Simplistic NJFET RIAA

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Salas

Salas

diyAudio Chief Moderator
Joined 2002
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alexkosha said:
Hi Nick, I know that is not the right forom. But any way, that bypass is little messy since all resistors are installed into small PCB and potentiometer soldered too.
Please see attached picture. It will be clear what I tried.
What I did first (Modified 1) , I disconnected wiper.
Second (Modified 2) bypassed R7. At that case, R7 is irrelevant since it is shored and straight signal is going in. But, VR1 is 100K behave as load resistor and interacts with R8 installed parallel. So, the total load will be 68.75k.
Third step (Modified 3), I disconnected R8. So, my total load will remain 100k from Alps where 1 (GND) -3 (IN) on VR1.
I plan to disconnect VR1 #1 (GND) and to install “nice” 100k Vishay and the RCA input instead.
What do you think?

I can reduce C2Y if this what you caledl Cout. I’m using about 250pF now since my C2 is 14.950nF. Is this what you meant?
Click to expand...

I don't see the variable element schematically anymore in those possible mods. Cout is C4.
 
alexkosha

alexkosha

Member
Joined 2013
I made a mess to you and myself. Sorry about such chaos. It will be more smart to replace Alps with step attenuators and that it is.
I’ll get rid of carbon potentiometers and I’ll be able to play with the max power with no distortion.

So, it is output cap. I do not what to change it since my FSP is sounds amazing. Should have to install Mills MRA-5 for R13 (1.2K) and additional PRP 8.2R at the end of this week. Now I use some temporary installed resistors (8.2R made of 2 parallel 22R and one 33). Also found 4 Vishay Z Foil 4.7k resistors. Going to test RCruz's advice for 2200 Ohm load (4.7K parallel with 47K main shoulkd give me 2.24K load).

About subwoofer, I do not know what to do “today”. Need some brain storm and deep test of my B&W ASW825.
 
Last edited:
Siberia

Siberia

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Joined 2011
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RCruz said:
I know Benz carts "like" high resistor values for loading, but IMO I was never pleased with values higher than 2200ohms.

So I normally go between 470 ohms and 2200 ohms depending on the carts I use.

Denon DL160 - 1100ohms
Denon DL103 - 1000ohms
Benz ACE M - 2200ohms
Benz Glider SL - 2200ohms
Goldenote Baldinoti - 470ohms
Goldenote Tuscany - 470ohms
Ortofon Quintet Blue or Red - 475ohms
Koetsu Black (VdH) - 1200ohms
Zyx Bloom H - 1600ohms
Benz LP - 2300ohms
Kiseki Lapis Lazuli - 1200 ohms
Lyra Atlas - 850ohms
Click to expand...

Benz German HQ recommended me to load Benz ACE S at 1000R. That's what I did.
 
Salas

Salas

diyAudio Chief Moderator
Joined 2002
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There could be ringing vs electrical load damping changes. I don't think there are test records with repetitive transient signals devised for such purposes. Maybe I am mistaken, never researched it well. There won't be evident frequency response differences on pink noise tracks.
 
S

stajo

Member
Joined 2011
Salad, greek. Kind of.
 

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A

andyr

Member
Joined 2003
RCruz said:
So I normally go between 470 ohms and 2200 ohms depending on the carts I use.

Denon DL160 - 1100ohms
Denon DL103 - 1000ohms
Benz ACE M - 2200ohms
Benz Glider SL - 2200ohms
Goldenote Baldinoti - 470ohms
Goldenote Tuscany - 470ohms
Ortofon Quintet Blue or Red - 475ohms
Koetsu Black (VdH) - 1200ohms
Zyx Bloom H - 1600ohms
Benz LP - 2300ohms
Kiseki Lapis Lazuli - 1200 ohms
Lyra Atlas - 850ohms
Click to expand...

Did you try higher with the Benz LP, RC? I am currently using 2200 ohms with my LP (the original LP, not the 'LP-S') but will try 2300, as soon as I get those resistors.

Did you try, say, 3300 or 4700 ohms?

And have you tried 'C' loading MCs? I read an article which suggested that - despite commonly-accepted belief that MCs are impervious to 'C' loading - as high as 1uF was appropriate for some. :)


Regards,

Andy
 
RCruz

RCruz

Member
Joined 2006
Paid Member
andyr said:
Did you try higher with the Benz LP, RC? I am currently using 2200 ohms with my LP (the original LP, not the 'LP-S') but will try 2300, as soon as I get those resistors.

Did you try, say, 3300 or 4700 ohms?

And have you tried 'C' loading MCs? I read an article which suggested that - despite commonly-accepted belief that MCs are impervious to 'C' loading - as high as 1uF was appropriate for some. :)


Regards,

Andy
Click to expand...
I had a very good time with the LP and experimented from 100 to 5000ohms... in some systems I did like 2300 and others I prefered 2200.

Please bear in mind the type of resistor used is determinant.

With Shinkoh I prefered 2300, with Vishay bulk metal I found a better result with 2200.
 
Salas

Salas

diyAudio Chief Moderator
Joined 2002
Paid Member
merlin el mago said:
Μου λείπει το μουσακά!!!!!!!

I kind of miss musaka!!!!!!
Click to expand...

Maybe you miss a desoldering pump also given the rework you had to go through enough times on double sided boards of HV PSUS etc. ;)
Saves time, frustration, and pads of valuable PCBs. In fact its probable that many members here miss one as well.
https://www.youtube.com/watch?v=hmNJ8pdA1AQ
(Not as efficient, powerful, or clean working as a desoldering station, but much cheaper, portable, takes no space on the bench, needs drastically lower maintenance).

Slimmer sized and better looking 2015 black version I had seen on very few Aliexpress stores recently. "30w desoldering pump black" should bring them up on Ali's search.

An externally hosted image should be here but it was not working when we last tested it.


(Found in 220V 50HZ version only)
 
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