Hypex UcD AS2.100

[imagemachine]

Originally Posted by Matthijs_Hypex

Hi,
To use SPDIF on the AES input you'll need some kind of converter.
You can find some searching for SPDIF to AES/EBU converter

Hi, thanks...there's all sorts of conflicting views on SPDIF to AES conversion, some say just wire hot and cold (pin 2 pin 3) to phono + and gnd, leaving pin 1 (gnd) floating, or using transformer coupling, or resistor networks for the 110Ω - 75Ω for impedance matching etc etc, so confusing. Also, won't the AES 7vp input find the 0.5vpp output of the SPDIF too weak?

[TheShaman]

Check "INTERFACING AES3 & S/PDIF" from Rane.

[imagemachine]

I've found the answer:

LUNDAHL LL1574 TRANSFORMER Digital audio impedance matching, PC mounting, 100/75 ohms

I don't think it's a good idea to direct wire pin to pin...it may well work but I've got a feeling the impedance mismatch may well be inviting cable reflections and therefore jitter problems - if you are hotwiring SPDIF RCA to AES XLR at present, I bet introducing this tranny would bring audible improvements. This is the route I'll go anyway.

[Vathek]

Originally Posted by imagemachine

I've found the answer:

LUNDAHL LL1574 TRANSFORMER Digital audio impedance matching, PC mounting, 100/75 ohms

I don't think it's a good idea to direct wire pin to pin...it may well work but I've got a feeling the impedance mismatch may well be inviting cable reflections and therefore jitter problems - if you are hotwiring SPDIF RCA to AES XLR at present, I bet introducing this tranny would bring audible improvements. This is the route I'll go anyway.

I agree, this seems the way to go. I was just pointing out that it works going from SPDIF straight into AES/EBU, not trying to imply it was the optimal solution!

Now that you've brought this up, I want to finally do this properly myself. Did you notice in the data sheet for the LL1574, they mention two versions of AES/EBU. One on 1.2 Volts and one on 4 Volts with the latter requiring two resistors in addition to the transformer as well. I wasn't aware of that distinction, now which one is it with the PSC2.400?

[Vathek]

Matthijs, could you maybe shed some light on this question about the AES/EBU voltage? I'm getting occasional random spikes in my setup and was thinking it might have something to do with not perfectly matched impedances.

My setup is TC-BMC2 into PSC2.400 (l) into PSC2.400 (r) into Behringer DCX2496 (for the subs) all digital.

The spike occurs every couple of minutes and it's basically a loud thump in the subs, but I assume it's a full range spike before it's low-passed in the DCX.

Or any other ideas what could be causing this spike?

[Sam Lord]

I'm no Class D expert but I've encountered many of these. Either a cap or large conductor like a chassis is loading up then dumping (discharging) somehow. You need to probe DC voltages in several spots w.r.t. ground, especially chassis and large, normally-neutral conductors w.r.t. ground, over at least one cycle of the behavior per test lead. It's a starting point.

[der_yeti]

Hello,

I currently have two AS2.100 modules on hand and would like to power one subwoofer each.

1. Which configuration would be the right one to get "stereo-subwoofers"?

2. Is it possible to get separate signals for left and right to the subwoofers, or do I only have the sum of both?

3. To which positions do I have to connect the subwoofer to get the "bridged power"?

Thanks and regards,
Alex

[Vathek]

Originally Posted by Sam Lord

I'm no Class D expert but I've encountered many of these. Either a cap or large conductor like a chassis is loading up then dumping (discharging) somehow. You need to probe DC voltages in several spots w.r.t. ground, especially chassis and large, normally-neutral conductors w.r.t. ground, over at least one cycle of the behavior per test lead. It's a starting point.

Hmm, yeah. But those plate amps are self contained units really, so it would be case of warranty rather than me starting to troubleshoot the units.

But I'll have to do some further testing to find out which one of the units it actually is (the spike is always on the right channel), which means hooking them up one by one and also trying analog, to see if the problem persists.

And I've just noticed that there's a software update to 2.2 available, so I'll try that as well.

It would still be nice to know about the correct voltage with witch to drive these things digitally, Matthijs or anyone?

[Matthijs_Hypex]

Originally Posted by der_yeti

Hello,

I currently have two AS2.100 modules on hand and would like to power one subwoofer each.

1. Which configuration would be the right one to get "stereo-subwoofers"?

2. Is it possible to get separate signals for left and right to the subwoofers, or do I only have the sum of both?

3. To which positions do I have to connect the subwoofer to get the "bridged power"?

Thanks and regards,
Alex

Hi,

1 & 2. For this option you should set the AS2.100 to "Bridged" & "Left" or "Right".

3. To connect your woofer in bridged mode you should connect it to the two plusses of the amps.

Please see page 10 of the manual for more information about the bridged mode and connecting your speaker.

What load will you use in bridge mode?

[Matthijs_Hypex]

Originally Posted by Vathek

Hmm, yeah. But those plate amps are self contained units really, so it would be case of warranty rather than me starting to troubleshoot the units.

But I'll have to do some further testing to find out which one of the units it actually is (the spike is always on the right channel), which means hooking them up one by one and also trying analog, to see if the problem persists.

And I've just noticed that there's a software update to 2.2 available, so I'll try that as well.

It would still be nice to know about the correct voltage with witch to drive these things digitally, Matthijs or anyone?

Hi,
I send you a private message yesterday.

Signal levels for the AES should be as defined in the standard. I thonk it was 110Ohms and >2Volts p-p, but you'll have to check this to be sure.