[mmerrill99]

Quote:

Originally Posted by glt /img/forum/go_quote.gif jkeny, "- put in some extra capacitance where USB comes onto the board" Is that across the 5V?

Yep, just behind the USB connector you'll see a green sleeved 2,200uf capacitor connected across the 6 legged chip (don't know what ID or function this chip has but it connects across gnd & 5V).

 

[mmerrill99]

Quote:

Originally Posted by glt /img/forum/go_quote.gif I just did a comparison between usb power and battery power. Can't tell if there is any difference... (94/24 material in iTunes for windows, Lenovo laptop, headphone output, HD580). This means USB power filtering is pretty good...

Did you use the laptop running on it's batteries or a separate external battery? I noticed a distinctly better sound on external supply - somewhat better with SMPS than batteries (but I'll try batteries again with large capacitance across the terminals)

Yes the internal PS filtering is quiet good - all the extra circuitry in the 01 US seems to be concerned with PS filtering smoothing for the DAC & output stage (& to generate the -5V for OP275 op-amp). It only feeds the output stage - the USB 5V is directly fed to the 3.3V & 1.2V regulators.

 

[Mr.Mantas]

Quote:

Originally Posted by jkeny /img/forum/go_quote.gif Here's what I've done so far and I must say the sound of this 01 US is stunning - replaced capacitors on digital 3.3V with Oscons - put in some extra capacitance where USB comes onto the board - put some extra capacitors (10uf) at the PCM1793 supply pins - put a socket in place for Vcom so I can experiment with different capacitors - put Oscon caps across the input & ground of both regulators Great improvement in sound when running from external power supply Vcom capacitors seems to act like signal passing capacitors so big capacitance needed for good bass but film capacitor needed for clean high frequencies. Still experimenting.

Great job jkeny !!!

i following your mod job with big interest, because i believe that 01US can sound really great!

Please keep updating your mods

 

[MikeW]

Been following this thread and have a few questions, I understand the need for a device like this if you are using a laptop. But how does this thing compare to high end PC Sound cards for Digital output, for example EMU 0404 (PCI), with it's transformer coupled SPDIF output, or EMU 1212m, or a High end Asus card, M-Audio, etc. I currently use an X-FI's flexijack Digital output with a custom made (blue jeans) 3.5 > coax cable. Im curious if a device like this, or just upgrading to somthing like a 0404 would give a jitter improvment to my dac. I've seen on this thread people saying it sounds better then an 0404 USB, but it seems to me you'd get better performance out of the PCI Version, for SPDIF Output anyways. So much talk of the usb 0404 everyone forgot about the PCI version. (which can be had for the same price as this device)

 

[rated1975]

DD please keep us posted with your results


Quote:

Originally Posted by denydog /img/forum/go_quote.gif I've been following this thread with interest, but some of you are getting out of my league with the mods, though I can see what you're trying to do. I ordered a monitor 01 USD last night. my hopes for it are modest, and I think pretty common. First off, I just want to feed PC based music to my Grace m902 using other than its USB input, which has a reputation for fairly high jitter. I'm hoping this will result in an overall improvement in sq, even with the Internet radio I've come to enjoy. Secondly, this will also allow me to play some of my music files with higher rez than 16/44.1-48 I have been considering the Bel Canto converter for some time, but it's a lot of money just to see if I'd like it. The 01 USD is a lower stakes gamble. I've been encouraged by some of the reports and comparisons I've read on this thread, and will look forward to more.

 

[chipzahoy]

Sorry, but neither the 0404 nor the 1212M come close to "Hi-End" devices without an extensive of modding.

