advertisement


Very low-level listening and sensitive speakers?

JTC

PFM Villager...
I really like my amp and speakers, but when I want super-quiet background music*, I find that when I turn the volume pot below a certain level my Luxman integrated cuts off rather than having a smooth fade to inaudibility like some other amps I've owned. I am guessing it must be using a fancy resistor ladder type volume pot - is this the LECUA they bang on about? - and, with 93dB/8ohm speakers that seem to sip parsimoniously at the electrons, means I'm getting too much speaker output and am not able to control the volume much down in the sissy-boy end of the pot.

My Mytek DAC outputs XLR balanced into the Luxman, and said DAC already has the attenuation jumpers set internally (though its own internal volume is bypassed). Would switching to RCA Phono as an i/c reduce the output gain and give me more range? I don't have a long enough pair of RCA cables to experiment with, and perhaps that might also degrade the sound? Or should I put up with the possible degradation that might occur if I re-activated the DAC's volume pot?

I'm guessing I can't be the only one to have experienced this with their fancy pants systems? So what did you smarter folks do?

* I know, get a radio or use a phone or something. But, hey, my system still sounds superb at really low levels and I wouldn't really want to compromise that.
 
Would switching to RCA Phono as an i/c reduce the output gain and give me more range? I don't have a long enough pair of RCA cables to experiment with, and perhaps that might also degrade the sound? Or should I put up with the possible degradation that might occur if I re-activated the DAC's volume pot?

Switching to RCA should in theory lower the input level by -6dB but this depends on your amp's input sensitivity on each input. You might, for example, find that your Luxman already attenuates its balanced inputs by -6dB so that when you switch to your other line inputs you don't experience a significant difference in output levels. My A-S3000 has an -6dB attenuator switch for its balanced inputs which I have engaged to do just this.

As for balanced vs unbalanced from a sound quality POV, that's a whole other can of worms. I can only speak from my own experience, which is that my DAC sounds audibly superior through its balanced output, which is why I use the balanced output. This will not be the case for all DACs so I suggest you compare your own DAC's balanced and unbalanced outs and use whatever sounds best.

Another option that might be the best compromise is to reactivate your DAC's volume pot for the occasions when you want to listen quietly? Most modern digital attenuators are pretty transparent if they have enough bit depth for dithering.
 
If your amp has a -20dB muting switch you could also use that for quiet listening. You do however run the risk of LOUD if you accidentally disengage the muting switch! :D
 
Sounds like a perfect application for the attenuator in your DAC - why not use this?
I think JTC is using the internal attenuators but not the internal volume control.
I avoid switching in my DAC internal volume control because of degradation of the sound.
It seems like the only option though if sound is cutting out at low level.
 
I run my DAC via balanced cables into my Luxman which feeds 90dB speakers. I have no problem achieving low listening levels, although it is very low on the volume scale. Using the internal phono stage with about a 0.4mV output MC cartridge I can have the volume control a lot higher for the same volume - so have superior low volume control.

With my previous amps I had a stepped volume control as well but experienced the problem you have now (with the single ended output from the DAC). I tried Rothwell attenuators but decided using the digital attenuation in the DAC sounded better. At those low levels I didn't notice any significant degradation in sound quality from this (but I was never doing any serious listening at such low volumes).
 
I had the opposite problem with a Densen B-250 preamp. I thought it was broken when I kept turning up the volume and heard nothing more than a faint whisper. Then I realised the relay-driven stepped attenuator goes up to 200. Normal level for me was between 120 and 150.
 
If your source is ripped music you could use the digital volume control on your music player to lower the volume, leaving you more useful range on your DAC or amp. Decent music players like JRiver use 64 bit arithmetic with a choice of dithering algorithms. I would have thought it is unlikely that any analogue or DAC based volume control could be as good.
 
I agree with others above- use the digital volume control in the dac to attenuate its output first.

At low levels the preference discussion about which is 'better' becomes a bit moot anyway (noise floor considerations - analogue, and acoustic) - but the digital vol control is likely to offer better channel balance, and likely linearity, than a vol 'pot' right at the low end of travel. Taking the dac output signal down say 20-24dB even 30dB isn't going to harm a thing, but will still leave you with fine/final control on the amp vol control. Very definitely worth a play.
 
  • Like
Reactions: JTC
@JTC : MANUAL Page 13 point 8. User Adjustments
8.1 Reduction the output level

Internal -6db Gain Jumpers: these 4 jumpers allow the user to reduce the output level of the Brooklyn DAC by 6 db without affecting sound quality. All 4 jumpers must be engaged to ensure proper operation and should only be used when the DAC is clearly overloading the following amplifier stage in the chain.

;)
 
@JTC : MANUAL Page 13 point 8. User Adjustments
8.1 Reduction the output level

Internal -6db Gain Jumpers: these 4 jumpers allow the user to reduce the output level of the Brooklyn DAC by 6 db without affecting sound quality. All 4 jumpers must be engaged to ensure proper operation and should only be used when the DAC is clearly overloading the following amplifier stage in the chain.

;)
If you read my original post again, you’ll see that I’ve done that already…
 
Gonna run with volume pot on DAC set to -20dB to see how that works out and whether it changes the SQ in any way…
 


advertisement


Back
Top