Cheap optical dac with high gain

[OAV]

We have an issue with sky boxes for commercial projects - they have a very low output when feedin an optical dac, and no analog outputs anymore can anyone recommend a cheap cheap dac with high gain, to feed into a back ground music system for football.. I have tested a handfull and found 1 that is 7dB louder than the others (with the same optical input level) but could really do with more

Many Thanks

 

[RayDunzl]

What output voltage are you looking for?

2V max is common, 4V less common, higher than that uncommon, may not fit your cheap cheap requirement.

 

[DVDdoug]

and no analog outputs anymore

There is an analog amplifier somewhere and it possibly needs more gain... Usually the analog amplifier has enough gain to go to full power.

A "pro" DAC should have more output than a consumer product. Consumer & pro line levels are different.

But not everything is calibrated and some program material is louder than others, etc. Usually there is enough signal (the "line level' is a little hot) and there is enough extra gain in the amplifier so that everything works together.

Except sometimes when you connect a consumer device to a pro power amp, the pro power amp doesn't have enough gain because it's expecting a hotter signal.

We have an issue with sky boxes for commercial projects - they have a very low output when feedin an optical dac, and no analog outputs anymore can anyone recommend a cheap cheap dac

I didn't think sky boxes are cheap, or anything in them.

 

[Nutul]

We have an issue with sky boxes for commercial projects - they have a very low output when feedin an optical dac, and no analog outputs anymore can anyone recommend a cheap cheap dac with high gain, to feed into a back ground music system for football.. I have tested a handfull and found 1 that is 7dB louder than the others (with the same optical input level) but could really do with more

Many Thanks

A DAC is not an amplifier... And if you find one with "more gain" it simply means it acts also as an active pre-amp...
I would look for a proper pre-amp in your case; or a better matched DAC-AMP couple, in terms of input levels and gain.

 

[staticV3]

We have an issue with sky boxes for commercial projects - they have a very low output when feedin an optical dac, and no analog outputs anymore can anyone recommend a cheap cheap dac with high gain, to feed into a back ground music system for football.. I have tested a handfull and found 1 that is 7dB louder than the others (with the same optical input level) but could really do with more

Many Thanks

The SMSL PS100 will get you standard 2V output at a cheap price.

It's not a particularly good DAC though:

SMSL PS100 *$30.00* DAC (some limitations apply)

May or may not help: On your Sony TV, check if you have an option under Settings -> Channels & Inputs -> External Inputs -> Bravia Sync Settings -> Device Auto Power off Well, it turns out you've solved my issue! I followed your advice and the DAC stays on irrespective of the TV. It looks like...

www.audiosciencereview.com

 

[RayDunzl]

On the other hand, maybe the optical signal (the numbers in the data stream) is low.

What's in the signal chain from source to speaker?

 

[OAV]

So these are commercial installations input output chain is either

Sky Box - Optical Dac - BSS Blu100 DSP (Note1) - Amplifiers - Speakers
OR
Sky Box - Optical Dac - Analog Zone Mixer (Note2) - Crossovers - Amplifiers - Speakers

Note1 these new sky boxes are replacing old ones, so the soundweb (which has more than enough input gain available to boost anything) is already setup, and we often dont have the soundweb file to adjust it

Note2 The analog zone mixers even with input gain at +10db is not enough

I was just hoping someone may have come across a cheap and cheerful optical dac that would output a higher than usual amount

It is a known issue that sky boxes output a low signal level from the optical port

This is not for critical listening or music, just for sports audio - football etc as such sound quality is a distant second concern over gain, a few percent THD will not matter if they can't hear the commentator!

A pub full of people watching footie is loud!

I did some tests on the bench with a cd player, sine wave recorded at 0db 1khz, through various dacs
1 output 0dBu (0.775mv)
another was +2.2dBu (1v)
and the best one output +7dBu (1.75v)

All of these would be fine IF the sky boxs optical output got anywhere near full scale, but they do not - by a long way!

 

[staticV3]

I was just hoping someone may have come across a cheap and cheerful optical dac that would output a higher than usual amount

For that it would be useful to know how much your current DACs are outputting, both via your Sky boxes and via some other Toslink source with known bit-exact, 0dBFS output.

A basic $10 multimeter is really all that you need for this.