Anyone familiar with this Lite remote volume kit?

[mcs]

Originally posted by MBK
- there seems to be a lot of possible configurations. What level of software / programming is needed, if any, to put the control boards together with the volume boards?

None. If you order one of the small control boards together with a volume board, the control board will be supplied with a chip with the correct software. The big Control2 board has a setup menu for selecting the boards you have connected.

Say, if one would like as mentioned above, to have volume and balance with either the chip volume control or a relay control...

Balance is only possible on boards where the two channels can be adjusted seperately. That means the RelVol2 and ChipVol1 currently. The RelVol1 board shares the relays for both channels, so balance isn't possible.

- you mentioned that you haven't tested all the boards yet... that's quite important...

No, I haven't tested the RelVol2 board yet, as it hasn't arrived yet. I don't feel like breadboarding that circuit
I don't sell any boards untill they have been tested of course!

- and, related to the above, any special philosophy as to circuit layout considerations - ground planes, bypassing, separation of digital and aalog grounds, etc

I use ground planes for the digital sections typically. I don't think ground planes are always a good idea for the audio sections. If you use high impedance circuits, why limit the bandwith with a lot of ground capacitance? If the circuits are low impedance, the ground plane won't cause problems of course, which is why I do use it on the ChipVol1 board for instance.
[edit]I forgot the ground separation question. I separate the grounds of course. I then make space for a small choke to connect the grounds on the board. In a large system with many boards, they should only be connected one place.[/edit]

- what type and quality relays in the relay boards?

I use Omron DIL-relays with gold plated contacts (G5V-2). I always use the low-power type (H1) for circuits where many relays are on at the same type, and some times I use the standard version for circuits where only one or two relays are on at the same time (like an input selector or the RelVol2 circuit).

Best regards,

Mikkel C. Simonsen

[MBK]

That sounds good...

So I gather, one could use say, the VolControl together with the ChipVol1 and have remote volume and balance and a display, and no programming. That is more or less what I am looking for (blame it on the wife: we need a remote volume quick, any playing around relayed to later ).

Just a quick thought about getting the maximum mileage out of the PGA2310: from data sheet its minimum THD+N is around 4 V rms. Given that typical CD has 2V output and that the typical average volume on a CD is 10-20 dB below FS, one could raise the volume say, by a factor of 3 (ca 10 dB) ahead of the PGA2310.

Not only has the PGA2310 plenty enough volume steps to spare to get the volume down again, but by its construction (changing feedback R of the op amp via FETs I suppose, from data sheet) you actually get less resistance (noise) the lower you set the volume.

ANyway that can be tweaked after the fact... no need to redesign the PCB

MBK

[mcs]

I have finally had some time to experiment with the PGA2310. It works very well actually...

Without an input buffer it sounds a bit dark. With an input buffer, it sounds more like the relay attenuators. I used an OP275 for the input buffer, as that's what I had in the opamp drawer

There's no hum or noise, so the high input impedance is not a problem. It's the high output impedance of the 50k relay attenuator that caused the hiss. But as the PGA chip is buffered internally, there's no problem here.

Best regards,

Mikkel C. Simonsen

[maxw]

Originally posted by mcs
I have finally had some time to experiment with the PGA2310. It works very well actually...

Without an input buffer it sounds a bit dark. With an input buffer, it sounds more like the relay attenuators. I used an OP275 for the input buffer, as that's what I had in the opamp drawer

There's no hum or noise, so the high input impedance is not a problem. It's the high output impedance of the 50k relay attenuator that caused the hiss. But as the PGA chip is buffered internally, there's no problem here.

Best regards,

Mikkel C. Simonsen

Wickid! I will be ordering mine soon, cant wait

[marchewd]

Hello,
I just ordered this volume/input board(s). I currently have a 12v 1A transformer, which these boards require. I have an extra 1/2A left on this transformer. Does anyone know how much power these boards require? I would really like to use my exisiting transformer and regulator, instead of adding a second transformer and the included regulator to run these boards. Any help would be greatly appreciated.

Thanks,
Dan

[Cobra2]

I just put one of these together, added a few small mods, and I'm fairly surprised about the sound-quality.
Not like the best attenuators or TVC, but close!

Arne K

[Cobra2]

Mods: I cut traces between psu-caps(+/-15V), added a 5-10 ohm 2W+ resistor for some CRC-filtering.
I took out the input DC-blocking-caps/replace with jumpers.(small resistors).
Added a cheap china-J-Fet-buffer for output, powered by a group-buy psu.

To come: a small output-mute relay w/delay...

Arne K