 Cleaning up a USB signal coming from a computer before it is sent to a DA converter does pay, as we have seen in the reviews of the i5 reclockers. This time we look at a costly model by SOtM, the TX USB Ultra, which is twice the price of the i5 Micro iUSB 3.0 I reviewed earlier. On the outside the TX USB Ultra looks identical to the SMS 200 Ultra and while the concept is also the same, take a digital audio interface and improve the signal by reclocking and reshaping, the device could not be different otherwise. Both are based on a standard non-Ultra version and where the SMS 200 is essentially a small computer functioning as a network audio interface, the TX USB is a USB 2.0 hub with noise reduction measures and improved clock timing. The Ultra Edition is a very high precision clocking circuit, but where in the case of the SMS 200 Ultra, the dual clock SCLKEX2425 board is used, the TX USB Ultra has the SCLKEX12 board included. This board has a single frequency clock oscillator. The unit measures 106 x 227 x 48 mm. The front holds the power led that does not function as a power button as with the other SOtM products in that same housing. On the rear the power inlet for the supplied switching mode power supply or any audio fault power supply that can deliver 9 volts DC at 2 amps. Next to it the USB type B input and below that the USB type A outputs. Each output has a power switch that enables or disables the power on the USB output. Ideally you don't want to power the DAC over USB, but the universal plug and plague protocol requires power over USB. This is how it works. When you connect the DAC to a computer, the computer powers the interface chip in the DAC so it can report back to the computer its identity like what brand and model it is. Since the power comes from the computer, the DAC doesn't need to be switched on or even be powered. This protocol was designed for printers, scanners, drives and the like and some DAC manufacturers were not too happy with the power and therefore provided the interface chip with the power from within the DAC and also when switched off and cut the power coming from the computer. Back to the rear. Although there are two USB outputs, SOtM advises to use only one at a time. Optionally a clock input can be ordered but given the high quality clock inside this seems only functional when you need to use a number of DACs in parallel as with multi-channel setups. I used my Intel NUC running RoonRock server that was powered from a 19V DCS booster. The 8TB USB 3 drive that holds the music was powered from a first gen 12V DCS booster power supply. Normally the NUC and the drive are placed two floors up and connected over ethernet to the SOtMS-200 Ultra and fed from the original switching mode power supplies. But I don't like cheap switching mode power supplies so close to my set of one. Hence the audiophile power supplies. The TX USB Ultra was powered using the S booster 9V DC Ultra that normally powers my SMS-200 Ultra. A short word on other power supplies. The simple switching mode power supply that comes with the SOtM products was only used for burning in since I know the difference in audio quality using an audiophile power supply on the SMS-200 Ultra. But it just as well could have been the SOtM SPS 500 power supply. I just already owned the S booster and there was no audible difference when reviewing the SMS-200 Ultra. The SOtM power supply does have a wide range of voltages 7, 9, 12 and 19 volts DC and is more pleasing to the eye especially in combination with either SOtM Ultra devices. It's also clearly more expensive. Back to the setup. The TX USB Ultra comes with a USB cable, not one of the cables they sell separately. I use this between the Intel NUC and the TX USB Ultra. The connection to the MiTek Brooklyn DAC was my standard cable, the AudioQuest Diamond. My thoughts were that the cleaned up signal should be transported with the utmost care not to ruin it again. It also gave a fair comparison between the TX USB Ultra and the SMS-200 Ultra on which later on more. One last remark. All devices on test start off with at least a week of burning in. I usually don't listen to the device during this period so the first time I hear it is after a week or more playing muted. If I think to hear problems that could be related to burning in I give it another week, and so on. In the case of digital players it is especially the clock oscillator that needs to settle. So a cold DAC or streamer most likely will sound harsh, have little tonal qualities in the low and so on. The fingerprints of Jitta. I started off with a sound quality I didn't associate with SOtM. I had the TX USB Ultra connected to the left USB socket on the front of the NUC since that is the low power outlet. It was messy and uninspiring. I thought the right USB socket was the USB 2 and might sound better. It did but later on I found out that it was a USB 3 socket as well that provides high current for fast charging of tablets and the like. I guess this USB socket was on another lane than the USB drive connected to the rear although I couldn't find any information on this. It does illustrate that trying out several options does pay. The sound now was in the realm of the top end of my setup 2 and the lower end of my setup 1. That's clearly better than the i5 micro iUSB 3.0 which by the way costs less than half. There are still people that claim that digital is digital, zeros are zeros and ones are ones. And they seem completely right but it does make a difference in audio if those zeros and ones arrive in time. And when not in time a zero can become a one and vice versa, making error corrections do its work and that again takes time. Simple buffering doesn't cure this either since reading the average buffer causes noise and draws extra current from the power supply and so on. But when done right, like here, the impact on the sound is easily audible, provided the stereo is of sufficient quality and properly set up. It is of course comparing apples and oranges, but you would have asked me anyway. So let's compare the sound of the TX USB Ultra to the sound of the SMS-200 Ultra. To make the comparison as honest as possible, the setup remained fully identical. Only in the case of the TX USB Ultra the internal knock was connected over USB while in the case of the SMS-200 Ultra it was over the network. Both units were fed from the same S-booster and both were connected to the Brooklyn DAC using the same AudioQuest Diamond USB cable. Nevertheless, the TX USB Ultra could not produce the magic of the SMS-200 Ultra. The TX USB Ultra sounds great, it really does, but it is fascinating to hear how free, real, uncompressed, fast and natural the SMS-200 Ultra reproduces when combined with the Brooklyn DAC. A thousand euros is a lot of money for a USB hub that improves the signal. Just like 1400 euros is a lot of money for a streamer. But I find 35.000 euros for a kilogram of gold a lot of money, especially since I don't care for gold as such, only for the value it represents. But I do care for sound and find these SOTM products offering a quality that, to my knowledge, can't be bought cheaper. If you can spare the extra 400 euros and don't mind using the network, the SMS-200 Ultra remains the best choice. But if you want to use USB for audio and your stereo is in the realm of my setup 2 or even setup 1, it certainly is a second best. At least, up till now, for already another manufacturer promised me a USB condition as soon. So, if you want to stay informed, subscribe to this channel or follow me on Facebook, Twitter or Google+. See the show notes for the links. If you like this video, please consider supporting the channel through Patreon or Paypal. Just one dollar a month will do. The links are in the show notes, just as the link to the description of my three setups. Help me to help even more people with their stereos by telling your friends on the web about this channel. I am Hans Beekhuyzen, thank you for watching and see you in the next show or on theHBproject.com. And whatever you do, enjoy the music.