Volume Adjustment

Thanks for the answers !  The volume control knob is smooth as silk and no crackling or popping. ( I have that issue on a MA-6500 I bought about 7 years ago and for which I just bought a can of Deoxit D5 but have not applied yet. Opening up the case was cake. Just a little hesitant on using the spray.)

And, yes, the Trim Controls work great and there are .5 db increases/decreases to Input Trim and 1.0 db increase/decrease for treble and bass which seem to be on target. 

SO . . duh . . the iPhone in my hand has a built spl app.  I will test 52 vs 53 volume setting and report back.  Problem will be I don’t have a sound source that is steady and a regular CD will have built in volume fluctuations.  Maybe I can find a volume test signal tone on Spotify. We shall see.  Over. 

Okay . . . found CD Test track on Spotify (something like decibel.org from Amazon for free).

Used a 1,000 hertz test tone and it appeared that each Volume increase from 52 to 53 to 54 increased the volume by 3 dbs. 

So am guessing the MA-252, not being a high priced amplifier with a large volume knob like those on a Pass Labs amp, had compromised volume adjustment to about 3 db per volume control display. 

 Makes me recall what my Dad would say, “Poor people got poor ways.”

Uncle.  Over and out ! 

Ask Mac I seriously doubt the 3db step in right…. 

Also w test tones and a decent SPL meter you are ahead of many here….. 

The McIntosh MA252 does not use an old-style rheostat for volume control. Instead, its electronic attenuation system (reflected in the volume display) follows a logarithmic attenuation curve. As a result, the volume increase per step is not uniform; in some regions, each step may represent a larger change than in others.

It is quite possible that the 52–53 transition crosses one of these regions where the attenuation curve changes slope. My Cambridge Audio Azur 851A integrated amplifier has a similar type of volume control behavior, and I can also notice a slight jump at certain points on the dial.

On my system, the jump is noticeable but still within expectations. If you feel the step change is unusually large compared to normal behavior, it may be worth raising the question with McIntosh for confirmation.