VAC Renaissance 30/70 - Manual (Page 8)

6
TIPS & ADVICE
A Word About Output Tubes
Your VAC Amplifier uses the 300B or 300A filamentary triode. It is strongly recommended that replacement tubes be
purchased only from VAC, as stated in the Safety Notice at the front of this manual. If, however, you want to customize
the sound to your tastes, be aware that as with interconnects and speaker cables, each tube manufacturer's 300B tends
to have a distinct sound. Here is a brief summary of our experiences with currently available tubes from different
sources.
Western Electric 300B (U.S.):
The original and definitive manufacturer. This tube was made by WECo through 1989. Older production (pre-
1980) is preferable to later production and is heartily recommended. World wide supply is limited. Be
careful...used tubes and WECo rejects have been seen on the market at premium prices. The sound is somewhat
midrangey, with soft bass and treble. Similar: Western Electric 300A (U.S.), the initial WECo production code,
differs from the 300B in the shape of its bulb and the location of the bayonet locator pin - very rare.
VAC Tested 4-300B:
A new version of the 300B designed in Great Britain and manufactured in China. A very good tube, more open
and detailed than the WECo. Current production, our preferred tube, highly recommended.
Cetron 300B (U.S.):
A bit buzzy in sound, a bit more prone to microphony than the WECo or VAC. Some arcing may be observed
at turn-on.
Sovtek (Russia):
Made by the Reflector factory in Saratov. Not recommended. Not reliable under the VAC operating conditions.
Svetlana (Russia):
Rather hard and airless sound.
JJ / Tesla (Slovakia):
Somewhat hard and airless sound, a bit buzzy in the midrange. Some arcing at turn-on. Excessive input
capacitance.
Vaic:
Many versions produced, may sound good in some systems. Be certain that the version you use conforms to the
WECo 300B standard for filament current (1.5A) or amplifier damage may result.
KR Enterprises:
Many versions produced, most deviant from 300B standards. Be certain that the version you use conforms to
the WECo 300B standard for filament current (1.5A) or amplifier damage may result.
The Japanese publication MJ Audio Technology (Footnote 5) compared 300B from WECo, Golden Dragon (China), and
Cetron, concluding that the WECo and Golden Dragon were comparable and superb in performance.
Please note that firms such as Gold Aero, RAM, and Penta do not design or manufacture their own 300B tubes. Various
US companies marketed 300B tubes during the 1950's. Not much is known about their quality.