We keep repeating for years, that the “wall wart” power supplies for small devices like phonostages, DACs, headphone amplifiers, ets, are real scoundrels, which limit the capabilities of those devices. But never before the case was so important as it is now. Because currently the hot topic are high resolution files. In case of computers the issue lies in very high noise generated by them as well as high jitter. And hi-res files are prone to noise and jitter. The theory of signals tells, that the higher the signal flow is, so in reality the higher the sampling frequency and word length, the more such signal is vulnerable to jitter. And it is generated by many elements, usually depending on power supplies. So why companies do not equip DACs with integrated power supplies, or large, external ones? The answer is very simple – savings (read: “money”), although it goes both ways. First of all, a wall plug power supply is extremely cheap. With inexpensive devices, like the tested ones, this is key. Secondly, using an external power supply with low output voltage (here 6 and 12V DC) no special CE certificates for the devices are required, because those are only needed for power supplies, and their manufacturer pays for those. And this means additional savings.

Fortunately, the prayers of audiophiles were answers by small (usually micro) manufacturers, like Teddy Pardo, interested with audio gear from their childhood. In the 70-ties he owned a system based on Linn and Naim components. The latter offer a way of upgrading them by an external power supply. So did Teddy, building his own HiCap power supply. And he continued like that. In contrast to most solutions of that kind, the Israeli power supplies, Teddy is an Israeli, are made using transistors and not integrated stabilization circuits. This is a more sophisticated solution, requiring knowledge and experience. But Teddy Pardo is not a weakling, he is a qualified engineer, who graduated Hardware and Software engineering, and worked in many big and smaller companies leading their R&D departments – for example in National Semiconductor, RadWare and Cisco.
This time the impulse came from a different side than usual, namely from Adam Mokrzycki, the organizer of the Audio Shows and audiophile by heart. He found Teddy and ordered power supplies for two DACs, which I tested some time ago for “Audio” – to the rDAC from Arcam and V-DAC from Musical Fidelity. Both are very nice, and both use the wall warts – Arcam uses a 6VDC and Musical a 12VDC one.
Because I know both devices well, I concentrated now on finding the changes in sound brought by the new power supplies. But to make the test coherent, I will repeat what I wrote in the test of the DACs themselves, using the standard power supplies.

SOUND

Recordings used in the test (selection):

• Brian Eno, Craft On A Milk Sea, Warp Records, WAV 24/44,1.
• Cassandra Wilson, Silver Pony, Blue Note, 29752, CD;
• Charlie Haden & Antonio Forcione, Heartplay, Naim Label, 24/96 FLAC.
• David Sylvian, Gone To Earth, Virgin/EMI Music Japan, VJCP-68877-78, 2 x CD.
• Diana Krall, From This Moment On, Verve, 1705042, CD.
• Dominic Miller, Fourth Wall, Qrious Music, QRM 108-2, CD;
• G. F. Haendel, Messiah (Dublin Version, 1742), Dunedin Consort&Players, Linn Records, CKH 312, FLAC 24/88,2;
• George Shearing Quintet with Nancy Wilson, The Swing’s Mutual!, Capitol/Toshiba-EMI, TOCJ-9468, CD.
• Harry Belafonte, Belafonte at Carnegie Hall, RCA/Sony Music, 7783322, LPCD-M2 Mastering, No. 0953, HQCD.
• Helge Lien Trio Hello Troll, Ozella Music, OZ021CD, FLAC 24/96;
• Stan Getz & Joao Gilberto, Getz/Gilberto, Verve, 24/96 FLAC.
• The George Shearing Quintet&Nancy Wilson, The Swing’s Mutual!, Capitol/Toshiba-EMI, TOCJ-9468, CD.

Japan versions of CD, SHM-CD, XQCD, SHM-SACD etc. you can find HERE.

Arcam rDAC

(The initial version of the listening test of the rDAC with standard power supply was first published in “Audio” 11/2010. We present it here in an extended version.)

