by Kevin OBrien on August 28, 2013


We were able to test our YFS HD.Ref-3 computer transport with the latest SOtM USB 3.0 compliant PCIe output card back in May of 2012. Unfortunately, we quickly returned the card due to its incompatibility with the M2Tech v1 OEM USB input receiver. These USB input receivers are used in a variety of DAC's ranging from Wyred4Sound, Eastern Electric, Chord, Empirical Audio, Metrum Acoustics, Playback Designs, as well as MSB. Obviously, some current and older M2Tech products are included as well, except for the HiFace MKII which uses the XMOS USB input chip.

Can we implement a product within our YFS Reference 3 Transport that isn't compatible with several USB devices currently on the market? The very easy answer to that question is, "No". So, we sadly soldiered on using the original SOtM tx-USB card.

Fast-Forward to August of 2013. We got our hands on a SOtM tx-USBexp PCIe output card and we gave it another shot. We were hoping to see new drivers packaged along with the card. We were a little bummed out to see the card came with the same drivers we received previously.

So, I contacted the man himself, Jesus of Sonore. I described to him how the SOtM exp card works with Windows 8, however, it just won't work with Windows 7. The next day I received an email from Jesus containing a link to the latest tx-USBexp Windows 7 drivers. After uninstalling the current TI USB 3.0 drivers, and then replacing them with these latest ones, everything worked great. AWESOME! This opens up an entire new world for M2Tech, W4S, Eastern Electric, Empirical Audio, MSB, etc. owners! For instance, now we can use our tricked out M2Tech EVO with our YFS HD.Ref-3 transport and live happily once again.

Oh and by the way, the latest SOtM USB PCIe card allows us to not only drop our latency buffers to non-existent values but, it also sounds better than the original!




We updated our Windows 7 based HD.Ref-3 via the Windows Update website after RMAF 2013 and the SOtM USB 3.0 card is not recognizing ANY of our USB-based devices now. Something tells me this has to do with drivers. As this is usually the case when a fully functioning component stops working after Windows Update. So, we're right back where we started. We know it's due to Windows Update as we only updated one of our Ref-3's on demo in our showroom. The units we did not update are still working fine. It's a bummer but that is the way it goes in the computer world sometimes. We will give further updates as they become available. We recommend using Windows 8.1 in conjunction with the SOtM USB 3.0 card. USB 3.0 is natively supported in Windows 8 and functionality is guaranteed with no need for drivers.

Thanks for reading.

Until next time...

-YFS Design Team


by Kevin OBrien, Brad Easton, and Mike OBrien on February 2012


UPDATED 03/11/2012!!!

So, in our last review of the computer vs CD transport, we let readers in on our opinions of both sources. We said the computer was essentially more user-friendly and had a slight advantage in the sound department. We recently decided to compare computer transports since we have not covered that yet. Fortunately for us, we stumbled on to what we here at YFS believe to be one of the BEST music sources, period.

We have heard vinyl playback systems costing well over $120,000 (just the vinyl source equipment) as well as CD playback systems in the same league and I can tell you this is it. Unfortunately, we cannot give you all the details of our computer source because we are still currently in the design phase of our product. We feel it can go head to head with ANY other computer source and BEAT IT, hands down!

I know that's a bold statement but once you've heard what we have, we are convinced you'll feel the same way. Let us describe how we came up with our findings and we'll give you some more details on our listening tests and finally the sound.

We figured we'd keep everything the same from the previous 'computer vs CD transport' shootout so we are using the original Musical Fidelity V-DAC with USB input and the Acer 5735z laptop. As we mentioned in that review, we were not able to get bit-perfect output via USB based on the V-DAC's design. Apparently, many folks have reported the same issues so we ended up using the "direct sound" mode within Foobar 2000 for the Acer. We ripped our CD's to WAV files using EAC CD ripping software. We then set up our custom YFS music server prototype (still in it's design stage) to see what we could find out about this whole computer audio craze. We're glad we did!

We played an album on the Acer after letting our system warm up for a bit and then we switched sources. Our YFS prototype was outfitted with Windows 7 and Foobar 2000 in "direct sound" mode with all the exact same settings to make the comparison fair. We used the USB 2.0 output as well to try and even out the playing field. We immediately noticed everything sounded better! We're talking a night and day difference here. In fact, we didn't need to switch back to the Acer it was that good. We then realized we were hearing things we haven't heard in our favorite recordings EVER.

