Simplistic NJFET RIAA

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Joined 2006
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Today I finished replacing the 15,7 SM for 15,33 on my old 48dB build and now I have an issue.

Left channel does not work... Leds do not lit, so I removed the board and tryed to lit up the leds using a 9v baterie over the ccs fet. I could not lit the leds so I lifted gnd below the leds and they lit.

Something is wrong because the leds only work if not connected to star gnd.... It seems there is some short circuit :(

Is there any component in the second stage that could cause a short between +v and GND ?
 
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Joined 2009
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The sound now is more clear but seems lose gain, still needs more body & right channel need to lower to 15nF to have more highs, the right channel it's OK for highs also I suspect that now I have less body cap because interstage cap was changed now I have 0.047uF 200V instead 0.1uF 600V, what do you think?
 
Member
Joined 2009
Paid Member
Today I finished replacing the 15,7 SM for 15,33 on my old 48dB build and now I have an issue.

Left channel does not work... Leds do not lit, so I removed the board and tryed to lit up the leds using a 9v baterie over the ccs fet. I could not lit the leds so I lifted gnd below the leds and they lit.

Something is wrong because the leds only work if not connected to star gnd.... It seems there is some short circuit :(

Is there any component in the second stage that could cause a short between +v and GND ?

Wich schematic do you use Ricardo, I will check the nearest transistor to Leds.
 
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Joined 2009
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0.1uF FT-3 Teflon cap Vref several weeks ago upgraded, recently upgraded resistor Vref with a Vishay VSH1 290R
 

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Hi all,

Im planning the build of a second Simplistic RIAA to implement several of the changes that have been suggested since my first effort.

I have the 10.12.F0 document (is this the latest?) to follow, though I can't easily find recommendations on what filtering is best after rectification. My first Simplistic just had a single 15,000uF can into a single Salas Shunt for both channels. Is there a better configuration that I should try for my second shot? I'll be using 2 Salas shunts (1 per channel) in this build, but only 1 transformer... unless I get convinced otherwise. Are 2 separate bridge rectifiers worth trying?

I realise that this has probably been covered recently, though there are many, many posts and searching didn't expose what I was looking for. Your help is greatly appreciated, as always.

Regards,
Tani.
 
Member
Joined 2009
Paid Member
Member
Joined 2009
Paid Member
Hi all,

Im planning the build of a second Simplistic RIAA to implement several of the changes that have been suggested since my first effort.

I have the 10.12.F0 document (is this the latest?) to follow, though I can't easily find recommendations on what filtering is best after rectification. My first Simplistic just had a single 15,000uF can into a single Salas Shunt for both channels. Is there a better configuration that I should try for my second shot? I'll be using 2 Salas shunts (1 per channel) in this build, but only 1 transformer... unless I get convinced otherwise. Are 2 separate bridge rectifiers worth trying?

I realise that this has probably been covered recently, though there are many, many posts and searching didn't expose what I was looking for. Your help is greatly appreciated, as always.

Regards,
Tani.

I use two R-Core Tx, two rectifiers Stealth II with two BG 10.000uF & two Salas LV shunt reg V1.2R & sounds very good:)
 
Questions

Hi, Salas,
I have built your phono stage for MM cartridge. I use the phono stage with transformers Sowter 9580 with Denon DL103; the sound is very good.
But I have some questions for you:
I have used for the shunt regulator and phono stage N°11 red Led (V1.85), but the measuring gave only V1.62. I have to add more LEDs?
My Jfet 2SK170BL are matched to 7.5mA. I have to replace them with between 8-8.5 mA or should substituted other components?
Attached schematic positioning and photo of JFET in phono stage. It's correctly? Because i have seen in other schematic of people that have built the phono stage, the Jfet mounted wrongly (Drain and the Source reversed).
Many thanks.
Mario.
 

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