Silent 12AX7's

soundmasterg · Post by **soundmasterg** » Mon Jan 19, 2004 4:16 am

Hey Phillip, the funny thing is the EI 12AX7's sound better in my AC30 than Telefunkens do....or Mullards for that matter. The EI's may be a copy of the Tele's, but they have them beat in this application! The one thing I did notice about the Telefunkens compared to any other tube I've tried in there is how smooth and balanced their tone is.
For EL84's, I like the EI a lot, but the GE sound better and last alot longer to boot. Now if I could just find a reasonable price on a quartet of GE's....

philco · Post by **philco** » Mon Jan 19, 2004 7:55 am

Greg, you might get good prices at Angela Instruments for your NOS EL84 needs. Steve often charges less because he only guarantees electrical function and not microphonic or tonal problems. He has Ei ECC83 shiny plate tubes for $5 the last time I looked. I'll take the cheap price and throw away the microphonic ones when they show up. My father has used one of those $5 Ei tubes in his Tube 12 amp for nearly a year with no problems. A definite improvement over the Chinese Ruby tube that came in it. I tried the $5 shiny plate and $8 gray plate Ei tubes, and I couldn't tell a bit of difference in the sound. Everybody else charges $10-$15 for these same tubes with a microphonic return privilege. Just order twice as many as you need and do your own culling. If you like bright extended highs, the Ei ECC83 is your tube.

philco · Post by **philco** » Mon Jan 19, 2004 8:13 am

ATTENTION ALL! I just checked Angela Instruments at www.angela.com and Steve is having a sale on the Ei ECC83 gray plates. He is letting them go for $60/10 or $7/ea.

This is a good time to stock up on your 12AX7 needs at a bargain basement price. They sound as nice as he states in his ad.

darkrider1 · Post by **darkrider1** » Wed Jan 21, 2004 2:00 pm

Two EH 12AX7's and one Mullard 12AT7WA are the nicest sounding combination in my Peavey Classic, and my Peavey Delta Blues amps..

philco · Post by **philco** » Fri Jan 23, 2004 3:13 pm

Mullards are great tubes, if you can lay hands on them. I use Mullard tubes in my Conrad-Johnson stereo preamp. They sound fabulous. Audiophiles swear by them, as well as Amperex and Telefunken. If you want the very best tested tubes, try Vintage Tube Services, BUT you will pay for them because the guy sells mainly to extremist audiophiles and ultra serious musicians who are willing to pay for ultra selected tubes. A set of his tubes can cost more than you paid for a used amp, because he rejects as much as 75% of the tubes he buys (which somebody else buys and sells as "premium" tubes, in many cases). His test lab is probably the best in existence for testing vintage tubes, because his testing equipment is laboratory grade as used by RCA and other premium manufacturers for their R&D departments. I heard of one guy that got 50,000 hours out of a set of Telefunken preamp tubes!

toneman · Post by **toneman** » Mon Feb 02, 2004 10:16 am

You have to also consider that unless you buy NOS, all your tubes/(really thermonic valves) comes from the places:
Sovtek & E-H: Reflector Factory in Russia
Ei's: the former Yugoslavia republic-factory was once owned by Phillips who also owned Mullard.
J/J: the old Tesla Factory in the Czech republic
Svetlana or Winged"C": Svetlana Factory in St. Petersburg, Russia
Chinese Ruby's & Valve Arts-China..
Groove Tubes is coming out with a U.S. made 12AX7/ ECC83 this month that is a clone of the long plate Mullard from the sixties. This tube is being made at their facility in San Fernando, Ca. which also makes their clone of the old G.E. 6L6 on the original G.E. equipment.

360dave · Post by **360dave** » Wed Feb 04, 2004 4:38 pm

Hey Phil, Don....somebody.....I was rooting around in the junquebox and found a pair of GE 5751 that have shiny black plates and the bottles have 5 stars printed on the side.
I know these cross to the 12AX7A but do you have any opinions on what the sound of them should be like in a Fender preamp?

sir_andrew_of_left_coast · Wed Feb 04, 2004 5:32 pm

5751 tubes are a lower gain tube. Whereas 12ax7 tubes have an amplification factor of 100, the 5751 tubes are 70.

Legend has it that SRV used 5751 tubes in the phase inverter position of his Fender amps.

360dave · Post by **360dave** » Thu Feb 05, 2004 10:15 am

Thanks Andrew....I'll play around with them and see what happens.

philco · Post by **philco** » Thu Feb 05, 2004 2:43 pm

My C-J phono amp uses a 5751 in the second stage of gain. I could use a 12AX7 if I wanted more gain, or a 12AY7 if I wanted less. 40, 70, and 100 are the gain factors of the tubes. My spare 5751 tube is an RCA tube, but I think the 5 stars represented a premium grade tube in the GE line.

admin · Post by **admin** » Mon Feb 23, 2004 7:52 am

David: I replaced the 12AX7s with the 5751s in the preamp portion of my Fender Hot Rod Deluxe and was very pleased with the result. The outcome was that of a more vintage tone. The amp does run a little hotter, however.

rictified · Post by **rictified** » Mon Feb 23, 2004 11:58 am

Not positive Peter, but if the 5751's have a mu of 70 vs 100 for 12AX7's your power tubes are probably working harder, do you have the volume knob higher than usual for the same output?

philco · Post by **philco** » Mon Feb 23, 2004 5:25 pm

My Traynor YCV40 has outrageous gain. Setting the volume knob on 2 will blow you out of the room. I think I should investigate using a good set of 5751 tubs the next time around in the #1 and #2 positions. Of course, if you play high gain rock like my brother, the JJ ECC83S tubes will have you grinning like a jackass eating briars.

Peter, I finally upgraded the speaker in my YCV40 with a NOS Celestion G12H80. WHOA, DUDE! That's some speaker!!! Not only is it louder and ballsier than all getout, it changed the YCV40 into a really nice bass practice amp as well. That G12H80 refuses to fart out or sound bad no matter what you do to it. No wonder it was the standard hard rock speaker of the 70's. I never knew an open-backed guitar combo could have such a killer bottom end. I mean, the volume that single 12" can generate on 40 watts will bleed your ears with a guitar, and give you all the bass practice volume you ever need. This is another GREAT combination for the YCV40 owner with a preference for the 70's rock sound.

toneman · Post by **toneman** » Fri Mar 05, 2004 3:25 pm

Philip; Those are great speakers!! They were the staple in most Marshall openback combos from the `70's. Sure wish they make those again.

philco · Post by **philco** » Fri Mar 05, 2004 7:05 pm

Avatar Speakers was closing out the entire inventory that Marshall had stockpiled in England.....for a measly $42 per speaker + $8 S&H. So I got a pair delivered for $100. I'm putting the other one in my Marshall AVT50 combo and installing a Scan-Speak vent and some Acousta-Stuf damping fiber like I did to my AVT20.