You are probably asking, "What about your vinyl set-up?" This was definitely on par with our vinyl set-up and even surpassing it after listening for a couple hours. We are very familiar with our vinyl rig's sound and we were immediately impressed with this server!

Here's where it gets interesting. We decided we should try JRiver Media Center and see what effect that had on the overall sound in our YFS prototype. Let's just say this was an eye-opener as well. (Unfortunately, the trial version lasts for 30 days and then you must pay the $50 to unlock it) Using the WASAPI playback setting within JRiver, we were able to get a bit-perfect digital signal out of the YFS prototype via our USB 3.0 output and we were literally floored!  WOW!  I know we wanted to keep things fair at first but now that we knew it wasn't even close, we decided to go all in. Most folks have not had luck getting the MF V-DAC to play nicely with any bit-perfect playback scenario. After hours of tinkering, I guess we just got lucky. We then cued up the Talking Heads' Speaking In Tongues 24/96 digital files and we almost blew the roof off the joint! INCREDIBLE! Talk about P.R.A.T.! I haven't heard a source with more slam, attack, detail, and good high's, lows, and mids like this ever before.

If the end-user was to use one of the many Asynchronous USB DAC's on the market right now, none of this would be an issue. The user would download their DAC's proprietary drivers, install them, and then select that driver under the "Options" menu under "Audio". Then the user would select either ASIO or WASAPI from the same menu and he or she would be on their way to bit-perfect digital music via USB!

We then switched back to "direct sound" mode which actually sounded really good but with more emphasis on the high end of the frequency response. It reminded me of switching between a tubed CD player and a solid state CD player. VERY COOL. So, we've decided that JRiver is definitely worth your time experimenting with. The user can actually fine-tune the sound he or she is looking for with the various output options available WITHIN the JRiver suite. No need to download and install plug-ins. Again, VERY COOL. 

Stay tuned for more details about our YFS music server prototype. If we're this excited about something, we figure you will be too. It's just a matter of time!



We have been very busy testing our HD-Ref-1 computer music server. We feel it's almost ready to release to the general public. We have a few more odds and ends to clean up and we'll be all set. Contact us for pricing and availability of our very first few units!!! Click here for more information on the YFS HD-Ref-1.


Associated Equipment for this Review:

  • YFS/ SCH Custom Speakers
  • YFS Custom Room Treatment
  • VPI Scoutmaster with VPI Zephyr Cartridge
  • YFS Custom Phono Preamplifier
  • Musical Fidelity V-DAC
  • YFS Custom Direct Preamp and Custom 6L6 Tube Power Amp
  • YFS Custom Interconnects and Cables


by Kevin OBrien on 6/13/2011


I am comparing my IBM Thinkpad T43 laptop to my Theta Digital Carmen II CD transport. I am wondering which is a better digital source component. I will be describing my findings after setting up the IBM T43 for use with my M2Tech Evo USB to SPDIF converter. This allows my laptop to become another digital source component with a digital output just like a CD transport. I will NOT be using the USB input on my DAC. This allows me to switch between older and newer DACs that do not possess a USB input.

It has come to my attention that the best way to hook up a CD transport to a DAC is through the AES/ EBU digital output or the BNC digital output if possible. The RCA digital output inherently introduces too much jitter. I will be implementing the Theta Carmen II's AES/ EBU digital output hooked up to an EE Minimax DAC via a Better Cables Silver Serpent balanced digital cable. I will be implementing the IBM T43/ M2Tech EVO hooked up to an EE Minimax DAC via a Black Cat Cable Veloce BNC digital cable. The USB cable linking the EVO and the IBM will be the 1 meter Silnote Audio Poseidon Silver Reference USB. I will be toggling back and forth between the two components by selecting the corresponding input on the Minimax DAC.

First, let me describe my IBM T43 laptop. It is not in the stock form. I have installed 2GB of RAM and added a more recent 350GB HDD to accommodate my digital files library. The computer comes with a 1.83 GHz Pentium M 750 processor which has NOT been overclocked. I am running XP Service Pack 3 for an operating system with all Windows sounds and standby modes turned off. I also unplug the laptop from the internet so Windows will not check for updates (The computer is allowed to update itself before and after listening sessions). I am implementing the Foobar 2000 digital media player with the Kernel Streaming Plug-In installed. This allows me to output a bit-perfect digital stream via USB to the M2Tech EVO. From the EVO the Veloce 75 ohm BNC digital cable sends the data to the DAC. Simple enough.

