Mpp

[Salas]

Originally Posted by Salas

2. Use them 10n at the ground side of the input sockets straight to chassis, so to help clensing some gremlins possible to be coming in riding on the cable shield and listen. Best there would be COG ceramics with sort legs.

Did #2. Beneficial. Less background hash, tone untouched.

[Joachim Gerhard]

fine, i am happy i could help i use an old wire-world eclipse it is a hollow coaxial design i tried a lot of different cables for example AWG24 solid core tefzell wire twisted (that is wire-wrap cable for high tech prototyping and is tinned copper with foamed teflon isolation) i always come back to that old eclipse in my system it gives a very welcome "fat and warm" tone in my quite analytic system i sit very close to the speakers (less then two meters) and they are very far apart when you get used to that setup you miss dynamics and immediacy in other setups i will post some photos of my setup when i find the time i have a triplanar arm that has a box with rca jacks i connect all metal in the system to ground it is hard to explain in words so pictures describe the setup much better i also have a long copper pole buried in the ground and that goes to a jack where i connect things too although i use very wide band electronics i have no problem with hf and hum

[Salas]

Is that the wide/near set up you used to recommend in the AP speakers firm products manuals?

I got that idea to ground very high frequencies at the input since the 10nF across the load worked against your results with my cart and phono and I thought they might be useful somewhere since I cut their leads enough, so I used them in the same notion we RF bypass a ground lift resistor. No special copper ground rod opportunity for me unfortunately. Ceramics at the input ring to chassis is an old tube practice in low level inputs. MKT in my case but my phono isn't that wideband anyway.

[Joachim Gerhard]

yes, it is the audio physic setup i did an AES paper about, only that i got more radical recently. i can listen to the speakers i have very close because they behave very homogenious.
yes you are right, you can put the cap where you use it. i do that on one of my pre-pres that has a floating supply and does not like a direct connection to the chassis.
whatever with a little patience and inspiration special grounding techniques can make a big difference i think it just needs a little empiric experimentation because it`s hard to predict although syn08 whould argue otherwise on the other hand my turtable setup should eat his vpi for breakfast ( oh, that was not very polite, sorry syn08)

[Joachim Gerhard]

I worked a bit on the ASAP-FET.
This version has lower noise and distortion plus adjustable offset. I call it ASAP-FET-LNLD. I like it.
Does anybody know where to get some low noise P channel-Fets ?
My friend is sales manager at Toshiba and even he could not help me. Toshiba stopped to make anything the do not make money with. He told me that in quantity the could only charge a few cents in the past per piece.
I would like to build it and listen to it. I tried N- channel fets from Linear Systems and they are very good. unfortunately they make no P channel. I see so many people searching for low noise P-channel that this could be a busyness opportunity.

[Joachim Gerhard]

Salas, i am not very good with power supplies. Maybe you have a good idea.

[Salas]

A CLC prefiltered CCS fed shunt reg. Will help the op amp with loop Riaa to flesh out a bit too. You can set it to +/-15V for the op amp, and then RC drop n' filter/decouple down to the 1st stage. If you want one, I even got board art. Mind you it will imprint Salas sonic stuff dramatically on your phono.

[Joachim Gerhard]

ok send it over i am prepared for desaster C:
when i can help you with something else tell me !

[Salas]

How many mA you think your circuit is going to constantly need per reg's side? So I will prepare the values for you. Also as a German speaker designer and Sonics owner, you must know companies like Mundorf. Can they make you a couple of 300mH 1A 6R-10R frame chokes? Something like the Hammond 159ZA.

[Joachim Gerhard]

the MPP needs around 50mA per side per channel
i have good relationships to mundorf and they can make all kind of chokes although 300mH is quite unusual i have to ask