[AmpDesigner333]

What are your power supplies?

Maraschino Cherry Amps: 48V or 60V
DAC DAC: 12V

[audioengr]

I'm going to throw in my experience with digital volume controls.  The best one I have found is with Amarra.  Very transparent, provided that you only attenuate less than 10dB.  With more than 10dB attenuation I have heard distortion with all digital volumes, at least with my highly resolving system.  In most systems 10dB is insufficient, therefore when I have used it I also used another analog attenuator or similar at the same time.

At shows for instance, mostly for convenience, I used a digital volume control only after reducing the volume with my DAC volume, which is exactly like directly connecting the line outs to the amps.  This way I can provide a good level for all tracks without exceeding -10dB on the digital volume. 

My DAC volume control is unique in the industry because it uses no attenuator, gain control or decimation.

Steve N.
Empirical Audio

[mojave]

JRiver has a 64-bit volume control????
http://wiki.jriver.com/index.php/Volume

Seems overkill, but maybe they just do everything with 64-bit resolution anyway.

Can anyone verify this?

The internal DSP path of JRiver is 64-bit floating point on their Windows, MAC, and Linux versions. This ensures that all DSP is done with maximum precision. However, the bit-depth of your DAC chips determines the final output.

JRiver has two dither methods available for the highest quality output and volume control. The default method is what they call JRiver Bit-Exact and ensures that any conversion to 64-bit and back to the DAC bitdepth, without any DSP, is completely bit-perfect. You can also use Triangular Probability Density Function (TPDF) dithering. If you compare both with an oscilloscope, you will see that TPDF has lower noise overall and pushes the noise above the audible bandwidth.

Most DAC's with an ASIO driver will request the data as 32-bits even though the final output may be 24-bit. This is because ASIO requires a 32-bit pipeline to be open to the audio device. To deal with this, JRiver allows one to specify the bit-depth of the final DAC chip. If the final output is 24-bit, JRiver will dither to 24-bits and pad the output to 32-bits to comply with the ASIO requirement. Other software will dither to 32-bit and the DAC will truncate to 24-bit and you get reports of digital volume control not sounding that great.

So, with JRiver all volume control is done at 64-bits and dithered to either 24 or 32-bits for output. This means that you can use volume control with a 24-bit DAC and use up to -60 dB of attenuation without any audible artifacts. With a 32-bit DAC you get more attenuation than is ever necessary.

With Maraschino Cherry amps and high efficiency JTR Speakers, it was demonstrated at RMAF last year (24-bit) and this year (32-bit) that digital volume control is implemented in such a way in JRiver that it is completely lossless even for 24-bit. When you playback in a range of over 100 dB at the show (maximum around 132 dB), it gives the listeners the opportunity to notice any audible artifacts.

[AmpDesigner333]

I'm going to throw in my experience with digital volume controls.  The best one I have found is with Amarra.  Very transparent, provided that you only attenuate less than 10dB.  With more than 10dB attenuation I have heard distortion with all digital volumes, at least with my highly resolving system.  In most systems 10dB is insufficient, therefore when I have used it I also used another analog attenuator or similar at the same time.

At shows for instance, mostly for convenience, I used a digital volume control only after reducing the volume with my DAC volume, which is exactly like directly connecting the line outs to the amps.  This way I can provide a good level for all tracks without exceeding -10dB on the digital volume. 

My DAC volume control is unique in the industry because it uses no attenuator, gain control or decimation.

Steve N.
Empirical Audio

Steve,

I guess results vary a lot system-to-system.  I've had "way beyond very good" results with digital volume control on both the systems described at the beginning of this thread, and other setups, even when attenuated heavily in a very quiet room, medium efficiency speakers.  With DAC DAC, listeners are also experiencing excellent results with digital volume control on a variety of speakers/amps.

