1 (edited by djselbeck 2011-02-21 10:40:03)

Topic: Multiface2 connected to power amplifier. Loosing host connection.

Hello, i've my multiface II connected to an Audiolab 8000p stereo power amplifier so I can use the audio device as an preamp.

It works nicely but, if I power on the amplifier the multiface seems to loose it's host connection for 1-2 seconds.

It is connected unbalanced with TRS to RCA cable. (high qualitv)

I want to ask if this is bad for the device and which I can do against this?

Greetings.

2 (edited by vinark 2011-02-21 11:24:17)

Re: Multiface2 connected to power amplifier. Loosing host connection.

I don´t know if it is harmful.
What might help though is checking how the cable is connected (HQ or not) Ideal would be if ground and tip and ring have a separate connection ( so 2 signal and 1 ground cable) and at the rca side tip is connected to signal and ring to ground. Ground/sleeve is unconnected at the rca side and connected normally at the TRS side.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
Babyface pro fs, HDSP9652+ADI-8AE, HDSP9632

3 (edited by djselbeck 2011-02-21 12:11:10)

Re: Multiface2 connected to power amplifier. Loosing host connection.

Ok I checked my cable. And it consist of two mono TRS plugs. So there is no second ring. So should I buy/build a cable like you said with 2 "stereo" TRS plugs? I think I'll try this because it is getting on my nervs smile

Re: Multiface2 connected to power amplifier. Loosing host connection.

I think you mean a mono TS plug then (no ring, just a simple jack plug).
It,s not that easy to exactly understand what we mean without drawings, but here it goes. Use balanced cable (mic cable). On RME side 2 TRS plugs (same as big headphones plug)  on amp side  2 rca plugs. That´s 2 cables one L one R. Solder as in previous post. I believe there might be an example somewhere here on the RME site or maybe even in the manual.
Hope it helps! (it might cause the cable you use now connects the ring to ground).

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
Babyface pro fs, HDSP9652+ADI-8AE, HDSP9632

Re: Multiface2 connected to power amplifier. Loosing host connection.

I've just tried two TRS Stereo cables(stereo TRS on one side and two RCA plugs on the other) and only connect the left channel of each, which means tip and ground to RCA plug. The effect was the same. Lost host connection and have to restart the multiface to get it running.

Re: Multiface2 connected to power amplifier. Loosing host connection.

Ah but that is exactly the issue, the ground should not be connected on the rca side, only the 2 signal lines (T and R). Apparently the amp is sending some spike or voltage through it´s ground which disrupts the RME.  If you want a cheap and chearful version change on the trs side the ground from sleeve to ring and leave the signal of ring disconnected. Now you have no real sleave so it might be a little more noisy, but you can check if it helps. Remember the ground of the rme should not be connected to the amp.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
Babyface pro fs, HDSP9652+ADI-8AE, HDSP9632

Re: Multiface2 connected to power amplifier. Loosing host connection.

Ah ok now I get it. wink This will take some time because I need to solder. Thanks for your help

Re: Multiface2 connected to power amplifier. Loosing host connection.

Hello, at the moment I'm waiting for my cable components to arrive. Today I tried connecting the ground of the RCA Connector of the amplifier to the case of my pc. So the RCA is really grounded and any distortion pulse goes through this line. Now I'm not completely sure if this is an saftey issue or not. Because the power amplifier only has 2 powerconnections (no what we call "Schutzleiter") .

with the ground connected I can switch the amplifier on without loosing the connection between PC and Multiface.

greetings

9 (edited by djselbeck 2011-02-24 11:45:15)

Re: Multiface2 connected to power amplifier. Loosing host connection.

Hi vinark, today I soldered the cable. two TRS plugs on one side and two RCA on the other. On TRS side I connected hot and cold, and then ground to the shielding. And on rca side I only connected hot to the pin and cold to RCA ground. But as you said now I can hear a hum. But the turn off spike seams to be solved. If I connect my PC parallel on the line-in the hum gets also away.

Re: Multiface2 connected to power amplifier. Loosing host connection.

To be honest, I didn´t expect the hum HeadScratch . If the hum goes away if you also connect the in (What in exactly?) and then also no problems with turning off or on any more? Then problem solved. If not,be a little more specific.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
Babyface pro fs, HDSP9652+ADI-8AE, HDSP9632

11 (edited by djselbeck 2011-02-24 11:46:54)

Re: Multiface2 connected to power amplifier. Loosing host connection.

The power amplifier has to RCA Plugs which a connected parallel to the input. If I connect an RCA cable to the linein off the pc(onboard soundcard) the hum goes away. But I think this is an acceptable solution

Re: Multiface2 connected to power amplifier. Loosing host connection.

Yes I think so too, that way the amp is connected to the ground of the pc (hence no hum) but doesn´t disturb the RME. Great work!

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
Babyface pro fs, HDSP9652+ADI-8AE, HDSP9632