cheap analog to digital converters

cricky81

New member
If I recorded condensor mics from the rca outs on my mixing board (behringer eurorack) into a cheap analog to digital converter (like one found on amazon for 30 bucks) would the result be passable? I already have an optical in on my audio interface (apogee element) and want to add a couple channels when recording drums. I'm really asking if there is a fundamental issue with recording through RCA outs

P.S. I have no money
 
If you have the stuff and no money, I don't see any reason to not just try it and see if the quality is Ok.

If you are using SPDIF (from A/D to Apogee) input you do need to be able to sync the clocks would be one question, i.e., is that possible with the A/D and Apogee s/w?

RCA outputs are unbalanced is the main issue, so keep the cables short and clear of anything that's going to generate noise. And it's going to be LINE level, so that cheap A/D needs to have the ability to handle that input level. If the level is clipping once you set it up, you'll have to pull the output level down at the mixer.
 
An interface with a SPDIF input should be able to sync from that input, either automatically or through the control panel.

If you want to get technical, it does mean that all the converters in the interface are then running on the external clock, which is probably going to mean a very slight, possibly inconsequential, reduction in conversion quality.
 
What [MENTION=103008]bouldersoundguy[/MENTION] said.

I'm assuming you have a control panel app for the Apogee and when you configure a digital (SPDIF or ADAT) input for the interface, you usually use that app to specify which device is the master clock. If there's no wordclock connection (and more often used with an external clock to sync several devices), it will usually be the device providing the digital input, and the receiving one will sync to the clock detected there. (At least that's how it always worked when I had an ADAT unit!)
 
I am going to guess Cricky81 that the "$30" interface you refer to is the Behringer UCA202/222?

If so then yes, it will work really quite well, had several such converters in the past. There are caveats...

The devices are 16bit only and so the noise floor is at best some -80dB fs. This is however well below the likely noise in a microphone recording since even with the best mic pres in the world, 'room noise' is not likely below -70dB fs.

The other problem with the UCAs is low headroom. One volt rms is all they can take and you would be well advised to stay a good 6dB below that. Even though the mixers outs are RCA I suspect they are still at the full fat +4dBu OP level and so you will need to keep the main fader well down.
Far better is a couple of pots* on the RCA outs to set an appropriate level into the 202 whilst having a good level from the mixer.

Pity you are in $ land as I would happily post you all this kit. I have no need anymore (and better)

*You could use a stereo potentiometer 10,000 Ohms 'log' taper but individual 10ks give you channel balance setting. You don't even need to put the pots in a tin as a rule. Set then gaffer tape to stop accidental buzzes.

Yup, just pulled the manual for the Berry 1204 Eu mixer and the RCA (CD) out run at +22dBu max. Bit silly really for outputs that are intended to connect to 'domestic' kit such as hi fi amps and cassette machines that run at neg ten.

Dave.
 
I am going to guess Cricky81 that the "$30" interface you refer to is the Behringer UCA202/222?

If so then yes, it will work really quite well, had several such converters in the past. There are caveats...

The devices are 16bit only and so the noise floor is at best some -80dB fs. This is however well below the likely noise in a microphone recording since even with the best mic pres in the world, 'room noise' is not likely below -70dB fs.

The other problem with the UCAs is low headroom. One volt rms is all they can take and you would be well advised to stay a good 6dB below that. Even though the mixers outs are RCA I suspect they are still at the full fat +4dBu OP level and so you will need to keep the main fader well down.
Far better is a couple of pots* on the RCA outs to set an appropriate level into the 202 whilst having a good level from the mixer.

Pity you are in $ land as I would happily post you all this kit. I have no need anymore (and better)

*You could use a stereo potentiometer 10,000 Ohms 'log' taper but individual 10ks give you channel balance setting. You don't even need to put the pots in a tin as a rule. Set then gaffer tape to stop accidental buzzes.

Yup, just pulled the manual for the Berry 1204 Eu mixer and the RCA (CD) out run at +22dBu max. Bit silly really for outputs that are intended to connect to 'domestic' kit such as hi fi amps and cassette machines that run at neg ten.

Dave.
If that's the A/D [MENTION=203963]cricky81[/MENTION] has, then he doesn't have SPDIF coming out of the RCA. Maybe we should confirm what outputs that device actually has...
 
If that's the A/D [MENTION=203963]cricky81[/MENTION] has, then he doesn't have SPDIF coming out of the RCA. Maybe we should confirm what outputs that device actually has...

Well, TBH Keith I never did see what all the chat was about 'S/PDIF' and 'king clocks!

Top of Q op asks "Analogue to digital converter" and quotes the Eurorack mixer as the RCA source. The mixer does not have S/PDIF.

Maybe he DOES mean an analogue to "S/PDIF" converter but if that is the case WTF is he going to do with that digital signal?

This> Portta Audio Converter Analog R/L RCA to Digital Coax: Amazon.co.uk: Electronics
Would do that for him but if analogue to S/PDIF is what he seeks can I ask him to be very careful? The vast majority of such boxes are in fact DACs and not at all what he needs. Then there are innumerable optical to RCA and V/V converters. Look twice, pay once!

Dave.

Dave.
 
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meh, I'll just wait till I have enough money to buy a cheap digital preamp. I wish you could buy a simple converter that has like one XLR/1/4 inch input and an optical out but, alas, I guess the market has spoken. thanks for your time though- very informative!
 
james perrett,

yea, that's the one. It's a hair-brained idea, I know, but I actually like the eurorack for recording drums and I hate throwing things out. wish there was a simple, effective way to connect the eurorack to the optical input on the apogee
 
meh, I'll just wait till I have enough money to buy a cheap digital preamp. I wish you could buy a simple converter that has like one XLR/1/4 inch input and an optical out but, alas, I guess the market has spoken. thanks for your time though- very informative!

The UCA 202 has an optical, toslink output so all you then need is a mic pre amp. Small mixer? Plenty of those about from Mackie, Yamaha and of course Behringer, can often be found in Cash Generator shops.

Bit of a messy faff but, when the devil drives?...

Dave.
 
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