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Ross martin audio Audio Interfaces
Old 25th September 2012
  #61
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Has anyone tried his preamp?

Sent from my Transformer TF101
Old 5th October 2012
  #62
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At the price point it is at, and with the component selection and circuit design these DA converters are a no-brainer.

Replace the caps and plug and play with your op amps and you can have an DA that whips products costing 20x as much.
Old 5th October 2012
  #63
nms
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Or at least that's how the fable goes. No offense btw. I did buy one of these myself so I don't blame anyone for getting caught up in the hype. Any technical measurement tests will paint a different picture though not to mention side by side listening tests with a good DAC and monitors. If anyone out there can get a Right Mark Audio Analyzer test result that isn't worrisome please do get ahold of me. In particular if someone has one of the DACs and also owns a clean ADC to use for a loopback of the RMAA file please contact me and I'll send you the test file then process the result.

A good converter is far more than a few Burr Brown components. Design trumps components any day. Look at the new Lynx Hilo. Same converter chip as the Auroras yet totally different sound and one of the top praised converters out at the moment.
Old 5th October 2012
  #64
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Quote:
Originally Posted by nms View Post
Or at least that's how the fable goes. No offense btw. I did buy one of these myself so I don't blame anyone for getting caught up in the hype. Any technical measurement tests will paint a different picture though not to mention side by side listening tests with a good DAC and monitors. If anyone out there can get a Right Mark Audio Analyzer test result that isn't worrisome please do get ahold of me. In particular if someone has one of the DACs and also owns a clean ADC to use for a loopback of the RMAA file please contact me and I'll send you the test file then process the result.

A good converter is far more than a few Burr Brown components. Design trumps components any day. Look at the new Lynx Hilo. Same converter chip as the Auroras yet totally different sound and one of the top praised converters out at the moment.
Out of the box I'd totally agree with you. It was universally worse than my JW modified hd24xr in blind tests with 3 participants. Both circuits were direct coupled lme47910/20/40 into the respective converters if I recall correctly.

Out of the box I noticed there were subtle phase problems in the midrange. 'breaking in' did not help. I opened it up to find and INCREDIBLE circuit board with awful caps! Changed them out and poof, it was roughly equivalent, except with superior low end approx 40 and below, and superior extreme high detailing. After many op amp swaps and tests, the little bugger was incredible.

The extremely high quality circuit board, excellent design (direct coupling), and unbeatable converter chip means this little guy has the basis to become a beast that cannot be beaten by a retail item. However, right out of the box, it's not exactly the bees knees.

Ask Ross to 'upgrade' it to your specs, or do it yourself

edit: I should really add though, even out of the box, for the price, I can't imagine finding anything of that quality at that price point
Old 6th October 2012
  #65
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Great perspective, guys.

Having upgraded from (pretty close to) crap converters, I really dig my PCM1794, but am intrigued by the notion of making it better!

Any guidance you can offer on component upgrades, caps & op amps? I went with the National LME op amps rather than the Burr Brown on Ross's advice & after comparing the specs. Curious if you'd share which op amps you settled on after swapping & testing & which caps you swapped out with what. Thanks!
Old 7th October 2012
  #66
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Quote:
Originally Posted by spice house View Post
Out of the box I'd totally agree with you. It was universally worse than my JW modified hd24xr in blind tests with 3 participants. Both circuits were direct coupled lme47910/20/40 into the respective converters if I recall correctly.

Out of the box I noticed there were subtle phase problems in the midrange. 'breaking in' did not help. I opened it up to find and INCREDIBLE circuit board with awful caps! Changed them out and poof, it was roughly equivalent, except with superior low end approx 40 and below, and superior extreme high detailing. After many op amp swaps and tests, the little bugger was incredible.

The extremely high quality circuit board, excellent design (direct coupling), and unbeatable converter chip means this little guy has the basis to become a beast that cannot be beaten by a retail item. However, right out of the box, it's not exactly the bees knees.

Ask Ross to 'upgrade' it to your specs, or do it yourself

edit: I should really add though, even out of the box, for the price, I can't imagine finding anything of that quality at that price point
Could you specify what modifications you've performed on which caps?
Old 7th October 2012
  #67
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Quote:
Originally Posted by D3R1D3X View Post
Could you specify what modifications you've performed on which caps?
No because 1. it's not a 'final' design, or as exact as I'd like it (no schematics available) and 2. I don't want to argue or defend my design to our more deaf members who believe caps/wire/op amps don't sound different.

