5.1 Amplifiers with Optical inputs

**ajscomp372** · 10-10-2008, 08:59 AM

If I correctly understand what you're saying, that setup should work. Now, the Performance Teknique ICBM-5.1 amplifier has the optical input and the 5.1 rca input, which is what you're looking for. If you can still find it, it could be your best bet.

BTW: For anyone who doesn't have a remote for this amp, I have a solution. Just message me for more info.

**jschrauwen** · 10-10-2008, 02:03 PM

Originally Posted by ajscomp372

BTW: For anyone who doesn't have a remote for this amp, I have a solution. Just message me for more info.

Still running the PT 5.1?
I STILL haven't installed it yet because of the nagging delays for that double din all singing all dancing unit fromt Brent. So frustrating that my CarPC has been ready to install for over a year and a half.
Love to see/hear what your solution was for the MIA remote.

**ajscomp372** · 10-10-2008, 06:49 PM

Originally Posted by jschrauwen

Love to see/hear what your solution was for the MIA remote.

Well, I actually did originally receive a remote with my amp, and because of incredible foresight, I decided to record the IR signals using winlirc on my computer, thinking that I would use them to have the computer control the amp in the future. Several months later when I lost the remote, I simply hooked up the IR transmitter to my serial port and set winlirc to simulate pushing the power button on the remote when it booted up. Now I basically have a virtual remote on the computer, that I can program or script to manipulate the amp any way I want.

If anyone needs the config file for winlirc that would allow you to simulate the remote, I could give the file and (if they wanted) build them the box that connects between the computer and the amp (PT ICBM-5.1).

**MeeM** · 01-03-2009, 10:07 AM

ajscomp372: good job with the IR capturing.

So excuse my ignorance ppl, but what's wrong with setting the volume to a decent level on the amp, and then controlling the PC volume thru ur touchscreen as normal? Atm, with my desktop PC here in my room, I've got an optical cable from my PC to my amp ... and the amp is turned up to a decent level and I hardly adjust it (except for movies etc.). I usually just control my volume in Winamp or Windows Media Player or the taskbar volume control.

Am I missing somethin in this thread?

**jschrauwen** · 01-03-2009, 12:21 PM

^^^ Are you using the ICBM5.1 as well?

**MeeM** · 01-03-2009, 07:03 PM

Nope, I haven't got a 5.1ch amp with optical input yet.

**enigma9o7** · 01-05-2009, 09:07 PM

Originally Posted by MeeM

ajscomp372: good job with the IR capturing.

So excuse my ignorance ppl, but what's wrong with setting the volume to a decent level on the amp, and then controlling the PC volume thru ur touchscreen as normal? Atm, with my desktop PC here in my room, I've got an optical cable from my PC to my amp ... and the amp is turned up to a decent level and I hardly adjust it (except for movies etc.). I usually just control my volume in Winamp or Windows Media Player or the taskbar volume control.

Am I missing somethin in this thread?

Unless I'm also ignorant, when the signal goes from your deck/pc to an amp optically, there's no volume control from the sending device... you adjust the volume with the amp. All that's going thru the fiber is the digitally encoded audio.... there are no levels involved, either the led/laser is on or off to indicate 1 or 0. I can set the volume to 0 on my deck and optical signal is not affected. The same thing happens with my home theatre components - i.e. I can set my HDTV volume to zero, but signal coming optical out into my amp doesn't change.

However, if the signal is coming from your deck/pc to an amp analog, then when you change the volume on your deck/pc it is changing the voltage levels going into the amp, so it does control volume, in essence your amp is applying the same amplification to whatever comes into it if you dont change it. i.e. if the amp does 3db gain, it'll apply that gain/increase to whatever voltage is coming in.

What I did in my car was run optical from my deck to the the phoenix gold 5.1 amp and use pacswix to have my steering wheel volume control adjust the amp volume. This worked for cds, mp3s & dvds. For the radio & tv, I didn't get sound from my deck on the optical (I wasn't lucky enough to get a deck with analog to pcm encoding) so I also ran rca's from my deck to the amp. I made one of my steering wheel buttons the input select on the amp, and then adjusted the volume on the deck so it was approx the same level as a CD via optical, then from there never touched the deck volume again.

**MeeM** · 01-05-2009, 09:52 PM

Originally Posted by enigma9o7

Unless I'm also ignorant, when the signal goes from your deck/pc to an amp optically, there's no volume control from the sending device... you adjust the volume with the amp. All that's going thru the fiber is the digitally encoded audio.... there are no levels involved, either the led/laser is on or off to indicate 1 or 0. I can set the volume to 0 on my deck and optical signal is not affected. The same thing happens with my home theatre components - i.e. I can set my HDTV volume to zero, but signal coming optical out into my amp doesn't change.

However, if the signal is coming from your deck/pc to an amp analog, then when you change the volume on your deck/pc it is changing the voltage levels going into the amp, so it does control volume, in essence your amp is applying the same amplification to whatever comes into it if you dont change it. i.e. if the amp does 3db gain, it'll apply that gain/increase to whatever voltage is coming in.

What I did in my car was run optical from my deck to the the phoenix gold 5.1 amp and use pacswix to have my steering wheel volume control adjust the amp volume. This worked for cds, mp3s & dvds. For the radio & tv, I didn't get sound from my deck on the optical (I wasn't lucky enough to get a deck with analog to pcm encoding) so I also ran rca's from my deck to the amp. I made one of my steering wheel buttons the input select on the amp, and then adjusted the volume on the deck so it was approx the same level as a CD via optical, then from there never touched the deck volume again.

Thanks for your input. You worked around the problem quite well in your car

when the signal goes from your deck/pc to an amp optically, there's no volume control from the sending device

I'm still not sure about this. I understand your reasoning and in theory that's how it probably should (or would?) work. But most optical setups I've used (including my current desktop PC with optical cable running to my 5.1 ch amp) allow volume to be adjusted at the source. So maybe the optical output on PCs might be setup differently to other devices

**pcpete** · 01-05-2009, 10:07 PM

I think , at least in winamp, if I select 'wavout' as path I can't control volume, if set for directsound then windows mixer messes with the bits (ie adjusts volume) and then sends to spdif out, if so configured.

The holy grail is to have the bits untouched and sent through spdif out, hence no volume control without losing quality...

**MeeM** · 01-06-2009, 04:30 AM

ye my winamp is set to directsound. If I use directsound, the audio output is softer compared to the output if I used waveout. Not sure why that is so ...

And now I've just noticed that because I have my PC connected to my amp with an optical cable, the master volume slider in the windows mixer has no effect on the volume. So I guess this is what ppl are talking about in this thread.

Still though, if I had the same setup in my car, I'd use winamp and I'd use the volume in winamp cos that still works with an optical cable. It's just the windows master volume that seems useless with optical.