The upcoming MINT amplifier has a volume control, and I've actually experienced better results with the TL version of DAC DAC driving the MINT with the volume digitally attenuated and the MINT's volume at full blast.  When the opposite is true, distortion is measurably higher, and you can definitely hear the difference.  Another point (don't remember seeing it on this thread before) is that the gain of the rest of the system must be set correctly for this to work.  I'm typically driving Maraschino Cherry monoblocks, and they have relatively low gain (22dB), and the DAC DAC is designed to provide full scale output of 4.5Vrms.  When you do the math, this allows the DAC to drive the amps a few dB into clipping, even with the 60V power supply.  The MINT has slightly higher gain (24dB) with the volume all the way up, so the DAC can send it farther into clipping.  Either way, the background is super quiet because the DAC DAC's SNR is better than 120dB (both versions).  Add a preamp, and you know....

Are you familiar with the ESS volume control in their D/A chips?  What do you think of their chips versus TI/BB and others?

Thanks for your post.

-Tommy O

[AmpDesigner333]

The internal DSP path of JRiver is 64-bit floating point on their Windows, MAC, and Linux versions. This ensures that all DSP is done with maximum precision. However, the bit-depth of your DAC chips determines the final output.

JRiver has two dither methods available for the highest quality output and volume control. The default method is what they call JRiver Bit-Exact and ensures that any conversion to 64-bit and back to the DAC bitdepth, without any DSP, is completely bit-perfect. You can also use Triangular Probability Density Function (TPDF) dithering. If you compare both with an oscilloscope, you will see that TPDF has lower noise overall and pushes the noise above the audible bandwidth.

Most DAC's with an ASIO driver will request the data as 32-bits even though the final output may be 24-bit. This is because ASIO requires a 32-bit pipeline to be open to the audio device. To deal with this, JRiver allows one to specify the bit-depth of the final DAC chip. If the final output is 24-bit, JRiver will dither to 24-bits and pad the output to 32-bits to comply with the ASIO requirement. Other software will dither to 32-bit and the DAC will truncate to 24-bit and you get reports of digital volume control not sounding that great.

So, with JRiver all volume control is done at 64-bits and dithered to either 24 or 32-bits for output. This means that you can use volume control with a 24-bit DAC and use up to -60 dB of attenuation without any audible artifacts. With a 32-bit DAC you get more attenuation than is ever necessary.

With Maraschino Cherry amps and high efficiency JTR Speakers, it was demonstrated at RMAF last year (24-bit) and this year (32-bit) that digital volume control is implemented in such a way in JRiver that it is completely lossless even for 24-bit. When you playback in a range of over 100 dB at the show (maximum around 132 dB), it gives the listeners the opportunity to notice any audible artifacts.

Very impressive.  I especially like your numerical explanation.  Looks like JRiver has done their homework!  Thanks for your post.

[audioengr]

Steve,

I guess results vary a lot system-to-system.  I've had "way beyond very good" results with digital volume control on both the systems described at the beginning of this thread, and other setups, even when attenuated heavily in a very quiet room, medium efficiency speakers.  With DAC DAC, listeners are also experiencing excellent results with digital volume control on a variety of speakers/amps.

The upcoming MINT amplifier has a volume control, and I've actually experienced better results with the TL version of DAC DAC driving the MINT with the volume digitally attenuated and the MINT's volume at full blast.  When the opposite is true, distortion is measurably higher, and you can definitely hear the difference.  Another point (don't remember seeing it on this thread before) is that the gain of the rest of the system must be set correctly for this to work.  I'm typically driving Maraschino Cherry monoblocks, and they have relatively low gain (22dB), and the DAC DAC is designed to provide full scale output of 4.5Vrms.  When you do the math, this allows the DAC to drive the amps a few dB into clipping, even with the 60V power supply.  The MINT has slightly higher gain (24dB) with the volume all the way up, so the DAC can send it farther into clipping.  Either way, the background is super quiet because the DAC DAC's SNR is better than 120dB (both versions).  Add a preamp, and you know....

Are you familiar with the ESS volume control in their D/A chips?  What do you think of their chips versus TI/BB and others?

Thanks for your post.

