Structo wrote:
Gary and other pros,
What is the criteria for choosing a tube for the PI spot?
Are you listening for good harmonic content or matching plate voltages or what other things?
Harmonic content and balance are the main considerations. There are also a few other things that I look at, but those are particular to my amps and how I set them up.
Gary
Located in the St Croix River Valley- Afton, MN
About 5 miles south of I-94
aka K0GWA, K0 Glas Werks Amplification www.glaswerks.com
Along with the things Gary listed are headroom smoothness of breakup sustain and low frequency responce...To me just as important as the other tubes.. NOS tubes offer up a smoother breakup but less punch.. Larger plate tubes like the 803 and EH's LPS give you better lowend stability but the breakup can get crunchy if there not well balanced.. more prominiate with 470 ohm cathode and the 10k tail ala Bluesmaster ..My 2 cents
Tony VVT
Last edited by talbany on Thu Jan 22, 2009 10:13 pm, edited 1 time in total.
Pre-amp tubes differ upon taste. I tend to voice the preamp a little Fenderesc. Poweramp tubes; JJ 6L6 for more tight (direct) response, TAD 6l6 WGC for Fenderesc lose bottem / smooth highs response. Personal preference is TAD 6L6 WGC. No experience with TAD pre-amp tubes however.
I loved the TAD 6L6's that came with my D'Lite kit but one of them redplated after only about 8-10 hours.
Then Normster said he had the same thing happen to one of his TAD's.
Kind of made me gun shy.
Right now I'm pretty happy with the Winged =C= 6L6GC's.
heisthl wrote:I always thought agonizing about tube choice was about getting that last few % of tone/feel/character out of the amp, I usually pick reliability over tone if it's close. Don't you think it varies from amp to amp, and probably more specifically voltage to voltage which brand works best? I did an interview for 300guitars.com a few weeks ago and they specifically asked about tube choices like it was a big deal, it doesn't seem to concern Fender or Peavey. I'm still liking the EH12ax7 except for the PI (Sovtek LP) The verdict is still out on the Svelana's, I have been having really good luck with them lately. Believe it or not I like the sound of the EH6L6's and the short bottle TAD's.
Well, I used to think that tubes brand and type, didn't matter that much to tones achieved. And I used to use Sovtek's 12ax7wa in genereal and 12ax7 LPS for the first tube, until I got into dumble clones.
In D'clones, I find the sovtek's to be quite hard sounding. Shifted to JJ 12ax7, which I find have a soffter responce and tone.
There was a big long thread at The Gear Page talking about the Tung Sol reissues. Well reissue is not accurate at all, but the Tung Sol branded 12ax7.
I had been hearing pretty good things about those but in reading that thread there were a lot of failures reported.
Especially from the guys buying flats of tubes.
I don't know if it was a QC problem that got ironed out or what.
It was a thread that was a year long and it seemed as time marched on the reviews improved a bit.
I had read that Mike Matthews was having trouble with the Russian mafia over there so perhaps organised crime has an effect on how much they are pumping out of the factories, I don't know.
So I know this is a little late in the game, but I thought I would chime in. I'm using a d'lite 22/33 with 100K plates in v1, and 150/220K in v2, and a BM PI circuit. I had been using the stock EH's in all the positions, but recently went down the vintage tube path and found an interesting mix that sounds awesome in this amp. So thought I would share this oddball mix.
V1 - JAN GE 12AX7WA
V2 - Telefunken 12AX7
V3 - Mullard 12AT7
Power tubes - JAN Philips 6L6WGB
Speaker- Old EVM12L in a pacific woodworks ported 1x12 cab.
It really warmed up this amp and gives it wonderful note articulation while retaining some nice percussive tight bass.
Okay, okay ... it sounds cool, but does it look cool?
The 12AT7 is compensating for the lack of headroom in the BM PI at the cost of less desirable overtones - you may find that going back to the standard PI with a 12AX7 will get you to the same place headroom wise but with cleaner overtones.
