Has anyone used this volume control?

[Frosteh]

I stumbled upon a neat little volume control that I'd like to use to control volume after my DCX2496. While this has been talked about extensively, I have yet to see any talk of this component. Has anyone used it or can anyone give an opinion on it? It looks to be much better made than the cheap ones on eBay and is also much cheaper than a DACT pot or the kit from Selectronic.

IRVC2 remote volume control with LCD

Mods: I wasn't sure where to post so please move this to the right location if need be.

[stratus46]

I haven't but the specs on the datasheet look very good. Other Burr-Brown chips (TI) I've used in the past have worked as well as the data sheets promised. Outside of possibly getting digital noise from the microprocessor (not very likely if the board is done well) it should be very impressive.

G²

[nightanole]

This looks ok, however i would get rid of the preamp that goes infront of the pgas. You shouldnt need them and will affect sound. so with that in mind, just hook your sources up to c7/c8 ect. Unless your source is a tube output, you dont need the preamp buffers. They are for sources that cant play into a 10k load, which in the modern world doesnt exist.

[Frosteh]

Originally Posted by nightanole

This looks ok, however i would get rid of the preamp that goes infront of the pgas. You shouldnt need them and will affect sound. so with that in mind, just hook your sources up to c7/c8 ect. Unless your source is a tube output, you dont need the preamp buffers. They are for sources that cant play into a 10k load, which in the modern world doesnt exist.

I'm not really following. I'm already a bit confused as to where the ins and outs are, but it appears the ins are at the top of the board and the outs are in the middle by the caps. I don't want to source select. I want to be able to control all 6 channels at the same time. Is this possible? I haven't really found much on the site that could tell me that.

[nightanole]

It looks like there is not source select, the pic just controls 3 pga's at the same time. so 6 ins and 6 outs, and they all go up and down in volume simultaneously.

What im talking about is bypassing the buffers. Look at the schematic. You would want your inputs plugged into c7/c8 c16/c17 c25/c26.

PS: this design is dc out. so Everything you plug into it needs to have dc blocking caps on their inputs. also i would add a 100ohm resistor at each output to protect the chips.

[col_s]

the input buffer is probably there because of this comment in the datasheet: "It is important to drive the PGA2310 with a low source impedance. If a source impedance of greater than 600Ω is used, the distortion performance of the PGA2310 will begin to degrade."

So you can lose the input buffer if your source output impedance is OK.

I built one of these a few years ago for use with a DCX2496. I replaced the input buffer with the AK4396 single opamp output buffer circuit from the datasheet. It worked well enough. The control software works nicely. It's not the most sophisticated PCB and the layout could be better, but it's a very good price and i had no real problems with it.

[jaycee]

Keep the buffer but configure it for unity gain. Use a low offset output opamp like OPA2134. Bypass the coupling capacitor.

With just a little more thought this board could've been designed to control an input selector.