-Tommy O

Tommy - I guess the operative term is "compared to what?".  Most preamps add a lot of coloration, particularly active ones.  Even the passive ones can impact the dynamics of the amps by not providing enough current or inserting so much resistance that the cables become low-pass filters.  When most folks replace a preamp with digital volume, there is a huge improvement, I'm not arguing with that.

My system allows me to compare a "naked" system with no decimation and no preamp to a digital volume control and I find that software digital volumes color the sound after about -10dB.  That is my experience.  Most folks don't have this kind of comparison available to them.

As for Sabre chipsets, I have modded a number of DACs with these in the past.  I modded stuff for almost 10 years before designing my own products.  There is no path in Sabre without their reclocking circuitry involved, and I have issue with this.  Comparing the SQ to other D/A chips, I find them to be good but not better.  I have compared my own DAC to the W4S DAC2 and the PS Audio, both driven with low-jitter S/PDIF and HDMI I2S.  I have never tried the Sabre volume control.  I have a distrust of digital volume because a failure can easily blow up speaker drivers.

BTW, comparing D/A chips is not easy.  One must have a "level playing field" to properly do this, which means that the power delivery to the chip must not be a limited in any way and the digital feed to the chip must have the same jitter for all comparisons.  Even the I/V conversion and output driver must be identical or its not apples-to-apples.

BTW, I have also compared PC and Mac versions of Jriver to Amarra using USB output.  Amarra (the specific version that I use) edges it out every time.  I will be using Jriver probably more in the future with my Ethernet interfaces.

Steve N.

[SteveMiller]

HI Steve,

Respectfully, my experience differs somewhat.  I have enjoyed the BelCanto DAC 3.5VB for a time, than and for much longer and much happier listening I used the W4S Dac2 and Dac2DSDSE....   The W4S Sabre throttled volume control was very good, and any losses it might have suffered at full attenuation were well below the sensitivity of my speakers.  In short, at regular listening levels and at a displayed volume level that according to some W4S literature was lossless certainly sounded so. In my system.   Now, to be clear that was with DAC Maraschino's being driven direct.  With a previous large and expensive amplifier, the W4S could not drive the amp sufficiently by itself.  In that system I needed a pre-amp as without it the dac-direct model sounded thin at anything less than full levels.  Same advertised gain structure and overall similar levels in room.  So I think that there are a lot of variables at work here. Input and gain stages and self noise at each component along the way.

I want to be clear that what Tommy advocates for applies and is true with his components. I have heard the same results with his devices in my listening room.  AND in the experience I have, the DACDAC/Maraschino combo makes for a very affordable VERY high-end system.  Any talk of distortion, loss, or other issues evaporates when you hear this pair as Tommy intended. 

Try this at home.  Using a dead simple iTunes interface.  Turn the volume down as far as iTunes allows and with your own dac directly connected to your amps, do you still have good clean wiry bass? Does your system still layer and image in front and behind and beyond the outer edges of the speaker baffles. Do you still find the music involving, the lyrics engaging. Can you tell the emotional intent of the performance.  This is what I hear, when iTunes is completely throttled down. No special software.  But the noisefloor of the dac and amps is sooo good in the Digital Amplifier Company equipment that even at these extremely lower  than normal listening levels its still very satisfying.

Lets be honest, iTunes is not the be all end all player.  And I previously couldn't stand it played into my W4S product. I had a memory player with better results.  But now when I plumb iTunes through a Halide Bridge usb>spdif convertor into DACDAC.... all is wonderful.  That's why even though I know what I am hearing I am still a little gobsmacked that something so simple can sound so good.

For those who want an analog volume control as good as these components are please see AudioZone in Toronto. Pre-T2 is the balanced xlr version of their very very good TVC.  Its better than a several thrice priced solid state and passives.  The only pre-amp I ever had that got completely out of the way. just my findings, hopefully might save others some time and money.
 

[audioengr]

Steve - we are all at different levels in our personal audio evolution.  One mans excellent is anothers mediocre. I have no doubts that the amps are excellent.  Its the source that I have doubts about.

