Article: exaSound e28 Multichannel USB DAC Review

[jdw]

Do you have the e28 Mk III - or an earlier version? I thought that you need the Mk III version to get 4xDSD and perhaps Multichannel at all three resolutions (DSD, 2xDSD, 4xDSD). Maybe it's more involved.

I am not sure that a e28MkIII exists. On Exasound site, the only model with am MK III evolution is the e20.

I have no problem to convert PCM to DSD or 2xDSD (in JRiver, but only stereo) or 4xDSD (in Foobar2000 in multichannel). My problem is which settings to select to convert DSD to 2xDSD in JRiver. In his comment, Matt Ashland said “you need to accept that doing any sort of processing with DSD requires transition to a multi-bit intermediate format” and I am not sure if this mean to select in the settings of MC19 : Bitstreaming : None.

[bmoura]

I am not sure that a e28MkIII exists. On Exasound site, the only model with am MK III evolution is the e20.

I have no problem to convert PCM to DSD or 2xDSD (in JRiver, but only stereo) or 4xDSD (in Foobar2000 in multichannel). My problem is which settings to select to convert DSD to 2xDSD in JRiver. In his comment, Matt Ashland said “you need to accept that doing any sort of processing with DSD requires transition to a multi-bit intermediate format” and I am not sure if this mean to select in the settings of MC19 : Bitstreaming : None.

 

JDW, thanks for the correction. I'm still in learning mode here - hence the confusion about the e20 and e28!

[wisnon]

Excellent work Ted!

[jaffar]

Since the exasound DAC has USB output, you would need a processing engine to build the Xovers running on a PC and use the Exasound as the downstream DAC. As far as I know, the boxes that are currently used to build these cross-overs (e.g. Behringer, DEQX and Trinnov) are all dedicated boxes, so you cannot use a USB MCH DAC in the chain. I suspect their boxes are all Linux based, so don't expect a Windows based PC app allowing you to do this anytime soon.

There are several VST plugins that can do any x-over tasks under Windows. The Thuneau Allocator, for example. I personally use very transparent PLParEQ. Any Behringer/DEQX/etc-based system falls short in sound quality and flexibility compared to a good PC-based crossover. e18 and e28 are great for doing 4-way XO considering their quality d/a conversion.

[jaffar]

Ted, can you compare the sound quality of the built-in volume control (e28 directly to power amps) versus e28+MVC? Are there any advantages with less components in the signal path? Can't deside if I need a preamp for my 4-way crossover. Maybe e28 is good enough to be used directly to amps. MSB MVC seems to be the only 8-channel preamp on the market...

[ted_b]

Jaffar,

I still haven't gotten my MVC to work quite right (user error) so I am 100% using my 6 channel Sony TAP-9000ES analog preamp when running the E28. I have not tried the E28's own volume (too much work to then redo channel trims, etc) but I promise I'll try again.

[jaffar]

I have not tried the E28's own volume (too much work to then redo channel trims, etc) but I promise I'll try again.

 

Yes, it would be very interesting comparison, esp. with the MVC. Thanks!

[bmoura]

The folks at exaSound are offering attendees at RMAF a special deal on their DSD DACs. If you order one at the show, you will be able to save 15% from their normal prices. This brings the cost of their 8 Channel Surround Sound DAC - the e28 - down from the normal price of $3,299 to $2,804, a savings of $495.

 

exaSound is also demoing their DACs at the show with several files - including a Surround Sound DSD recording of Mahler's 5th Symphony from Channel Classics. Definitely worth stopping by their booth on the 5th Floor for a listen.

 

There's also a review of the e28 that just came out in the November issue of Stereophile. Copies of the November issue are available at the show.

[untangle]

For those wishing to do a digital crossover on a Mac...

 

Firstly, this requires DSP so DSD must be converted to PCM. From there, two approaches are common:

 

1. USE A PLAYER WITH THIS FUNCTIONALITY BUILT-IN. PM is the pioneer here, and their implementation is very clean sonically. Of course, as usual with the product, the user interface gymnastics required are arcane and difficult. Thankfully, the docs are pretty good. Other players may now have digital crossover capability, but I haven't kept up.

