Simplistic NJFET RIAA

[RCruz]

Very good looking boards NPower... did you etch them yourself ?

With the 56dB you must be very carefull about the TX positioning..... best would be to enclose the TX, rectifiers and smoothers in a shielded box.

Where did you get the silver micas ?

What are those green caps you are using ?

Ricardo

[NPower]

Originally Posted by merlin el mago

How performs Cout - Obbligato Cu 3.3uF?

If you can afford better two regs & two psu, one for each channel.

Originally Posted by RCruz

Very good looking boards NPower... did you etch them yourself ?

With the 56dB you must be very carefull about the TX positioning..... best would be to enclose the TX, rectifiers and smoothers in a shielded box.

Where did you get the silver micas ?

What are those green caps you are using ?

Ricardo

Merlin

I don't know how to explain this to, six months ago I started building my first draft of audio, 300b SE Aikido, and during a conversation with my friends they challenged me to build a phono stage for a mutual friend (kind of expert). After some reading I decided to build this, therefore I have no references, only my DAC ( Valab with custom build cables ), my amp (Yamaha) speakers (AE109SE with QED cables). This is far away better than my DAC ( except noise). I don't like to use words like stage, deep, etc, etc ,etc. It's music, it's velvet and I want to dance, so it's good, it's very good ( and I think that I have good ears)
If you look close to the picture you can see a dual shunt PSU with a common rectifier ( fast recovery hexfred's with 3 // 4700hF cap's)

Boa noite Ricardo

Thanks by your kind words.
Yes I etch them by myself ( got some problems with Positive 20 but for now is ok).
For the enclosure I'm thinking in a different approach ( sorry, right now top secret)
Lemco silver micas from here:
0.047UF 200V DC Lemco Silver Mica Capacitors - eBay (item 360166226282 end time Jul-24-10 03:55:10 PDT)
0.016UF 200V DC Lemco Silver Mica Capacitors - eBay (item 360166226156 end time Jul-24-10 03:53:47 PDT)
Green caps brand Lelon RGA series ( I think from Taiwan)

[Salas]

I would solve my noise problems in a cheap box first. The gain you got can give -110dB ref 1V 0dB in its worse lows region if executed properly. You don't listen to its full now with some noise, only a portion.

[merlin el mago]

NPower, yes sorry I don't see the dual reg. but I insist if you can afford will be better dual PS & dual Tx for top performance.

Don't forget Salas advice to box the phono to avoid hum.

[massimo]

Originally Posted by merlin el mago

NPower, yes sorry I don't see the dual reg.

Watch the pic: 4 mosfet, two of them clamped to small heatsinks and thus partially hidden, double led arrays, double set of caps, etc.
Follow the wiring: two set of cables going to the Riaa boards coming out from different point of the PS pcb......

[merlin el mago]

massimo, 1st time a didn't see, 2nd time I saw the dual reg (but don't see dual PSU), now you show me the dual PSU so only needs dual TX.

[massimo]

No, not only a second Xfrm, but one more bridge and a new set of filter caps. NPower's board has a dual Shunt Reg, but they are both sharing the same raw PS (bridge&caps). He clearly explained this arrangement in post #4162

[Salas]

And somewhere they must be mixing something ground with filter caps return currents quite possibly.

[massimo]

Colud be Salas.....
A further test could be to isolate one Shunt Reg (removing CCS Rset + the first led of the array) and listen to one ch. only. Or connect the 2nd Riaa board to the same Shunt Reg if it can deliver the extra current.

[merlin el mago]

@massimo
@Salas
That's helps NPower, let us know NPower?