Volume Control Options

[BigHat]

I hope this post is okay for the "General Comments" section. Want to reach the max number of you tech wizards. Last night I set up my second computer audio rig. It's just for listening to music while at the computer. I"m using a HRT Music Streamer II and Dynaudio active speakers, the Sub 250 and the Focus 110As. Of course I'm outputting from my Mac via USB and the HRT has no volume control. Fortunately, the Focus 110As have a -10db cut option, but I still feel a bit uncomfortable about the lack of volume control. Thinking that the Mac can't attenuate the USB output and that it just acts like a std level input. True?

 

So if I can't control the volume via the computer in any way other than the iTunes volume control, is there a fairly sonically clean way to control the volume after it leaves the HRT and before the active monitors that anyone is aware of?

 

Not totally wedded to the HRT either if there's reasonable USB DAC options that might have a volume control.

 

Thanks,

Matt

 

[One and a half]

http://www.computeraudiophile.com/content/Volume-Control-1

 

http://www.computeraudiophile.com/content/Digital-Volume-Control

 

http://www.computeraudiophile.com/content/Volume-here-volume-there-volume-everywhere

 

 

 

Choices :

 

a) Analog

b) Analog

c) Analog (with a Pre-amp)

 

[Audio_ELF]

Various companies produce passive volume controls.

 

TC Electronics Level Pilot is one; Creek Audio another.

 

Eloise

 

[seta]

1) Two types of digital volume controls

1.1) truncate bits - as in iTunes --> no good, you lose resolution

1.2) dithered - as in some software and high-end DACs --> much better, resolution intact with increase noise floor as its downside. Some say this is way better than any analog volume control as there are no analog distortions etc.

 

2) Two types of analog volume controls

2.1) passive volume control - good and mostly with better transparency than active. But dynamic may suffers and rely on DAC or CDP's ability to drive loads.

2.1.1) traditional - resister ladder, pots, etc --> performance depends on quality of component

2.1.2) Light dependent resistors - LDR preamps --> very transparent but may have component matching issues due to impedance variances

2.1.3) Transformer based passive - TVC, AVC --> easier to match, easier for loads, may have high frequency roll-off, transparency depending on quality of transformer

 

2.2) active preamp - dynamic retained, but the most colored of them all, even the best ones.

 

Personally I have tried them all with an open mind. To me, even if they do have more distortion, active tube preamp makes music sound more "real" than anything else out there. With dithered digital volume second, and a passive TVC close third.

 

 

 

[barrows]

simple system, I would suggest using the volume control in Pure Music, with dither. As it appears you can cut the gain at the speakers, you ought to be able to set up the system so that minimum attenuation is needed with the Pure Music (digital) volume control. Additionally, you will get sonic benefits by adding Pure Music, and it is more affordable than any hardware you might add to control volume. Be sure to keep the interconnects from the HRT Streamer to the speakers as short as possible, as the Streamers are a little limited when it comes to driving cables (due to the limits of USB power).

 

[BigHat]

Thank you all for the input. I did a cursory scan and didn't notice the excellent threads (shared above) so appreciate that too.

 

I will look into Pure Music. Use Amarra on my main system with an Ayre DAC, but don't want to spend that type of cash for this system. Using 1 meter interconnects from the HRT to the 250 Sub and 1 meters from that to the 110As. System seems to work great, aside from the subject volume control issue.

 

Again, thank you all for taking the tie to share your expertise. I'll report back on the outcome.

 

Matt

 

 

 

[audioengr]

First, I would stay with Amarra, but download rev 1.2. I think you will like the SQ better. email me for a link. Also, try the EQ function. It is transparent and very helpful. It can transform your system. Just a few dB with Q of around 1 at the right frequency can make all the difference.

 

Second, active preamp or transformer-based passive delivers the best SQ. Active will be very expensive in order to sound transparent, at least $10K IME.

 

If you can find a silver-wound transformer passive, this is by far the best, however it is a good idea to cryo-treat it since there is significant damage to the crystal lattice of the conductors in fabricating these devices. Here are a couple of decent ones, both copper and silver:

 

http://www.stereoknight.com/silverstone%20passive%20preamp.html

 

http://www.mfaudio.co.uk/classic.htm

 

If you need remote volume control, use your iPod Touch or iPhone with Amarra for fine-tuning after setting the volume to a comfortable listening level with the passive linestage.

