The Phonoclone and VSPS PCB Help Desk

[rjm]

Yeah it seems they are. That's useful!

Richard

[kaban]

Thanks for the feedback regarding the set up of the transformer/rectifier, you were all very helpful!

I am really pleased to announce that I powered my Phonoclone up tonight, after almost a year since I received the boards and so far, so good!

I have a Denon DL-103 that I am going to get a nearby audiophile company to install in my Project III debut turntable. I will need to get them to change the counterweight as a heavier one is required for the Denon.

In the meantime I tested out the phonoclone by using a standard moving magnet cart that I have and it confirmed that both channels were functioning ok and working. I will have to hear it with the Denon though before I can make any real judgment...

Again, thanks! :-)

[rjm]

In the meantime I tested out the phonoclone by using a standard moving magnet cart that I have ...

Don't try this at home kids...

[kaban]

Originally posted by rjm




Don't try this at home kids...

Well.. the funny thing is I expected the output to be fully distorted because I thought MC carts put out less output than MM carts, but it didn't?! Plus the overall tonality is a bit treble shy? Like I say, I only did it as a check to see if it was working ok so I will wait till I get the DL103 working.

[superhkm]

I sent you an e-mail Richard, I want a Phonoclone RC Limited as well..

hk

[rjm]

kaban,

The system is self-compensating to a degree as a high output cart will normally have a high impedance and therefore reduce the gain automatically.

The main issue is the high inductance of MM carts, which causes the impedance to rise - and the gain to fall - as the frequency increases. Thus the reduced treble you notice.

As a test its not going to damage anything.

To hk and others, Phonoclone Limited Kit update info:

I ran into a minor snag when I discovered all one hundred of the C-D 1000 pF mica caps I bought off ebay some time ago were measuring between 1030 and 1040 pF. That's within the stated 5% tolerance, but still 3-4% high off the proper Phonoclone values. The response is a slightly (+1/3 dB) enhanced lower midrange.. not unpleasant but not acceptable for the standards of the RC Limited Kit! So I've another 24 from a different source on order... also waiting for the ZA caps to arrive before sending the .brd file to Olimex. OP27's on backorder at Digikey, ETA Sept 9th. Everything else is in my posession, and last night in a marathon session I matched all the RIAA components, excepting C1.

4 kits left for sale.

Richard

[kaban]

Originally posted by rjm
kaban,

The system is self-compensating to a degree as a high output cart will normally have a high impedance and therefore reduce the gain automatically.

The main issue is the high inductance of MM carts, which causes the impedance to rise - and the gain to fall - as the frequency increases. Thus the reduced treble you notice.

As a test its not going to damage anything.

Phew! I am glad about that.. mind you it was only a quick test as I don't have anything else to really check it with. Can't wait to fire it up with the DL103!

I also just wanted to say thanks - the reason why I like to build kits like this is to learn something and also get satisfaction in using equipment I have built myself. I appreciate you taking the time to respond here and steer us in the right direction! I'll be sure to take pics of my complete setup once it is all going. DIY is great!

[tube 300]

Originally posted by rjm




To hk and others, Phonoclone Limited Kit update info:

I ran into a minor snag when I discovered all one hundred of the C-D 1000 pF mica caps I bought off ebay some time ago were measuring between 1030 and 1040 pF. That's within the stated 5% tolerance, but still 3-4% high off the proper Phonoclone values. The response is a slightly (+1/3 dB) enhanced lower midrange.. not unpleasant but not acceptable for the standards of the RC Limited Kit! So I've another 24 from a different source on order... also waiting for the ZA caps to arrive before sending the .brd file to Olimex. OP27's on backorder at Digikey, ETA Sept 9th. Everything else is in my posession, and last night in a marathon session I matched all the RIAA components, excepting C1.

4 kits left for sale.

Richard

Hi Richard
Thanks for the perfection and good work
i think there is no companie that take so much time on the matching of the components
and trail and error before building the final produkt.
This can only done by diy guys like you
i think that i own a very special phono stage then
regards Robert

[woodturner-fran]

Hi all,


I'm just getting going on parts for the power supply for the ultimate kit.

I'm looking at the rectification and wondering if there isn't something better than a standard bridge. After all, this kit deserves something a bit better than the usual.

So I was thinking of something like the one on pg 162 of morgan jones building valve amplifiers. Uses 12 diodes each bypassed with a film cap.


If I can get a scan later I'll put one up.

What do you think?

Fran

[rjm]

The RC Limited Kits have all been sold. Thanks for your interest and support.

Situation update:

I'm rather disappointed with Reference Audio Mods, the site from where I ordered the Rubycon ZAs. I paid with Paypal on Aug 22nd. Since then: no confirmation of my order, no confirmation of shipping, nothing whatsoever. Everyone I have dealt with from Digikey down to the guy selling stuff from his garage on eBay have offered better communication than this outfit.

Its annoying because I can't finalize the PCB design until I have these caps in hand, since if I have to make a substitute the size and lead spacing will most likely change.

Other than that everything is according to plan, and the proposed Oct 1 ship date holds, pending the arrival of the ZAs this week. If that doesnt happen I will let you know.

Also: I'm kinda swimming in mica caps at the moment. The 10 piece limit on the RC Kit is firm, dont email to ask for "just one more". I will however offer the RIAA parts kit, with matched mica caps and the resistors R3-8, for $25. If you just say "Richard, I dont care about the matching, or about the accuracy, just gimme some caps an stuff!" I will be happy to send you a selection from the reject bin for just $5. I will at some stage fold the improvements seen in the RC Limited PCB back into the regular version for download on the web page, I may even have keep a small stock for sale, but this wont be happening until towards Christmas.

To those who ordered the Kit, I will be contacting you by email shortly. If you dont hear from me by Sept 5th please contact me.

regards

Richard