Like I said in the test of that DAC made for “Audio” I was the first person in Poland and one of the first in Europe, who touched the production version of this device – I could still smell the glue used to attach the rubber foot to the enclosure… But it was worth the wait. The rDAC sounds with a beautifully composed, subtle sound. Its dynamics is overwhelming and goes in the direction of the best DACs I know. Initially I wrote that it equals those, but the new power amplifier I own, the Solution 710, allowed me to reach deeper into the sound and show the differences I am talking about. This is still a very good result, but now I hear, that this is a step in the right direction, and not the end of the path there. However in systems, where the Arcam is going to be used, “going in the direction of” and “equal” will mean the same.
The gravity point of the sound is shifted a little in the direction of the turn of midrange and bass, what makes things happening in the midrange – voices, trumpets, etc – sound in a very authoritarian way. Those are big and nice – this is important: the rDAC does not compress the virtual sources to the size of a peanut, but tries to reproduce them in their rightful proportions. The treble is slightly rounded and withdrawn. But to notice that, we have to compare the Arcam DAC to much more expensive players. Only then we will hear, that the upper treble is warm and rounded. But how! There is not a trace of sand, no annoying sibilants – nothing that would distract us from music and point our attention towards hi-fi. The lower bass is also slightly withdrawn, but this cannot be heard – like I say – the upper bass, and also mid-bass sound strong, with emphasis, dynamic.
The hi-res files sent via the RCA input have an even better depth, even better holography. It happened, that on the same day I received the Arcam, I installed new software in my file player, which allowed for outputting 192kHz signals. The rDAC accepted those without a glitch, although I did not hear much of a difference between the 96kHz and 192kHz versions. However switching from the CD quality to 24 bits and 96kHz resulted in a significant improvement.
This is important, because the Arcam works with USB 24/96. After logging in we can hear, what it all is about – this is a very transparent input, I could not really discern it from the S/PDIF one, especially – like I said – as the rDAC does not really differentiate 192 and 96kHz recordings. This is a very resolved, dynamic sound with very nice timbres. For something like that the price asked by Arcam is just ridiculous.

Price: 1500 zł | Distribution in Poland: Audio Center Poland | URL: www.arcam.pl

Arcam rDAC + TeddyPardo TeddyRDAC

Listening to the Arcam with the wall wart and then with the TeddyPardo power supply, it is hard not draw some general conclusions based on this experience (in all meanings of that word). Because later also the V-DAC behaved in a similar way, I think this has significant Gnostic value.
First of all we should not expect, that a power supply will change any DAC into a rocket sailing the skies and grounding all hi-end, beefed up DACs with every reproduced note. This does not work like that. Please do not believe such stories. But please do also not disregard them – maybe they do not inform about the rational part of the changes, but they show their emotional expression well. Adding the TeddyPardo PSU improves the sound, and that in a significant way, leading it in a direction, we feel, is the right one. And this is probably what we perceive in an emotional way – after the change of the power supply we feel an euphoric reaction – this is it! – Compared to the wall wart supply we can say that it is a breakthrough. The emotions cool down, when we compare the rDAC equipped with the new power supply with an expensive CD or audio file player (in my case it was the Olive O6HD).

But this is not what I wanted to talk about: the rDAC with TeddyPardo sounds brilliant, when listend to! We should not have any doubts – the change of the PSU makes a big, and even very big change. It is mostly a structural one. Because – this is the second general statement – such changes can only deepen the assets of a device, while covering some of its flaws, but they do not change its musical DNA. In case of the Arcam, the treble was still quite soft, and the reverb of the bass slightly enlarged and not as well controlled as from my Lektor Air. I had no doubts about that.
But the assessment of the sound changed. Now it was much more mature and palpable. In case of the rDAC the change the most important changes happened in the midrange. Voices of vocalists like Diana Krall from From This Moment On, or Nancy Wilson from the disc recorded together with George Shearing The Swing’s Mutual! were stronger, had a more three-dimensional shape. Without the help of the Israeli power supply their drawing was not bad, especially taking into account the price of the rDAC. But with the big PSU it was much, much better. The sound got more dense, between the performers was a kind of “film”, a thin layer of air, but not a thin one, like in the stratosphear, but resembling rather a hot evening in Chicago. This is an artifact of the recordings, of the recording technique, but the more expensive a system is, the better it is audible. There is no talking about pushing it outside “music”, this happens only in the top analog and digital sources, but the fact, that it appeared here at all, is already a big achievement.
Like I said earlier, the top range of Arcam is a bit withdrawn, similar to the upper midrange. The new power supply does not change that, it modifies only what was before. The treble is sweeter. I know, I know – this is not always well understood. “Sweet” treble means, that there are no annoying colorings, sharpness, sand. This is not always a positive asset, but in this price range, this is world championship.
Also bass will not get shorter, but the internal differentiation improves. Due to that, the very low, bass synthesizer generated passages on the disc Fourth Wall Dominic Miller, gathered more musical sense, I did not wait when those passages will end, because they were a part of something bigger, and I waited for that bigger part to resolve.

