SOtM dX-USB-HD question

[Harpy]

I was wondering if there any advantage using the SOtM dX-USB-HD with a USB DAC. I was under the impression it reclocked the USB when converting to other formats along with some power filters. I know there are dedicated reclocking units with Atomic clocks, but wondered if it performed the same function in a more humble way?

[iago]

I was wondering if there any advantage using the SOtM dX-USB-HD with a USB DAC

 

Quite a number of people on this web site reported it makes a positive difference. I experimented with PCIe plug-in cards in notebooks but found no noticable difference, maybe because of reclocking downstream in my setup.

 

I know there are dedicated reclocking units with Atomic clocks, but wondered if it performed the same function in a more humble way?

 

The USB protocol is just a wrapper around audio data. Especially with isochronous transmission in asynch mode (usually just called "asynchronous") the USB clock (12 MHz) is only used between the endpoints. After unpacking the audio data, your DAC (or USB converter) would apply it's own clock.

 

My personal experince is that converting USB to S/PDIF (a) makes a positive difference, probably due to the reclocking applied within the device, which (b) can still be improved upon by using another reclocker afterwards (which is currently synchronized to a RB clock).

 

If your DAC supports it, you could time it with an external clock, which is what one of the devices in a dCS or Antelope setup is good for.

[Harpy]

Thanks for the good info. I managed to drop the unit on the floor and when I picked it up it rattled inside and no longer played. The two Oscillators had fallen out of their sockets and reversed them when I reinstalled them. The music speed was all goofy until I corrected my mistake. Are the Oscillators the "clock" of the SoTM? Would higher quality Oscillators theoretically improve clocking?

[iago]

Nice experiment ;-)

 

Actually, I gave you some unrelated information, because I confused your device with the USB PCI(e) card from SotM. In retrospect, my post reads a bit like ranting; sorry about that.

 

This is a reclocking device, and replacing the clocks can make a difference. I saw some reference on 6moons that SotM is offering clock upgrades for this. Unfortunately, the clock voltage supply also plays an important role, so if you upgrade clocks, also look to the voltage source (voltage regulators on the PCB, not the power supply).

 

If you would like some examples, there is a guy posting on a German forum who heavily mods digital sections of well known audio devices. It's a fascinating read, but a little outside my current area of expertise. Postings are structured by device, sometimes modification level.

 

Instead of upgrading your device (which is technically the better option, but may be inconvienient /expensive) you could also go the easy way and use an external reclocker between your S/PDIF interface and the DAC. The Mutec MC-3+ that I am using is one of those.

[Melvin]

I was wondering if there any advantage using the SOtM dX-USB-HD with a USB DAC. I was under the impression it reclocked the USB when converting to other formats along with some power filters. I know there are dedicated reclocking units with Atomic clocks, but wondered if it performed the same function in a more humble way?

 

Harpy .. it depends on your DACs USB implementation. The SOtM converter (which I own) is a terrific little device and can offer improvement. For example, I was using Schiit's Bifrost DAC (1st generation) when I decided to try the SOtM dX-USB HD and found a substantial improvement using both coax and toslink in comparison to the Bifrost USB input. There is some good info and specs here:

 

USB-to-S/PDIF Convertors

 

afterthought:

 

An interesting (to me anyway) feature of this converter is its ability to pass 24/192 via toslink. Most audiophiles poo-poo toslink in general but IMO the unit sounds superb through this connection (jitter measured at 38ps). In fact, I liked it better than coax. Not sure but, perhaps it involves removing the electrical connection (coax) that helps here. The sound quality is smooth, relaxed, detailed, and dynamic. So much for crappy toslink. Of course YMMV.

[Harpy]

I didn't know it could pass 24/192 via toslink. I am running coax now, but I am going to look for my glass cable.

 

I was thinking about external battery power for the unit. The power out of the mBPS-d2 battery module is 6.5 -8.4 vdc, 1.5A. I found a 2S 950 mah LiPo had the same specs. Is it a bad idea to run pure battery with no circuits? Wouldn't that be about as pure power source as you could get? The battery also has the connector for balanced charging across all cells I was also wondering if that could have a positive effect? Maybe a stupid idea, but going to play with it tonight and see if I can hear any difference between the USB vs battery power and see how long a charge lasts. Hopefully I don't fry anything.

 

[iago]

The power out of the mBPS-d2 battery module is 6.5 -8.4 vdc, 1.5A. I found a 2S 950 mah LiPo had the same specs.