 

2. ROLL YOUR OWN. You will need three components for this: an audio router, a host for audio plugins, and the DSP plugins themselves. I usually use Jack, Plogue Bidule, and Fabfilters respectively. This is more flexible and a ton of plugin choices are available (yes, they all sound different). Jack and Bidule must be launched prior to launching your player. I believe that I have explained the process in greater detail elsewhere on these forums and won't repeat it here.

 

As you have probably gleaned, these solutions require dedication and specific knowledge. Measurement equipment is highly recommended. They also require multi-channel amplification and many cables. But IME the control afforded is exquisite (e.g., time alignment of drivers) and the sonic reward is rich.

 

Bob Walters

President, Bay Area Audiophile Society

[jaffar]

Ted, any news on the E28 volume control versus the MVC?

[eugenius]

A 3300$ dac that needs a cheap PSU upgrade? Really?

[elcorso]

A 3300$ dac that needs a cheap PSU upgrade? Really?

 

You don't extrictly need a PSU upgrade, it could be better, but regarding the noise a SPSU could inject noise on your music system, as almost all SPSU.

 

I guess the manufacturer wise invested the money in better DAC components, like clocks and a very immune, galvanic isolated, USB interface, where you don't have to invert in very expensive (exotic) USB cables, etc.

 

Roch

[Geardaddy]

You don't extrictly need a PSU upgrade, it could be better, but regarding the noise a SPSU could inject noise on your music system, as almost all SPSU.

 

I guess the manufacturer wise invested the money in better DAC components, like clocks and a very immune, galvanic isolated, USB interface, where you don't have to invert in very expensive (exotic) USB cables, etc.

 

Roch

 

Nicely done Ted. A friend owns this dac and uses it to the full measure including the active xover thing. He loves it....

[deanorthk]

Would this work if I send 7 channel DTS HD in PCM through jriver, to the the EX28, and then output to a P7 pre amp..?

[rbienstock42]

This looks like such a great unit, but it appears to fall short in one respect: exaSound's other processor, the e32 also uses an 8 channel ESS SABRE chip, but it is stereo-only and merges the 8 channels into 2 which improves sound quality. But the e28, which can do both stereo and 8-channel, uses only 2 channels of its SABRE chip in stereo mode instead of merging them like the e32 does. Note that merging the 8 to 2 for stereo while maintaining the ability to do multichannel is definitely possible as the $11,000 Merging+NADAC does that. But the NADAC uses a SABRE 9008 chip while the exaSound uses the superior 9018S. If it only merged the 8 channels like the NADAC, it would be a world beater at 1/3 the price of the NADAC. I'm so torn, because the e28/PlayPoint makes so much sense to me, but 85% of my listening is in 2-channel, so I'm sorely tempted by the NADAC.

[Keith_W]

This looks like such a great unit, but it appears to fall short in one respect: exaSound's other processor, the e32 also uses an 8 channel ESS SABRE chip, but it is stereo-only and merges the 8 channels into 2 which improves sound quality. But the e28, which can do both stereo and 8-channel, uses only 2 channels of its SABRE chip in stereo mode instead of merging them like the e32 does. Note that merging the 8 to 2 for stereo while maintaining the ability to do multichannel is definitely possible as the $11,000 Merging+NADAC does that. But the NADAC uses a SABRE 9008 chip while the exaSound uses the superior 9018S. If it only merged the 8 channels like the NADAC, it would be a world beater at 1/3 the price of the NADAC. I'm so torn, because the e28/PlayPoint makes so much sense to me, but 85% of my listening is in 2-channel, so I'm sorely tempted by the NADAC.

 

I happen to own an 8 channel NADAC. If you look inside, there are only TWO ESS 9008 chips. For 8 channels.

 

So yes, you will get the benefit of 8 channels merged into 2 if you listen to 2 channel. But if you are using 8 channel, the channels will not be merged.

 

That raises the question - if you are only listening to 2 channels, why bother with the NADAC unless you need its network capability? There are many DAC's which are superior to the NADAC which are cheaper, like MSB.