Simplistic NJFET RIAA

iko

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Here's a good illustrated guide on the method:

http://electrons.psychogenic.com/modules/arms/art/10/PrintedCircuitBoardPCBHOWTOAnIllustratedGuide.php

We got these "dollar" stores here, where everything costs $1. I buy the glossiest inkjet photo paper there, and it works very well. Some people buy the Canon paper, or whatever. Once you get the procedure right, you'll be amazed at how easy it can be.

Do yourself a favour and get lacquer thinner, otherwise it's hard to get the toner off of the board.
 
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Here is one LED shunt for you to mate with Ikoflexer's PSU board you gonna iron on copper.
 

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diyAudio Chief Moderator
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ikoflexer said:
... and it's top. My apologies for the picture quality.

Look to use supple sonic quality RIAA capacitors, smooth resistors, especially for R input load and 47k RIAA, a PIO interstage coupler. Listen for adequate treble determining if you really need that 150pF (or more or less) for Cin, given your cabling, and don't use a ceramic. Align that MM and DUAL well, because when listening to headphones there will be no acoustics to manipulate, harshness waits just around the corner especially with basic TTs and carts. You don't have a Koetsu on a Goldmund, vinyl isn't plug and play heaven. Picture quality is great, your PCB is fine...see to tune sonic quality. After 48 hours it will settle, then you play with parts.
I wish you a fast and balanced enough first result. You have done great preparation work with sims and PCBs it will surely work out.
Anything you feel isn't working right we will solve. Just ask.
 

iko

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Joined 2008
Thanks for the kind words and encouragement. Just tested the regulator and it works. Couldn't finish the phono boards because all three drill bits broke :D

There is an error on the regulator board I posted earlier, insted of D G S on the power mosfets should be G D S. I don't know where my head was. I will try to fix it and edit that post soon. It's late now, so I'll call it quits.

salas, thanks for the advice, I will in time get some good caps and resistors. For now it will be regular parts.
 
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nicoch46 said:
for ground route good pratice are

connect direct the in&out RCA gnd
connect in gnd RCA to pcb gnd
use the out gnd pcb only for screen without connect the wire on RCA out gnd

if you want do this are better put the pcb in the parralell to back side of box ,for very short wire....(RCA for pcb ?)

inportant are put the trafo in separate box ,if you do, use EI split coil ,cheaps and are good filter for dirty AC.....

box better alu , hammond diecast are cheaps and good for RFI
Hi nicoch
Looks like the the Strar GND technique to avoid loop issues. I use it on my CDP DOS with great results.

About the outboard TX, what do you mean by EI split coil ?

Ricardo
 
old classic trafo design ,but with split coil
if you dont want separate box now the best are R-core that have the advantage of toroid ie low flux/ leakage , compact and low band wide -capacitance of EI split coil,
selectronic. fr have some,I use 500VA for my amp dead quiet ,no hot no buzz,
Some daley on my Salas shunt ,life problem sob :( ,I hope next week.

I have found at schuro good audio toroid 65VA 40Vac full potted ,magnetic and electric shield for 41€

PS

Cruz don't forget the 46 is a magic and the faster italian number ;)
 
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nicoch46 said:

I have found at schuro good audio toroid 65VA 40Vac full potted ,magnetic and electric shield for 41€

PS

Cruz don't forget the 46 is a magic and the faster italian number ;)

Hi nicoch46.... (Sorry for the error... I will never forget!)

I can easily get a toroid but after your comment I start to see there is a benefit using a R core.
I also understand there is a benefit on "normal" TX ... would you please explain "low band wide -capacitance of EI split coil" and what is a split coil ? (Is it better than a toroid in some way?)

I am very interested in the schuro shielded TX... Would it be suitable to feed the +28V led shunt Salas posted for me ?

I will use the lazer tech to build the shunt pcb (Lee informed me that he already etched the Riaa pcb for me ;) ) so I will need a good psu very soon.

I am already building a buffer that I intend to use as preamp.

My idea is:
Phono RCA (GND to star)
-> Riaa + shunt+ TX??
-> 25k linear ALPS pot (Major issue here :scratch1: can not decide between 10k, 20k, 25k, 50k, linear or log type ???)
-> buffer (1X voltage follower) + +-15v psu using a toroid 50VA + Hexfred + 15000uF Mundorfs +sregs
-> Meridian 103 power amp.

Can I put everything in the same box ? (My CD53 has 6 TX inside, I am using a jfet output stage and I do not have any hum issues)

Also my Meridian 101b preamp has only one psu +-15 with a nude toroid placed near the Riaa and now it is sounding awesome !

Regards

Ricardo