Clipped output in 2235B at about 75 percent volume.

[Grenadablues]

I recently acquired this receiver which was dusty but otherwise functional. No appearance of any service performed. I cleaned the unit internally and Deoxed the pots and switches. Under power the unit has a minor 60 Hz hum on the phono inputs but the aux in is quiet. Those are the only two inputs I have worked with to this point.

Regardless of input, the unit clips when the volume is taken to about 75 percent or greater. I would appreciate opinions on this clip and/or hum. My thoughts are the hum may be due to a poor ground (which I have not addressed so far). OR the hum and clip might be due to weak failed caps on the power supply. I am not using this unit other than to test.

I would like to return this unit to use as I like the look and that Marantz sound i remember from others I have heard years ago. This is my first Matantz. I plan to recap the power supply at least and will likely follow up with the phono input board.

Any comments are appreciated and I will post any results.

 

[Steven Tate]

75% volume sounds about right for where clipping might begin. Did you have speakers hooked up? If so, I would think the volume would be ear splitting by then.

 

[catrafter]

The last 2235B I worked on clipped at about 45W into 8Ω dummy loads.
The volume knob position is relative to the input signal level which is unknown in this case.

Tom

 

[bryans12v]

Using a sine wave, I would actually measure the VAC across the load or calculate your Vpp to determine exactly when clipping occurs. Odds are the volume pot is prob close to wide open at that point.

 

[bryans12v]

Are you getting any crossover distortion at zero crossing when this occurs?

 

[Grenadablues]

Using a sine wave, I would actually measure the VAC across the load or calculate your Vpp to determine exactly when clipping occurs. Odds are the volume pot is prob close to wide open at that point.

I do not have a freq. generator but can probably get s decent 1khz with a phone. I will see what I can do.
Many thanks for the comments.
Barry

 

[Grenadablues]

Are you getting any crossover distortion at zero crossing when this occurs?

Not sure what you mean here. The distortion is across both channels.
Barry