[Occam]

I ran accross this pci multichannel / external breakout box soundcard -
http://www.audiotrak.net/maya1010.htm

It appears quite similar to the MAudio Delta 1010, but lacks the word-clock synchronization, but adds the feature of analog attenuation via the very highly thought of Wolfson WM8816. This offers the possibility of a PC based dsp multiamped speaker crossover/equalization  and room correction that addresses the very real problem of output level adjustment and synchronization between channels.
Ideally, its analog circuitry is housed totally within the external breakout box which might make modding easier.
Its inclusion of the Via Envy24/Ice1712 asic digital mixing chip (like MAudio's), also potentially facilitates implementation of linear phase dsp.

Can anyone comment on their experience with this product specifically, or AudioTrak in general?

TIA

PS - is this more appropriate for the Square Circle?

[Occam]

I'll also add the yet to be delivered Ego Systems (ESi) ESP1010. from the same Korean parent company, as sharing those same features of the Wolfson chip and Via mixer -
http://www.esi-pro.com/viewProduct.php?pid=49&page=1

[JoshK]

Haven't heard of either but am very intrigued.

[Occam]

I'm assuming your interest is due to the presence of the Wolfson 8816 on each of the analog I/O channels. My idealized crossover/equalization dsp can take either an analog or digital input, do its voodoo, and supply synchronized, yet individually adjustable, analog ouputs to power the per channel/ driver amplifiers. I certainly don't want to drive the input of the of the dsp sytem with a variable analog pre, nor do I want digital attenuation, for both lead to potential concerns over resolution loss and/or overloads. The appeal of Wolfson attenuators built into the soundcard is very appealing when the alternative is an outboard 6 channel DACT, VGAs or BB PGA4311s.

Sadly, the rub is that no matter how good the Wolfson's reputation, the ultimate quality is dependant on the care and feeding of the analog section, op amps, components, powersupply and layout. And then there is the quality of the codecs.......

Anyone with any experience with Ego and/or AudioTrak products?

[dwk]

I don't have any direct experience, but EgoSys has been around the pro-card circles for a while and has a decent reputation. I think it's pretty clear these are the same unit in different packaging - the way the specs are laid out is too similar for them to be different.

I agree with your basic idea that the Wolfson attenuators make these attractive. However, the Audiotrak is on the street for $300, so I wouldn't expect miracles.  It certainly is unlikely to match a Lynx, and probably will even fall short of the Emu 1820M, which is 'only' ~$200 more.  Of course, neither of those have analog attenuation , so it's not a directly equivalent comparison.

IMHO, people are a *bit* too scared of digital attenuation. You can use 10-15 dB of digital attenuation without any problem whatsoever on these modern cards (assuming you properly use the 24-bit output word).  If you set up the gain structure of your source, amp and speakers properly (and I guess that's a big if in some cases) so that digital full-scale corresponds to your desired peak level, then  this should actually be fine for a dedicated audio system. At worst, adding one or two steps of -10dB attenuation via a stepped resistor switch is all that you need - this can be done much cheaper than a full-out Goldpoint or Dact.  

The big problem with these cards in the short run is
a) still no software (other than SoundEasy AFAIK) that will do FIR xovers on Windows
b) the non-standard hardware (Wolfson at least, maybe more) will mean no Linux support in the near term, if ever

[Occam]

dwk,

I'm not against digital attenuation, but my intent would be to use that Wolfson funtionality, not only for balance adjustment between the individual drivers, but volume control as well. This calls for substantial resolution as well as range. The 60db range and the .5db resolution as offered in the AudioTrac/ESi implementation is just the ticket. Certainly, Wolfson's attenuation provided by its control of an inverting opamp introduces its own concerns over noise and distortion, but Wolfson has address these issues quite impressively -
http://www.wolfsonmicro.com/products/digital_audio/volumecontrol/WM8816/?flash=true

[JoshK]

I liked the idea of having all the analog 'stuff' in a box outside of the computer and off the soundcard because, as you mentioned, it opens the possibility of easier modding.  I have not read anything about the Wolfon's attenuators but know that they make reportedly good DACs.  

My thoughts on the solution of volume control after the dsp/xo is to build the 6ch VCA that Davey provides on his website.  Looks simple enough for even a beginner like me to build.  I was going to do two channels up first and have a listen, if I don't like it I'll then try out the chip volume scheme such as BBs, I know a kit in this case.  Anyway, neither have to be expensive but may not be ideal, don't know yet.  

Frank was going ot loan me his Merlin DSP xo to play with.

[dwk]

Occam - don't worry, I understand how you're thinking of using the unit. I've been wrestling with multichannel DSP xover ideas for the better part of 10 years, and have been through every idea out there. I still have a batch of CS3310 and PGA2311(??I think that's the number)  chips to do essentially what the Wolfson chips on the Maya do.  I abandoned that when it looked like the general concensus was that the 3310 wasn't really that transparent; from everything I see, though, the Wolfson is a clear step up from the older chips.

My point was simply that a great analog attenuation solution coupled with a marginal card is not necessarily better than a good card with another volume approach. Since none of my candidate approaches (Delta 1010, Emu1820M, Behringer DCX) implement analog volume control of any sort, I was outlining what I think is a viable strategy.   Basically, if what we're given is the ability to use ~15dB of digital attenuation without impact, what would the rest of the system have to look like to make this an acceptable approach?