That being said, opening it up you'll find cheap 5c bulk caps. Safe to say anything you put in there as replacement will be an improvement.
Old 29th October 2012
  #68
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come on.. nobody is going to argue with You.. we (people who don't read schematics, and don't know much about different capacitors or opamps) would like to have a more detailed hint as to what to change to get better (not best in the world) results.. simple as that..
I will be ordering Ross Martin Audio converters, I'll be trying to make some custom box (either 8ch ad OR 2ch adda with usb) and I'd love to know what to suggest to mr Ross.. that's all..
Old 10th November 2012
  #69
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Just got my 1794. Made some prelim listening compared to the AF2, Duet1 and the integrated output of MacBookPro using an AKG K550. My first impressions are mixed. But definitely would not say that this thing is bad.

Question:
do you guys hear any difference between the USB in and the SPDIF in?
Old 10th November 2012
  #70
spdif

Quote:
Originally Posted by D3R1D3X View Post
Just got my 1794. Made some prelim listening compared to the AF2, Duet1 and the integrated output of MacBookPro using an AKG K550. My first impressions are mixed. But definitely would not say that this thing is bad.

Question:
do you guys hear any difference between the USB in and the SPDIF in?
Yes, I can hear the difference, the SPDIF and and the AES sounds the best, the optical is a little "glassy" and the usb sounds a bit "thin",but this is obvious I think ,because there is a spdif to usb converter which applies another conversion in the signal path(this is true to the spdif optical conversion also)
Old 10th November 2012
  #71
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Quote:
Originally Posted by noiselab View Post
Yes, I can hear the difference, the SPDIF and and the AES sounds the best, the optical is a little "glassy" and the usb sounds a bit "thin",but this is obvious I think ,because there is a spdif to usb converter which applies another conversion in the signal path(this is true to the spdif optical conversion also)
Thanks. Two-three years ago, when I was really down to chip porn, the USB input chips they used for audio peaked at a <105 dB dynamic range.

I A/B-d the RMA1794A HeadPhone ADA vs. the Duet 1.

METHODS

Headphones
I used an AKG K550 and a Sennheiser HD555.
Impedance of the K550 is 32 Ohms, and 50 ohms on the HD555.
The K550 is closed, IME extremely accurate, with a recessed but very accurate bass, decent midrange and good highs, but tends to get a bit harsh on the highs if the material has a lot of of in a certain frequencies (approx between 12-14khz). Due to the low impedance, it can produce a decent volume with almost anything. However, the higher the volume, the more irritating the harshness can get on the highs. At mid-to-low volumes this is the most accurate headphones I've heard.
The HD555 is open, and compared to the K550, has more but a bit "blurred"/less accurate bass, a bit less volume due to the higher impedance and openness. It has a more HI-FI character, with a generally more flattering character.

Signal path
Surge protected outlet=> Desktop Windows PC with low noise PSU=> Foobar 2000=> AudioFire2 (powered off FW)=> Spdif out => RMA1794-HP-ADA=> filter position 2 (dunno if it's working) => Headphone out
MacBookPro on battery power=> Audirvana=> FW Duet 1=> headphone out
I set the volume to the maximum in the digital pathways, so that the entire available bit range is utilized.
I tried to set up the same perceived volumes on both units, although it's not really achievable (see below).
I turned off all resampling on both computers, and strictly played everything in 44.1Khz (see explanation below)

I played the same soundfiles on both computers and switched between the headphone outputs.

RESULTS
First, the RMA1794 has a little noise on the HP out that I could only hear with the closed K550. It's so minimal that I had to take off the cans to check if it were coming from the background. Interestingly this noise was only audible when the volume was all the way down. Keep in mind, it's almost inaudible.

The noise floor of the Duet is definitely lower, in fact you hear no noise on it at all. The Duet has a character, which is more like what people tend to refer to as "digital" - in a good sense. Very clear all over, especially on the high-end, bass is recessed but decent and maybe a little bit lacking in the mids. The latter greatly contributes to the clean character of the Duet.

The RMA1794 is more of an "analog" sounding converter. More bass, less sibilant highs. The main difference is that the RMA1794 has way more in the mid frequencies, which decreases the perception of "cleanness" with this DAC. Due to this, the volumes on the two DACs aren't really matchable. I caught myself increasing the volume on the Duet to get the oomph the RMA1794 has. Any time I switched back to the RMA1794 I always realized, that it wasn't the volume I was missing from the Duet, but the warmth.