Musical Fidelity V-DAC

(The initial version of the V-DAC test with supplied PSU appeared first in “Audio” 11/2010. Here we present it in a slightly longer version).

Michaelson says the following about the V-DAC: “In fact overall the technical performance of the V-DAC is probably about the best in the world regardless of price.” This is of course not true, I know many DACs measuring even better, but it shows well the attitude of the owner of Musical to his product. To keep it short – it is positive, even enthusiastic. But such good attitude is founded on a solid base here. Because the main asset of the British DAC is the very even frequency response, which – for an inexpensive product – mimics that, what we can find in much more expensive CD players. Even very demanding recordings keep their original (assumed, of course) structure, they are not chopped or especially modified. And looking from that perspective, the V-DAC fulfills the assumptions of the manufacturer with ease. However some changes did happen. The most important ones are related to both frequency spectrum borders, and their influence on dynamics. I mean, that both the upper treble and lower bass are withdrawn here. So the cymbals are not as elucidate as elsewhere, and the lower band of the contrabass and bass drum are softened. Those changes are maybe not big, but they influence the overall character of the sound more, than could have been expected from their separate “weight”.
The general character of the V-DAC is rather “forgiving”, conciliate than “restrictive”. So all recordings sound pleasantly. When in some recordings we have any sanding, raised sibilants in voices, etc, the Musical will soften that and lay it back. So when we assume, that this unit will work together with inexpensive DVD and CD players, then this character should be received very well – this is an important ability and a very required one with budget gear. Applause for that! On the other hand, this is a kind of unification, depriving the listener from a part of the information. You have to know that and decide, if this is what you want. And this is something, that discerns the V-DAC from more expensive converters.
The USB input sounded very well. Yes, despite lack of information about that in the manual, the V-DAV installed in Windows Vista without a glitch and played without any problems. Taking into account the technology used by Michaelson, we can even say, that this is a surprisingly good result. The files played from my PC sounded convincing, with splendid dynamics and very well kept timbre – I had the impression, that it was even better than from the RCA input. It sounded better than the USB input in the Cambridge Audio DacMagic. Only the technologically more advanced Arcam solution allowed to go a step further.

And finally the hi-res files send by S/PDIF. Those sounded better than the CD, what tells good things about the resolution of the V-DAC. The saturation of the treble became better, the soundstage also got enriched, which was a bit narrowed from CD. The resolution was also better, but here the changes were smallest. This is a solid, well made device, without ornaments, which is a very interesting alternative to CD and DVD players at its price – so it ideally fulfills the assumptions of its author...

Price: 999 zł | Distribution in Poland: Audio Klan | URL: www.audioklan.com.pl

Musical Fidelity V-DAC + + TeddyPardo TeddyVDAC

The price difference between the Arcam and Musical Fidelity, the first one being almost twice as expensive, is clear from the very beginning. The rDAC has a more resolved, fuller sound. However it does not change the fact, that the V-DAC rules below 1000zl. Like I mentioned above, its sound is very pleasant and “not tenacious”. In inexpensive systems, with inexpensive amplifiers and loudspeakers, which have a tendency to sharpen and thin the sound, it will prove itself best.
Changing the power supply results in much deeper changes here, that with the rDAC. Attention please: I would like to be clearly understood here – changes introduced in both DACs are very similar, but those in the V-DAC have more “weight”. The Michaelson device is very nice when listened to soute, I am sure, it will be liked. But when we listen to it with the TeddyPardo power supply, we will not want to switch it off. It was different with the Arcam – the PSU changed the sound to a similar extent, but even without the new power supply it was fine. Musical Fidelity – I’ll repeat that – is very nice. There is no “fault” there. It appears AFTER listening to it with the new PSU, as if in case of this device, the external PSU would be more important.

