Saturday, January 19, 2013

USB SPDIF WARS - Audiophileo vs Yellowtec PUC 2 review.

I have just compared two USB spdif converters. This is the review

In one corner, the extremely well reviewed Audiophilleo 1.

In the second corner the relatively unknown, in hi fi circles - Yellowtec PUC 2.

Yellowtec, distributed in Australia by Production Audio Video Technology, is a German company that is well known in the professional broadcast industry.  The Yellowtec PUC 2 has been around since around 2006.

The PUC 2 is a USB to AES converter, providing 24 bit 192khz playback and recording. It provides AES input and output, and a pair of balanced analog inputs and outputs. This means it really is aimed at the professional market, which is the primary user of balanced signals and XLR connectors.

My DAC has an RCA SPDIF input so I had to make up an XLR to RCA adaptor.  I used a female XLR connector with pins 2 and 3 connected to a digital transformer and the secondary connected to a female  RCA cable. Ideal? Yes, no, maybee? It did the job!

The comparison was done using a stock standard un-optimised XP desktop computer. Software used was Foobar, and cPlay (running on the desktop - not in CMP mode).

A low noise external aftermarket linear power supply, powered both converters, by "injecting" power into the device-end of a home-made USB cable. External power is the best way to power any USB audio device.

The review:
The Audiophilleo 1 is a really good sounding converter. It is nicely balanced, smooth and detailed, and clearly has low jitter, and exceptional clarity. I don't think I need to say much more. It has been reviewed before in so many other forums and online places. Just do an internet search.

The Yellowtec PUC 2 in direct comparison, gave that little bit extra of everything. Deeper cleaner more defined bass. Cleaner mids and highs. We did listen to a few test tracks but one that increased the obviousness of the improvement was German band "Focus"  the track "Hocus pocus" typically using a lower fidelity source with this 1970's (by today's standards - low-fi) recording, the separation between bass guitar and bass drum is usually very hard to pick. The bass frequencies usually sound murky.

The Audiophilleo did a good job, but the PUC 2 was so much better. I could hear the bass guitar being picked, the "twang" of the strings, and the hit of the mallet on the bass drum even more clearly. The Audiophilleo just didn't do this as well - the murk was still there!

Many times when I have tried a cleaner audio transport, there seems to be the perception of less bass, but with the PUC 2, you get to have your cake and eat it too. Bass gets cleaner, deeper, and more tonal, yet maintains the same perceived amplitude.  Perhaps giving even a little more perceived bass.

The PUC 2 presents a more forward detailed midrange,  in a way that seems to strip back layers of muck, that I never knew was there, revealing the full clarity on the recording, yet without ever sounding harsh or clinical.

In conclusion, the PUC 2 retains all the smooth grain free sound of the Audiophilleo, but takes clarity, musicality and tone to a higher level, right across the frequency spectrum.

Professional users will be delighted with its robust functional exterior, and highest quality sound. The domestic audiophile will be suitably impressed with never before heard detail, and lowest jitter performance from a USB audio converter.

To me, at first it seemed strange that this professional device would out perform the highly reviewed and widely advertised Audiophilleo. I guess the marketing hype had got to me. However after thinking about it for a while, it makes perfect sense - the professional audio industry requires and demands the highest standards of audio capture and reproduction.

Sometimes there can be confusion regarding professional audio products. It can be difficult to know which ones are the real deal.

"Prosumer"  (Professional products for the domestic consumer) come at a budget price and have XLR connectors, they "look" professional, and they do the job, but sound like nothing special.

Then you have real professional products, with real electronics engineering behind them, striving to push the boundaries, and developing new technology and techniques to beat the competition. Yellowtec falls into this category. Underneath the PUC 2's functional exterior lies a finely engineered circuit,  designed to give the ultimate audio performance.

The PUC 2 comes supplied with a low latency ASIO driver developed by Ploytec. Even though the device is plug and play, and does not need a bespoke driver, use of the supplied driver provides even higher sound quality when running a windows operating system. The PUC 2 is not officially supported with a Linux driver, however it has been tested with the latest Vortexbox software and works perfectly and sounds wonderful.

For those who don't need analog inputs and outputs, Yellowtec also make a PUC 2 lite . I suspect this might sound even better than the unit reviewed, due to the lack of power demands from the analog circuitry.

