Does something like this exist on the cheap?

[oivavoi]

Ok, here's the thing: For the speakers I'm considering buying, the manufacturer uses the DBX driveracks for crossover and eq (he's a cheapskate just like me). He uses the PA2. I'm debating with myself, however, whether I should go for the more expensive Venu360. Venu360 has a digital input, so that might save me a D/A/D-conversion. The Venu360 also has a better processor all over. I know that this D/A/D-conversion will probably not be audible at all... but still, the anxious audiophile in me thinks it could be worthwhile to keep the signal pure all the way to the final D/A-conversion when the Driverack feeds the signal to the amps.

The problem is that the Venu360 only has AES/EBU inputs. It's a problem, since the Driverack doesn't have independent master volume control, and I need something (preferrably with a remote) to control the volume and get all my sources connected. With the PA2, I would have used a dac with balanced out as my pre. All my sources have optical/coax out (sonos connect, BR-player and Apple TV). I therefore need something which has consumer grade digital inputs, and AES/EBU output - AND a volume control.

But this product category seems to be almost non-existent!

The only thing I've found so far is the Minidsp Opendrc-DI. It does what I need, and more. I just feel like I'm paying for much more functionality than I need with the Opendrc-DI. I don't need all that DSP stuff (the Driverack does that), I just need digital format conversion and digital volume control. There must surely exist some cheap knockoff on ebay? Or not?

Or maybe I should just do it simple and accept the extra D/A/D-conversion

EDIT: The title should have been "Does something like THIS exist..."! Apparently one can't edit thread titles.

 

[Blumlein 88]

I have not used one of these, but it would do coax to AES/EBU conversion for $89. No toslink optical.
https://www.amazon.com/Hosa-CDL-313-Coaxial-SPDIF-AES-EBU-Link/dp/B000068OGS
http://hosatech.com/product/cdl-313/

You can get optical to coax converters for like $15.

For around $45 you could do this although I am not sure if they would work. They really mean to be used in pairs.
http://www.neutrik.com/en/accessories/aes-ebu-impedance-transformers/

That does not do any digital volume control for you. Do some AV pres or AVRs do volume control of digital outputs?

The Tact RCS 2 or 2.2 units would do what you need. They had AES/EBU, toslink, and coax inputs and also those three outputs with the digital outputs being volume controlled because their early power amps had digital only input. It might be possible to find one of those on Audiogon or US audio mart without it being too dearly priced.

So I haven't solved your problem. Maybe someone else knows a better route to take.

And yes your final sentence is probably about right. Don't know if you listened to the 8th generation copies vs digital originals I posted in a thread here, but one AD/DA conversion is not really going to be a problem if people could not hear eight of those conversions. I don't have the files up for download currently, but could send them to you if you want to hear it.

 

[Blumlein 88]

This Bheringer DEQ2496 might work for you. Those do volume control of the digital output. AES is one of the output options.

https://www.amazon.com/Behringer-DEQ2496-BEHRINGER-ULTRACURVE-PRO/dp/B000CCN152

Now I warn you, though this seems like a tremendously useful tool, I have used them for other people and I hate them. The way everything is controlled and you interface with all the possibilities is maddening. They have been out several years and generally are easy to find second hand.

Another possibility is an old Merdian 518 processor. It took digital input, you could select different dither or none, change word lengths between 16 and 24 bit, and it had AES/EBU output. Limitations are it works only up to 48 khz. Would do 48/24 fine. I used it as a digital volume control with a few DACs. Nice unit. Expensive at one time perhaps a used one is not dear. Can't imagine much demand for such a thing now days.
http://www.stereophile.com/digitalprocessors/367/index.html#bSyZ8odpAaEA6jkS.97

 

[amirm]

EDIT: The title should have been "Does something like THIS exist..."! Apparently one can't edit thread titles.

I made the change for you. You should be able to do it too. For some odd reason that option is under the drop down on the right, "Thread Tools->Edit Thread."

