VC23, my new PGA2310 project

[hifimediy]

yes, you can even use a DC 12V~15V for digital supply.

[hifimediy]

2x PGA4311 will be used. And with OP buffer each channel like we do on VC23.

[platenspeler]

I finished my little pre-amp based on the VC23 of Hifimediy yesterday. Some time ago I built a small/simple pre-amp with rotary switches and 2 opamps, but as one channel broke, I decided I wanted remote control as well.

So I took out the old board an replaced with the VC23 board. Two pictures attached (hope pictures are not too large).



As you see, I made a mod to one of the power connectors (the other one was too tight). The PCB fits in a standard eurocard case, however due to the placement of the power terminals you can't easily slide it into one of those boxes.


In the picture below the preamp is the power supply delivering 15-0-15 V dc(!). The two boxes on either side are gainclones/chipamps based on the LM3875


Initial listening confirms that this amp is an improvement over my previous pre amp. Not so much the sound quality, that was already very good, but ease of use is fantastic.

Some other remarks:

• I think Hifimediy should include some sort of short manual. Of course lot's of material can be found on the forum, but it's no substitute. Also the website does not contain such documents for download.
• There is no list of parts that are or should be in the box. So it is hard to say whether or not you received all components.
• Only two connecting cables are included. Since it has one output and 4 inputs, this is not enough. Are the others missing, or should I buy the others myself :-)
• Both of the Opamps were dropping out of their sockets as they were fitted too loose.

Above comments not meant to be too critical, but maybe they help to improve the product.

regards,

Maarten

[IBM5150]

Nice job Maarten, very well executed - looks professional. Amps look great as well.

I am trying to install my VC23 in an old PC power supply case. Will post pics when I get something together, but I am not such a craftsman. Will need an amp solution after the preamp is done.

[ecodoppler]

Hi
we wait the second improved version, a manual and maybe a good power supply.
Platenspeler, your listening impression?
regards
ecodoppler

[hifimediy]

hi Maarten, very nice work. The ALU case is a good choice for diyer.

[IBM5150]

Maarten: How is it you are able to use 15-0-15 VDC?

I powered mine up and got a horribly loud 60Hz buzz and the amplifier wasn't even turned on. I used one leg of the 12.6-0-12.6 VAC for the digital circuit.

Agreed, some instructions should be included. Does the board need to be grounded?

[platenspeler]

Originally Posted by IBM5150

Maarten: How is it you are able to use 15-0-15 VDC?

I powered mine up and got a horribly loud 60Hz buzz and the amplifier wasn't even turned on. I used one leg of the 12.6-0-12.6 VAC for the digital circuit.

Agreed, some instructions should be included. Does the board need to be grounded?

i just happened to have the 15-0-15 Vdc power supply. i figured that 12Vac would probably result in 17vdc after rectification, so 15Vdc would probably still be Ok. On the picture you can see the wiring (red/red and green/blue) are same.

i did not ground the amp itself, but looking at my documentation of the ps the black (0vdc) wire is probably connected to safety earth somewhere inside the ps (have to check)

Maarten

[IBM5150]

Here are some pics, still trying to figure out the buzz... Switched the digital input to 15 VDC and still had the buzz, then a 2nd tone started and was getting louder very quickly. Does the polarity matter on the digital input?

[hifimediy]

Hi, IBM5150, when your system use not only VC23 boards, I suggest test each board separately, that will more easy to find what's the problem.
And I also suggest use a standalone power supply for the digital part of VC23, and VC23 already has a (analog and digital)ground junction itself on board.