SPDIF In & BOSS GT-6 Digital Out

mrichman

I am trying to connect the "Digital Out" from my BOSS GT-6 Guitar Effects Processor via a 75ohm RCA cable to the "SPDIF In" connector on my SB Live! I am running an AMD Athlon 1GHz, 1GB RAM, Windows Server 2003.

All other audio apps work just fine (WMP, iTunes, etc.).

It looks like I have SPDIF In enabled in the kX mixer, but I don't hear anything. When I go to "SPDIF/I2S Status" I see this info:

SPDIF Inputs: [R-Rate Locked; S-Stream Locked; V-Valid Audio]
spdif A: unused
spdif B: unused
spdif C: unused or same as B
SPDIF Outputs:
(0): 2109204 (1): 2109204 (2): 2109204 (24 bits / 48000 Hz)

I have never used SPDIF or Digital In/Out before, so I have nothing to compare my experience to. Here is some more info from the kX driver that may be helpful:

----Hardware / Software configuration---------------
Driver Name:kX Audio Driver (Debug)
Driver Date: Feb 17 2004 00:43:22
Driver Version: 5.10.00.3537 - debug
DB Name:none
CT4620 10k1 [ffe0]
PCI Information:
Device: 21102 Subsys: 211102 ChipRev: 5
Card has MPU device
Card HAS AC97 codec
Codec name: TriTech TR A5/CT1297 TAT
3D Extension: No 3D Stereo Enhancement
Codec is 1.0 compliant
Capabilities[0] :
DAC resolutions : -16-bit-
ADC resolutions : -16-bit-
Ext Capabilities [0]:
Port: ffe0 Irq: 0x12(18)
Playback buffer: 20a0
Record buffer: 4000
Number of AC3 buffers: 4
Tank memory: 256 kb
GSIF buffer: 256 samples
OS version: [2 5 2 ; 2 5 2 ; 156 148]
----------------------------------------------------

Thanks!

- Mark

dj_stick

try using a standard RCA cable(ie no resistance)

mrichman

I actually tried an old cheapo cable I had first. Having no luck with that, I switched to the 75ohm video RCA cable.

Do I need to have a particular app running to hear sound from the Digital Out of my amp, or will the mixer just magically play it through my desktop speakers?

I'm trying to avoid the expensive "special" cable.

Thanks,
Mark

dj_stick

the kX mixer should detect incoming valid s/pdif streams

mrichman

So, you're saying either my cable is insufficient, or my amp isnt outputting a SPDIF signal? Can you recommend a good cable, and a program to test recording from SPDIF?

Thanks,
Mark

Daniel Drummond

Either you have a bad cable or the GT-6 isn't outputing a digital signal which can be read by the card. Have you set up the GT-6 correctly? Any el-cheapo cable should work, as long as it isn't too long (up to 2 or 3 meter should be fine).

mrichman

Does it matter that the GT-6 outputs 44.1kHz and the SB Live samples at 48kHz?

I got that spec from here: http://www.bosscorp.co.jp/products/en/GT-6/specs.html

dj_stick

it shouldn't matter, as the DSP will resample… but test the GT-6 with another digital input cable device (hook a super-brigh RED LED to the end of the cable and put into the MD optical slot if you have an MD Recorder)

mrichman

The GT-6 is not an optical device - its just digital coax. And I don't think I have any other devices with a SPDIF In to test with.

dj_stick

thats why i hinted at the LED on the end of the RCA cable - it works…

mrichman

Would a multimeter serve the same purpose? I don't have an LED handy

What DC volts or amps am I looking for when signal is present?

dj_stick

standard spif should pulse at ±0.5 v, or TTL level should pulse between 0 and 5 volts

TravelRec.

Hi!

If the GT-6 has coax out, then the LED option will not work. Or you have to boost the signal to reach higher levels for driving the LED, maybe a high frequency transistor will work, but it´s not tested here. Crystal SPDIF receiver-ICs are able to work at both, low coax and high TTL-levels and they are able to convert them...


Greetings!

TravelRec.