 

Steve N.

Empirical Audio

 

[C37]

Let us pretend you found a "perfect" attenuator @ the digital level.

 

Zout of music streamer?

Zin of your active speakers?

Lenght of cable? Capacitance /meter of said cables? Using adapter cable unbalanced to balanced? No one has asked these fairly basic yet essential questions.

No wonder however "perfect" digital attenuator you could go, it's going to be a disaster when you add say 5 meters of adapter cables on a feeble output stage.

 

The only "useful" answer i've read in this thread is to get a 10K$ preamp. If you have them, go ahead, i'm sure lots of people will advise you on which one...

 

I had the same problem when wanting to connect my Genelec 1031A's 10 years ago to the variable output of a cd player and found the results lacking.

 

 

 

 

[barrows]

I did comment that he should keep his interconnects to the active speakers short in order to achieve good performance from the HRT Streamer. The OP responded by mentioning that his cables are just a meter in length.

Remember, this is a secondary, desktop system-for most people a $10K+ preamp will be a little bit of overkill in this context (paired with the HRT and Focus 110As). I really think the best approach will be to use the Pure Music volume control, keeping it simple in this desktop system, as the speakers have a course gain adjustment, he should be able to utilize minimal attenuation in the digital realm.

 

[BigHat]

Thanks for weighing in. Have to admit I'm primarily focusing on just getting it useable. It already beats the $160 HK Sound Sticks fed by the sound card in the MacPro I was using. LOL

 

Thinking the software may help, but the problem I worry about is that even with the monitors set to -10db I'm still in the lower half of my iTunes volume control. Just need to sort that out. No question the Amarra or Pure Music is a better volume control. That said though, if I have too much gain, any volume control with limited flexibility doesn't accomplish much in terms of attenuation. Agree a dithering control beats iTunes for quality though.

 

I have about $3.2K in this office computer rig (audio piece) and have that "$10K+ preamp" elsewhere in my house -- I ain't buying another one so I can listen to music while surfing the web. :-)

 

Edit: Barrows commented while I was typing and he hits the nail on the head. A $10K pre-amp with a $350 DAC and fairly modest speakers would seem to be VERY unbalanced in addition to being just plain unaffordable for this role.

 

Going to try a Pure Music (Vinyl) trial as soon as I get home and see what happens.

 

Really appreciate the great info you're all sharing.

 

[C37]

In my experience a buffer (Dact ct 101+ dact attenuator fed by 2x12V sla batteries) trounced a direct connection with 1,5 meters interconnects choosen for their very low capacitance.

Of course if it's to listen to music while surfing - enough said :-)

 

 

 

[Audio_ELF]

Thinking again about your problem, if you need to get the output level down so you have more control with a software volume; have you tried additional fixed attenuators?

 

Various companies make such attenuators including Rothwell and Kimber cables can have attenuation built in. You could also DIY then easily enough.

 

Eloise

 

[C37]

Great suggestion here (just above). Try it out.

 

 

[BigHat]

Downloaded Pure Music and an couple of other software options. Actually ended up shifting my speakers back to flat from minus 10db. Apparently some AC/DC tracks (iTunes library alphabetically) were super hot recordings and that what I was playing with initially as they were right there after loading iTunes. Still in the lower part of the volume control so these better "players" should prove useful. I have a brand new DAC and brand new Dynaudio speakers. If past is prologue, the Dyns take a few hundreds hours to loosen up. No idea about the DAC, but others report improvements after a few hundred hours too. Time to let this system settle in and then tweak as required.

 

Appreciate the scoop on the attenuators and all the earlier advice. Actually, the concept of a cable attenuator is precisely what I think the ideal solution to initial problem would be. They start at -11db though and that's pretty close to the -10db switch position on the speakers so based on the latest experiment don't seem to be required.

 

Anyway, I'm active on a number of sites covering a variety of topics. Just want to note that we have a great group of bright and caring folks here eager to help each other. Great place to be.