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Simplistic NJFET RIAA
Simplistic NJFET RIAA
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Old 12th February 2013, 10:11 PM   #9291
Salas is online now Salas  Greece
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Simplistic NJFET RIAA
Even 3R each. Depends on what cart I want to use it for, how much mS I want from a particular JFET in single or more -given a stash- how much additional Johnson from resistive elementsI find excusable as a stability and capacitance trade off. And I judge it in use for small tunings.
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Old 12th February 2013, 10:16 PM   #9292
Salas is online now Salas  Greece
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Quote:
Originally Posted by massimo View Post
Not only
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Old 16th February 2013, 05:55 AM   #9293
noSmoking is offline noSmoking  United States
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Simplistic NJFET RIAA
Hi Salas,
I built this one from the first pages ,It's almost ready ,waiting on some parts to get here,I made 2 power supply boards so each board could have it's own power source,What do you recommend to feed the power supply boards? I am using the MM cartridge 47k load, I got out my old techniques sl 230 turn table and cleaned it up ,it's ready to go ,I realized I didn't have anything to plug it into,so I built your layout !
Thanks,
NS
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Old 16th February 2013, 09:36 AM   #9294
Salas is online now Salas  Greece
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Simplistic NJFET RIAA
Compact and following the schematic lines will do. Do I see leds light down the Nichicons on photo#2? Powered already with own psu or just a lab psu test? Feed the power boards with 0.47R 1W to 4700uF RC after some soft recovery bridge.

P.S. Keep the Tx+bridge+main lytics at a distance or even in another box.
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Old 16th February 2013, 06:47 PM   #9295
Jallhalla is offline Jallhalla  Norway
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Originally Posted by Salas View Post
The demands are monopole +35V @ 30-35mA per channel. We usually set the SSLV regulator much higher for it to work its MOSFETS better. Usually at 150-300mA CCS per channel depending on how much sinking you are prepared to use.
I just needed the ratings to have the right resistor for adjusting it. I plan to have plenty of overhead current.

Thanks a lot for the reply! I have been reading threads here for years. IŽll let you know how my ears like the design later.
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Old 16th February 2013, 06:51 PM   #9296
Salas is online now Salas  Greece
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OK. Good luck with building.
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Old 17th February 2013, 02:08 AM   #9297
noSmoking is offline noSmoking  United States
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Simplistic NJFET RIAA
Hi Salas,
I wish they were LED's burning but no must be a reflection,Thanks for the info on the supply ,I am waiting on fet's for the PS board ,I can be patient,lol.
I have the transformers,bridge .47R and some caps(10,000-4700-1000-470-100,10uf-and a .1) to run the supply boards ,and hope that's good enought,The box can be moved if it's LOF interfers!
Happy Listening!
NS

Last edited by noSmoking; 17th February 2013 at 02:12 AM.
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Old 21st February 2013, 11:25 AM   #9298
noSmoking is offline noSmoking  United States
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Hi Salas ,
Got the parts today and got the the shunt regs working fine They adjust from 18 to 30 volts,I will check for a 30 volt or better xformer tomorrow,I used a 24 vac,was in the junk box.
Got a problem ,I checked the layout and still don't see what I have done wrong,the last fet Q3 at the output isn't working,I have signal on the base of Q2 ,I have the PS at 30 vdc and get 18 v on Q3,Do I need to adjust R10,
It's bed time,,,, I will work on it tomorrow,,,,and get 'er done,lol.
Thanks for anyone help!
NS
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Old 21st February 2013, 12:56 PM   #9299
Salas is online now Salas  Greece
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You should have about 4mA running through R10. Whatever voltage in respect to ground that resistor's drop imposes on Q2's drain gets to Q3's source minus little something. Your R9 value should allow double that voltage on its drain. Check those conditions. Trim R9 accordingly if Q3 is healthy. R10 changes the gain, better don't go there first.
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Old 21st February 2013, 04:24 PM   #9300
RCruz is offline RCruz  Switzerland
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Simplistic NJFET RIAA
Hi Salas

Look at this: Diyaudio.com
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