverborocket )

Have a quick look at the tube data for the various 12a_'s etc on the net and you'll get the idea.
Heres something I lifted from a similar post a while back which will help you see the difference.

12AX7: mu=100, plate resistance = 62K
12AT7: mu=60, plate resistance = 15K
12AY7: mu=40, plate resistance = 22.8K
12AU7: mu=20, plate resistance = 8K


Now, as for what brand of 12aX7 to use ( or ECC83 - EU/UK equivalent ) well thats a different question entirely and you'll get lots of opinions here on which tubes are best to use in these positions . Many people here seem to like the JJ's and tung sols, but YMMV, so search the forum and see what peoples opinions have been recently.

Personally I like NOS mullard ECC83's but they are like proverbial rocking horse poo nowadays - even in the UK.

At moment I have tung sol, sovtek and mullard in my HRM ODS 50W - they just seemed to work nice in this amp!

you will also see 12Ax7's listed as 5751's sometimes too - but i think the 5751 has a slightly lower gain but i could be wrong ( anyone ? )

Good Luck

Pete

[odourboy]

I've been using Tung-Sol in V1 and V2 (and the loop if I have one) and EH in the PI position. I'm going to try some Shuguang in the PI as soon as I get some - they've worked well for me in other amps. Very reliable in the PI where others tend to crap out prematurely (due to high plate voltage maybe?)

Dogears posted some killer clips a few weeks ago showing off some RFTs. I'm curious what others are using also so please post your preferences.

[dave g]

EI are amazing if you can find some good ones...right now I'm using a NOS Bugle Boy in V1 and an EI in V2

[Funkalicousgroove]

JJ's are the way to go imho, That's what was in both RF and LC's amps when I saw them-

[stelligan]

Funk,
Have you tried the JJ high gain ECC803s? I have tried those and like them. Never developed a taste for NOS and pricey tubes because it seems like I'm getting what I want from EH and JJ in the preamp and SED or Sovtek power tubes. Seems like there's enough to tinker with regarding all other variables. I guess ignorance is bliss.........

[stelligan]

duplicate post. Server seems to be slow lately....

[Funkalicousgroove]

I typically steer clear of long plate tubes except in the PI, FWIW the ECC803 is actually about 90% of the gain of the ECC83S, but from what I hear VERY chimy!!

I have some NOS Stuff, and for the most part it does sound a tad better- but not enough to warrant the difference in price- I pay about $9 for a JJ, I think I paid $100 for my Amperex Bugle Boy

[Structo]

Yes, I will have to agree on the NOS tubes.
I tried some Sylvania grey plates that cost $25 each in V1 and V2.
To my ears there wasn't enough difference to warrant the price.
Currently I have some new EH, JJ and some Ruby Chinese tubes to try.

[ayan]

Yes, I will have to agree on the NOS tubes.
I tried some Sylvania grey plates that cost $25 each in V1 and V2.
To my ears there wasn't enough difference to warrant the price.
Currently I have some new EH, JJ and some Ruby Chinese tubes to try.

That's too bad! Preamp tubes will make a tremendous difference, and possibly more in non HRM amps -- which have a more "refined" or "unaltered" type of timbre, for lack of a better word. One simple test: play your amp in clean mode with PAB, at a loud volume and check for singing feedback depending on the tube you have in the V1 position. My findings are that NOS tubes tend to do great here, Chinese 12AX7s at a rate of maybe 20% and JJs maybe 30%. I have found it hard to get either a real good or real bad sounding Chinese 12AX7A; I have found it easier to get a very good or real bad JJ, and they all tend to be pretty noisy. As per my experience, an amp that sings a bit at home will sing like a mocking bird at the gig.

Cheers,

Gil

[Funkalicousgroove]

Perhaps I'm spoiled, all the JJ's I buy have been tested for gain, noise, and microphonics by Lord Valve, then I test them again on my VTV tester for gain, noise, and triode balance- At that point I have a number to go off of, and know before hand what tube will do what-

[ayan]

Perhaps I'm spoiled, all the JJ's I buy have been tested for gain, noise, and microphonics by Lord Valve, then I test them again on my VTV tester for gain, noise, and triode balance- At that point I have a number to go off of, and know before hand what tube will do what-

Sounds like the extra couple of bucks is well worth it, Brandon, cause I get them from CE and you've heard my statistics (as well as others', as we've read here and elsewhere). Too bad I can't buy from F.W. -- potential digestive complications, you know?

Gil