The sound with TeddyPardo is much deeper and more differentiated. It improves almost everything, starting with the depth of the stage, through extension of the frequency response and finishing with palpability. And this last characteristic seemed most interesting to me. The voice of Sylvian from the disc Gone to Earth was finally close to what I know from the reference player. To have that music sound like it should, it needs enormous vividness, otherwise it will get lost in a cacophony of unrelated sounds. With the new power supply the V-DAC offered something like such sound. Dynamics was very good, and strong percussion from the piece Taking the Vail, opening that disc, sounded strong, dynamic and showed well what is BEHIND it. Equally important changes were to the presentation of voices. With the wall wart PSU they were blended into the background. This is not unpleasant, it even sounds nice, but we cannot talk about palpability and shape – the latter does not exist. With the TeddyPardo things changed. The stage got deeper, and with it the size of the shapes, including voices. Finally Krall was in front of the instruments, like with my player, and Miller’s guitar sounded strong and distinct. Bravo!

CONCLUSION

I will repeat what I wrote in the beginning – this is important, to understand well the case of the power supplies: changing the PSU does not create something completely different. Better power deepens the assets, that were there before, but it does not change the musical DNA.
The changes between the “with” and “without” are undisputable and introduce changes moving in the direction of the best digital players. Most of all the palpability of the sound improves. Everything is clearer, but without brightening of the sound, without sharpening or contouring. I would even say, that the sound is slightly softer, but in the good meaning of that word, I mean we pay more attention to the music than to the sounds.
This is probably the best way to upgrade a DAC, especially for the given money. We can go even further, adding a better power cable to the power supply. And it is worth it – really worth it!

DESCRIPTION

TeddyCap

Teddy Pardo power supplies have a common enclosure, regardless of which device they are destined to. And this enclosure is quite big, twice the size of the rDAC and V-DAC they are powering. This is a metal, aluminum shape with plastic yokes covering the places where the cabinet walls come together. In the front there is a single, green LED, and on the back two sockets – one IEC with integrated mechanical power switch and a fuse, and a metal, old type socket, where we connect the powered device. Teddy supplies a nicely looking, quite rigid, while thin, cable – but you have to send him the original plug he needs to replace.
The Israeli power supplies are built using universal PCBs, stuffed with parts suitable for the given project. Those are not simple integrated stabilizers, but discrete circuits on transistors. This results in much lower noise and faster slew rate.
The circuit for the rDAC and V-DAC is mounted on one of the six sections. It has seven transistors and a few capacitors, including one big. An efficient rectifying bridge is bolted to the bottom plate, which works a a heat sink. The voltage to that bridge comes from a medium sized toroidal transformer from Noratel (with the “hedgehog” logo). The circuit seems very simple, but as usual with simple circuits (look at tube amplifiers) the final effect depends most on the skills of its designer. In worked out circuits it is easier to correct something with a next stage, etc. Here you can’t.

Arcam rDAC

The Arcam device is not big, but very nicely looking. It looks as if a professional industrial design company would be responsible for its exterior. A sleek, finished in matte, enclosure of the rDAC is made from aluminum, and its bottom from a steel plate, with a rubber foot glued to it. On the top there are four slots with longitudinal LEDs, visible from top and front sides – they light red, when there is no signal, and green when synchronization with the drive has been achieved. They indicate signals available on one of the inputs – RCA, TOSLINK, USB or (optional) WiFi. In this last case, there will be a small antenna protruding from the back. On the top cover there is only a logo and a small input selector.

On the back it is (almost) classical: RCA (electrical S/PDIF) input, TOSLINK (optical) and USB. To the side there is a pair of RCAs with the analog output. There is also a hole plug in the place of the WiFi antenna. On the side we have also a mechanical power switch and a socket for the 6VDC power supply.