Try this at home.  Using a dead simple iTunes interface.  Turn the volume down as far as iTunes allows and with your own dac directly connected to your amps, do you still have good clean wiry bass? Does your system still layer and image in front and behind and beyond the outer edges of the speaker baffles. Do you still find the music involving, the lyrics engaging. Can you tell the emotional intent of the performance.  This is what I hear, when iTunes is completely throttled down.

I have listened to iTunes plenty of times.  I hear detail and good bass, but the detail is not focused or 3-D as when using my particular version of Amarra (not the latest BTW).  The better the rendering, the better the engagement and listening involvement.  If I had used iTunes at shows, I guarantee I would never have gotten best of shows, which I have several.  My DAC only connects directly to my amps.  The volume control has no parts in the signal path.

BTW, I have a TVC. Its an $8K pure silver Music First and although its very good, it still has an audible effect on the music, so I don't use it.

Steve N.

[AmpDesigner333]

Steve - we are all at different levels in our personal audio evolution.  One mans excellent is anothers mediocre. I have no doubts that the amps are excellent.  Its the source that I have doubts about.

I have listened to iTunes plenty of times.  I hear detail and good bass, but the detail is not focused or 3-D as when using my particular version of Amarra (not the latest BTW).  The better the rendering, the better the engagement and listening involvement.  If I had used iTunes at shows, I guarantee I would never have gotten best of shows, which I have several.  My DAC only connects directly to my amps.  The volume control has no parts in the signal path.

BTW, I have a TVC. Its an $8K pure silver Music First and although its very good, it still has an audible effect on the music, so I don't use it.

Steve N.

If "whatever" media player software is playing lossless tracks, and the gain is set to unity (no attenuation), how could the data (not the timing, just the DATA) fed to the DAC be any different?

If just the timing is different, in what way is it different?  This is a leading question!

How can you control the volume without touching the signal (you said "no parts in the signal path")?

Looking forward to your answers.  At some point, we'll address above-unity digital gain, another interesting topic....  Thanks.

[SteveMiller]

Thanks SteveN
I have read several individuals seem to think the fully silver versions of TVC by any manufacturer to have a slightly drying effect on the sound.  That's why I stuck with copper wiring for my choice.  Perhaps silver having a much faster signal propagation somehow suffers at the induction part of the path as concerns the windings in the transformers?  Either way I do agree most strongly that we are all on our own path and we do each need to recognize that much off what's stated in the threads and forums is "system dependant".

I think I would like to just leave a few facts just stated and users can make their own moves.
1) In my system, Tommy's DACDAC whipped butt in all areas sonically that I haven't been able to achieve yet or before with mainstream dacs and CD players from $3k to $9k   
2) Once I heard how good DACDAC was, I couldn't find an analog volume control in the $3k to $5k range that didn't kill the magic .... Until I tried the TVC from AudioZone ....but that was my system

A 3rd provisional point here is that the USB to SPDIF/PCM conversion might well have a large part to do with my positive results, but simply using the same HalideBridge on other dacs did not reap the system wide coherence as when DACDAC was running the show

My point being that if you hang DACDAC behind an inferior passive or active Analog volume control you WILL kill the magic and miss the point of this devices' inherent strengths. I think Tommy is trying to get users to get the inferior components out of the signal chain. BUT the rest of the signal chain has to be up to the task. The DACDAC should be considered an absolute MUST LISTEN for current Marashino owners. It's the product DNA pairing that's special. Other matches may exist but DigitalAmplifierCo pieces play extremely well together.

[Fredly]

Just been reading this thread and had to say a few words.

First off, Tommy I have your Amps on my radar and I’m pretty confident, when money is available, I will be buying one of your products to replace my good but aging AKSA Amplifier.

Second, I wanted to share my experience in creating a minimalist System that once included a Squeezebox Touch.

For many years my Ethernet connect modded Squeezebox Touch/with Paul Hynes Power Supply was coaxially connected to my DAC (the Schiit BiFrost).

Life was good as was the sound and I loved the ability to control everything via my Ipad using the SqueezePad Application.

