Stepped Attenuator to replace Potentiometer.

Try Shallco.. http://www.shallco.com/attenuators.html

Thanks for the responses. I have not contacted Henry Wolcott as of yet; he and Mr. Lomax are quite busy (great, knowledgeable gentlemen by the way!), so I might first try the technician who knows these amps well enough to wrestle with their intricacies and quirks. Eldartford, I went to the DACT website and they offer the reknown CT-2 Attenuator, with the greatest resistance rating at 500kOhm. Given the gain pot on these monos indicates 25 meg Ohm -- and if my calculations are on track -- do you mean I would need to increase resistance by 50 Ohm were I to get the 500kOhm Attenuator? I'm not an engineer, so I just want to clarify.

I called Shallco and await response on an attenuator with a closer if not equal impedance match. You guys sure seem to know your stuff: Thank you for your informative suggestions, and long live audio engineering in advancing the Arts & Sciences.

Somut...You better check on the resistance of that pot. 25 megohms is far higher than any audio gain pot I have seen. I could believe 25 Kohms, although that would be a bit low.

Marchand can make custom attenuators. More expensive than DACT but at least worth an email. The DACT is series, as opposed to ladder, if I remember correctly. Size might be an issue as well. Goldpoint could be another option (goldpt.com). I have never seen anything over 100K but it might be possible with a shunt. What wattage are we talking about here? And what range? Is it possible to get a meter on it? Powered off, of course.

Good evening to all. Pardon the misperception: I just zoomed in on the gain pot of each monoblock and I saw a faint "." stamp followed by a space in "OHMITE TYPE-AB 0. 25 MEG OHM." Apparently, this means I could substitute a 250kOhm resistance attenuator. Please correct me if I'm wrong, as I was with the previous calculation above. Thanks gentlemen.