Let me describe my Foobar 2000 set-up as well to let you know the basic settings I am using as there are a lot of options within the program. I have the output files set to play at 24 bits and my buffer is set to somewhere near the middle of the supplied range. I turn off all the Replay Gain settings and do not fade in or out of tracks. I want the most dumbed down settings I can get so I alter the original sound of the digital files as little as possible. There is an ongoing debate on whether Foobar or JRiver sounds better. I have heard from both sides that each is better for several reasons. I am sticking with Foobar since it costs me nothing to use. Feel free to experiment but be aware that JRiver will set you back $50 for the non-trial version. Now that we've covered the laptop set-up let's talk about the files I'm playing within Foobar 2000.

I use the EAC CD ripping software mainly because it's free and I am not familiar with the Foobar ripping software yet. I have heard Foobar is the way to go in terms of sound quality but I'm pretty sure EAC is very close. I choose to rip CDs directly to WAV files so I know I am playing the exact same quality file as on the CD. Some folks choose to use FLAC files but I am hesitant to go that route. I do not want to compromise performance in any way and WAVs seem like a safe bet to me. If you are interested in hi-res digital files you can buy them from They sell a variety of digital FLAC files in a variety of formats such as: 16/44.1, 24/44.1, 24/48, 24/88, 24/96, 24/176, and 24/192. Make sure your DAC can play all these formats BEFORE you purchase. The EVO can handle every available format right now so I do not have to worry. Unfortunately, not all DACs can handle 24/192 digital input streams from a digital cable other than USB. A lot of DACs and SPDIF converters are only compatible with files that are 24/96 or less. Do your homework! I want to mention Media Monkey here as well since that is the software I use to convert my FLAC files from to WAVs. It's a nice program in that it keeps the sampling rates of the source FLAC files intact when converting to WAV files. A 24/96 FLAC file turns into a 24/96 WAV file. Very cool.

So, about the sound already. I let things warm up for a while before doing any serious listening. It turns out that comparing the two sources wasn't as easy as I thought. Switching back and forth between the sources was easy but I could not tell a night and day difference between them. I did notice right away that the laptop had more mid-range detail. I kept listening and flip-flopping between the two sources and I realized the computer was giving me a better mid-range response to my ears but that was the main difference. Keep in mind I am comparing 16/44.1 WAV files to the same CD. If we are talking about 24/96 files, the computer beats the same CD every time. To me, it makes sense to go with the laptop for ease of use. CDs are not difficult to load but they can become a pain when they get dirty or scratched. A CD transport laser can become stuck, not track correctly, or fail, etc. When my laptop breaks, I will just buy another one. If my CD transport breaks, I cannot afford to go out and spend just under $4000 on a new one and Theta no longer supports any legacy products. The decision was easy for me. I'm moving in the direction of the future, not the past. I still love vinyl but I don't think vinyl can beat a great music server.


Associated Equipment for this Review:

  • Von Schweikert VR-5 HSE (Hovland Special Edition) Speakers
  • Quicksilver 12AX7 Tubed Linestage and Silver 60 Monoblocks
  • EE Minimax DAC
  • EE Minimax Phono Stage
  • VPI Scoutmaster Turntable with VPI Zephyr Cartridge
  • PS Audio PPP/ Equitech 1.5Q COMBO
  • YFS Custom Cables & Interconnects
  • YFS Custom Room Treatment
  • Herbies Audio Lab Dampening Devices and Tube Dampers


by Kevin OBrien on May 15, 2011


We are comparing the McCormack Audio SST-1 Digital Drive CD Transport to an average Acer Aspire 5735z laptop from 4 years ago running XP which could be had at your local box store. I figured this was a good comparison point as both of these source components can be had for around a $400 street price. Obviously the SST-1 is no longer in production but on the used market can be bought for much less than its retail price of $1495 back in the mid-90's. We did not want to use a current model computer either as that would stack the review up unfairly to one side. I feel the two components are comparable based on their current price points.

We decided to use the Musical Fidelity V-DAC MkI for a DAC keeping in tune with the whole "affordability" theme. The V-DAC goes for around $350 with the Pyramid external power supply option. All in all I feel this source configuration is attainable by most audiophiles on a budget. Hopefully this appeals to more folks out there in the real world. Especially since the economy isn't exactly picking up steam as fast as we would all like!