After a lot of investigating and in an effort to reduce the length of distance my Music had to travel before it got spit out to my speakers, I ended up replacing my Squeezebox Touch with a Raspberry Pi 2.

The Raspberry Pi 2 acts as both Server (LMS) and Player (Squeezelite), has my Music Library locally attached via USB 2.5 2TB external hard drive and connects coaxially to my DAC with the HifiBerry Digi+ board

This solution, which is about the size of a pack of smokes, was head and shoulders better in overall sound than my Squeezebox Touch Config, and continues to impress me every day and is HIGHLY recommended.

So, in short, the Music/Data travels approximately 6 inches before it’s sent out to the DAC.

The Software used to configure the Raspberry Pi is freeware called Max2Play.

The Raspberry Pi 2, Case, Power Supply and Digital Board cost approximately $150 bucks

It uses Hardware Volume Control as well as supports Airplay from my Ipad.

So in my setup, my B1 Buffer Preamp always has the Volume Control all the way to Max and frankly can probably be removed from the System entirely.

It really is cool stuff, very compact, inexpensive and rock solid/always on.

Tommy, you should really give this config a try, it’s truly amazing in my opinion.

Fred in Canada

------------

Raspberry Pi 2

http://www.amazon.com/Raspberry-Pi-Model-Project-Board/dp/B00T2U7R7I

HifiBerry Digi+

https://www.hifiberry.com/digiplus/

Max2Play (Free software that installs everything you need)

http://www.max2play.com/en/max2play-image/

SqueezePad App

http://www.squeezepad.com/

Max2Play Change Log (Where they discuss Hardware Volume Control and other capabilities)

http://www.max2play.com/changelog-max2play/

[mfsoa]

Hi Fred,

Nice to see you in Tommy's circle. Excellent advice once again.

First of all, regarding Tommy's Maraschinos, I can't imagine anyone being anything other than thrilled with them , unless you judge sound quality by the pound or the size of the box. Doesn't sound like you do...

Could you (or Tommy) elaborate on what is meant by "hardware" volume control?

In my world, VC done in the digital domain is software-based; that done in the analog domain is hardware-based. Simplified definition I guess but I'd appreciate it if someone could flesh-out the accepted definition for me.

Thanks in advance

-Mike not in Canada

[audioengr]

If "whatever" media player software is playing lossless tracks, and the gain is set to unity (no attenuation), how could the data (not the timing, just the DATA) fed to the DAC be any different?

The CODECs are different and sometimes the offset is incorrect, particularly with iTunes on a PC.  There is the data, the control info and the offset as well as the jitter.  I have this discussion a lot with folks that have not tried a lot of different players on a highly resolving system.  I have examples of tracks with different offsets and the same music data and they all sound different, does not matter what player you use.

How can you control the volume without touching the signal (you said "no parts in the signal path")?

I control the volume in my Overdrive DAC by changing the D/A reference voltage.  This is the voltage "height" of the stairsteps.

Steve N.

[audioengr]

Thanks SteveN
I have read several individuals seem to think the fully silver versions of TVC by any manufacturer to have a slightly drying effect on the sound.  That's why I stuck with copper wiring for my choice.  Perhaps silver having a much faster signal propagation somehow suffers at the induction part of the path as concerns the windings in the transformers?

It sounds drier because of all of the fractures in the silver crystal lattice.  Silver done right does not have this effect.  Silver wire can suffer from the same thing.  That is why I had the Music First TVC cryo-treated by a competent company. It fixes most of that.  Silver wire if annealed properly will not have this problem either.  I used to sell silver IC's and I actually have that cable company up for sale.

My point being that if you hang DACDAC behind an inferior passive or active Analog volume control you WILL kill the magic and miss the point of this devices' inherent strengths.

This is the case with any decent source component.  Most folks don't spend the change needed for a good preamp.

Steve N.

