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Old 17th December 2009, 08:25 PM   #221
RCruz is offline RCruz  Switzerland
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Just follow that thread and you will find the needed answers.

I already built 7 working shunts.
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Old 17th December 2009, 08:41 PM   #222
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Default Look here lucas

Quote:
Originally Posted by Salas View Post
After some time all 3 sensitivity versions adopted that feature. Go at post 2706 there. A download link has a pdf overview made by member psgr and kindly hosted by Ikoflexer.
click on that tiny down arrow near the thread numbers and go to page 271.
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Old 17th December 2009, 08:49 PM   #223
Salas is online now Salas  Greece
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Hey ra7, did you eliminate the ''hotness'' by now?
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Old 17th December 2009, 10:02 PM   #224
RCruz is offline RCruz  Switzerland
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It would be very usefull to have some kind of index for these threads.... everytime I have a doubt and need to consult the info (or want to help others) I feel the same pain.

I keep a log in excel but it is not very straitforward to read......

As for iko´s pdf.... It is good !!!

Ricardo
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Old 22nd December 2009, 05:24 PM   #225
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i have read this and several other threads about the Pacific and some of its derivatives. A long time ago when it first appeared i was going to build it, but that didn't happen. I was about to start again, and realised the Idss of my 2sk170s are all around 12. Is it worthwhile continuing with these, or should i acquire a lower matched quad?

The original schematics did not specify the jfet grade, and that may be why some people really disliked it when they made it with higher Idss jfets?
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Old 22nd December 2009, 06:17 PM   #226
ra7 is offline ra7  United States
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It is quite possible to make this with higher Idss JFETs. I have some at 8mA. You can play with supply voltage, load and source resistors. It will also depend on what gain you want for your cartridge and main amp.

Look back a few pages, Salas had some suggestions for higher Idss JFETs. You could also try his simplistic NJFET RIAA - Page 270, post 2706 from ikoflexer has the main pdf with the full design.
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Old 22nd December 2009, 07:43 PM   #227
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Quote:
Originally Posted by Salas View Post
Look for Vishay and Wima polypropylenes, also Koa Speer resistors in Mouser.
Koa Speer resistors in Mouser, type carbons ok?
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Old 22nd December 2009, 08:05 PM   #228
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They look like Kiwame, don't they? Dale RN series they carry, very good too.
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Old 23rd December 2009, 01:25 AM   #229
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Never used Kiwame/Riken/Allen Bradley or other carbons, I used Dale RN series that aren't carbons in Borbelys PS & are goods. I asked the Koa Speer to Mouser for regs.
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Old 23rd December 2009, 10:20 PM   #230
studeb is offline studeb  United States
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Quote:
Originally Posted by ra7 View Post
It is quite possible to make this with higher Idss JFETs. I have some at 8mA. You can play with supply voltage, load and source resistors. It will also depend on what gain you want for your cartridge and main amp.

Look back a few pages, Salas had some suggestions for higher Idss JFETs. You could also try his simplistic NJFET RIAA - Page 270, post 2706 from ikoflexer has the main pdf with the full design.
i remembered that post, and tried to find it. Was that using 50R timmers on the second stage source to ground to adjust the output? Or did i miss it? I was going to go with 18V, 2k4 for R2 and R5 on your post 192, omir R3, R7 and R9, and slightly different RIAA values.
Will increasing the V (say 27V) increase the gain? my current cart has 0.5mV output, phono is stage is a Dyna Pas (40db) and it lacks gas for this cart running into a B1 buffer.

I have a feeling i will end up with something else in the end, but would like to start here.
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