We let the units warm up for an hour before we did any critical testing. We used a budget USB cable to try and level the playing field as well. There are USB cables currently costing over $2000 but that would not make sense in this review setting. We set up the Foobar 2000 Digital Media Player on the Acer in "Direct Sound" mode. This is important as we did not get a bit-perfect digital signal coming out of the Acer but we did turn off all sounds under the "Sounds" menu in the "Control Panel" and changed the power scheme to always on. (No screen savers or standby modes for hard drives and monitor outputs) We also disabled the internet connection and removed the current audio driver suite for better performance.

I have been able to get the Kernel Streaming module in Foobar 2K to work in the past but we tried and could not get it working with the original MF V-DAC. I have heard other folks having the exact same problem so we moved on. The MF V-DAC does not require drivers and is not "asynchronous". This makes it truly "plug and play". We will follow up in the near future with a computer transport comparison with at least one computer running Windows 7 with bit-perfect digital output but for now we are concentrating on the Acer XP machine from several years ago.

Lets talk a little about the files we were using as well. We downloaded the free EAC CD ripping software online and ripped the CDs were going to use as test material into 16/44.1 WAV files. I know FLAC files are lossless but we wanted to make sure our comparison was as fair as possible so we used WAV files.

Enough about the set-up already and let's get to the real substance of the article, the sound! Well, we were able to do an A-B comparison by toggling back and forth between the CD Transport and the Acer 5735z with the input switch on the V-DAC. We cued up a CD on the SST-1 and matched the timing of the digital player to the timing of the CD track and then matched the output levels. This made it very easy to get a feel for what we were hearing. I must say that at first we could not tell a difference right away. After switching back and forth for a couple minutes we noticed the laptop set-up was more "in-your-face" and the CD Transport was a hair more laid back with its presentation. After we listened for a couple hours we decided the laptop set-up did indeed sound better but not by a huge margin. We did prefer it though to the CD Transport after our extended listening session with both sources.

After considering the ease of use with the digital files and the fact that we can now download 24/96 digital files that sound even better than a CD, why would we keep using the CD Transport? It just doesn't make sense any more. When you factor in that it is getting harder and harder to find CD Transports it makes the decision even easier. Again, CDs sound fine (and vinyl is even better) but the computer gets my nod for the source component of the foreseeable future among my various systems.


Equipment Associated for this Review:

  • YFS/ SCH Custom Speakers
  • YFS Custom Room Treatment
  • Musical Fidelity V-DAC
  • YFS Custom CA-60a Preamp and Custom 6L6 Tube Power Amp
  • YFS Custom Interconnects and Cables


by Yuri Hajtko on September 18, 2018


I set out to do a USB cable shootout this summer to see if I could actually hear a difference between USB cables from various manufacturers. The test was simple: I play the same test track (2 Cellos 'May It Be') using several different USB cables, starting with a $5 printer cable I had laying around. I inserted each cable into my rig and gave my comparisons via a set of notes I kept after listening to each cable. I did not test a 'Split' USB design and went with a standard 4-conductor cable to make the comparison fair.

I have listed the cables in order from best to worst performance with my listening notes laid out below each cable title. Read on for my findings which I thought were very interesting.


1) Hemingway Audio USB

This was the best cable out of the bunch. More dynamics noticed in the background. Attack is very good. Air on bow pulls feels more natural than every other cable tested. Individual notes of timpani are noticed as well as their positioning in the performance (panning in channels). The speed of the cable is excellent. Loud passages have great dynamics and the largest sound stage. Great width, depth, and height. Small micro details were noticed that were not heard before using any of the other cables. 


2) YFS Ref USB

This was my winner based upon price to performance ratio. If basing my tests purely on performance though, the Hemingway wins. With that being said, The Hemingway Audio, JCAT Reference, and Albedo Silver Monocrystal sounded VERY similar to the YFS cable but were MUCH more expensive. Background strings were more prominent from the very beginning of my tests and much more dynamic. Cellos have clean sounding vibrato. Air on bow pulls sound stronger and deeper. The low end is also smooth and powerful. Timpani notes have great separation just like the Graham Slee Lautus. Loud passages have good dynamics and are controlled without any frequencies overpowering each other. Overall, the music sounded natural and lifelike.


