Ross Martin Audio

[Dal-Tech]

Purchased a Ross Martin analog to digital converter. It is supposed to be very high end at a very low price and hand made in the USA. The downside is I've been waiting 2+ months. It's only a two man operation. When I receive the unit I'll update this post.

Here's the info on the unit I bought:

PCM4222 ADC



The PCM4222 represents the state of the art in Analog-to-Digital conversion. It is based on Texas Instruments' PCM4222 chip, a high-performance, two-channel analog-to-digital (A/D) converter designed for use in professional audio applications. Offering outstanding dynamic performance, the PCM4222 supports 24-bit linear PCM, 1-bit Direct Stream Digital (DSD), and 6-bit modulator data outputs. The supported output formats make the PCM4222 ideal for digital audio recording and processing applications. The multi-bit modulator output adds versatility, allowing customers to design their own digital decimation filter and processing hardware. The on-chip, linear phase decimation filtering engine supports Classic and Low Group Delay filter responses, allowing optimization for either studio or live sound applications.

Supported Sample Rates (KHz):

32
44.1
48
88.2
96
192
Supported Bit Depths:

24
20
18
16
Additional Features:

Master/Slave Mode
Word Clock Out
Master Clock Out
Selectable Filter Response
Led VU Meters With Overflow Indicators
OPA1632 1.3nv op amps
Inputs (Analog):

Balanced XLR
1/4” TRS
Outputs (Digital):

AES
SPDIF COAX
Optical

[oblioblioblio]

let us know how it turned out. I'm still not 100% about how much a difference a high quality ADC will make, but I often hear people voice issues with how digital recordings can sound, and as vinyl doesn't really seem to be my thing, I thought quite a bit about getting a good ADC. As I think part of the problem with digital is that a lot of products lack the attention to detail that goes into analogue products. I have an analogue oscillator that goes into an 8 bit digital wavetable, and that has really convinced me that digital can sound great. It's a purist's nightmare, all that high quality analogue charm going into a crappy digital wavetable? but when I hear it I know what my ears and body tell me.

I was looking at getting this ADC chip as Texas instruments sell a developer board with the analogue front end and all the pin outs, but it would have cost a lot to build my own case, power supply etc etc. Plus I think the analogue parts make a difference. So this looks like a good option.

Mytek are also worth looking at in this kind of price range.

[Dal-Tech]

let us know how it turned out. I'm still not 100% about how much a difference a high quality ADC will make, but I often hear people voice issues with how digital recordings can sound, and as vinyl doesn't really seem to be my thing, I thought quite a bit about getting a good ADC. As I think part of the problem with digital is that a lot of products lack the attention to detail that goes into analogue products. I have an analogue oscillator that goes into an 8 bit digital wavetable, and that has really convinced me that digital can sound great. It's a purist's nightmare, all that high quality analogue charm going into a crappy digital wavetable? but when I hear it I know what my ears and body tell me.

I was looking at getting this ADC chip as Texas instruments sell a developer board with the analogue front end and all the pin outs, but it would have cost a lot to build my own case, power supply etc etc. Plus I think the analogue parts make a difference. So this looks like a good option.

Mytek are also worth looking at in this kind of price range.

It still hasn't arrived. They do respond to E-mail, we are a two man operation, swamped, I promise yours is next yadada... Mytek is more expensive, double the price, but probably worth it for less hastle.

I tried using the SPIDF on a Lexicon MPX200 = sucks, cheap converters.

I bought a Tascam US‑122mkII with SPIDIF IN OUT and the analog ins audio quality sucks. I'm just using it for SPIDIF.

My M Audio USB analog ins sucks.

I'll be surprised if the Ross Martin ADC isn't way better then the cheapy M Audio, Tascam USB audio interfaces or the Lexicon MPX200...

[Dal-Tech]

It should be arriving soon (fingers crossed). I'll put up a comparison sample when it comes in.

[oblioblioblio]

Well I splurged and got an expensive ADC. I found a good price on a Forssell MADC-2 second hand which I found to be probably the best audio quality from my research. Although looking at the number of components and some of the build quality I think I got ripped off a bit... gear for the mastering market is often quite heavily priced. I'm used to the modular world where people really aren't charging that much.

Anyways, running at 96k samples per second and 24bit depth, (my Echo Audiofire can't go any higher) I can hear a big difference in depth and clarity compared to the converters on the Audiofire, I was thinking it would be really subtle but I noticed it very quickly. However, if I AB it against the straight analogue signal it still doesn't match up, most noticeable in the midrange, where there is an alive liquid quality to the sound that dissapears when you go digital.

However, I don't have an expensive DAC so it's quite possible that if I had that it would bring the digital quality a little closer to the full analogue sound, also if I was able to go to full 192K.

I don't think I would get anything from a sample, but I would be interested in what you notice or perceive to be different.

I'm gonna keep the ADC as I can't really escape the fact that digital is a good medium and very popular, but I'm thinking about what I can do in the analogue domain regarding recording and distribution.

[Dal-Tech]

However, I don't have an expensive DAC so it's quite possible that if I had that it would bring the digital quality a little closer to the full analogue sound, also if I was able to go to full 192K.

They say it does make a difference like you can hear details that you couldn't before, you can tell in a piece of music was poorly recorded or you can't believe hi end audio is coming out of your laptop. That sort of thing

I'm gonna keep the ADC as I can't really escape the fact that digital is a good medium and very popular, but I'm thinking about what I can do in the analogue domain regarding recording and distribution.

I bought an ADC mainly for recording. I nice DAC doesn't really fit my needs at the moment. If I was an audiophile with a hi-fi system then you know, I would have a nice DAC.

[Dal-Tech]

Okay I got the unit and did a sound comparison. Will post a pic later.

The first audio clip you'll hear is the Mbox Mini.
The same audio is played again through a Ross Martin DAC.
I repeate this process two or three times.
Ignore the synth toward the end since they are not the same.
I ran a stereo out from a drum machine directly into both units.

Here's the Soundcloud link.



https://soundcloud.com/sabstractcontact ... mini-sound

edit - a full track into the PCM4222 ADC:



The Burr Brown PCM4222 ADC sounds better to my ears. It seems to have a crisper high end with more depth although it does sound thinner played back my laptop speakers. One thing I noticed is it does not record a hot signal even if I crank up the volume compared to the Mbox. The Mbox sounds more mid rangey, completely different.

Edit - I included a raw track from a Behringer mixer recorded into the ADC. I plan to upgrade to a Dangerous summing bus soon and ditch the cheapy mixers.