The other main difference was in the perception of the mixes. Maybe the RMA1794 has a little narrower stereo width, maybe because of the warmer character, but mixes sounded much more "together"/blended/as one compared to the Duet. This was especially noticeable with vocals. While most of the gear I use nowadays tends to make the vocals jump out of the mix - as does the duet, the RMA1794 reproduces vocals embedded deep in the mix, as the vocals were an inseparable part of the mix.

One very peculiar thing I've noticed was the weird noise I heard when I used resampling at 96Khz with the RMA. It made me feel that everything is squashed in the RMA, thus the dynamic range was low. I don't really know the explanation for this, the only explanation that comes into my mind is that the 44.1KHz clock in the RMA is better than for 48KHz. Any other hypotheses?


CONCLUSION
I compared two excellent converters from the same price level. The Duet is an ADDAC in a very portable package, it's Mac and FireWire only - both are significant limitations. The RMA is a pretty versatile DAC that you can use with many kinds of equipment, but is less portable and has no ADC (duh.
While the Duet is more of a nicely digital sounding surgically clean DAC, the RMA1794-HP-ADA is a warmer, thicker, and just a bit noisier DAC that provides excellent integration of instruments especially vocals into the mix.

The differences are obvious, however I doubt that I would have been able to spot them without directly A/B-ing the two units. Since both of these are excellent converters, I would say that preference of one over the other is a matter of taste and there's no absolute winner.

Keep in mind that this review only covers the headphone outputs of these units. I might try to do a comparison for the speaker outputs later. Please feel free to "up" my post if you found it useful.
Old 20th November 2012
  #72
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Lol, I think I pretty much killed the topic:D
Old 15th December 2012
  #73
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I have here his PC4222ADC.

Cant tell much cause i only have an UA Apollo on the ADC department and the Ross Box.
But i have some experience with DACs as i had many and also right now have 2 boxes here, the BLA White DAC and the Yulong D18, both use the new 32 bit technology, very stable clocks, good electronics and some of the best DACs builded lately.

Both DACs sound less colapsed than the Apollo Master Out, transients and separation are better, of course its not a nigh and day diff, but its there.

The Ross ADC has on paper some nice stuff, but it uses a Wall Wart, and as someone mentioned the OP-Amps, Caps and other stuff inside are far from top notch.

So the unit needs a lot of tweaks to rival the big boys.

A toroidal Tranny with an internal PSU
A better division between the Digital and Analog parts
Better Caps
Better OP-Amps
A better case ( its markeing bull**** only, but helps )

Dont take me wrong, for what ive payed its a great unit and probably the only high end ADC on this price range i ever saw...

But this guy can come in some years with ADC and DAC designs that rivals the big boys and costing 3x less.

So i give my best wishes for the man for comming up from scratch in the market with some cheaper units that do a wonderful job.
Old 17th December 2012
  #74
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I just got and tested his AD converter as well

For those who didn't read my post earlier in this thread, the DA I got from Ross didn't beat my JW modded hd24xr out of the box, but it blew it away after some simple modifications.

This AD out of the box blew away my hd24xr. Not even a comparison, totally different league. I noticed Ross used higher quality caps throughout the signal chain on this unit, though the PS caps were the same. There is a differential lme49724 in there as well - very good specs. Not too many many amps to swap there unless you made some sort of adapter.

For the price? Don't think anything comes close. With a full overhaul in the spirit of Jim Williams I'd have no doubt this would be the best AD available currently. These new chips from TI line are incredible, and unbelievable to me that you can get them for this price when you can pay several times more for 10 yr old technology. Keep it up Ross! exciting things to come.

Last edited by spice house; 8th January 2013 at 07:21 PM.. Reason: more testing
Old 18th December 2012
  #75
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Brilliant! I'll open mine and take pictures when I'll have the time, so we can start a dialog about future tweaks!

