biamping with a arc 150.2 and vtl mb125

Hi Sy,

I recall from your other thread a couple of months ago that you are using Ascendo C7 speakers. I wasn't able to find detailed information about their impedance vs. frequency characteristics, just that they have a nominal impedance rating of 6 ohms.

The VTL amp has a specified output impedance of 1.6 ohms, which is high to the extent that I would expect its sonic character to vary significantly as a function of the impedance vs. frequency characteristics of the particular speaker. Therefore I don't think it is possible to predict how well its sonic character will match that of the ARC amp without experience using those amps on your particular speakers.

Also, according to my calculations there is likely to be a gain mismatch of a few db between the two amps, in the direction of the gain of the VTL's being greater. Especially if they are used in the higher powered tetrode mode.

Best regards,
-- Al

Hi Sy,

That could be true, but I'm not sure.

Everything else being equal, a balanced interface will provide 6db greater gain than an unbalanced one, because the balanced input responds to the difference between two equal and opposite signal polarities, rather than to the difference between one of those polarities and ground (0 volts).

However, I'm not sure if that fact is or is not already "built into" the spec for the 150.2 which indicates identical 1.4 volt sensitivity and 27 db gain numbers for both the balanced and unbalanced inputs.

Best regards,
-- Al

Hi Sy,

My instinct would be "no," given that you don't have a means of trying it out which is both convenient and without obligation. There are too many variables, unknowns, and causes for concern.

I would suggest not bi-amping and simply buying a more powerful amplifier, and waiting however long it takes to find a buyer for the VTL's. At only $1600 a buyer certainly figures to be forthcoming eventually.

Best regards,
-- Al