Simplistic NJFET RIAA - Page 415 - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 13th July 2010, 07:30 AM   #4141
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by le´flu View Post
Good Morning,

so i did match some 2sk170bl and got four pairs with idss 6,61mA.
Would you please recommend a circuit including salas-reg-psu to
me to ideally play with my lyra dorian cartridge as asked some post-
ings before.

Greetings Ulf
Use your matched ones for Q1,Q2,Q3,Q4. I fixed it for double njfet first stage so you make full use of your available pairs. Find two near ones for Q7, within 1mA any idss from 6-10mA, not critical. 2V green LEDS everywhere. In the PS use for Q2 your lowest IDSS.
Make sure that the idss you mentioned is correct. I use the 9V battery and current mode DVM in series with no resistor simplest method and is always spot on. Good luck.
Attached Images
File Type: gif LeFlu.gif (7.8 KB, 1613 views)
File Type: gif LeFluPS.gif (8.0 KB, 322 views)
  Reply With Quote
Old 13th July 2010, 09:15 AM   #4142
le´flu is offline le´flu  Germany
diyAudio Member
 
Join Date: Mar 2004
Location: Hoexter
Salas,
you´re great, thanks allot. I´ll build this pre then ;-)
One question at the moment: What jfets should be
thermally bonded? Q1/2 i guess
What about q3/4 then? And psu fets, should they be
thermally be bonded?
Do you have an idea what´s the Zout of this phonopre?

Greetings ulf
  Reply With Quote
Old 13th July 2010, 09:47 AM   #4143
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
No one FET needs to get bonded. Q1, Q2 have highish sharing source resistors they won't current hog, Q3, Q4 run different currents, are different stages, and PSU has no stage pair either. With your IDSS, Zo should be around 40 Ohm. You should expect around 0.01% THD second harmonic dominated, and good background silence. Will be nice to know your impressions after all works well, since you got so many carts, arms and phono stages. Good luck.
  Reply With Quote
Old 13th July 2010, 10:29 AM   #4144
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by SGregory View Post
Salas,
How far back in this thread do I have to go to get what is needed to build and inderstand this design? The size of this thread is daunting.

Thanks
I'm not Salas,

Go here post 2331 psgr acrobat rader attached files: Simplistic NJFET RIAA

Waiting to help.

Felipe

Last edited by merlin el mago; 13th July 2010 at 10:31 AM.
  Reply With Quote
Old 13th July 2010, 11:38 AM   #4145
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
Hi Merlin... cannot open any document with the link inside the pdf
  Reply With Quote
Old 13th July 2010, 11:55 AM   #4146
NPower is offline NPower  Portugal
diyAudio Member
 
NPower's Avatar
 
Join Date: Sep 2007
Location: Right now, no idea !
Quote:
Originally Posted by Salas View Post
R3 disconnects the first stage if you take it out. So it comes from first stage.The voltages you posted are pretty OK.
Quote:
Originally Posted by Salas View Post
Those are hum frequencies. Is it wired for signal input and output with coaxial? Also take out the 220uf over the leds and see if it has anything to do. If there is 0.1uf across B+ on phono take that out too.
Hello
Today I just removed C1-220uF and I get same result. So I start to remove some other components.
1º I removed ground from D1-D4 and R2V and put a wire to star ground - no
effect
2º R2V replaced by fixed resistor - no effect
3º Remove Q3 (led's still on) - no noise
4º change Q3 to japanese equivalent - no effect-noise
5º Q1 replaced by one with Idss 10mA - still the same - noise
Did anyone tried this 56db version ?
__________________
Performance is a state of mind !!
  Reply With Quote
Old 13th July 2010, 12:11 PM   #4147
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Everybody does this cascode with a Q3. Its in the pdf for over a year now. Every different schematic you see member's made is this one backbone. Franz made it recently for 60dB on horn speakers for example, said many times its very silent. I have one 61dB playing with even double Q3 and 4 fets. Mystery is your case. But if you solve it by removing q3 and you still like it, its a way. Having made it cascode and non cascode, the former has better analysis. Lets think a bit, whatever comes from q3, can be 2 things. Either noise at its base (what kind of leds you use?) or easier EMI or magnetic field pick up since the cascode ups the impedance and opens the bandwidth. How far is the transformer, and do you have incidents of RF interference with other machines in your area?

P.S. One thing I see reviewing again your pcb, is that the LEDS are located far away from Q3's base. I hope that the track's inductance does not put it into oscillation. Stick a 33R base stopper on it, hard wired on the base pin, very small lead, AFTER the smoothing 220uF cap.
  Reply With Quote
Old 13th July 2010, 02:07 PM   #4148
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by RCruz View Post
Hi Merlin... cannot open any document with the link inside the pdf
Hi Rcruz, here is the pdf information metallized & film both teflon:

$15 each
Custom-Balco Data TexCap Data
TEFLON FILM/FOIL: F=1%, H=3%, J=5%, K=10%, M=20% Picture

.0001, +20/-10, 1000V, Custom TFHT

.001, J, 200V, TexCap 43

.0015, G, 200V, TexCap 200GGS

.002, J, 200V, TexCap 43

.0022, J, 200V, TexCap 43

.0025, G, 400V, TexCap 200GGS

.0027, J, 200V, TexCap 200GGS

.0033, J, 200V, TexCap 43
.006, J, 200V, TexCap 200
.01. J, 200V, TexCap 43
.01, K, 200V, Custom TFHT

.015, J, 200V, TexCap 43

.015, F, 200V, TexCap 43

.015, K, 400V, TexCap 200GGS

.018, J, 200V, TexCap 200GGS

.02, J, 200V, TexCap 200GGS


.022, J, 200V, Balco HT2

.022, K, 200V, Custom TFHT

.023, J, 200V, TexCap 200GGS

.027, K, 200V, TexCap 43

.027, K, 50V, Balco RTWG wrap-n-fill

.03, F, 100V, Custom TFHT

.033, J, 200V, TexCap 200

.047, J, 200V, Custom TFHT

.05, J, 100V, TexCap 200

.05, J, 100V, Custom TFHT

.056, J, 200V, Custom TFHT

.18, J, 200V, TexCap 200GGS

NOTE: Some of these capacitors have solderable/weldable leads. They solder easily, but require extra heat.






$15 each
Custom-Balco Data TexCap Data
METALLIZED TEFLON: F=1%, H=3%, J=5%, K=10%, M=20% Picture soon

.02, J, 200V, TexCap 83

.02, F, 200V, TexCap 83

.047, K, 400V, Custom TMHT

.06, K, 400V, TexCap 83

.10, J, 50/100V, TexCap 83

.10, K, 200V, TexCap 83

.18, J, 50V, TexCap 83

.20, J, 200V, Custom TMHT

.22, K, 400V, Custom TMHT

.25, K, 200V, TexCap 83

.25, K, 200V, Custom TMHT

.50, J, 50V, TexCap 83

NOTE: Type 83 is not in the Texcap datasheet. Samples were opened to verify metallized teflon. Teflon has a white tint and stretches easily. Other dielectrics do not have these qualities.

You also can try looking at the web: Surplus USA Film Capacitors Teflon Polycarbonate Polyester Polypropylene

If you can enter & you need the datasheet of any cap let me know?
  Reply With Quote
Old 13th July 2010, 02:20 PM   #4149
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
Thank you so much Merlin
  Reply With Quote
Old 13th July 2010, 02:56 PM   #4150
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by RCruz View Post
Thank you so much Merlin
Your welcome RCruz, if you have problems to buy or needs anything else let me know to help you.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 01:08 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2