 

[oivavoi]

This Bheringer DEQ2496 might work for you. Those do volume control of the digital output. AES is one of the output options.

https://www.amazon.com/Behringer-DEQ2496-BEHRINGER-ULTRACURVE-PRO/dp/B000CCN152

Now I warn you, though this seems like a tremendously useful tool, I have used them for other people and I hate them. The way everything is controlled and you interface with all the possibilities is maddening. They have been out several years and generally are easy to find second hand.

Another possibility is an old Merdian 518 processor. It took digital input, you could select different dither or none, change word lengths between 16 and 24 bit, and it had AES/EBU output. Limitations are it works only up to 48 khz. Would do 48/24 fine. I used it as a digital volume control with a few DACs. Nice unit. Expensive at one time perhaps a used one is not dear. Can't imagine much demand for such a thing now days.
http://www.stereophile.com/digitalprocessors/367/index.html#bSyZ8odpAaEA6jkS.97

Thanks! Very useful info. Several possibilites there. It seems, though, that the easiest and simplest solution by far is the minidsp unit...

The other possibility might be to find a dac with coaxial out (they must exist?) and use the hosa unit for converting it to aes3.

I must admit though that I'm a bit skeptical of using digital volume control in 24-bit dacs. Isn't there a danger for degrading the signal if it's not 32-bit? Or is that audiophoolery?

 

[Blumlein 88]

Thanks! Very useful info. Several possibilites there. It seems, though, that the easiest and simplest solution by far is the minidsp unit...

The other possibility might be to find a dac with coaxial out (they must exist?) and use the hosa unit for converting it to aes3.

I must admit though that I'm a bit skeptical of using digital volume control in 24-bit dacs. Isn't there a danger for degrading the signal if it's not 32-bit? Or is that audiophoolery?

Depends upon how it is done, though in general it is audiophoolery. For instance the old Meridian 518 from 20 years ago used 72 bit DSP to do conversion, dither and volume control. I think those Tact units worked at 54 bit for volume control. Much software works at 64 bit. The issues with that simply aren't worth worrying about at all.

This below is an excerpt from the jriver wiki about volume control in their media center.



The precision offered by Media Center's 64bit audio engine is billions of times greater than the best hardware can utilize. In other words, it is bit-perfect on all known hardware.




To demonstrate the incredible precision of 64bit audio, imagine applying 100 million random volume changes (huge changes from -100 to 100 dB), and then applying those same 100 million volume changes again in the opposite direction.




Amazingly, you will have the exact same signal at 32bit after 200 million huge volume changes as when you started.




In other words, this incredible number of changes results in a bit-perfect output at 32bit, which is the highest hardware output bitdepth (most high-end hardware is 24bit).




This also means one volume change or a series of 100 million volume changes that add up to the same net result is bit-identical.

 

[March Audio]

Ok, here's the thing: For the speakers I'm considering buying, the manufacturer uses the DBX driveracks for crossover and eq (he's a cheapskate just like me). He uses the PA2. I'm debating with myself, however, whether I should go for the more expensive Venu360. Venu360 has a digital input, so that might save me a D/A/D-conversion. The Venu360 also has a better processor all over. I know that this D/A/D-conversion will probably not be audible at all... but still, the anxious audiophile in me thinks it could be worthwhile to keep the signal pure all the way to the final D/A-conversion when the Driverack feeds the signal to the amps.

The problem is that the Venu360 only has AES/EBU inputs. It's a problem, since the Driverack doesn't have independent master volume control, and I need something (preferrably with a remote) to control the volume and get all my sources connected. With the PA2, I would have used a dac with balanced out as my pre. All my sources have optical/coax out (sonos connect, BR-player and Apple TV). I therefore need something which has consumer grade digital inputs, and AES/EBU output - AND a volume control.

But this product category seems to be almost non-existent!

The only thing I've found so far is the Minidsp Opendrc-DI. It does what I need, and more. I just feel like I'm paying for much more functionality than I need with the Opendrc-DI. I don't need all that DSP stuff (the Driverack does that), I just need digital format conversion and digital volume control. There must surely exist some cheap knockoff on ebay? Or not?

