The Phonoclone and VSPS PCB Help Desk

[GregD]

Originally posted by rjm
I'm working on the LM317 version. It will have only two regulators per channel, not four. I have had the single-sided layout in my head since way back - theres practically only one way to do it single-sided without jumpers - but putting it on half a Eurocard in a logical way is proving hard, unless I drop back to smaller resistors and offer less flexibility on the RIAA capacitor selection. Alternatively I could go with a double-sided layout, the problem is there are so many layout options to choose from I cant decide where to start.

To be single or double sided, that is the question....

-rjm

My vote is for double sided with a ground plane.

[Algar_emi]

Just completed my PhonoCLone and the sound is just WOW
I was using a NAD PP2 before and the upgrade is just breathtaking. I can hear layers in the music, the different mike technics used. The sound is organic and fluid.

The noise is almost no existent. It is below the LP surface noise.
The supply noise is there because the supply caps are so small, but you hear it only at deafening sound level with no music. In normal use, it is nothing. If the small caps contribute to this speedy and great sound, I take them anytime

It is the best phono preamp that I had built so far. I'm still working of my ONO preamp but this one is much easier to build and much cheaper too.

Very recommended.

Here a view of the preamp's rear. Both supply connectors on the side. The input and output RCA in the middle.

[Algar_emi]

Here the inside view

[rjm]

Nice work.

[steenoe]

Thats really nice work, Algar_emi How did you make the extern psu? Is it built to RJM's spec's?

Steen

[earsandeyes]

I have tested the phoneclone now with two cartridges:
DENON 160 (Yes I am aware, high output)but this is my test set-up) and

ZYX RS10-02 (low output) in my real listening set-up.

I do use 4 opa27's and onboard regulation of 15V (78/7915)

The DC comes either from batteries or from a preregulated 18V DC (LM 317/337).

Denon 160
Apart from some hum due to layout, really awsome
At the moment I do prefer the preregulated use, some more steady low. Less spectacular, more musical.

ZYX RS10-02
Relatively high noise level, both with batteries as well as with Prereg DC. Better system thus anyhow better sound.
As the Rs of this cartidge is (only) 4 ohm I brought down R2 to 1k. This did help somewhat with the noise level. The R1 is at 150R because input impedance is quoted >100R.
With no cartridge connected no-noise (ink black), as soon as this cartridge is connected I have noise, far above vinyl surface noise?

I did hear some what longer time ago a ZYX20 on an original phonecube. No relevant noise. The only difference between the 10 and 20 is the shape of the stylus.

In what direction should I search to get rid of the noise?

Thanks for all inputs.


E&E

[Algar_emi]

Thanks for your nice words. Check page 20 for my supply details and images.

[earsandeyes]

I don't know how to edit my previous post?

But DENON 160 should read DENON 110.

I don't know where that confusion came from. I do own a 110 and a 103

E&E

[rjm]

E&E

- you can only edit text for 1h or so after you post it.

- with the ZYX RS10-02, R1 should be a couple of ohms or zero. Set R2 to about 400 ohms.

- the rest of the noise may be due to layout issues. See back to the discussion earlier in this thread.

- R1 should always be set to the cartridge impedance or less, never the rated load resistance. At 150 ohms, you've unnecessarily added a significant noise source into your circuit.

/R

[Algar_emi]

I'm using a Denon 110 too. In my preamp I have a jumper to select the R1 resistor. I'm also using a 160R value at the moment, but I can also use a 47R. I'll try the 47R and I'll report of my finding.