The Phonoclone and VSPS PCB Help Desk

[rjm]

R1/R2 will be nominally chosen for the Dl-103, but should give good results with a wide range of cartridges and systems.

You can contact me about this by email, rjm003.geo at yahoo.com.

/R

[rjm]

By the way, a great place to get mica caps for the RIAA section is westfloridacomponents ebay store...

http://myworld.ebay.com/westfloridacomponents/

(I typically went with C1= 1000pF, C2= 2800pF + 120pF, unfortunately while he has plenty of 2200pF there are no 680 pF complement offered...)

he also has some good prices on bridge rectifiers...

Also, today I'm going to buy a bk precision 810C capacitance meter. I've been meaning to get something better than my Fluke 83 for some time. This means that the RIAA components shipping with the Special Edition Phonoclone RC will be fully matched to 0.5% accuracy!

/Richard

[lancer]

Dear rjm,

Please put me in for 1 complete kit. Thanks.

[rjm]

As promised, a revised layout for the RC Limited.

Olimex are on summer vacation until early September, so tentatively the ship date for the kits is Oct 1st.

/R

[rjm]

Time for a status report. All parts except for the board themselves and the ZA caps have been ordered. The OP27s are backordered from Digikey until Sept 20th, but since Olimex wont be open until Sept 3rd, everything is still on track for Oct 1 ship date.

Here is the detailed parts list:

Part // Description // Quantity Supplied

U1,U2 Analog Devices OP27GP 4
(socket) 8 pin gold-plated DIP socket 4
LM7810 +10 V positive fixed voltage regulator 2
LM7910 -10 V positive fixed voltage regulator 2
C1 1000 pF Cornell Dubilier mica capacitor (matched) 2
C2a 2200 / 2800 pF Cornell Dubilier mica capacitor (matched)* 2
C2b 680 / 120 pF Cornell Dubilier mica capacitor (matched)* 2
C3 4.7 uF 50 V Black Gate N non-polar electrolytic capacitor 2
C4,5 1000 uF 25 V Nichicon FW (audio) electrolytic capacitor 4
C6,7 100 uF 25 V Nichicon FW (audio) electrolytic capacitor 4
C8-11 100 uF 35 V Rubycon ZA ultra low impedance electrolytic capacitor 8
R1 30 ohm 1/4W Riken Ohm precision carbon film resistor 2
R2 1 kohm 1/4W Riken Ohm precision carbon film resistor 2
R3,R4 2.2 kohm 1/4W Takman carbon film resistor 4
R5 110 kohm 1/4W Takman carbon film resistor (matched) 2
R6 750 kohm 1/4W Takman carbon film resistor (matched) 2
R7 33 kohm 1/4W Takman carbon film resistor 2
R8 47 ohm 1/4W Allen Bradley carbon composition resistor 2
R9-12 5.1 ohm 1/4W Allen Bradley carbon composition resistor 8

Yes, there are still plenty of kits left!

Richard

[Toaster]

I'll take one of those please! I'll send an email too.

[kaban]

Hi there!

I have now built the phonoclone and I am putting together the power supply, and I just want to clarify something.

I have a power transformer with 24v out, tapped at 12v, so there are three leads - 0, 12v, 24v.

Do I connect the 0v and 24v secondary to the AC input of the rectifier and output it like so:

- out on Rectifier = -12v rail on Phonoclone PCB
+ out on Rectifier = +12v rail on Phonoclone PCB
12v (CT) tap from transformer = 0v rail on Phonoclone PCB

Is that the correct way to do it?

The reason why I am confused is that I also got another design printed from somewhere on the website that requested 2x12v secondaries, putting both through an arrangement of 2 bridge rectifiers (the instructions call it a "Gainclone-style power supply"). Am I correct in saying that because my power transformer is 24v center tapped, I do not need to do this?

I hope you can understand what I mean!

Thanks

Kaban.

[woodturner-fran]

Eh, no expert here. but I think so.

Its easy to check though. Wire it up that way and check with a DMM before connecting it to the phonoclone. Neg lead on the CT, and you should see the + and - 12V on the 2 rectifier outputs.

Have you seen the construction guide on the phonoclone page or RJMs site?

Fran

[troystg]

Like this.

[kaban]

OK!

Now I have done that, I am not getting any reading at all in volts across the + - of the rectifier in DC. To double check I desoldered the 24v AC lead and tested for AC across the secondary coil with no results.

Could it be I fried the transformer? I dont really know how easy it is to do, but I did arrange two rectifiers on the secondary coil probably in an incorrect manner (as per the "gainclone" PS instructions). Maybe that did it? Hmm.