VAC Renaissance 70/70 - Manual (Page 11)

9
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 ofthis 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. Successor to the earlier Golden Dragon series. 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.