Having said all that, either of these cards presents a much easier an probably more useable solution, and if the performance of the DACs is even 'decent' by pro standards, I think the overall performance of the system will be good.  If I hadn't already shelled out for the Emu and just recently the Behringer, I might be willing to be the test subject.

[Occam]

dwk - your points are spot on. I certainly wouldn't think that these Ego/Audiotrak products are the equals of the Lynx or RME. I don't think my own dac is their equal. The comparison that I'm actually trying to resovle is -

How would this soundcard sound/measure in comparison to a DEQX PDC-2.6P, while functioning soley as a preamp?
Essentially - How well is their, clock(ing), A/D, D/A, attenuation, and analog I/O circuitry implemented?

Obviously, this $3,450 Deqx digital preamp does substantially more than just preamp functionality.  Those other very sophisticated capabilities cannot be provided by a mere soundcard.

[JoshK]

Guys, not sure if you have seen this or not, whether you would want or need such a kit since both of you are quite a bit more savvy than I, but never-the-less this is a kit using the BB 2310.   I have not seen anything similar using the Wolfson.

surf to ChipVol1

[Occam]

Thanks for the reference Josh. The DEQX, preamp version, also uses the BB PGA chip for analalog volume control.

[JoshK]

Any speculation on whether the Wolfson would be better than the BB?  I know it is probably hard to guess but you engineer types might have an inkling.  Would it be hard to modify such a kit to take the wolfsons.  I saw that the wolfsons require similar voltages as BB iirc, wonder if the control interface would be similar.  This is an area I know nill about.

[Occam]

Josh- modifying a BB PGA based volume attenuator kit to use a Wolfson would be quite difficult. The BB PGA implements its attenuator using its own internal op amp. The Wolfson chip implements its attenuation by providing a feedback network for a user supplied/chosen opamp. It would be quite difficult (not even considering the probable different control structure which would require, at minimum a reprogramming of the pic control microprocessor generally used)

That being said, the BB PGA chips have generated excellent reviews as used in the EVO preamp, FWIW. But there are many routes, and the ultimate quality depends largely on implementation, especially its powersupply. No doubt, a VCA solution could also deliver excellent results (though it is not trivial to implement individual adjustments for specific amplifier and driver sensitivity. This is relatively straightforwar with the PGA or Wolfson).

In the best of all possible worlds, my preference would be for the Wolfson, as it provides the flexibility of choosing your own inverting opamp, which could be either discrete or integrated. A number of folks, who's opinions I trust, feel that the Wolfson is the best of the current crop.....
Which is what piqued my interest in these AudioTrak/ESi products.

[JoshK]

Thanks for your thoughts.

I guess I should have asked whether one, who isn't an OEM, could even source these creatures.  I am going to have to poke around on DIYaudio and see if anyone smarting than myself has taken a crack at implementing such a thing.  I know a few good designs for decent and suitable PSUs, or so I think.

You are right, I have no idea on how to implement the VCA control for relative differences in sensitivity and gain but I figure that much digital attenuation I could swallow if the rest was done analog.

[JoshK]

Yo Pauly,

As if we didn't already have enough on our platters but what do you think about co-designing a remote 6-7ch volume control using the Wolfson WM8816 & the TI THS41x1?  For me, I am not in a rush, so we can take our time working on it.

My objectives would be this:

-1 7ch XLR input (for active 3 way xo & mono sub)
-1 7ch XLR output
-Must be able to remotely control volume
-Must use WM8816
-Must have a knob on the front of panel for manual vol control. (rotary encoder?)
-Must be sonically transparent

Is this a pie-in-the-sky dream or do you think it is doable?  I have seen some threads on diyaudio that seem close but not there, most use the PGA3310.

[Occam]

Josh - an admiral project indeed. I know of 3 different folks who are working on just that, for HT. But sadly, they're being rather close mouthed. Nor is the Wolfon's requisite inverting op/diffamp restricted to monolythic integrated circuits. I still believe that the best op/differential amps are discrete. But this is a project that would require at least three circuit board revisions, a controlling micro with both hardware and software, scaling the project from one channel to 6+, the greif of proper powersupply design.
For my specific selfish needs, and skills,  the idea of a $230 pc card (this is for a hypothetical pc based dsp speaker control) and also throws in the requisite AtoD/DtoAs, too boot, if far more appealing. While I don't expect state of the art for this price, its a given that someone, somewhere, will start modding this (or something similar). As to whether these current boards with my desired multichannel analog domain volume control have potential, dunno.
I've minimal doubt that Lynx, RME.... will offer that feature in the future.

Great project though. Let me know how it progresses .

[JoshK]

I believe this project is beyond my reach now, not that I mind the challenge, it would be a good learning experience.  However, it seems that many, or atleast the thundering voice of Thoersten, still believe the relay stepped attenuator to still be a better solution.   I dinked around and asked a few questions and came up with the following easy solution.

http://electronics.dantimax.dk/Kits/index.html

The RelVol1 kit can be tied together in parrallel use a VolControl2 to adjust volume and use remote.   The whole project san PSU and case is around $100.  More my style.  He also has a prototype of these boards for Balanced operation which is said is more or less ready.

[JoshK]

ok, ok....you convinced me that the Audiotrak solution looks very intriguing.   Have you purchased one yet?