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
noromance's avatar
noromance
9,769 posts
 
You can try an in-line attenuator. AR do a mod to change the feedback and lower gain so you might ask them as a last resort. You could also try replacing the 12AX7 tubes to 5751 as they have 70% of the gain. GE black plate triple mica.
georgehifi's avatar
georgehifi
10,312 posts
 
tenoris
Does this affect the signal quality
Yes very much so, as Nelson says below, your throwing away much of the sources output level by turning down the volume of the AR, so the tube gain stage of the AR preamp can make it back up again, which means noise figures are worse, with added distortion.

Perfect reason to go direct if you dac has volume or  just get a good passive.

Nelson Pass,

“We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.”


Cheers George

tenoris OP
15 posts
 
Thank you very much for these answers, they are very useful!
yogiboy's avatar
yogiboy
5,668 posts
 
This Schiit SYS is worth a try. I use one between my CDP and preamp to lower the output and it works great!
https://www.schiit.com/products/sys
georgehifi's avatar
georgehifi
10,312 posts
 
Even better to use the Schiit Sys straight into the amp, if the amps input is 30kohm or higher like the OP's 100kohm A30.

Cheers George
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