From larrys–(at)–ol.com Thu May 16 10:18:43 CDT 1996
Article: 9787 of rec.audio.tubes
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From: larrys–(at)–ol.com (LarrySB)
Newsgroups: rec.audio.tubes
Subject: Review: Svetlana EL34
Date: 15 May 1996 19:01:52 -0400
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I recently purchased a matched quad of Svetlana EL-34 from Antique
Electronic supply in Tempe, Arizona. AES sells the Svetlana for $16.50
each, plus $2.00 for matching labor. They were replacing a set of RAM
EL-34’s, which I beleive were Teslas. I was never happy with that set of
tubes.

I also purchased a pair of NOS 7199, made by RCA but branded and boxed
under the Seeburg name. (Seeburg made jukeboxes, if I am not mistaken).
The NOS 7199 cost $24 each, rather high for a signal tube but a bargain in
today’s market. The Parts Connection is getting $45 each for the same
7199 tube.

The tubes were installed in a good working, essentially stock Dynaco
St-70. This particular example was factory wired. Only minor
modfications have been made, resistors upgraded to mil surplus precision
MF parts, WIMA .15 polypropelene blue film caps and some surplus polyester
yellow body tubulars .047. The stock 82pf and 390pf caps are still in
place. (both test good). Power supply filter uses the original values
(30,20,20,20–(at)–500wvdc) and a GE 5AR4 rectifier with the copper plates.
Bias supply uses a 1n4007 in place of the original selenium unit. It also
uses a 24v zener in the last leg of the divider chain off the control
pots. Input connectors are gold plated teflon units, insulated from the
chassis. The mono switch is removed. Input load resistors were changed
to 270K, to better suit the solid state preamp temporarily being used.

Interconnects are mogami, speaker wire is new JSC OFHC “monster cable”
type, 10AWG. The wire pairs are seperated along the center, and held
together with small plastic spacers every 8 inches. (this dramatically
lowers the capacitance of the cable, an easy and reccomended tweak).
Connectors are simple crimp on terminals on the amps side, and none on the
speaker side.

Speakers are Magnepan SMG, about 8 years old. All original everything.
The speakers have been carefully positioned symmetrical to the listening
position, slightly wider than tangent to an arc drawn from the center.

Signal source is a Magnavox CDB-650, upgraded with a Phillips Crown Chip
D/A and matching digital filter chip. No other significant changes were
made. Signal was drawn from the “extra filtering” outputs.

Volume control was handled by an early Carver C1 preamp (my all tube
homebrew unit is out of commission for the moment.) I also used a passive
control, composed of Pas3 volume pot and a couple of jacks. Guess which
sounded better. .

I inspected the EL34’s, and overall construction appears to be quite good.
Svetlana uses two topside getters, small rivets in the mica supports,
along with spot welded plates and small support fingers to the glass
envelope. Bases are applied with a good bit light brown glue (epoxy?).
Bases are black, numbered and pins are nicely soldered. This tube is a
true pentode, with a suppressor grid rather than beam forming elements.
There is a large red painted “S” symbol on the side, and “EL34 made in
Russia” in small gold letters.

AES matched the tubes as a quad, and conveniently wrote the matching
numbers on an inside flap of the box. I paired them by the closest
numbers. The tubes biased up nicely, well within the expected range for
EL34. The tubes warmed up in about a minute, drifted slightly for the
next 30 minutes when I re-biased them again. The bias held rock-steady
for hours afterward.

These tubes sound very good, with an extremely detailed and focused middle
range, enhancing the stereo image. The high end was bit splashy, but
fairly well controlled. Bass was strong, but a tad flabby – probably due
to the lack of capacitance in the stock ST70 power supply. I strongly
suspect a larger reservoir will tighten this up tremendously.

Overall, I would describe the sound as “etchy.” Details really came
through, clearly. Even minute details become well defined.

Listening material:

Mulligan Meets Monk (a favorite of mine)
Wonderful tone on the barri-sax. Got a nice dose of reed “raspiness” that
makes it sound like it is in the room with you. Piano was well focused
and controlled. Bass was a little fuzzy, kick drum was right on and
palpable. This recording a has a peculiar doubling on the high hat, so
that it sounds from two places in the image.

The mono tracks were very crisp, and sharply focused. Mono is a great
test for your stereo image, just like grey scale is for testing a color
monitor or printout. Everything should appear focused along the center of
your listening space. If it isn’t, you know something is out of kilter.

Buddy Guy and Junior Wells, Alone and Acoustic (alligator CD)
Yeah! The thin woody sound of Buddy Guy’s Guild acoustic come through
loud and clear. Vocals were natural and clean, very expressive. The
reverb effect shimmered around the listening room.

Dave Brubeck’s Out of Time
Take Five’s left channel high-hat was prominent, sweet, well defined. All
the sizzle it should have, and a good strong “tack” with the strike of a
the stick. Instrument positioning was well defined, and three dimensional.

Stevie Ray Vaughan, “The Sky Is Crying”
Stevie’s gritty, dark tone came through nicely, especially on Wham. It
really sounded like the amp was in the room, burnin away! Every little
bit of edge was there. Bass response was nice and clean on this one too,
but a tad loose.

I’d say these were some of the best EL-34s I’ve had in a long time. I
highly reccomend these. I wish I had a guitar amp handy to try them in as
well. But, as good as they sound in a ST-70, I’d be willing to bet they
sound great in any amp. AES is a great place to get them, good price and a
good enough job matching them. These tubes are available from other
matching/testing providers if you are so inclined.

Cheers,


Dr. Nuketopia
Technology Director of the World-Wide Monetary Conspiracy
All opinions strictly reflect the party line

 

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