Topic: running a d/a in front of a njb3 for a soundboard recording...is it doable?

[George]

I have a Denecke AD-20 and was wondering how the hell can i use this as a dac with my njb3 for a sbd patch.  I'll be taping from rca outs to line in from the board and was wondering if the ad-20 can work into the chain.

What the hell is up with the spdif miniplug anyway?  If this thing can't cut it, what da-20 would work well with the njb3 and M1?

Finally, is it worthwhile to run a outboard dac for sbd's?

tia!

[Brian Skalinder]

First, I think you mean ADC (analog to digital conversion), not DAC (digital to analog conversion).

Second, the AD-20 adds a minimum of 17dB gain (if memory serves).  A typical SBD output may prove to hot for the AD-20 and will either [1] overload the analog inputs, or more likely [2] overload the AD-20s ADC since you're taking the SBD signal - which is usually a hot signal anyway - and adding the AD-20s minimum +17dB on top of it.  So If you run RCA line outs from the board to the AD-20 you'll likely need some way of reducing strength of the signal before it hits the AD-20 - either [1] significant control over the SBD output level (to drop it low enough so tha the additional +17dB of gain in the AD-20 doesn't add so much gain that you clip the ADC), or [2] attenuators between the board and AD-20.

I believe the AD-20 offers both a S/PDIF mini optical and coax,  If you're recording to JB3, use the optical.  If you're recording to M1, use the coax + 7-pin into your M1.

An outboard ADC is worth it for SBDs, if the internal ADC is not up to snuff.  Whether it's up to snuff or not depends on your ears.  Personally, in this case, I'd run either:

SBD > AD-20 > JB3
or
SBD > M1

[Roving Sign]

If the board has RCA outs...dont be afraid to use the JB3 internal AD. I think it sounds fine...but as brian said, whether it's up to snuff or not depends on your ears...

[NJFunk]

I bought RCA => XLR attenuator cables from Core Sounds to use with the AD-20 for line-level feeds (i.e. SBD...).  They were cheap and worked just fine.  As Brian said, a line-level signal is probably too hot to use the AD-20 without the attenuators.

[George]

I bought RCA => XLR attenuator cables from Core Sounds to use with the AD-20 for line-level feeds (i.e. SBD...).  They were cheap and worked just fine.  As Brian said, a line-level signal is probably too hot to use the AD-20 without the attenuators.

Brian, Yep, i think the board does run hot and the levels are fixed, so i set the gain to -12db to ensure it comes out fine.  I learned this the hard way the first time around when i ran the gain +12 and the vocals were distorted.  The second time around it sounded ok, but i felt the urge to fiddle with the a/d 20 since it collects dust otherwise and the band is very cool with providing me a board patch   

NJFunk, just to clarify, you use these rca>xlr's to run into the a/d 20 right?  Because i was wondering how the hell i would patch the a/d 20 to the sbd. 

Brian, you're right, i was confusing adc and dac. 

[NJFunk]

I bought RCA => XLR attenuator cables from Core Sounds to use with the AD-20 for line-level feeds (i.e. SBD...).  They were cheap and worked just fine.  As Brian said, a line-level signal is probably too hot to use the AD-20 without the attenuators.

Brian, Yep, i think the board does run hot and the levels are fixed, so i set the gain to -12db to ensure it comes out fine.  I learned this the hard way the first time around when i ran the gain +12 and the vocals were distorted.  The second time around it sounded ok, but i felt the urge to fiddle with the a/d 20 since it collects dust otherwise and the band is very cool with providing me a board patch   

NJFunk, just to clarify, you use these rca>xlr's to run into the a/d 20 right?  Because i was wondering how the hell i would patch the a/d 20 to the sbd. 

Brian, you're right, i was confusing adc and dac. 

Yes.  The RCA end of the attenator cables are RCA-f.  So, I have a normal m-m RCA cable plugged into the board, then that is plugged into the RCA-f ends on the attenuator cables, then the XLR end is plugged into the AD-20.  The attenuator cables are short, like maybe 8-12" long.

[George]

I bought RCA => XLR attenuator cables from Core Sounds to use with the AD-20 for line-level feeds (i.e. SBD...).  They were cheap and worked just fine.  As Brian said, a line-level signal is probably too hot to use the AD-20 without the attenuators.

Brian, Yep, i think the board does run hot and the levels are fixed, so i set the gain to -12db to ensure it comes out fine.  I learned this the hard way the first time around when i ran the gain +12 and the vocals were distorted.  The second time around it sounded ok, but i felt the urge to fiddle with the a/d 20 since it collects dust otherwise and the band is very cool with providing me a board patch   

NJFunk, just to clarify, you use these rca>xlr's to run into the a/d 20 right?  Because i was wondering how the hell i would patch the a/d 20 to the sbd. 

Brian, you're right, i was confusing adc and dac. 

Yes.  The RCA end of the attenator cables are RCA-f.  So, I have a normal m-m RCA cable plugged into the board, then that is plugged into the RCA-f ends on the attenuator cables, then the XLR end is plugged into the AD-20.  The attenuator cables are short, like maybe 8-12" long.

sweet!  Thanks for the excellent description, i'll make a point to order these rca>xlr attenuators so i can start using them in the near future!  +T's all around in 12 hrs again.

[dklein]

I would definitely question whether or not using the AD-20 is worthwhile.  You need major attenuation to drop a board level output to mic level (though it could be sonically neutral).  Then the AD-20 is bringing it back up with analog gain (not neutral) and doing the conversion with a ?10 year old? ADC.

I'd just go straight into the JB3 and use the 12 dB of attenuation available there.  Really, the JB3 a>d isn't horrible sounding or anything.

[George]

I would definitely question whether or not using the AD-20 is worthwhile.  You need major attenuation to drop a board level output to mic level (though it could be sonically neutral).  Then the AD-20 is bringing it back up with analog gain (not neutral) and doing the conversion with a ?10 year old? ADC.

I'd just go straight into the JB3 and use the 12 dB of attenuation available there.  Really, the JB3 a>d isn't horrible sounding or anything.

True, i've never had any issues with the a>d section on the njb3, i guess i just wanted to put the ad20 to use. 

I'll probably wind up selling it soon on ts so someone else may put it to use...

[dklein]

True, i've never had any issues with the a>d section on the njb3, i guess i just wanted to put the ad20 to use. 

what's up - got a pile of 9v batteries you're dying to drain? 

[George]

True, i've never had any issues with the a>d section on the njb3, i guess i just wanted to put the ad20 to use. 

what's up - got a pile of 9v batteries you're dying to drain? 

lol...damn!  I do have a box of those fancy hospital grade suckers...guess the mv-100 will have to do