Or maybe I should just do it simple and accept the extra D/A/D-conversion

EDIT: The title should have been "Does something like THIS exist..."! Apparently one can't edit thread titles.

Just a comment regarding thd minidsp, I would check out if this unit converts ASRC all inputs to 48 or 96 kHz.

This may not be an issue for you even if it does, but my usage of the nano and minisharc boards (which do this) left me feeling they werent entirely transparant even when they were just passing the signal straight through

 

[RayDunzl]

The OpenDRC-DI converts to output 24/48kHz

The Dirac version does 96kHz but is closed to other software

Then my DAC takes the signal to 211kHz internally, so, I'm like, Ok, whatever...

The Behringer DEQ2496 has no remote and the volume control only cuts -15dB, it is more like an input pad, to create some digital headroom if you choose to boost some frequencies with one of the EQ facilities.

 

[March Audio]

The OpenDRC-DI converts to output 24/48kHz

The Dirac version does 96kHz but is closed to other software

Then my DAC takes the signal to 211kHz internally, so, I'm like, Ok, whatever...

The Behringer DEQ2496 has no remote and the volume control only cuts -15dB, it is more like an input pad, to create some digital headroom if you choose to boost some frequencies with one of the EQ facilities.

Yeah, its not that I have an issue with sample rate conversion, I was just trying to identify a possible reason for the difference I have heard.

 

[oivavoi]

Depends upon how it is done, though in general it is audiophoolery. For instance the old Meridian 518 from 20 years ago used 72 bit DSP to do conversion, dither and volume control. I think those Tact units worked at 54 bit for volume control. Much software works at 64 bit. The issues with that simply aren't worth worrying about at all.

This below is an excerpt from the jriver wiki about volume control in their media center.

The precision offered by Media Center's 64bit audio engine is billions of times greater than the best hardware can utilize. In other words, it is bit-perfect on all known hardware.

To demonstrate the incredible precision of 64bit audio, imagine applying 100 million random volume changes (huge changes from -100 to 100 dB), and then applying those same 100 million volume changes again in the opposite direction.

Amazingly, you will have the exact same signal at 32bit after 200 million huge volume changes as when you started.

In other words, this incredible number of changes results in a bit-perfect output at 32bit, which is the highest hardware output bitdepth (most high-end hardware is 24bit).

This also means one volume change or a series of 100 million volume changes that add up to the same net result is bit-identical.

Thanks. I'll try to put that bit of my audiophoolery away, then.

 

[oivavoi]

Here's a dac with remote and coaxial out: http://www.stereophile.com/budgetco...hone_amplifier/index.html#VGv5qRggXf27EOTG.97

Saw one on the local second hand market. However, it's still too expensive for my taste, especially when I need to get the hosa adapter to make it work.

 

[oivavoi]

Thanks. I'll try to put that bit of my audiophoolery away, then.

This guy seems skeptical of digital audio controls, though: http://www.soundstageultra.com/inde...311-what-s-wrong-with-digital-volume-controls

EDIT: On closer inspection, that site seems to have lots of questionable content. Probably not a trusworthy source.

 

[DonH56]

The issue with digital volume control is real albeit often overstated.

If the quantization noise is fixed (a fair assumption) then you'll give up 6 dB in SNR for every halving of the signal level (i.e. reducing the level by one bit). How many bits before the DAC doesn't really matter all that much since at the DAC is where you must reduce the output if there is no other volume control in the system. (There are very good reasons for maintaining much higher bit depths through the signal-processing chain to preserve the final dynamic range to the DAC.) What is generally missing in these arguments is that the analog noise floor is also usually fixed and typically about the same level as the quantization noise (hopefully a little better). That means you also lose some dynamic range (SNR) when you turn down the level on an analog volume control as well...

 

[oivavoi]

Resurrecting my own thread: I think I find the solution - in principle. The logitech transporter. Streamer, digital volume control, remote, optical inputs, and aes/ebu out. If I'm lucky I'll be able to find one on the cheap.