Moreplay Volume Pot- different power amps

[scipio31975]

I recently completed the Moreplay kit. I am quite pleased with it. I bought the combo Moreplay + S.E.X. 4 and I completed the Moreplay first.

Prior to hooking the Moreplay up to the S.E.X. 4, I had it in front of an NAD C 3050 integrated hybrid amp by bypassing the pre amp stage of the NAD and plugging the Moreplay directly into the power amp portion. These were driving Zu Audio DW6 loudspeakers.

With the NAD, the usable range of the volume pot was the first about 1/3 of its rotation. It was very sensitive in that first 1/3, almost difficult to adjust incrementally, and then it would not increase the volume meaningfully for a ways and then it just sounded bad as it reached what was clearly some limit of power or speaker capability.

Once I had the S.E.X. 4 completed and hooked up, the volume pot became much more linear in its sweep from top to bottom. Certainly, above a certain point of the total rotation, the sound being created was becoming distorted, but the useful range of the volume pot was much more in line with how I would expect it to work- steadily increasing the volume in a linear way as the knob was rotated.

Clearly, nothing changed with the Moreplay. So the difference is somehow in the two power amps.

Was this something to do with the architecture of the NAD when bypassing the pre amp section? Or was this something to do with overall power? Or the class of power? Or the speakers?

Not that it is likely to matter as the NAD is going to be moved to a different system. But I’d sure like to understand what caused such a noticeable difference if anyone knows.

 

[Paul Joppa]

The NAD is a high-gain, powerful amp (100 watts from 540 millivolts) designed to handle the worst-case low-output source and low-efficiency speakers (like 82dB). You have very efficient speakers (rated 96dB). That's a classic conundrum for SET users.; the system has way too much gain for us. The NAD will put out 4 watts with a tenth of a volt input.

 

[scipio31975]

The NAD is a high-gain, powerful amp (100 watts from 540 millivolts) designed to handle the worst-case low-output source and low-efficiency speakers (like 82dB). You have very efficient speakers (rated 96dB). That's a classic conundrum for SET users.; the system has way too much gain for us. The NAD will put out 4 watts with a tenth of a

This makes sense to me. I guess I had never really experienced truly incompatible components before, but this is an example of that. I’ve certainly read about it, but this was a very tangible example of that. Thanks Paul.