GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Melquiades Amplifier
In the Thread: The short "6C33C Survival Guide".

Post Subject: Also, a few wood about the AudioValve heat design.Posted by Romy the Cat on: 8/21/2009

I understand that AudioValve would like to keep their generic chasses for all their models but I think what they did with Assistant 100 amp is very wrong in term of chasses architecture. They claim the “special familiarity with 6C33C” but it is not what I see and sine it is a new amp and not one has it I would like to warn people about the faulty (in my view) design decision the AudioValve took.

Take a look the 4 6C33C clustered VERY close together on the circuit board. The meters are grades up to 500mV, that I am sure are mA of B+. So, they do drive the 6C33C very hot. The 4 sitting together 6C33C even at 60W on plate produce tremendous amount of heat. 240W on plate + 12.6x3.5x4 = 176W. So, we have 420W only from output stage that is concentrated in very narrow spade – almost a chimney. I have seen that a single 6C33C in enclosed space burns 120 degree capacitors from 3 inches. My Melquiades has 3 6C33C, two of them run with half-heaters; it has 4 time larger chasses then AudioValve, no power supplies and the tubes outside. Still, if I shut down the forced cooling then after 3-4 hours the amp gets uncomfortably hot. The AudioValve has 4 6C33C sitting INSIDER and no signed of forced air as there are no holes drilled through the circuit board. Those parts that are between the tubes will be burn soon on later; I put all money in my pocket to bet on it.

The only justification might be that they run the amp in some kind of tricky B or C class and PP where in idle mode they dissipate not a lot of power on plate. Well, if so then I do not think it shall sound right … I hope it is a parallel SET and if so then they must advertise is as a …toaster.

The Cat

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