[mfsoa]

Fred, another (noob to Linux/Pi) question please:

(Tommy, sorry if veering off-topic but germane to the "Minimalist" theme - and I'd love to get a Pi up and running so you'll surely be able to check it out  )

You posted a link to the Max2Play software page but there are a number of items available for download. Is it the green box on top? Does this include LMS or does that get added on later? Thanks very much for your help!

-Mike

[AmpDesigner333]

It sounds drier because of all of the fractures in the silver crystal lattice.  Silver done right does not have this effect.  Silver wire can suffer from the same thing.  That is why I had the Music First TVC cryo-treated by a competent company. It fixes most of that.  Silver wire if annealed properly will not have this problem either.  I used to sell silver IC's and I actually have that cable company up for sale.

This is getting way out-of-scope, and into territory where you probably don't want to hear my opinion!  Let's get this thread back on track.  Thanks.

[AmpDesigner333]

The CODECs are different and sometimes the offset is incorrect, particularly with iTunes on a PC.  There is the data, the control info and the offset as well as the jitter.  I have this discussion a lot with folks that have not tried a lot of different players on a highly resolving system.  I have examples of tracks with different offsets and the same music data and they all sound different, does not matter what player you use.

A lossless codec, if working properly, will output the same data as any other properly working lossless codec, and the offset should also be the same.  It's like a ZIP file.  Carbon copy of the data, offset and all.

I control the volume in my Overdrive DAC by changing the D/A reference voltage.  This is the voltage "height" of the stairsteps.

That works, but you lose more dynamic range doing that than you gain by having "analog volume" (:

Thanks.

[audioengr]

A lossless codec, if working properly, will output the same data as any other properly working lossless codec, and the offset should also be the same.  It's like a ZIP file.  Carbon copy of the data, offset and all.

In theory, yes. In practice, no.  Dynamic playback has its issues.

That works, but you lose more dynamic range doing that than you gain by having "analog volume" (:

Thanks.
[/quote]

Actually, the dynamic range and the S/N is improved with my volume control technology.  It is the only technology where the S/N ratio actually increases as the volume is lowered.  No other volume does this.


Steve N.

[mojave]

A lossless codec, if working properly, will output the same data as any other properly working lossless codec, and the offset should also be the same.  It's like a ZIP file.  Carbon copy of the data, offset and all.

You are 100% correct.

In theory, yes. In practice, no.  Dynamic playback has its issues.

All codecs are decoded and converted to PCM within the player. The buffer in the media player that contains the PCM data has no idea what went on before. It just gets the PCM data, which is identical from all lossless codecs, and outputs to the DAC. Dynamic playback makes no difference.

This is easily verified by internally routing the input of a multi-channel DAC back to an output and passing on to program for recording.

To go along with Tommy's analogy, it is like me receiving 3 identical Word documents compressed with .zip, .rar, and .7z.  I decompress and save all three documents. I later view the three documents. I no longer know which compression method was used and all documents are identical.

People do this all the time with video files and nobody ever notices a difference - and with video you have both sight and sound to help discern things. You can rip a DVD and keep the original ISO, extract to TS folders, or convert to MKV. ISO and MKV are just containers like zip, flac, or any other lossless container.

[Fredly]

Hey mfsoa,

I don’t want to steal this thread from Tommy, so I will keep my answer short.

First question and a good one, how can an OS have “Hardware Volume Control” shouldn’t it be called Software Volume Control.

I’ll be honest, I do not have a straight answer for your, and believe me I tried to find a simple article online to explain it.

Basically, and this is the crux of what I DID discover concerning this topic, newer DACs are capable of "integrated" Hardware Volume Control (via ALSA) under Linux.

When the DAC is using this integrated Hardware Volume Control as opposed to Software Volume Control one is supposed to experience a more natural sounding curve, which results in overall better sound.

(Would LOVE if someone could dig more into this, as this stuff is all so new to me)

The Link I used to configure my Raspberry is NOT the green one, but rather below it, titled;

Hifiberry Max2Play HiFiBerry Image (Raspberry PI)

Link:
http://www.max2play.com/download/15184/

Hope this helps, Fred