The Phonoclone and VSPS PCB Help Desk

[rambojj]

110K 105K 271-105K-RC Xicon 1% metal film
750K 732K 271-732K-RC Xicon 1% metal film
Ich brauche die vier mal/ I need it 4 times
Wo gibt es die in Europa noch besser in Deutschland zu kaufen?
Where can I buy it in Europe or better in Germany?
Mouser will 20 Euro Fracht...
Mouser's price is some Cent for the resistors + 20 Euro shipping...

[Zigis]

hi rambojj,
here is my favorite German shop:
https://www.distrelec.de/ishopWebFro...&vendorPhrase=

[rambojj]

Vishay I have already in my VSPS. My friend ordered a kit from RJM. And there is the recomendation to use this two Xicon resistors. And the only shop I know by now is Mouser.
Maybe someone has tested Vishay nonmagnetic versus Xicon?

[rjm]

Originally Posted by rambojj

Maybe someone has tested Vishay nonmagnetic versus Xicon?

Time and energy best spent elsewhere, if you ask me.

For the RIAA values, get whatever you can find or make up a close value from two resistors in series or parallel.

110k = two 220k resistors in parallel, or 100k + 10k
105k = 100k + 4.7k

768k = 680k + 82k or any two values to get within 10k of list value
732k = 680k + 33k or any two values to get within 10k of list value

[ZirconiumZephyr]

I've built my VSPS from a kit I purchased but I'm having some problems. Put simply, it's just not working.

The output is very very quiet, not really louder than direct output from the TT. I've checked the input voltages (+18V and -18V), and there don't seem to be any shorts of the inputs. No sound comes through when powered off, and this faint sound comes through when powered on and my gainclone is running at full volume.

Could I have possibly fried the opamp? I may have wired the power incorrectly at the start (only 1 channel) and god knows what else. I rewired everything to be safe.

[kffern]

Originally Posted by rjm

Time and energy best spent elsewhere, if you ask me.

Agreed. I've built 2 Phonoclones. First was Rhys's kit w/ vishay resistors/Nichicon caps and the second Jaycar resistors/Nichicon caps. They have different loading for different cartridges but I'd have to say the Jaycar resistor version sounds a bit better. I was able to match to nearly exact values for each board and I have plenty of spares for a lot less $'s.

What I would be interested in knowing is how much improvement shielded toroidal transformers give over standard toroids and dual toroids over single.
I have one 80VA toroid using 2 rectifiers which I use for both P3s.

kffern

[woodturner-fran]

Zirconium: is it possible you have set the gain resistor incorrectly? The fact that you are getting some sound through means that the opamps aren't dead I think, just you have no gain.

Pictures would help.....

Fran

[ZirconiumZephyr]

Checked with multimeter:
R2 = 680R
R3 = 2.2K

All other resistors seem to match the parts list.

Anything else I can check?

[rjm]

Originally Posted by ZirconiumZephyr

I've built my VSPS from a kit I purchased but I'm having some problems. Put simply, it's just not working.

Could I have possibly fried the opamp? I may have wired the power incorrectly at the start (only 1 channel) and god knows what else. I rewired everything to be safe.

It could be something really silly like having the op amp inserted the wrong way, it could be a dead op amp. If could me mixing up the inputs and outputs.

I don't understand when you say "only 1 channel" as the VSPS Kit is a stereo board... where did you buy the kit, and what board revision?

Anyhow, I second Fran: a photo uploaded would at give us the basic facts.

@kffern

The better the transformers the better the sound. I think shielded toroids are a big improvement, not too sure about one vs. two, but using two has the advantage of a cleaner, more ideal grounding layout.

[ZirconiumZephyr]

Sorry, channel was probably the wrong terminology. I hadn't connected my rectifier up properly so I was only feeding +12V into the amp board.

I bought the kit off your site about 2 weeks ago. Chip is in the right way, inputs/outputs are checked.

I'll triple check everything and try and get a picture later tonight.