Mpp

[Joachim Gerhard]

Sorry, how much voltage do the originals have ?

[RCruz]

Originally Posted by Joachim Gerhard

Yes, 4 in series.

But Z201 should be a 5.6 v zener... why 4x 5.1v ?

[RCruz]

Ok... with the new 5.1v zener, TP203 is now -28.5V quite good

TP 201 still -44.3
TP 202 -45.6 not good

[Joachim Gerhard]

Ricardo, that was a mistake. You can use the 5.1V zener.

[FdW]

Originally Posted by RCruz

Ok... with the new 5.1v zener, TP203 is now -28.5V quite good

TP 201 still -44.3
TP 202 -45.6 not good

The 5.1V will work, but given the high input voltage I would prefer something higher. The 5.1V is the minimum value to be used; it just allows the CCS to work properly. The voltage at TP202 should be the same as at TP203 minus Vbe(Q202). The next thing to do is check the value of R203 and replace Q201 and Q202.

[Bksabath]

Update from me
I got both chanels working and played a couple of tracks.

Is not good news, but reading the last post I may know what is wrong.

As it is now back ground noise is preaty HI.

I have set the voltages so to have 17.5 V at the suply pins of the OPA134 and that may be where I am getting wrong.

As it is, there is quite a lot of noise when the nidle is up off the record.
I managed to take it down a fair bit by adding a bit of capacitance and comon mode coke near the Phono Boards, My traffo and pre regulator are about 1 meter away in a separaye box.

Now seeing Riccardo and FDW posts I know that the voltages I am using are to low.

What shuld the various voltages be on a working board ?
I am wrong in wooring about the suply to the op amp, spec sheet say 18V max?

I have 35V from Pre-reguators +17.5 at TP1 and -17.5 at TP2

[Joachim Gerhard]

Are you using Paradise R2, the new one ? That even works with 30V from the pre regulator. Is it hiss or is it hum ?
Hum comes from transformers near the circuit and such plus correct earthing issues. My R2 is very quiet in the hiss and hum department. What are you guys doing ?

[hesener]

Originally Posted by Joachim Gerhard

Are you using Paradise R2, the new one ? That even works with 30V from the pre regulator. Is it hiss or is it hum ?
Hum comes from transformers near the circuit and such plus correct earthing issues. My R2 is very quiet in the hiss and hum department. What are you guys doing ?

Yes, he has R2 boards. This is strange....

The 10turn pot went into the updated R2 board design, so the final boards will have offset adjustment possibility....

[Bksabath]

Hi Quick one before I get ready for flight to Venice.

Yes got R2 Boards
The noise is hiss, white noise.
There is no hum boards are realy good even with open box and fluereshent tube inches awayor moving things around there is none whatsoever the board design is absolutley brilant.

As Albert say it is strange and I think it's My fault seting up V at tp1 tp2
I have both a 25 25 Trafo and 30 30 trafo with 25 X 1.471 and diodedrops I got around 35 + - going in to the boards.

Once again I can change the V at the TP1 and TP2 (+17.5 - 17.5 at present) with the 2 k pots WHAT shuld it be set at please?

I am going to try to take it up to + - 25 at TP1 TP2



On regards to ofset I got 1.36 mV I tried the mod and it fit nice and easy on botom of boards.
It can be set to nothink and desapear with small loading resistor.
I like the space and the 2 set of pads round the imput pins Ideal for small caps and load resistor as needed by MC

[FdW]

Originally Posted by Bksabath

Update from me
I got both chanels working and played a couple of tracks.

Is not good news, but reading the last post I may know what is wrong.

As it is now back ground noise is preaty HI.

I have set the voltages so to have 17.5 V at the suply pins of the OPA134 and that may be where I am getting wrong.

As it is, there is quite a lot of noise when the nidle is up off the record.
I managed to take it down a fair bit by adding a bit of capacitance and comon mode coke near the Phono Boards, My traffo and pre regulator are about 1 meter away in a separaye box.

Now seeing Riccardo and FDW posts I know that the voltages I am using are to low.

What shuld the various voltages be on a working board ?
I am wrong in wooring about the suply to the op amp, spec sheet say 18V max?

I have 35V from Pre-reguators +17.5 at TP1 and -17.5 at TP2

I think (as Joachim noted) that you are using R2 and that runs at about 18V, Ricardo is using R1 (the original Paradise) and that runs of 24V.