Author Topic: Modifications for SD USBpre? (Read 8709 times)

KLowe · « **on:** June 12, 2007, 10:35:11 PM »

was wondering if anyone knows of any mods to the SD usbpre.

Wondering if the AD chip can be replaced to allow for 24/96 out or at least 24 bit out?

anyone know of any mods to this box?

Thanks

Kevin

sygdwm · « **Reply #1 on:** June 12, 2007, 10:56:14 PM »

i never heard about mods, but it does so 24bit out. usb 1.1 chokes on 24/96, hence the 24/48 ceiling. they sound great stock fwiw.

KLowe · « **Reply #2 on:** June 12, 2007, 11:26:55 PM »

Quote from: dre on June 12, 2007, 10:56:14 PM

i never heard about mods, but it does so 24bit out. usb 1.1 chokes on 24/96, hence the 24/48 ceiling. they sound great stock fwiw.

ive read the manual and it only does 1 bit out SPDIF (as far as I can tell).

What outs deliver the 24 bit signal?

Thanks Dre,

Kevin

sygdwm · « **Reply #3 on:** June 13, 2007, 12:05:02 AM »

the usb cable is the out. i sont remember the usb out and the spdif out being active at the same time. one or the other. also, i think the spidf out was for playback, but dont hold me to that. i sold mine a couple years ago. if i was ever to get back in to laptop taping

i would get one in a heartbeat. sounds waaaay better than a ua5(modded or not) and is waaay easier to use. also its fucking tiny and doesnt need batts.

BC · « **Reply #4 on:** June 13, 2007, 11:36:22 AM »

Quote from: dre on June 13, 2007, 12:05:02 AM

the usb cable is the out. i sont remember the usb out and the spdif out being active at the same time. one or the other. also, i think the spidf out was for playback, but dont hold me to that.

I think so too. The recording bit depth is selected using your recording software.

KLowe · « **Reply #5 on:** June 13, 2007, 12:53:02 PM »

Quote from: BC on June 13, 2007, 11:36:22 AM

Quote from: dre on June 13, 2007, 12:05:02 AM
the usb cable is the out. i sont remember the usb out and the spdif out being active at the same time. one or the other. also, i think the spidf out was for playback, but dont hold me to that.

I think so too. The recording bit depth is selected using your recording software.

so..... this thing can't be used in the field without a computer attached to it via USB?

If thats the case then back to ebay it goes

I'd be willing to let some of yall modders to poke around under the hood to see if yall can make the SPDIF out active during recording and at 24 bit.

I guess I'm going to have to read the manual.......

sygdwm · « **Reply #6 on:** June 13, 2007, 01:37:39 PM »

Quote

so..... this thing can't be used in the field without a computer attached to it via USB?

i dont believe so. they are so cheap it seems almost worthwhile to crack it open and look, but i am no hacker.

KLowe · « **Reply #7 on:** June 13, 2007, 02:15:55 PM »

Quote from: dre on June 13, 2007, 01:37:39 PM

Quote
so..... this thing can't be used in the field without a computer attached to it via USB?

i dont believe so. they are so cheap it seems almost worthwhile to crack it open and look, but i am no hacker.

Any takers on hacking this thing?
I'll open it up and take a peek around tonight. Not that I have any clue on what I'm doing in there.

KLowe · « **Reply #8 on:** June 13, 2007, 03:47:25 PM »

I found the following in the device manual.
I guess it can do SPDIF out?

Output
Because of a limitation in Microsoft's kmixer system file in Windows 98SE, 2000, and Me, the output of the USBPre is limited to 16-bit. A 20 or 24-bit signal sent to the USBPre will output 16-bit data.

To improve the transfer of digital audio, the USBPre Control Panel has an S/PDIF output sync selection. With no sync selected devices connected to the USBPre's S/PDIF output may take several seconds to "lock-up" to the S/PDIF signal. During lock-up, objectionable audible artifacts are present. When no audio is present the S/PDIF output is inactive. When an output sync sample rate is selected in the Control Panel the S/PDIF output port is always active, sending 0's at the selected sample rate when no audio is present. This greatly improves the performance of transfers from the S/PDIF output, since a lengthy pre-roll is not required to lock-up the data.