3) Albedo Silver Monocrystal USB

From the onset of my comparison the strings have a different 'airier' feel to them vs. the YFS cable. Vibrato is present and very similar to YFS. Air on bow pulls is again very similar to the YFS cable, but slightly less pronounced. Individual notes of timpani are better than YFS by a small margin. Very good controlled dynamics on loud passages - engaging but not overpowering. This cable is the best contender to the YFS Ref USB and is very well suited for the type of music I am comparing with (strings / classical).


4) JCAT Reference USB

This cable was almost identical to the YFS Ref USB but at 3 times the price! See YFS notes for how this cable performed.


5) Graham Slee Lautus USB

Strings are a bit more laid back than the AQVOX and similar to the printer cable. Background strings are a bit forward. Air on the bow seems to have more of an echo-type quality to it vs. the AQVOX which sounds more natural. The notes on the timpani and their separation is better than the AQVOX. Vibrato is present and similar to the AQVOX. This cable is more laid back compared to the AQVOX.


6) AQVOX Excel USB

This cable was stronger sounding than the printer cable I started out my test with. Strings have more air, vibrato is more noticeable than with the printer cable. Background strings are more separated and play subtly but are noticed. Air on the bows of the cellos is more pronounced than with the printer cable. Loud passages are more dynamic with a bigger sound stage.


7) Printer Cable

This cable sounds just "ok". Details are all there but do not pronounce themselves. There is very little separation in the music. The music sounds muted and dull. This was my baseline for my test from which I compared every other cable to and if not, compared to another cable that was way ahead of this one. You have to start somewhere but I would not recommend using this cable in an audiophile system unless money is tight and this is all you can afford. Cables matter! 


Thank you for reading. I wanted to get out a comparison that shows fellow audiophiles that cables do make a difference and that the most expensive option is not necessarily the best sounding option. I would like to thank Kevin at YFS for allowing me to get my thoughts down on his website for others to see.

Most importantly, I was not paid nor did I receive a discount for a weighted review towards a certain cable. I did not tell any of the manufacturers I was comparing their cables at the time of purchase. The results above represent an unbiased view point as I am not a professional reviewer nor did I have an agenda. My only goal with this test was to figure out the best USB cable I could buy for my system for my money.


- Yuri Hajtko in Toronto, Canada


by Kevin OBrien and Brad Easton on 03/28/2012


We were interested in seeing how our YFS USB-V2 stacked up to the MUCH more expensive Silnote Audio Poseidon Silver USB cable. We went ahead and compared the two with our Minimax DAC Plus using the USB input. We could not conduct an A-B comparison due to the equipment involved. One must take the care to turn off the DAC BEFORE unplugging his or her USB cable to avoid damaging both the DAC and the computer. This did not allow us to hot swap or A-B the cables unfortunately.

We started with the Silnote Audio Poseidon USB which is no longer available. Silnote Audio has recently come out with a newer version but you'll get the idea by checking that out here. The Poseidon Silver USB retailed for $400 for a 1 meter length. The 2 meter length was almost double that cost ($650-ish). Whoa! That's a little steep for our liking but plenty of folks are willing to shell that out apparently. The Poseidon uses silver conductors with isolated signal and power lines with a proprietary shielding technique. Pretty cool!

Don't get us wrong here. This Silnote Audio USB digital cable is the real deal. We've tested it against some other expensive cables such as the Revelation Audio Labs Silver Reference USB and it won every time.

Let's see how our YFS USB-V2 stacks up against the Silnote Audio USB.

We played some classical, pop, rock, and jazz with the Poseidon USB to get ourselves familiar with its signature sound. We then played the same selections using our USB-V2 cable. To be honest, we could not tell a difference (especially during our blind test) between the two. We did notice a very slight advantage in the P.R.a.T. department as well as the mid-range response over our YFS USB-V2 cable but again, it was a slight difference. It just had a different feeling to the music. All the information was still present in the mix with both cables. They both sounded EXCELLENT!

We are not entirely sure how the economy is faring country-wide yet but we think it's safe to say that most folks are still looking for great deals on audio gear at this point. We're not sure about our readers but we know we'd rather shell out $99 for a 2 meter USB cable instead of ~ $600 for practically the same performance. The final call is yours but we think you'll be overjoyed with the performance of our YFS USB-V2 compared to the other guys especially for the price.

