Stepped Attenuator to replace Potentiometer.


Hello: We have a set of Wolcott Monoblocks, for which I am researching replacing the volume pots with something like a DACT stepped attenuator for each mono block. The problem is that I can not seem to find a compatible attenuator that could replace the stock 25 meg ohm pots.

The circuitry is point-to-point wiring, powering eight 6ca7, two 6dw8, and two 12at7 tubes per side. It might be more of a hassle to mess with getting around the stock pots to substitute attenuators; however, I'm not an engineer and would therefore appreciate your informative advice and suggestions. Thank you.
somut
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.
Just to confuse you some more...

IAG used to carry Sowter based mono TVC attenuators. Input impedance was way off at 30K but offers galvanic isolation and conversion between balanced/SE. Impedance can be raised with series resistors, on each leg if balanced, but I'm not sure how that would affect the range.

Is it safe to assume, from the vintage, that it is single-ended?
The amps are not single-ended; they are push-pull at about 225W per side, each side using eight 6CA7's.