In search of simple home stereo type SPDIF I/O "preamp"

Greg Cameron

Greg Cameron

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Jan 11, 2011
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I have a friend looking a box to drive a home system trying to keep the signal path all digital until it reaches the D/A right before the amps. This would entail a box with SPDIF and maybe AES input as well as outputs with some type of volume knob. Something super simple. Maybe some tone control. Does anyone have any idea where such an item might exist that isn't thousands of dollars? Grace makes one like this, but it's >$3k.

Thanks.
 
Re: In search of simple home stereo type SPDIF I/O "preamp"

Emotiva XDA-1 - I have been thinking about buying one of these for a long time. Price has come down a lot, and everyone that has one speaks very highly of it.

If that will not work (i.e. they want to use a different D/A unit), consider the Adcom GDA-600. This unit has two S/PDIF, one AES and one Toslink input, analog out, and an S/PDIF output. Probably have to buy used. I use one, and I confirmed with Adcom a long time ago that the S/PDIF output passes 24 bits.

Doug
 
Re: In search of simple home stereo type SPDIF I/O "preamp"

Tim Weaver said:
AES and coax are somewhat interchangeable so there are a lot of EQ's or DSP's that accept AES can also accept SPDIF. I'm pretty sure the Berhinger DEQ2496 does this.
Click to expand...

+1

I'm using a Rane RPM26z (~$1000, new) as my home hi-fi "preamp" and love it. One thing to watch is that not all pro DSPs handle differing input sample rates gracefully. The Rane transparently converts all input sample rates to the internal 48k, which matters for me since I have a CD player (44.1k), computer sound card (48k or 96k), and a portable recorder (whatever I set it to) feeding it.

I made a control panel that lets you choose a digital source, a preset (1 of 6), and set the gain. With the 0-5v external gain control there are many fun possibilities since all you need is a 10k pot. For instance, I have remote gains in different parts of the house, and a remote gain on a dongle that I can take with me to the sofa to ride gain on movies or whatever. No iPad required :twisted:

--Frank
 
Re: In search of simple home stereo type SPDIF I/O "preamp"

Greg Cameron said:
I have a friend looking a box to drive a home system trying to keep the signal path all digital until it reaches the D/A right before the amps. This would entail a box with SPDIF and maybe AES input as well as outputs with some type of volume knob. Something super simple. Maybe some tone control. Does anyone have any idea where such an item might exist that isn't thousands of dollars? Grace makes one like this, but it's >$3k.

Thanks.
Click to expand...
Apogee Electronics > Products > Mini-DAC - no longer made, but you can find them around. They were <$1k new.
RME: ADI-2 - still available, and under $1k.
 
Re: In search of simple home stereo type SPDIF I/O "preamp"

kristianjohnsen said:
Just to make sure: If you're referring to just connecting a spidif signal to an AES inpur or vice-versa I believe this isn't a great ideas since AES is 5v p-p and spidif is 2v p-p, as well as the impedance being different.
Click to expand...

True. Some caution is advised. However, many AES3 devices will lock up just fine on an S/PDIF signal, and there is no danger of blowing anything up since the S/PDIF voltage is lower and the AES input impedance is higher. Going the other way a simple matching and attenuating pad does the job, although there may be protocol problems with some pro devices feeding some consumer devices. (I ran into this with a Sound Devices MixPre d and a Tascam DR100mkII recorder.)

When I first got the Rane box I fed its AES3 input directly from an S/PDIF out CD/DVD/BlueRay player and it worked fine. Since then I've built a proper S/PDIF to AES3 converter and distribution line-driver, since I "need" to pipe AES3 around the house :roll:.

I can supply circuits for this stuff if anyone is interested.

--Frank
 
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