2. amps-preamps
  3. 159398-150061

AR SP8 mk2 high output volume

Hello everyone, thank you for accepting me in this group. I have my AR  SP 8 mk2 preamplifier and I would like to know your opinion and if you consider its high output volume a problem with this power amp. Problem is the volume control is too low,  Very sensitive amp. I can't use much volume control.Does this affect the signal quality or is it just a drawback?I just want to know if it's something I need to worry about.

here I put the specifications of the power amp Puresound A30
ower output (Class A operation) 30 Watts/ch Ultra Linear, 18 Watts/ch Triode Coupled
Frequency Response 20Hz - 20kHz -0.25 to -0.3 dB
THD 0,3%
Input Impedance 100 KOhm
S/N ratio 88 dB
Input sensitivity for 0dB 100 mV
Power Consumption 260 Watts
Net Weight 28 Kg
Dimensions (mm) 436 W x 360 D x 190 H
Inputs 3. Line Level
Outputs 4 & 8 Ohm
tenoris
tenoris OP
15 posts
 
in fact I made that query, and it was not me who began to question about the possible degradation of the signal because we are talking about an integrated amplifier. I think is you who does not mind looking at what is said here, because here more things are being said than what you say.

I just received a direct response from the creator of the A30 Guy Sergeant, who had asked this question about the signal degradation when you use the potentiometer of the device as a power amp.

This is what he said:

If you use the potentiometer at full or nearly full that effectively takes it out of circuit. It presents a high resistance (100 Kohm) so the signal takes the easier path into the amplfier itself.


georgehifi's avatar
georgehifi
10,312 posts
 
I would like to know your opinion and if you consider its high output volume a problem with this power amp. AR SP 8 mk2 Problem is the volume control is too low, Very sensitive amp. I can’t use much volume control.Does this affect the signal quality.
This is what you asked, you’ve been told, now your making everyone dizzy.
tenoris OP
15 posts
 
Have they told me? Yes, there have been different opinions and arguments, all very valuable. You had your answer and others theirs. But I’m not going to apologize for this ...... it’s a forum DISCUSSION.. if you feel dizzy stop following.
georgehifi's avatar
georgehifi
10,312 posts
 

Whatever, Ralph's told you as well, you can see the forest for the trees, and not worth the effort.
atmasphere's avatar
atmasphere
11,803 posts
 
Good to know the A30 volume pot does not degrade the signal when set lower than full. I learned something.
@audite84  The volume control is a 100K device. Combined with the input capacitance of the voltage amplifier tubes (which are essentially 6SN7s) there will be a high frequency rolloff. This is called Miller Effect. But in this case the values have been chosen well so that the rolloff is occurring well outside the audio band. The worst area of rolloff is typically around the middle of the control range; on paper at least its affecting things around 90KHz and above.
More to discover