Inside there is a PCB that covers the whole surface, bolted not to the bottom, but the cast case forming all the other sides of the enclosure. For me the USB input was most important. This section has been licensed from a digital audio specialist, the company dCS – I am talking about the asynchronous mode. It allows decoding of signals up to 24/96 in an asynchronous way, clocked internally, without the need of following the host, computer clock. To be able to do that, a specific receiver must be used, a DSP, which is appropriately programmed. Here it was the chip TAS1020B, visible near the USB port, working in asynchronous mode. This is especially surprising taking into account the price of the rDAC. Next to it, there is a very good, temperature stabilized word clock. Let me just remind, that the cooperation between Arcam and dCS is not new – earlier both companies prepared the famous DAC chip Ring DAC used in the Alpha 9 and CD23 players from Arcam. The RCA and TOSLINK inputs are coupled with the digital receiver Wolfson Microelectronics WM8805. There are two receivers – seemingly one is for the S/PDIF inputs and the second for the optional WiFi receiver. The first one accepts 24 bits signals up to 192kHz, while the latter is limited to 24/48. There is only one DAC – a very nice, modern Wolfson chip WM8741, accepting signals up to 32 bits and 192kHz, with a very good, 125dB dynamics.
On the output we can see two chips L49722 International Semiconductor – low noise, quick ICs. The whole section is stuffed with very good Elna Silmic capacitors. The output – RCA (only the ground pin is gold plated) is coupled with a DC-servo circuit and activated with a small relay.
Most space is occupied by the power supply circuitry, with many stabilizing units, capacitors, etc. A part of the PCB is also ready for the optional WiFi module – there are sockets to plug in the pins of the additional PCB.

Musical Fidelity V-DAC

The V-DAC is a medium sized cuboid, supported on the largest wall. Differently to most other DACs the digital inputs are on one (side) wall, while the analog output on the other. It was clearly the intention to have the unit placed with the longest side facing the user.
There are three digital inputs: TOSLINK, RCA and USB type B. Two first ones are one group, and the USB is another – we switch between them using a small switch. On the same side there is a small socket for the external, 12VDC wall wart power supply. Next there are two LEDs – a blue one indicating power on, and a green one, lighting up when the unit is in sync with the drive. The manufacturer informs, that the V-DAC works with “real upsampling”, and that the USB input (talking about PC) was designed to work with Windows 98, ME, 2000 and XP. As it turned out, it played without any problems with Vista. However I did not find any information in the manual regarding the sampling frequencies and word lengths, which can be sent to the Musical.

Like I say, the enclosure is a simple, metal box, housing a single PCB filling the entire space inside. Looking at it we can see, that the placement of the inputs and outputs was the result of the chosen circuit solutions and the willingness to keep the signal path as short as possible. Because the signal flows from one side to the other, in a way of speech.
On the USB input we have a Burr-Brown PCM2706 chip, an old design, accepting at maximum 16 bits 48kHz signals. Next to it there is a 12kHz clock. It is interesting, this chip has a built-in headphone amplifier, which was not used here, and it would not even mean extra cost to do it. However Musical has a headphone amp in its catalog, V-CAN, and maybe did not want to compete against that one. The USB signal converted to PCM, or the PCM signal from the RCA and TOSLINK inputs (the switch is mechanical) runs to a very good upsampler BB SRC43921. This chip is used in many expensive devices, just to name the M1 player coming from Musical itself. The signal from the inputs, converted to 24/192 reaches the DAC chip, Burr-Brown DSD1792. This is a 24/192 delta-sigma IC with very good parameters, among others very high dynamics, 129dB (stereo). After it there is the I/V conversion on Motorola MC33079 chip, with metalized, precision resistors, polypropylene and tantalum capacitors all around. On the output, in the buffering and amplifying section, there is a single JRC5532 chip. Before the output RCAs (with ground pin gold plated) there is a relay and polypropylene coupling capacitors. We have to especially and strongly point out two things: a splendid clock for the upsampler and DAC, as well as worked out power supply circuits, separated in dedicated sections. Nice work, and only the USB input not handling higher frequencies is disappointing.

Manufacturers:

TeddyPardo
Izrael
e-mail: teddy@teddypardo.com
URL: www.teddypardo.com

Arcam
A&R Cambridge Ltd
Pembroke Avenue
Waterbeach
Cambridge CB25 9QR
Wielka Brytania
e-mail: support@arcam.co.uk
URL: www.arcam.co.uk
Distribution in Poland: Audio Center Poland

Musical Fidelity
Musical Fidelity Limited
24-26 Fulton Road
Fulton Road
Wembley
Middlesex
HA9 0TF
Wielka Brytania
tel.: +44 (0)20 8900 2866
fax: +44 (0)20 8900 2983
URL: www.musicalfidelity.com
Distribution in Poland: Audio Klan