Mpp

[FdW]

Some pictures (more than 20Kg EMPTY!)

[Joachim Gerhard]

Cool, that looks very professional. Can not wait to hear it.

[MiiB]

Ricardo if you lover the current to half.. You loose a little gain, but not that much.. app. 6 dB, but considering the higher output of the more windings and the low noise of the circuit I don't see that as an issue....for you cart the lower current and a recalculated RiAA section may just be the right medicine.

[Joachim Gerhard]

The Paradise R2 has a noise impedance of around 7.5 Ohm. That is the Rbb` ( ca. 30 Ohm / 8 ) plus the 8 x 33 Ohm of the degeneration resistors. There is some 1/F but not much because we use bipolars. Your Denon has 40 Ohm, so even at half the current, the noise will be still dominated by your cartridges Johnson noise.

[Bksabath]

Let There Be Light!

Well almost...
Little fault finding on second be fun…
Both boards are stuffed

Board quality is top, easy to solder on and pretty sturdy, they do take quite a lot of abuse, even from inexperienced soldering irons, it is the first time I solder SMD and the by pass capacitors on the bottom went in real easy.

There are few points I am discussing with hesener but nothing stopping build as they are.

On off the minor moods, Just to give you taste of it, is around Neumann resistor, I don't know if I like it or not, so I have soldered a bypass switch straight on the resistor leads.
Once I heard it either may go...


Now may job being to be dumb...
What is the voltage it should be set out of the regulator Say TP102?
Is there a post about the voltages at the test point across the board?

By the way if you look at my part list same quantity for the components are short
Change the QTY for 150K 147k and 18K to 4
I had plenty of choice of matched pairs with the capacitors; some how they measure on the low side, but with the quantity I have ordered it was no problem making the 2 boards exactly the same.

Tanks Ricardo for posting the calculated RIAA values.
I think that I will find difficult to ear much difference but at least I know which way to go if I have to round things up.
For example I did not have enough 147 K so I used 165K And 511k Which I had in my draw this give me 67K instead of 73.5K

Ricardo posted the following in post 6150
Quote> for 33.3n I get 9.545kr, 11.42n and 65675r (instead of 73.5k)

They will be changed to 147K to keep things as on spec ASAP.

This is it for now, Got little 4 year old coming to stay for couple of days so I am already booked with Spiderman Lego set….

[Bksabath]

Just quick one
Second board up and ok Just silly capacitor wrong way round

[brianco]

Nice job RV.

Like the 'Italian Racing Red'!!

[hesener]

Originally Posted by Bksabath

Just quick one
Second board up and ok Just silly capacitor wrong way round

hi, thats great news! from the picture it seems the amplifiers are not connected (yet), did you try and put the jumpers in (after checking VPLUS and VMINUS, the only two testpads with a name ;-) ?

[Joachim Gerhard]

Bksabath, that looks really tasty.

[Joachim Gerhard]

I got Morgan Jones " Valve Amplfiers ", forth edition.
Again it is very entertaining to read, some things are new and some familiar.
There is more on BJT and Mosfet current sources and also JFet-Tube and BJT-Tube cascodes. There is a new line driver and a new BJT cascode, balanced Phonostage.
The authors Power Amps look a bit complex to me. I am certainly not in the mood to make a tube Power Amp. There is a lot about dynamic range, distortion and noise but i have not read the complete content.