The PUC2 sounds better in all areas, and there are no compromises to be had.. The PUC2 costs less as well, and the Lite version is even cheaper!

Australian Pricing:

Audiophilleo 1 is  $986 delivered. 
PUC 2 is $761.00 inc 10% GST (Recommended retail price)
PUC 2 Lite is $599.00 inc 10% GST (Recommended retail price)

I guess its possible to get them cheaper than this, because no-one pays retail price anymore. Do they?
And I guess if you are in the industry you could probably get "dealer" (=cheaper)  pricing.

If you would like to read another review of the Yellowtec PUC 2 see this blog:


  1. Someone wrote to me, and this is an edited version of their comment ( I have removed their email address out of courtesy) - "Hi, Did you ever test this unit against an AP1 with pure power battery supply? I understand you do not want to make the AP1 sound bad, but I personally felt the AP2 was absolutely atrocious sounding and had no problem writing up a review about it. My friend felt the same way about the AP2. Of course others think AP1/2 sounds wonderful. Would love to hear some further thoughts on just how much superior this Yellowtec device is over the AP1 and also if you ever heard AP1+Purepower or would know basically what to expect, etc."


  2. In response to the above comment - No I did not try it with a pure power battery supply. I have tried other usb converters with battery supplies. And I think that SLA (sealed lead acid) batteries can reduce the perceived dynamics of the sound. I think batteries tend to smooth things over too much. I have read good reports about the A123 batteries, but never tried one. Perhaps they are an exception?

    I have been very pleased with the sound of external linear power supplies - These increase perceived dynamics, when compared to just running off USB power, and at the same time reduce the edgy sound that you get with most if not all "lower tech" budget USB converters.

    When I tried the PUC 2 on just USB power, it did not suffer from any "edgy" sort of sound that I would normally associate with running off USB power, but dynamics did seem to suffer. The sound did get a bit more "flat" sounding, and "smoothed" out more. I used a linear power supply because I know that this gives me the best sound when using a USB audio device. All the audio enthusiasts I know use external linear power power supplies for their USB converters.

    I assume from your comments that the AP2 must sound dramatically different from the AP1. Because I really had no problems with the AP1. It really is good, in my opinion. Perhaps you can send me a link to your site so I can read your comments? I am interested!

    How much superior you ask?

    In many respects the AP1 and PUC 2 sound quite similar, both don't suffer from sibilance and grain like cheaper units. The sonic balance is very good on both units - meaning that no frequency jumps out as being over dominant. Both provide a detailed, musical, listening experience.

    I try my best to avoid prolonged passages of "audiophile speak" because I find it mundane to read. So, I'll jump to the point - The PUC2 is better in all areas, because during complex passages of music the PUC 2 is able to metaphorically, very clearly draw a line around different instruments enabling each instrument to be clearly heard. Background sounds that were once buried in the mix were now easy to distinguish.

    I didn't have to strain or try hard to hear it. It was an obvious clearly audible improvement. One of my personal immediate reactions, whilst listing though the PUC 2 was - I didn't know my speaker drivers were this detailed! That is not something that happened for me when I was listening to the AP1.

  3. I own the AP1 used in this testing :)
    I was both surprised and very pleased with what we were hearing,when testing the Yellowtec Vs the AP1.

    I agree the Yellowtec Puc2 is the preferred usb to spdif converter on an A B comparison.
    Quite noticeably so. The difference is not small in my eyes.

    However in saying this the AP1 is still a very very decent converter, and it sounds fantastic.

    Its just the Yellowtec is better in nearly every area. Its musicality is pretty amazing. The best I have heard. The yellowtec throws out a very musical and detailed soundstage. Quite amazing considering its price.

    If I had my converter money back in my pocket, I would buy the Yellowtec in a second.

    Super smooth & detailed, awesome bass tone and beautiful high frequencies. FYI, linear power is a must... No converter sounds its best connected to usb power.

    I agree with agent 86, give batteries a side step... These solutions are overpriced and don’t provide superior results when compared to linear power solutions.

    A decent linear power solution can be purchased on ebay for $40, which will transform your converter.


  4. Thanks for the article. Focus is a Dutch band, not German. :)