Sent from my Nexus 7
Old 19th December 2012
  #76
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Quote:
Originally Posted by noiselab View Post
Yes, I can hear the difference, the SPDIF and and the AES sounds the best, the optical is a little "glassy" and the usb sounds a bit "thin",but this is obvious I think ,because there is a spdif to usb converter which applies another conversion in the signal path(this is true to the spdif optical conversion also)
I'm super curious about this.. I've been running USB (windows) and I wonder if anyone can opine...

will my stock soundcard's optical out:
1) Cause any performance problems?
2) Be willing/able to slave to the nice clock in the converter? *
3) Stop losing sync as often as the USB does (man, i hate windows)? **

* i'm guessing this depends on the card & the driver, i've never enabled or installed the drivers for my integrated audio hardware in my DAW machine.

** anytime you open a new track in WMP, sometimes when flash or java initializes.. it is a bummer that the DAC doesn't suppress the nasty little digital click when a sync change happens.

I'll pick up a TOSLINK cable & see how that all works & sounds.. Seems like if nothing else, any usb-induced jitter (adaptive isosynchronous if i'm not mistaken) will be alleviated.

Thoughts on if this might be a worthwhile endeavor? I'm pretty happy with my RM out-of-the-box, but would love to make it better.

This thing has become my daily driver, otherwise i'd be swappin' caps. Can't afford the potential downtime. At this price it might be worth picking up another & making a project out of it.
Old 21st December 2012
  #77
spdif

If you ask me just use the spdif/AES inputs. The DAC has an own clock, so it will sync itself to any soundcard(if the spdif/aes signal is standard)
I'm using it with an old RME Digi96 thru the AES, and it never loses the signal whatever I'm doing. Btw after the DAC arrived, the PSU screws had to be tightened otherwise the DAC lost the signal when I switch my lights on/off NOw I put the PSU box to an old Sennheiser shielded case, it works perfectly.


Quote:
Originally Posted by jruberto View Post
I'm super curious about this.. I've been running USB (windows) and I wonder if anyone can opine...

will my stock soundcard's optical out:
1) Cause any performance problems?
2) Be willing/able to slave to the nice clock in the converter? *
3) Stop losing sync as often as the USB does (man, i hate windows)? **

* i'm guessing this depends on the card & the driver, i've never enabled or installed the drivers for my integrated audio hardware in my DAW machine.

** anytime you open a new track in WMP, sometimes when flash or java initializes.. it is a bummer that the DAC doesn't suppress the nasty little digital click when a sync change happens.

I'll pick up a TOSLINK cable & see how that all works & sounds.. Seems like if nothing else, any usb-induced jitter (adaptive isosynchronous if i'm not mistaken) will be alleviated.

Thoughts on if this might be a worthwhile endeavor? I'm pretty happy with my RM out-of-the-box, but would love to make it better.

This thing has become my daily driver, otherwise i'd be swappin' caps. Can't afford the potential downtime. At this price it might be worth picking up another & making a project out of it.
Old 21st December 2012
  #78
I have a question from the modding guys: What kind of replacement caps do you use? As I remember the PSU has 3300uf/35V caps, but the max height of the caps can be 25mm(no more space in the rack) All the quality caps (ELNA,Nichicon,Rubycon,etc) are at least 30-35mm high. I only found Panasonic EB series at farnell, but I don't know that it would be a big step up. Btw Ross introduced the 8 channel ADC/DAC's on his website.
Old 21st December 2012
  #79
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Quote:
Originally Posted by D3R1D3X View Post
Brilliant! I'll open mine and take pictures when I'll have the time, so we can start a dialog about future tweaks!
Let's do it!
Old 22nd December 2012
  #80
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Quote:
Originally Posted by noiselab View Post
I have a question from the modding guys: What kind of replacement caps do you use? As I remember the PSU has 3300uf/35V caps, but the max height of the caps can be 25mm(no more space in the rack) All the quality caps (ELNA,Nichicon,Rubycon,etc) are at least 30-35mm high. I only found Panasonic EB series at farnell, but I don't know that it would be a big step up. Btw Ross introduced the 8 channel ADC/DAC's on his website.
I'll take quality caps over nice looking case any day!

Sent from my Galaxy Nexus
Old 22nd December 2012
  #81
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Quote:
Originally Posted by noiselab View Post
IBtw after the DAC arrived, the PSU screws had to be tightened otherwise the DAC lost the signal when I switch my lights on/off NOw I put the PSU box to an old Sennheiser shielded case, it works perfectly.
Ohh, I've had a *little* bit of this intermittently. Can you elaborate? You mean on the wallwart itself or somewhere in the box?

