Stereomour !! Shunt Reg; What the....!

[oztayls]

I added the Shunt Regulator kit on the weekend. It's a nice easy build with a low parts count. Like the main build, I took the the time to review every step in the manual and to check all the solder joints with a magnifier. I think it's a very worthwhile step to do as I caught an error in the main build that would have resulted in some diagnosing.

I must have been somewhat fatigued when we fired it up as it sounded pretty much the same as before. It was more of a test really, than a listening session. Then on Monday evening we settled down with a nice bottle of Hunter Valley Syrah for some listening. My God, what happened overnight?! This thing has gone to a place I could only describe as stratospheric! Output is higher as we are on just under 12 o'clock on volume control instead of the 1 o'clock we had before. To say we are happy with our S-II, or should I say S-!!, is an understatement. This amp is insanely good.

Now I have a question. Because we have fairly sensitive speakers (vintage Leak Sandwich and Mini Sandwich), I opted to get the DC Filament Supply kit at the same time as the S-!! kit. However, we have not experienced any hum from them, so what should I do, install the kit anyway, or just leave well alone? Will it still be of benefit anyway? I'm interested in what others have experienced after adding the Filament supply mod.

[2wo]

For me with a range of speakers from 97 on down, I find 2.5V tubes, 2A3, 45 are plenty quiet run on AC. When I get to 5V, 300b, the hum becomes intrusive.

I would sit back and enjoy the music and if something changes, you have the kit in your back pocket...John

[oztayls]

OK, that makes sense to me. Thank you!

[Paul Joppa]

There is a theoretical reason for DC heating, which is that hum intermodulates with the music signal, and is measureable. But I can't say that I've seen much sign on the internet that it's audible, if the hum itself is inaudible.

[oztayls]

There is a theoretical reason for DC heating, which is that hum intermodulates with the music signal, and is measureable. But I can't say that I've seen much sign on the internet that it's audible, if the hum itself is inaudible.

I guess I could take the hippocratic approach of "do no harm" and have a fully loaded Stereomour II.