Another Super High End Phono Stage! No expense spared...

[Ess El Emm]

Oh, cool, thank you. This thread is getting a little unwieldy to sift through... Unfortunately I'm adding to that by posting this.

[Renron]

This sure has changed from the original build with 6 OpA and a projected build price of over $100!!!

Bless you, (All whom are involved)

Ron

Originally Posted by omishra

Qty Value ------ Device------------- Parts
2 X 0.1uF/50V -- Ceramic-025X050---- C9, C10
2 X 2.2uF/100V - Poly-062X184 ------ C19, C20
2 X 8K2 -------- .25W, 1% MFR ------ R28, R30
2 X 10K -------- .25W, 1% MFR ------ R27, R29
2 X 10uF/35V ---- Electrolyte Cap -- C11, C12
2 X 100 -------- .25W, 1% MFR ------ R31, R32
2 X 100K ------- .25W, 1% MFR ------ R33, R34
1 X AD823 ------ AD823OP AMP ------- IC3

[Ess El Emm]

Ok, so I built a really unconventional CNC preamp, and it might be biting me in the ass. Instead of running both channels through both chips, I split them up so each one only handles one channel. In addition, it is all point to point circuitry using the component leads. Lastly, for the ground, I put in a solid sheet of copper about an inch below the main board, and any components that go to ground, I dropped the leads through the board and soldered them right to the copper sheet.

It sounds good, but it is a little noisy. Anyone have any ideas why? At high volumes there is kind of a rustling noise. Maybe I should have stuck to a PCB.

[Pio1980]

The chips are going to have far better channel separation than any cart that will be run thru them. That dead side may be part of the problem.

[Ess El Emm]

What do you mean, dead side? Both sides of the chip are in use, it's just that one side is used for the channel's first stage, and the other side handles the second stage.

Anyway, I swapped chips side to side, and it looks like I just have a noisy op-amp. I noticed that the noise was only coming from the left side, but after swapping, it is only coming from the right. Wouldn't have been able to do that with the conventional layout.

I knew I should've gotten an extra, but I didn't want to shell out the $6.

[HypnoToad]

I have noticed some op amps do have a rustling sound and some don't, you would think they would have better quality control.

[Ess El Emm]

I'm not going to guarantee that it wasn't damaged by handling. After all, technically we should all have grounding straps on when handling these. I believe that ICs can be damaged by far less static discharge than you can actually feel. Anyway, now that it actually works, I don't feel so embarrassed to post pictures of this monstrosity.

Yes, it's weird looking, but that's part of the fun. If you're going to build something yourself, why have it look like it came out of a factory? The switch is going to get moved a little bit. I plan on cutting a piece of lexan to cover the front of the box, and the switch will be mounted onto that.

[Pio1980]

OK, got it. Bad new chips are kinda unusual.

[Ess El Emm]

I agree completely. These things are usually not bad out of the box. I didn't think it was the chip, but I decided to swap chips side to side, and sure enough, it changed from the left to the right.

[sachu888]

Hi all,
I have just received PCBs for CNC and SSP.Please find pics below:
Uploaded with ImageShack.us
Uploaded with ImageShack.us

I am going to PM everyone who have shown interest for boards.

Regards,
Sachin

[HypnoToad]

Fantastic, three cheers for Sachin, great work!

[Grainger49]

Originally Posted by Ess El Emm

I'm not going to guarantee that it wasn't damaged by handling. After all, technically we should all have grounding straps on when handling these. I believe that ICs can be damaged by far less static discharge than you can actually feel. Anyway, now that it actually works, I don't feel so embarrassed to post pictures of this monstrosity.

I completely FRIED an MSB Link DAC III with a touch in winter. By fried I mean when I pulled back from touching it, I could hear the circuits sizzling. I could hear it! It was completely dead.

I sent it back for repair and put in a grounding plate that got touched before any of my equipment. Now in winter a humidifier runs as long as I am not listening.

Originally Posted by sachu888

Hi all,

I have just received PCBs for CNC and SSP. . .

I am going to PM everyone who have shown interest for boards.

Regards,
Sachin

Sachin, PP sent, your receipt confirmation received. Thanks from all of us.

[dodog]

Originally Posted by HypnoToad

Fantastic, three cheers for Sachin, great work!

+1. These look great!

[sachu888]

Hi all,
I will try to ship max boards tomorrow,remaining will be sent day after.

Regards,
Sachin

[aabottom]

Thanks sachu888. I look forward to getting my boards soon.

Thanks all for your hard efforts.