And my optical cable is on it's way, excited to try that out.
Old 22nd December 2012
  #82
RM

I'm living in Europe, so he sent me the unit without the plug. Check the wallwart cable screws, tighten them if they are loose. In the box everything was ok.

Quote:
Originally Posted by jruberto View Post
Ohh, I've had a *little* bit of this intermittently. Can you elaborate? You mean on the wallwart itself or somewhere in the box?

And my optical cable is on it's way, excited to try that out.
Old 22nd December 2012
  #83
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Quote:
Originally Posted by noiselab View Post
I'm living in Europe, so he sent me the unit without the plug. Check the wallwart cable screws, tighten them if they are loose. In the box everything was ok.
The terminal screws on my wall wart were just slightly beyond hand-tight. Tightened them down a bit more, nice catch.
Old 17th March 2013
  #84
Finally we modded my PCM1974 DA, changed all the caps to Panasonic EB/FR and Nichicons+bypassed the psu caps. I already ordered some TI ths4012's,but in the end I'm satisfied with the ADA4898's. The biggest difference is in the headphone amp, it had a weird modulation noise at high levels before the mod,now it is completely gone, and it sounds great even with my cheap Senn HD201's. Next step will be a custom toroid PSU.
Old 29th March 2013
  #85
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Hi Guys,

I went ahead and bought DACs and ADCs from this guy. A few points:

a.) Customer service and responsiveness is top-notch. I wanted a (not listed on the site) 8-channel DAC unit with a VERY particular set of specs. Ross figured out how to do it no problems and delivered a fantastic product.

Also, I needed a unit that could do both 120 & 220v, so I could use them in USA and EU. No problem. No extra charge (!) - even though he ended up sending a separate set of power transformers just for the EU.

b.) I shot out these DACs (they use the TI PCM1794A chips, mind you) and the 4222ADC against brand new Avid HD I/Os.

I won't get all esoteric, I will simply say: SIGNIFICANTLY better on all fronts (and the HD I/Os in turn are a whole new league over the Digi192s before them).

For the price Ross sells them at? JUST BUY THEM.

You can PM me and thank me once you listen to how awesome they are
Old 29th March 2013
  #86
MXX
Gear Nut
 

Quote:
Originally Posted by sirio.bm View Post
Hi Guys,

I went ahead and bought DACs and ADCs from this guy. A few points:

a.) Customer service and responsiveness is top-notch. I wanted a (not listed on the site) 8-channel DAC unit with a VERY particular set of specs. Ross figured out how to do it no problems and delivered a fantastic product.

Also, I needed a unit that could do both 120 & 220v, so I could use them in USA and EU. No problem. No extra charge (!) - even though he ended up sending a separate set of power transformers just for the EU.

b.) I shot out these DACs (they use the TI PCM1794A chips, mind you) and the 4222ADC against brand new Avid HD I/Os.

I won't get all esoteric, I will simply say: SIGNIFICANTLY better on all fronts (and the HD I/Os in turn are a whole new league over the Digi192s before them).

For the price Ross sells them at? JUST BUY THEM.

You can PM me and thank me once you listen to how awesome they are
a. wrong. most of the world is still waiting for any kind of reply about anything (search and see).

b. better than the Avid... nothing to say.

c. I wont PM you because I already know the answers.

If Ross answered emails, he would be a MILLIONAIRE!

fyi there are better german/korean/chinese units, far better components (circa next year ****) floating around now... the RMA thing came and went like, 2 years ago xmas? srriously
Old 29th March 2013
  #87
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Quote:
Originally Posted by MXX View Post
a. wrong. most of the world is still waiting for any kind of reply about anything (search and see).

b. better than the Avid... nothing to say.

c. I wont PM you because I already know the answers.

If Ross answered emails, he would be a MILLIONAIRE!

fyi there are better german/korean/chinese units, far better components (circa next year ****) floating around now... the RMA thing came and went like, 2 years ago xmas? srriously
poor baby
Old 29th March 2013
  #88
MXX
Gear Nut
 

Quote:
Originally Posted by OLDENGLISH View Post
poor baby
baby got back!
Old 30th March 2013
  #89
Gear Head
 
D3R1D3X's Avatar
 

Quote:
Originally Posted by MXX View Post
baby got back!
Do you wish to add something constructive to the topic as well?
Old 9th April 2013
  #90
Hey guys I am wondering how this thing stacks up against a BLA Sparrow White mkII in terms of performance, price aside.

Thanks
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