Until next time...


Associated Equipment for this Review:

  • YFS Computer Music Server - HD-Ref-1
  • Eastern Electric Minimax DAC Plus
  • Quicksilver Audio 12AX7 Preamp
  • Quicksilver Audio Silver 60 Monoblocks
  • Von Schweikert VR-5 HSE Speakers
  • YFS Custom Room Treatment
  • YFS Custom Interconnects and Cables
  • Herbie's Audio Lab Dampening Products


by Kevin OBrien on January 3, 2022


With so many new high end reference cans on the horizon or already shipping for 2022, how are we going to test and evaluate them all properly? I have it figured out, pick up a headphone amplifier that is as versatile as is it is good looking. I'm talking about an amplifier that can be right at home with a pair of Audeze LCD-XC and still power HiFiMAN Susvara well enough to make them sing. Hmmm? That's not an easy task for any amp now that you mention it.

If you're out of Poland and your name is Ferrum Audio, you don't have anything to worry about because this is exactly what you've been busy coming up with for the past two years. But honestly, how can one amp possibly fit all these flagship headphone models under one roof?  I am calling BS. Well I'll be damned, it turns out you can do just that. If you have flexibility with gain settings along with multiple connection options, from inputs to outputs, you're all set. That's where Ferrum comes in again.

Ferrum started out of a need from its parent company, HEM, to come up with a headphone-specific line-up of audio gear that could compete with the 'high end' gear but keep the prices closer to reality. HEM makes Mytek gear for the 2-channel world. HEM makes Ferrum gear for the headphone world. Problem solved.

Here comes Ferrum OOR mated to Ferrum HYPSOS to save the day. This pairing can power any headphone currently on the market (electrostats excluded obviously) with ease and do it with versatility in mind. The OOR + HYPSOS Stack is how versatility will be measured going forward. I know, that's a bold statement. Read on and see what we mean...

Let's begin by talking a bit about OOR. There is a single set of RCA and XLR inputs and outputs on the rear panel along with the volume control bypass switch and the power input connections. One power input is specifically designed to be used with HYPSOS and is called 'Ferrum Link'. The other power input is a 2.5mm x 5.5mm female DC barrel connector (use this if you want to try a YFS LPS with your OOR). You can use OOR as a stand-alone preamp if you so desire by implementing the outputs on the rear panel. OOR can bypass its volume control as well if you already have that covered elsewhere (like in your DAC). Working your way around OOR, there's a set of headphone outputs, one balanced 4-pin and one 1/4" (6.3 mm) single-ended, located on the front panel. Input (RCA, Stand-By, XLR) and gain selection (Low, Standard, High) are handled on the front panel as well. This is one handy and versatile amplifier.

HYPSOS is Ferrum's answer to multi-rail linear power supplies. This particular power supply is a linear / switching 'hybrid' design of sorts. It's not a linear or a switcher. Interesting. It definitely mates well with OOR and that is its ultimate purpose but it can be used to power all sorts of HiFi devices. HYPSOS comes pre-programmed from the factory with a multitude of device settings (Voltage and Current output settings). Select your device from the menu on the front panel OLED display, and you're ready to go. The front panel shows your device output voltage, current, and power output in Watts. Very cool! HYPSOS can output 5V up to 30V at a max of 6 Amps of current output ( 80 Watts max output -> W= (V x i) ). We must say, that all sounds pretty slick.

So anyway, how does it sound? It sounds great! The Ferrum Stack looks and feels like it should be clinical when judging a book by its cover. It's a solid state amp after all. As it turns out, OOR sounds more like a good tube amp than a solid state amp. This sounds crazy but it's true. We were able to test with our Audeze LCD-5 and HiFiMAN Susvara. These are two of the most difficult loads to drive on the market currently. The Ferrum Stack made quick work of the Susvara in 'high gain' mode. The Ferrum Stack made the LCD-5 sound incredible in 'standard gain' mode. There was never any hint of harshness or brightness at all but the presentation was ultra-detailed and bass was tight. Everything was spot on. WOW! Impressive. We have to hand it to Ferrum here. 

