WD Phono III Clone Questions!

pre65 · Post by **pre65** » Sat Dec 04, 2010 11:04 pm

And it gives you the 9V to feed the heater circuit 5V regulator.

I just happen to have some 9V transformers, two toroids and two frame.

Choices /decisions.

Mike H · Post by **Mike H** » Sat Dec 04, 2010 11:19 pm

pre65 wrote:And it gives you the 9V to feed the heater circuit 5V regulator.

We assume the power isn't a lot for that

Post by **Nick** » Sat Dec 04, 2010 11:21 pm

Mike H wrote:
pre65 wrote:And it gives you the 9V to feed the heater circuit 5V regulator.

We assume the power isn't a lot for that

3 * ECC83

pre65 · Post by **pre65** » Sat Dec 04, 2010 11:22 pm

Mike H wrote:
pre65 wrote:And it gives you the 9V to feed the heater circuit 5V regulator.

We assume the power isn't a lot for that

Pre 3 is two ECC82, so 0.6A in total.

Mike H · Post by **Mike H** » Sat Dec 04, 2010 11:23 pm

900mA?

pre65 · Post by **pre65** » Sat Dec 04, 2010 11:30 pm

I think Nick is talking about the Phono 3 but I want a PSU for Pre 3. They both share the same HT (ie 250V)

Mike H · Post by **Mike H** » Sat Dec 04, 2010 11:33 pm

It's all beyond me

pre65 · Post by **pre65** » Sat Dec 04, 2010 11:38 pm

Mike H wrote:It's all beyond me

Normally, the World Designs modular pre amp (Pre3) and phone pre amp (Phono3) share a common power supply (PSU3) which has two outlets.

Seems that if you have a separate PSU for each pre there is a performance gain.

Savvy ?

Mike H · Post by **Mike H** » Sun Dec 05, 2010 12:04 am

Thank you for the explanation

gninnam · Post by **gninnam** » Sun Dec 05, 2010 12:19 am

Mike H wrote:That's the $65,000 question! Offhand no idea, Duncan's PSU designer might give you a clue, otherwise means experimenting. Whatever it is will depend on the total current drain. Do we know what that will be?

Looks like 1K resistor is required to drop the voltage to 250V

Will dig it out tomorrow and have a play with it to see if I can get it to the voltage I want using the resister before the bridge.

Cheers

Graeme · Post by **Graeme** » Sun Dec 05, 2010 10:50 am

So i guess the 2 9v secondary tx's are used mainly because its cheaper?

Just wondered if it was done that way because it had other benefits over a transformer with 2 secondaries, or using 240-240 and a 240-9 (which is what ive done)

I think the old TX i used in mine is WAY over rated, its bigger than the TX for my kel84

Post by **Nick** » Sun Dec 05, 2010 12:23 pm

pre65 wrote:I think Nick is talking about the Phono 3 but I want a PSU for Pre 3. They both share the same HT (ie 250V)

Well, lets assume I don't know what I am talking about, I was just going by the topic of the thread and the fact my circuit for a phono II clone was linked to.

Post by **Nick** » Sun Dec 05, 2010 12:25 pm

So i guess the 2 9v secondary tx's are used mainly because its cheaper?

Mainly because its what I had, it does provide a bit more isolation as well.

Mike H · Post by **Mike H** » Sun Dec 05, 2010 1:33 pm

There you are!

There wasn't a deep meaningful underlying reason after all

Post by **Nick** » Sun Dec 05, 2010 2:50 pm

pre65 wrote:I think Nick is talking about the Phono 3 but I want a PSU for Pre 3. They both share the same HT (ie 250V)

Well, maybe it will avoid confusion if you start your own thread, this one started about the phono III as far as I can see.

audio-talk

WD Phono III Clone Questions!

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