2. tech-talk
  3. 1049317203

impedance mismatched ?

Audio Aero Capitol Mark 2 running directly into amplifiers via balanced outputs has a output impedance of 100 ohms.
My VTL 750 REFERENCE amplifiers balanced input impedance is 137 ohms. Is this a impedance mismatch which could possibly cause a audible [20 feet away] hum to result when using 1 meter balanced Interconnects? when using the RCA outputs and RCA inputs with same components as above [same impedance specifications for RCA also] their is absolutely zero hum. And yes the XLR pin configuration has been confirmed as being correct on my balanced Interconnects for these components. was suggested could be a ground loop causing the hum but when plugged all 3 components into a power strip the hum still remains, even if floating all the grounds with cheater plugs.
mejames

Showing 1 response by gregm

gregm
3,411 posts
 
Looks more & more like a system ground loop. OTOH the 100->137kOhm connection looks good on paper.
Excuse my stating the obvious but, why not stay with rca OR try plugging the cdp into another outlet, with & without floating the ground -- just to check. In a similar situation (but with barely perceptible hum), I plugged the cdp's into a different outlet and REDUCED the noise (but you've probably been there & done that...)
Note that I use a pre & short rca IC for the cdp... Cheers
More to discover