Tubes Asylum

Posted by EdT (i) on August 14, 2001 at 09:04:27

Note: I happened to have many amps over the last
couple weeks. So I thought something like this would be
interesting. This shootout was meant to be fun and to share.
Result is non-scientific, subjective, system dependent,
and relative to the amps used. If it differs from your view,
so be it.

Candidates in this shootout range from a 1958 Scott 299A to a Transcendent
Sound DIY OTL, from a 1.5W SET to a 48W pushpull power house. Shootout
system was made up of a Cambridge Audio transport, a JenaLab 22B DAC, Wireworld
Starlight digital, Silverline Audio vintage interconnect, Stan Warren CAT5
speaker cables, and last but not least, the Silverline Audio Sonatina speakers.

Room: 16x16x20, open upperhalf back, carpeted, furniture, plants, cat

Pack of wolfs:
--------------
Amp 1 - Jeff Korneff Integrated 76/45 (JK)
Custom built based on Bruce Berman 76 preamp and Eric Barbour 45 amp
circuits. Vintage Sansui transformers and UTC chokes. Jensen oil caps.
Tubes: Sylvania 76, RCA VT231 black glass, KenRad/Acturus 45

Amp 2 - Sun Audio SV2A3 (2A3)
On loan from my friend. I converted this into a switchable 2A3/300B
amp. Tamura transformers and chokes. Jensen oil caps. Black Gate WKZ.
Passive Nobel volume control.
Tubes: GE 5U4G, Sylvania brown base 6SN7GT, NOS RCA 2A3
Amp 3 - Sun Audio SV300BE (300B)
Same as above.
Tubes: GE 5U4G, RCA VT231 black glass, AVVT 300B C37

Amp 4 - Scott 299A (299)
Almost all stock, from 1958.
Tubes: Mullard/Amperex 7189, Amperex 6BL8, Mullard 5AR4, Telefunken 12AX7

Amp 5 - Transcendent Sound T8 OTL (T8/T8a)
Custom built by me. Circuit from Transcendent Sound.
Mallory, Sprague elcaps, Hammond/Avel Linberg transformers, Hammond
chokes. Sorry, no boutique parts in this amp. Passive volume control.
Tubes: Svetlana EL509, Yugo 12AX7, Yugo 12AU7 (T8)
Mullard gray plate 12AX7, RCA black plate 12AU7 (T8a)

Amp 6 - Art Audio Concerto Mk II (Art)
On loan from my friend. Stock. Passive volume control.
Tubes: Edicron KT90/III, Jan Philips 12AU7, some German 12AT7

Music used:
-----------
Esther
Belafonte the Complete Concert
Snow Rose (track 1)
Mozart Lieder (track 1-3)
Rob Wasserman Duet (track 2, 9)
Titanic soundtrack (track 10): bass response
Paganini Violin Concerto #1 1st movement: instrument
Rachimaninoff Piano Concerto #2 3rd movement, A theme of Paganini
New World Symphony Eugene Ormandy 3rd/4th movements
Carmen Fantasia Anne Sophie Mutter (track 1, 4)
Mary Black Song from Ireland
Cirque De Soleil "O"

How did they do in a glance: (5 being the best)
------------------------------------------

--------------JK-2A3-300B-299-T8-T8a -Art
------------------------------------------
Highs----------5---4---4---3---2---3---4
Midrange-------5---5---5---3---3---3---4
Presence--------5---5---5---3---3---3---4
Openness-------5---4---4---3---4---4---5
Musical---------5---5---5---3---3---4---4
Relax----------5---4---5---3---4---4---4
Transparency----5---5---5---3---3---4---5
Resolution------5---5---5---3---5---5---5
Air------------5---5---5---3---3---3---4
Soundstage Depth-5---5---5---3---5---5---4
Holographic-----5---4---5---3---5---5---5
Bass Depth------5---4---4---3---5---5---5
Bass Drive-------3---4---4---3---4---4---5
Attack----------4---4---4---3---5---5---5
----------------------------------------------
Total(max 70)----67--63--65--36--54--57--62
----------------------------------------------

Verdict:
--------

Top pick: JK 76/45 crushed all the opponents, single-ended-ly. Very open,
direct, and relax. Strangely that the ultimate bass drive was lacking,
the notes were all there.

2nd pick: Sun shined with the AVVT300B. Relax, polite, airy, intimate.
This may be a better all-around amp than the JK45 for some people.

3rd pick: Art Audio was on par with SET, although was still a notch lower in
midrange and musicality. Very good resolution and air. Tremendous
emotion was shown in the Paganini piece. Bass was the best in the
pack. May sound more scary with better input tubes.

4th pick: Sun 2A3 with the RCA VT231 was too warm and too much bloom. Using the
Sylvania brown base smoothed it out. I still preferred the AVVT300B tubes.

5th pick: T8 OTL with Mullard/RCA driver tubes was definitely smoother and warmer.
While the transistion from midrange to high was more coherent, there was
still a bit of stuffiness. The high although less bright, but
still compress. The presentation was also more emotional and composed.

6th pick: Scott 299A was a very polite amp. It is a great amp in its own right.
However, its weaknesses showed up right the way when compared
to other amps, especially in the transparency and bass department.
I picked this rather than a higher scored amp because it is a
good all-around amp without isolated shortcoming.

7th pick: T8 OTL with Yugo driver tubes was mediocre. While its bass and
soundstage were monster, the rest were not up to the mark.
Midrange was stuffy and veiled, and the highs carried some brightness.