BIG NOTE: Selecting an output sync sample rate in the control panel may have a negative on audio performance since all audio, regardless of its native sample rate, will output at the selected sync rate. Sample rate conversion will occur in Windows when the computer receives an audio signal at a frequency that is different from the selected sync sample rate. Again, make certain that the selected output sync sample rate matches the sample rate of the files being played, otherwise sample rate conversion will occur.

sygdwm · « **Reply #9 on:** June 13, 2007, 06:59:14 PM »

i never had a patcher, so i cannot attest to that, but i am pretty sure it has to connected to a pc to work as it is powered by usb.

KLowe · « **Reply #10 on:** June 13, 2007, 08:55:31 PM »

doing a quick experiment here.

cutting all but the 5v line in the USB cord and will see if it still sends a signal. If it does then creating a battery pack for this will be a cynch.

Something tells me it is going to be much more complicated than this and I'm about to ruin a USB cable.

KLowe · « **Reply #11 on:** June 13, 2007, 08:59:02 PM »

yep. wasted USB cable.

Unit fires up but will not allow phantom or in/out selection

gotta be some drivers in the comp that controls the box.

....damn.

Off to ebay it goes.

Jamos · « **Reply #12 on:** June 13, 2007, 10:08:42 PM »

Yeah these were designed to only be used w/a computer attached. Awesome little boxes though!

Great to use as a computer sound card if nothing else.

KLowe · « **Reply #13 on:** June 13, 2007, 10:27:52 PM »

Quote from: Jmos on June 13, 2007, 10:08:42 PM

Great to use as a computer sound card if nothing else.

good thought. Elaborate a little will ya. I can't think how that may work as a soundcard.... (i just finished dinner and had some wine

)

Jamos · « **Reply #14 on:** June 13, 2007, 10:40:26 PM »

Quote from: KLowe on June 13, 2007, 10:27:52 PM

Quote from: Jmos on June 13, 2007, 10:08:42 PM

Great to use as a computer sound card if nothing else.

good thought. Elaborate a little will ya. I can't think how that may work as a soundcard.... (i just finished dinner and had some wine )

mmmm...I could use a glass of wine right now...
well, I just meant that you can play audio out of it if you leave the USB connected to your computer. It gives you a clean, high quality output w/RCA's, and a strong headphone amp. Also you then have SP/DIF in & out of your computer...as well as XLR, 1/4", & RCA into your computer.

How much did you buy it for?

stirinthesauce · « **Reply #15 on:** June 13, 2007, 10:45:03 PM »

How much did you pay? I may buy it. Seriously.

timP · « **Reply #16 on:** June 13, 2007, 10:56:28 PM »

how about powering it with one of the usb battery packs like people are using with the microtracker?

KLowe · « **Reply #17 on:** June 13, 2007, 11:10:14 PM »

Quote from: timP on June 13, 2007, 10:56:28 PM

how about powering it with one of the usb battery packs like people are using with the microtracker?

kindof tried that experiment already and it didn't work.

I spoke with SD today and asked straight up if it could work as a standalone and he said nope. Needs a comp attached to it. I asked if there was any in-house mods to make it stand alone.... he paused and said no. Then went on to say that "maybe it could be modded" but it would no longer be under SD warrantee?

Damnit...... what does one make of this. I already own a W-UA5. Why do I care??? Is it because what "may be possible"?... bc I had to much shitty cabernet with dinner? B/c I'm a gear slut???

Someone help?

SmokinJoe · « **Reply #18 on:** June 14, 2007, 08:09:55 AM »

Do these have that transformer warmth like an MP2? If so, I might be interested in hacking on it...

My solution would probably involve a small single board computer (which I develop software for at work) running an embedded Linux to give it the info it needs, then ignore it. Does anyone know if this is usable in Linux? I have used an Maudio USB MobilePre, and I've read a UA-5 works too, using the generic usb sound driver.

KLowe · « **Reply #19 on:** June 14, 2007, 08:41:17 AM »

Yeah, sure.

