Audio Research VS110, VS115?

Hi,

Once again, thank you for all the great insight you provided!

If I were to once again, purchase a D70, how difficult is it, not to mention risky, to bias this amplifier.

You see, the D70MKII I bought years ago, from a friend, had the bias performed on it just prior to me aquiring it. The friend I purchased it from told me as much. He also stated that with average use it would not need to be biased again for quite a while as the tubes were fairly new.

Long story short, I regrettably ended up selling the amp before it needed this sort of attention. This aspect of it I no doubt, found "somewhat intimidating", to say the least. This, in a large way, was probably responsible for its sale.

Please respond,

Many thanks,

Adrian

Adrian, That's a very good question about the biasing of the D70..
Frankly, this is perhaps the only real drawback to the amp. The procedure is NOT for the faint of heart..:0(
I just re-tubed my D70 with rolled in tubes and there was NO way I was going to do the biasing myself. According to the ARC manual it is a procedure that any 'phile can do....BS!! Who ever wrote and thought that at ARC back then,must have been smoking something!! Nonetheless, once my tech had the amp biased, it hasn't wavered since and the sound is to die for. Luckily, i have a couple of very good tech's near me; if that isn't the case for you, then perhaps an auto-biasing ARC amp would be more appropriate. (Although, I think that the sound of these is inferior)

Assuming that you are putting a system together from scratch, you ought to tell us what speakers you intend to use, what your source(s) will be, and what type of sound you have liked or disliked in the past.
That said, I would suggest you call ARC and talk to Calvin. Even though some of the amps you are considering are out of production, you will get honest and knowledgeable advice. I can tell you that the VS115 is going to sound a bit more "authoritative" and extended at both frequency extremes than the VS110, but also a bit more solid-state like (or neutral). The VS110 goes for less than half the price of a used VS115. If you do get a VS110, invest $300 or so for an octet of SED6550s and 6N1P-EBs and bias it down from 65 to 55mv. I had the tech at ARC confirm this is the way to go.

Hi Daveyf and Fsonicsmith,

Thank you so very much for your useful information!

Daveyf, once putting new tubes into the D70 and having it biased, how long, on average, will the amp once again require biasing?

Thanks,

Adrian

Adrian, That is a very difficult question to answer... it probably depends to some extent on the quality of your tubes and the amount of turn on/turn off's that the tube cycles. Also, possibly there is a factor of how much ventilation etc. that the tube sees. In my case, I have had no drift of the bias setting after a couple of hundred hours, but i couldn't tell you how long that will last for.
I think that a more appropriate question would be how much is the typical re-biasing cost for a tech to do the work once the bias has floated or new tubes need to be inserted. That answer probably depends greatly on who is doing the work and again I would suggest asking questions of a nearby tech if you have access to one.