matrix wrote on Sat, 23 April 2005 04:11 |
Hi all. I want to connect the unbalanced out from my consoles inserts to my A/D converter, that uses balanced inputs.Do you think that Lundahl 1555 is ok for the job? If not what else do you propose? Is there a level difference between the two connections? Thank you in advance. John |
volki wrote on Mon, 08 August 2005 05:07 |
Brian, indeed, my MOTU2408 only has internal jumpers for +4 / -10 dB reference level... I wonder if there are AD-converters around which can take a higher level from a balanced source? That would be one reason to go balanced, actually. The thought comes to mind because e.g. ADAT's accept up to +19 dBu when driven balanced, but considerably less when driven unbalanced. |
Mark Donahue wrote on Mon, 08 August 2005 12:06 |
Der All, There's actually one more thing to think about. Some converters use a true balanced 2 converter topology to get the noise figures they need for the marketing people. one of these is the Benchmark AD-2004. I'm sure there were others. If either of these were driven single ended, the signal would peak at -6dBFS and would distort above that. |
matrix wrote on Sat, 23 April 2005 04:11 |
Hi all. I want to connect the unbalanced out from my consoles inserts to my A/D converter, that uses balanced inputs. ... |
volki wrote on Mon, 08 August 2005 05:07 | ||
Brian, indeed, my MOTU2408 only has internal jumpers for +4 / -10 dB reference level... as I write this Mark Donahue has brought up a point...
That hopefully is an exception to the rule - that would be the equivalent to a grounded center-tap transformer input and would be, in my opinion, stupid - good for specs and marketing and bad for using in a real world environment. One can design a differential input amplifier that has a differential input and a differential output to feeding two converters differentially that does not look like a center-tapped input. If Benchmark really did design their input circuit so that you loose 6dB of headroom in the input amplifier or it looses the input to one or the other of the two converters used differentially when the source is unbalanced I have to say I am disappointed. |