JW
Well-known member
Please see attached schematic.
Hmmmm. How can I make this story short? Let's see. In an effort to provide volume attenuation between my converters (IZ Radar D>A, IC output. Very low impedance) and my monitor amp (Class D. Presonus S8 Sceptre's 10K input impedance) I rigged up two multideck switches that would ostensibly keep the signal balanced all the way to the amp. Long story short, one of the switches buzzes. They're identical. They're multideck, and bought off ebay . . . Let's just say, I know it is that switch but can't figure out why, and I have ditched this idea for the moment.
I decided to then try one of these Alpha Blue dual 10K pots that I had anyway, and they are supposed to have better matching than the usual dual pot . . .
EVEN though the run from my Radar (machine room) to the speakers/amps is about 40ft and this move would de-balance the run.
Much to my surprise, it's very quiet, I like the feel of the pot, and maybe I want to keep it this way. .
I wonder about what some of my experiments with grounding yielded though.
In my drawing, the dotted line is the negative lead from the Radar outputs. I've experimented with grounding this lead at the pot, and not. It does eliminate some very faint noise to ground it, and it also boosts the signal a bit. It also seems to have more high end than when left floating. So one would assume I think that it would be best to ground the dotted line in my drawing.
I noticed no difference in lifting the shields on either side of the pot, so left them as is, and I also didn't notice any difference when grounding the pin 2 "minus" lead of the Presonus amp.
Then I tried bypassing the pot all together on one channel, keeping it "balanced" and judging against the other channel that was going through the pot, debalanced. Much to my surprise, it's at the same level. What gives? Why not a -6dB due to the unbalancing?
Guess we'd have to take a look at the Presonus' amps input more carefully. But I can't find much. Just the manual. Seems according to the manual though that both TRS and XLR are "balanced" inputs. Presonus just says to use a DI if not using a balanced run. They REALLY want me to balance this. But de balancing it sounds fine so far so why am I complaining?
Anyway, I've read the Rane documents and look at them all the time.
Just wondering if anyone can shed some light on my situation and look over the drawing.
Hmmmm. How can I make this story short? Let's see. In an effort to provide volume attenuation between my converters (IZ Radar D>A, IC output. Very low impedance) and my monitor amp (Class D. Presonus S8 Sceptre's 10K input impedance) I rigged up two multideck switches that would ostensibly keep the signal balanced all the way to the amp. Long story short, one of the switches buzzes. They're identical. They're multideck, and bought off ebay . . . Let's just say, I know it is that switch but can't figure out why, and I have ditched this idea for the moment.
I decided to then try one of these Alpha Blue dual 10K pots that I had anyway, and they are supposed to have better matching than the usual dual pot . . .
EVEN though the run from my Radar (machine room) to the speakers/amps is about 40ft and this move would de-balance the run.
Much to my surprise, it's very quiet, I like the feel of the pot, and maybe I want to keep it this way. .
I wonder about what some of my experiments with grounding yielded though.
In my drawing, the dotted line is the negative lead from the Radar outputs. I've experimented with grounding this lead at the pot, and not. It does eliminate some very faint noise to ground it, and it also boosts the signal a bit. It also seems to have more high end than when left floating. So one would assume I think that it would be best to ground the dotted line in my drawing.
I noticed no difference in lifting the shields on either side of the pot, so left them as is, and I also didn't notice any difference when grounding the pin 2 "minus" lead of the Presonus amp.
Then I tried bypassing the pot all together on one channel, keeping it "balanced" and judging against the other channel that was going through the pot, debalanced. Much to my surprise, it's at the same level. What gives? Why not a -6dB due to the unbalancing?
Guess we'd have to take a look at the Presonus' amps input more carefully. But I can't find much. Just the manual. Seems according to the manual though that both TRS and XLR are "balanced" inputs. Presonus just says to use a DI if not using a balanced run. They REALLY want me to balance this. But de balancing it sounds fine so far so why am I complaining?
Anyway, I've read the Rane documents and look at them all the time.
Just wondering if anyone can shed some light on my situation and look over the drawing.