 

Before you connect the battery plus the charger to your interface, measure the output voltage of the battery being charged. If it stays within the input voltage range of 7 - 12.6 V, it should be OK. The voltage at the end of the discharge cycle should be too low for operation, you might start to hear distortion as it goes below 7 V. Otherwise it should work.

 

Voltage noise from chemical cells is usually several magnitudes below that of standard power supplies. Here is an IEEE paper from 1995. One of their references was a LM317 regulator.

[Harpy]

It measured 8.2 vdc at full charge and after about 3.5 hours it dropped to 7.6 vdc, so maybe 4- 5 hours per charge.

Thought it sounded was great. Thank you for the idea and link.

[Melvin]

It measured 8.2 vdc at full charge and after about 3.5 hours it dropped to 7.6 vdc, so maybe 4- 5 hours per charge.

Thought it sounded was great. Thank you for the idea and link.

 

I have the mBPS-d2 also and thought it made a difference. Seems you found a nice alternative.

[Harpy]

Yea, I'll have to do more listening to see. Think I might use a 2s 2000 mah Lipo which would double(?) the run time between charges. The battery I was using has not been well cared for and will not balance charge without error. I read from link that Ni Cads had the lowest noise, but the Chinese Lipo's are cheap.

I am going to order some Vanguard Oscillators to replace the Sunny ones. If I read it right the pin outs and voltages are the same. There would be no soldering as these just plug into the sockets. I know there are existing upgrades and better gear (Mutec), but would like to see if any gains can be made with my existing unit and to keep it under well under $100. Here is a shot of the Vangards:

 

[juliocat]

 

I am going to order some Vanguard Oscillators to replace the Sunny ones. If I read it right the pin outs and voltages are the same. There would be no soldering as these just plug into the sockets. I know there are existing upgrades and better gear (Mutec), but would like to see if any gains can be made with my existing unit and to keep it under well under $100. Here is a shot of the Vangards:

 

 

Hello Harpy

 

Could you please be more specific about the Vangard Oscillators i'm very interested .

 

Thanks

[Harpy]

I really don't know if it will work, but I'll report back with results. The SOtM uses two full sized Sunny Oscillators that just lift out of their sockets:

 

The first value is 22.579200 MHz the second is 24.576000 MHz. The Vanguards are coming from Hong Kong, so I will know if they work in a week. Here is a link to one of the Vanguards both values are available.

 

Vanguard TCXO 0 1ppm 22 5792MHz Ultra Precision Golden Oscillator | eBay

 

I maybe all wet, but thought it was worth a try.

[juliocat]

We will waiting for your report.

[Harpy]

A good link to TCXO Oscillators: TCXO | Temperature Compensated Crystal Oscillator | Tutorial

[Harpy]

Just wanted to point out that a raw LI-Po is probably a bad idea: "•Never use Li-Ion battery pack without PCB (protection circuit board)". Will probably go to a LiFePO4 9.6 volt.

[juliocat]

This is my Battery experiment with SOTM dx-USB-HD

 

SLA 12 volt battery and DC-DC Regulator

 

 

I tried connecting the battery with and without the regulator, and the sound using the regulator is more refined, i hear more resolution and the perceived space of music is more spacious and light.

 

20W DC DC Step Down Converter Regulator Combine The Green LED Volt Meter | eBay

[juliocat]

This mod is a keeper the Regulated Battery Power has transform the SOTM dx-USB-HD in another beast, very very recommended!!!!!!

[Harpy]

Hey Juliocat that looks like a neat idea. Ordered a Turnigy 3s2P 4500 mah LiFePO4 9.9 volt battery. I think Red Wine Audio uses some sort of LiFePO4 battery as well. The thing I like about RC batteries is they have a balance connectors and a computer battery charger is nice to get the most out the batteries. LiFePO4 can take about 2000 charges and (I guess) deemed safer for circuits over lipos. Another quality is they come off the charger a little hot then go right into there rated voltage and stay there till discharge, so you can't really measure the voltage to determine how much battery life is left. You can get battery meters designed for Life batteries, however. I think a more constant voltage would be good like your regulator (which I'll try).

Anyway.... Don't know if this is interesting or helpful to anyone. If anyone sees any misinformation please point it out certainly not an expert.

[Harpy]

Here is the battery taking a balanced charge. The main disadvantage of running a this type of battery is you have to know the approximate run time. Units like Red Wine Audio use a circuit to disable the battery to prevent full discharge which can damage the battery. It's about a 1 volt over for the internal The SOtM tX-USBexp without regulation about right in the middle for the converter. I figure about 8-9 hours per charge and at $36 you can explore battery power without a large investment.