I let you hack on it. Don't know about the sound but seems to be alot of people fluffing the sound.

I'll PM ya.

the software that comes with it is VERY basic....so my bet is that it does use generic usb sound driver

sygdwm · « **Reply #20 on:** June 14, 2007, 03:17:18 PM »

the sound is warm, similar to that of an mp2, if not the same.

SmokinJoe · « **Reply #21 on:** June 14, 2007, 09:49:13 PM »

Quote from: SmokinJoe on June 14, 2007, 08:09:55 AM

Do these have that transformer warmth like an MP2? If so, I might be interested in hacking on it...

My solution would probably involve a small single board computer (which I develop software for at work) running an embedded Linux to give it the info it needs, then ignore it. Does anyone know if this is usable in Linux? I have used an Maudio USB MobilePre, and I've read a UA-5 works too, using the generic usb sound driver.

It appears my idea falls apart... this doesn't take a generic linux driver... and I'm not aware of any other.

BC · « **Reply #22 on:** June 15, 2007, 07:20:40 PM »

Quote from: Jmos on June 13, 2007, 10:40:26 PM

Quote from: KLowe on June 13, 2007, 10:27:52 PM
Quote from: Jmos on June 13, 2007, 10:08:42 PM

Great to use as a computer sound card if nothing else.

good thought. Elaborate a little will ya. I can't think how that may work as a soundcard.... (i just finished dinner and had some wine )

mmmm...I could use a glass of wine right now...
well, I just meant that you can play audio out of it if you leave the USB connected to your computer. It gives you a clean, high quality output w/RCA's, and a strong headphone amp. Also you then have SP/DIF in & out of your computer...as well as XLR, 1/4", & RCA into your computer.

How much did you buy it for?

FYI: mine would always play back with glitches from the analog outs.

BC · « **Reply #23 on:** June 15, 2007, 07:22:19 PM »

Quote from: KLowe on June 13, 2007, 03:47:25 PM

I found the following in the device manual.
I guess it can do SPDIF out?

Output
Because of a limitation in Microsoft's kmixer system file in Windows 98SE, 2000, and Me, the output of the USBPre is limited to 16-bit. A 20 or 24-bit signal sent to the USBPre will output 16-bit data.

AFAIK, the SPDIF out is not active when taking an input, it is only active on playback.

bdasilva · « **Reply #24 on:** June 17, 2007, 01:18:38 PM »

SmokinJoe... not a linux driver. Monitor the usb communications between the computer and Pre... Then, use a small processor to emulate the trafic..

SmokinJoe · « **Reply #25 on:** June 23, 2007, 11:32:42 PM »

Quote from: bdasilva on June 17, 2007, 01:18:38 PM

SmokinJoe... not a linux driver. Monitor the usb communications between the computer and Pre... Then, use a small processor to emulate the trafic..

My thought was this... use some simple, dedicated singleboard Linux computer (which I develop on) to give it the computer signal it wants, just to "initialize", i.e. use the computer to "boot" the preamp into digimod mode, so to speak. I know the M-audio USBmobilePre and the UA-5 use a generic usb_snd driver. This one doesn't use that driver, and I guess the pre doesn't feed to DigiOut anyway. I expect it's possible to do something to capture USB data and reverse engineer it, but I didn't have an real interest in getting into a big project.

larrysellers · « **Reply #26 on:** June 28, 2007, 08:24:53 AM »

Hopefully someone can come up with a way for these to work stand alone. After I retired from laptop taping, I couldn't justify keeping my usbpre. I figure that when usb technology goes the way of the floppy disc, these will be the equivilant to the word clock disabled ad1000/ad500. Not by way of chronic design problems, just outdated technology. In a nutshell, they sound too nice to become doorstops.

bdasilva · « **Reply #27 on:** June 28, 2007, 09:25:51 AM »

The reason there is no digimod is that there is no switches in the unit to set resulation and bitdepth... Once that is set and powered it should work. It does sound great... sell it to someone that will love and use it.

Author Topic: Modifications for SD USBpre? (Read 8709 times)

stirinthesauce