Simplistic NJFET RIAA

[AndrewT]

I do not know how to measure noise in the ve lines so I depend on my ears.

just measure the output of the quiescent amplifier.

 

[nicoch58]

contamination are on the main...motor ,home tool ,air wifi

 

[nicoch58]

11DQ are edge?

 

[RCruz]

11DQ09 are very fast so you must be carefull where you put them. Might make some systems seem edgy. Schotkys sound very good but I like hexfred even better.

 

[RCruz]

just measure the output of the quiescent amplifier.

Hi Andrew T

What do you mean ?

What unity are we talking about ? Current ? Volt ? Hz?

Please excuse my ignorance, if you give me a hint, you will be surprised with my evolution.... I am a fast learner.

Ricardo

 

[nicoch58]

you use caps across diode?

 

[RCruz]

Yes... 220u 35v ZA fast cap.

 

[RCruz]

just measure the output of the quiescent amplifier.

Do you mean measure the output of the Riaa in a quiescent state "idling" ?

You need a scope to see this right ?

Ricardo

 

[nicoch58]

Yes... 220u 35v ZA fast cap.

I mean snubber 0,1uf or so on on diode

 

[RCruz]

No, I just have a .22u between the tx and the bridge. I believe I should not bypass the hexfred diodes.

 

[nicoch58]

Ricardo look here

 

[RCruz]

Thank you nicoch46

I will now master in snubbers.

Please do not take my further actions as fundamental because the sound of the Riaa (10 hours latter) is becoming awesome... I can even listen to old records ! The image and detail are so strong I can really understand what was the original idea of the musitians ...

The residual noise I am trying to defeat is buried deep in the vinyl surface noise

I just want to get the best of the best "Primus Inter Pares" riaa.

Ricardo

 

[Salas]

I am happy that you like it.

 

[AndrewT]

if the noise coming out of the RIAA pre is too low for your equipment to measure, then amplify it and try measuring the difference in noise after the amplifier to make comparisons.

 

[RCruz]

Thank you AndrewT

I will try that.

Now I am wondering if using fast diodes /soft recovery like the hexfred, I would benefit from some kind of damping / snubering

Ricardo

 

[nicoch58]

if sound good..... some thinks that snubber ore not so good


shottky do not ring but still ring !

 

[nicoch58]

erno put snubber on byv27 , I live in place when I put stealt2 ,more detail but some edge ,cured after when I put nichicon KG ... but need to try without...

difficult see ring with scope ....and no one solution, trafo-diode caps work together...

interesting the resitor 0,1r series and 1kparallel to dump trafo in my link back ,or beetween diode and caps

http://www.hagtech.com/pdf/snubber.pdf

 

[nicoch58]

there is T-network caps at half price if you want burn some money , fortunately you need only two


jensen 4pole (F&T stuff as mundorf....)

he Jensen totally wipes the floor with the other two capacitors. Above 10KHz there is nothing left of the noise. At 5KHz the noise already dips below 1µV (-120dBV).
I don't know about you,but I'll gladly pay €33,- for this kind of an improvement. look

 

[nicoch58]

Salas what you thinks about Charge transfer" power supply from -ECdesigns to isolate /float the diodelink

and new rev here

 

[Salas]

Don't know, haven't made such.