Quote:

Originally Posted by MikeW /img/forum/go_quote.gif Been following this thread and have a few questions, I understand the need for a device like this if you are using a laptop. But how does this thing compare to high end PC Sound cards for Digital output, for example EMU 0404 (PCI), with it's transformer coupled SPDIF output, or EMU 1212m, or a High end Asus card, M-Audio, etc. I currently use an X-FI's flexijack Digital output with a custom made (blue jeans) 3.5 > coax cable. Im curious if a device like this, or just upgrading to somthing like a 0404 would give a jitter improvment to my dac. I've seen on this thread people saying it sounds better then an 0404 USB, but it seems to me you'd get better performance out of the PCI Version, for SPDIF Output anyways. So much talk of the usb 0404 everyone forgot about the PCI version. (which can be had for the same price as this device)

 

[MikeW]

I disagree, yes they are obviously not high end in comparision to stand-alone audiophile dacs, but compared to the vast majority of sound cards on the market, they are "high end" in their respective field. Keep in mind we're also only talking about SPDIF Output here, so any mods to the dac's opamps etc are usless, unless the mod directly effects the SPDIF output. ( most sound card mods focus on improving analog output )

 

[chipzahoy]

I was referring to the S/PDIF output quality of 0404 and 1212m.

Quote:

Originally Posted by MikeW /img/forum/go_quote.gif I disagree, yes they are obviously not high end in comparision to stand-alone audiophile dacs, but compared to the vast majority of sound cards on the market, they are "high end" in their respective field. Keep in mind we're also only talking about SPDIF Output here, so any mods to the dac's opamps etc are usless, unless the mod directly effects the SPDIF output. ( most sound card mods focus on improving analog output )

 

[erfmd]

have read through the forum and called pacific valve (Joe) about this device and am intrigued but remain confused. forgive my ignorance, but can someone explain - in layman's english - exactly what this device does and why it may or may not be useful with and without a standard DAC? thanks!! BTW, joe states he uses this out of his computer to power AKG701's without an amplifier which seems a bit far-fetched to me. any opinions on this?

 

[glt]

There are 3 models: USD01, US01 and US02. USD01 is USB to spdif and toslink converver. US01 adds a DAC and headphone amp. US02 adds a built in power supply to US01 and an extra headphone amp (one for high imp, one for low, I think). Volume is digital in the PC (there is no analog attenuation)

All 3 models are capable of passing 24bit 192KHz material. The devices require that you install their driver and right now it is only compatible with windows xp/vista.

 

[MikeW]

Dac's require a digital input signal, SPDIF, this device hooks into your USB port and creates the required SPDIF signal to be fed to your dac.

 

[HeatFan12]

Quote:

Originally Posted by erfmd /img/forum/go_quote.gif have read through the forum and called pacific valve (Joe) about this device and am intrigued but remain confused. forgive my ignorance, but can someone explain - in layman's english - exactly what this device does and why it may or may not be useful with and without a standard DAC? thanks!! BTW, joe states he uses this out of his computer to power AKG701's without an amplifier which seems a bit far-fetched to me. any opinions on this?

I believe PV stocks the 01 US...This thread was started for the 01 USD. The 01 US can be connected to an amp. The 01 USD is just a converter.

What glt wrote....Great description...

 

[erfmd]

thanks all. so, if i am understanding, a "USB DAC" actually first converts the usb signal to a digital signal and then converts this to an analog signal? thus a "usb dac" functions as the usd 01 plus a standard dac? if my understanding is correct, is there an advantage to having these steps broken up between two components rather than purchasing a "usb dac?" and, what is the quality of the dac portion of the us 01? and the headphone output?

Joe at PV was trying to explain this as follows: a usb dac "pushes" the upconversion through the dac from the computer whereas the monitor software performs the actual conversion within the computer and the monitor than "pulls" the information out. does this make any sense?

thanks again.

 

[coolfungadget]

Quote:

Originally Posted by glt /img/forum/go_quote.gif There are 3 models: USD01, US01 and US02. USD01 is USB to spdif and toslink converver. US01 adds a DAC and headphone amp. US02 adds a built in power supply to US01 and an extra headphone amp (one for high imp, one for low, I think). Volume is digital in the PC (there is no analog attenuation) All 3 models are capable of passing 24bit 192KHz material. The devices require that you install their driver and right now it is only compatible with windows xp/vista.

Actually 4 models. Take a look on the new Monitor 01MINI...

 

[erfmd]

another question: i read that one should use Foobar as the music server with this product. do you know if this is true? currently i use the zune software with lossless files. would i need to change servers? and is foobar easy and intuitive? thanks again.