Keep in mind the Ferrum Stack is fully balanced, even when using the single-ended inputs. The Stack converts all incoming signals to balanced, if they are not already, and then does its thing. OOR outputs 8 Watts into 60 Ohms via the XLR inputs and outputs 2 Watts into 60 Ohms via the RCA inputs. Not bad at all for a little 10 pound stack of gear with a 8.5"W x 8"D x 4.5"H footprint. This is impressive. If you're on a budget, you can purchase OOR by itself and then partner it up with HYPSOS later on. This is a smart way to go financially if money is tight. After all, this hobby isn't cheap. We tested OOR on its own and it does sound good but it doesn't 'wow us' like it does when mated to HYPSOS. If you can swing it, pick up the entire stack at once. You will be rewarded. We were SO impressed with OOR, we became dealers. YFS is an authorized Ferrum Audio dealer.

US Distribution for Ferrum Audio (VANA Ltd.) is out of NYC which is nice and convenient. It gets old sending money overseas when placing orders. The standard factory warranty is 2 years from date of purchase and defects are handled in NYC. What's not to love?

Thank you for spending your time with us and reading our review. Contact us for pricing and availability. Let us know if you have any questions or concerns.

Until next time..



by Kevin OBrien and Brad Easton on February 2012


We recently set out to prove that there is indeed a difference between USB digital interconnects. After reading this article I think you'll agree we accomplished our goal. There is a lot of talk going around claiming there is absolutely no difference between the various USB digital cables out there. Apparently these "audiophile" cables are just a waste of money and there is no way to hear a difference between them. Afterall, USB cables simply carry 0's and 1's to your DAC and they either arrive or they do not. I agree but I disagree as well.

Would you skimp out on any other digital cable in your system? I wouldn't! Your system sounds only as good as the weakest link in your audio chain. Why spend thousands on gear to turn around and use a 5 dollar USB cable from China?

It just doesn't make sense to us and we set up a test to see if what the general public was saying about USB cables was really true.

We went ahead and purchased a plain ordinary USB 2.0 cable from our local computer store. We made sure it was under 8 bucks in cost and under 3 feet in length. These are the USB cables everybody sees in your favorite box store or computer store. Nothing special.

We then constructed our YFS USB-V1 prototype USB 2.0 cable from some decent 4-conductor data cabling we had laying around the shop. We kept the length under 4 feet and used the same connectors you could find in the Chinese USB cables. I do not believe there is a supplier of "High End" USB connectors as we could not find them anywhere!

We burned in both cables for a day each and then set out to test both cables with the same set-up. We switched back and forth and we could barely tell a difference between our prototype and the 'budget' USB but it was there. The difference was mainly in the presentation of the music. Everything sounded more 'right' with the original YFS prototype.

We then figured we could do a much better job with a little more time and thought invested into the design. We subsequently came up with the YFS USB-V2 cable. We used the best data transfer cable we could find and employed our proprietary shielding technique and came up with our second iteration of our USB 2.0 cable. VERY COOL.

We did the same test as above but switched between our first prototype and our second. The only difference this time was that we did not burn in the new design and implemented it 'cold'. Apparently burn-in didn't play a big role in this test because what we heard between the two was very interesting. WOW! The USB-V2 produced bass that was noticeably more controlled and more present in the music mix. Highs were more extended and the mid response was nice and smooth. We hands down preferred the USB-V2 to the USB-V1. We all unanimously agreed. This was easy to notice unlike our previous test between the first prototype and the 'budget' USB cable. We were VERY excited indeed!

So, the moral of the story here is that there is in fact a difference between various USB cables, especially between the 8 dollar 'budget' cables and what are considered "audiophile" grade USB cables. We cannot speak for the other audiophile USB cable manufacturers but we can tell you our YFS USB-V2 cable is a VERY nice step up from what's coming out of your local box store these days.

If you'd like to know the technical aspect of our USB cable design, head over to our F.A.Q. section and read about what design decisions we made in coming up with our YFS USB-V2 cable and how digital cables are designed in general. Good stuff!

Don't compromise your system with a cheap USB cable. It's just not worth it. Spend a little extra on your USB cable and know you're getting everything you paid for everywhere else in your system!

Click HERE for more info on purchasing currently available YFS USB cables.

THANKS for reading!



