I purchased this pair as kits in 2007. They have the only original option, XLR balanced inputs in addition to the unbalanced RCA inputs. This goes through a transformer, and this makes possible the second RCA input, which also goes through the transformer to provide a floating unbalanced input as a way to avoid ground loops. I have used these amps in a few different situations, and have always found this floating unbalanced input to be better for lowest noise.
There were many parts upgrades during original construction: better diodes, better caps (Nichicon, Relcap. Black Gate, Clarity). Most caps were fitted with bypass caps. There are caps added at the IEC jack for some line filtering. There is a grounded strip of ERS material around the IEC jack, and most of the way around the inside of the chassis. The power switch is now on the rear near the IEC jack.
I have fitted the amps with Sovtek 12AX7LPS (two new ones included), Psavane 12AT7T (two slightly used of the same plus one new EH 12AT7WC included), and EH 12BH7A (one used, plus two unmatched Sylvania 12BH7A included). The main fuses are Hi-Fi tuning ones (some standard manufacture spares included). The tube fault fuses are standard manufacture 1 amp (some spares included). A main fuse has never blown. The tube fault fuses seem to have done their correct function, but were not effective when one of the output tubes developed an internal short from pin 4 to pin 5. By the time I found the problem, some 5 watt resistors had sacrificed themselves. I replaced them, and all is now OK (some more of these resistors included).
I have recently been using these amps with only the middle 8 output tubes in place, for 60 watts in to 8 ohm speakers.
Asking $4,800.00. Shipping weight will probably be 80-90 pounds, in 3 boxes, from ZIP 18661.
Thanks for looking.