Associated Equipment for this Review:

  • YFS CPU Prototype - HD Ref-1
  • Musical Fidelity V-DAC
  • YFS Custom Room Treatment
  • YFS/ SCH Custom Speakers
  • YFS Custom CA-60a Preamp and Custom 6L6 Tube Power Amp
  • YFS Custom Interconnects and Cables


by Kevin OBrien and Mike OBrien on 07/07/2011


I was wondering how the Quicksilver Audio Silver 60 monoblocks compared to my prized YFS modified McIntosh Labs MC75 monoblocks from circa 1960's era. Is this a fair comparison or are these two sets of monoblocks just not even in the same league? Is there really a worthy successor to the MC75 monos with a modified power supply? I will be using my reference Von Schweikert Audio VR-5 Hovland Special Edition speakers which are nominally rated at 4 ohms. One point to note is that both the MC75 and the Silver60 have 4 AND 8 ohm taps. I will be using the 4 ohm taps.

First, let's talk a little bit about what YFS did to the MC75 power supplies. The original power supply in the MC75 in the 1960's was unique for its time in it's use of a voltage doubler. In stock form the power supply has been known to break into motor boating as the B+ filter capacitors deteriorate. On the other hand, many MC75's are still operating today with no issues. To maintain physical layout, we chose to reform the original electrolytic capacitors since the original units had relatively low leakage. The second step was to replace the entire power supply with modern design using Panasonic TSHC series electrolytics and ultra fast recovery rectifiers. As it turned out, the sound was outstanding with the original components so we went no further.

At YFS we understand that the MC75 is a pure classic but can be taken to the next level with modern components and matched vacuum tubes. Basic electronic components have come a long way in 40+ years so it makes sense that an inherently sound topology can be improved by simple component substitution. No modifications were made to component values or the basic topology. We loaded the MC75 with matched Sylvania NOS 6550 output tubes and matched section (transconductance matched to 5%) NOS GE twin triodes (12AU7, 12BH7, and12AZ7). We also added a power switch, replaced the stock power cord, increased bias supply capacitance, replaced all signal capacitors with modern polypropylenes, and substituted metal film resistors in critical places to reduce noise. We also replaced the speaker output terminal strips and the RCA input jack.

In the Quicksilver Silver60 monoblocks we are using the popular SED 6550's for a tube compliment. Although the power ratings are not equal, 60 watts for the QS and 75 watts for the Mac, I feel we are close enough to do a fairly legit comparison. Check out the Quicksilver website. This is the only way to buy Mike Sanders' creations.

I played a few of my favorite albums on the Silver60 monos after they were run in for over 200 hours. I have to say that these monos sound pretty nice. We all know by now that Mike Sanders has a real handle on amp design and his designs are respected among the audiophile community. He doesn't even have to advertise for crying out loud. So, how do these puppies sound compared to the MC75's you ask? I thought the S60's sounded great! Great slam and resolution with a nice midrange but still PLENTY of detail. This is what you would expect from a quality set of monos.

I then switched back to the MC75's. I noticed just a bit better midrange and slightly more warmth but with all the detail still intact. Although both sets of monos sounded great, the MC75's just had that Mac magic that I just cannot seem to find anywhere else in a monoblock. Keep in mind we're talking about monoblocks under the $6,000/ pair range here. I am sure you can do better by spending more money but how much better, I'm not entirely sure.

So, if you're in the market for a pair of monoblocks do not hesitate to give the Silver60's a try. They have that Quicksilver signature sound that is nice and holographic while keeping that sweet tubey midrange sound intact that we tube-lovers enjoy. Can I reiterate that these babies really reveal a TON of detail when using the 6550 output tube. If you prefer a bit warmer sound, go with the EL34 output tube. You can also try a KT88 for a little more power output and that signature KT88 sound. The best part is that the S60's will not break the bank but still provide great audiophile performance. I know these are discontinued at this point but if you can find a pair used, JUST BUY THEM! Yup, I said it. DO IT!


Associated Equipment for this Review:

  • Von Schweikert VR-5 HSE (Hovland Special Edition) Speakers
  • Quicksilver tubed Linsestage
  • EE Minimax DAC Bolder Cables Level 1 Modified
  • IBM Laptop with Foobar 2000 Digital Audio Source
  • Theta Digital Carmen II CD Transport
  • EE Minimax Phono Stage
  • VPI Scoutmaster Turntable with VPI Zephyr Cartridge
  • Equitech/ PS Audio Balanced Power Conditioners
  • YFS Custom Cables & Interconnects
  • YFS Custom Room Treatment
  • Herbies Audio Lab Dampening Devices and Tube Dampers





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