Another RIAA Preamp - Page 2 - 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 9th May 2012, 03:15 AM   #11
diyAudio Member
 
wrenchone's Avatar
 
Join Date: Feb 2004
Location: Silicon Valley
An interesting convolution - I'll have to redraw it (always a good first step for understanding an unfamiliar circuit) and stare at it a bit, but the designer looks as if he is taking advantage of the high gm of the bipolar to squeeze all the juice out of a single SRPP gain stage. I have a long thread on jfet srpp in this forum, with more modest gain per stage.

In this particular preamp, I'm taking advantage of the lowish impedance of the second amp stage to optimally load a hotly biased (~10 ma) PN4393 first stage. In this first incarnation, the impedance is a little high on the second stage feedback network, and it looks like I can reduce it considerably for optimal performance (at least, by what PSpice says) for the first stage, and lower noise for the second half. Part of this exercise will be to check PSpice against what a real analyzer says, and also, what the listening characteristics will be like for this circus freak/chimera.
  Reply With Quote
Old 10th May 2012, 06:52 AM   #12
diyAudio Member
 
wrenchone's Avatar
 
Join Date: Feb 2004
Location: Silicon Valley
In the jfet SRPP thread (accessible right here in the "analog source" forum), I took a brief look at SRPP preamps using high gm jfets (they had a lot of gain). The circuit that teiffbassuebertr links to a couple of posts previous might be interesting using some high gm jfets in SRPP with equalization applied in-stage , and some modest amplification/buffering afterwards.

Right, he said - yet another project when my bench is already littered with stuff yearning towards completion. Well, as far as I have heard, no one has taken a hammer and broken all those busy little fingers out there (well, they should be busy), so they can take a look at the posited bipolar circuit and transpose it into jfet-land, mayhaps losing some nasty electrolytics along the way. What? You're waiting until I do it and offer a kit with parts and all that ? Ha! You'll be waiting quite a while, then... Call it a taunt, call it a challenge, call it anything you like. Start a thread.

Last edited by wrenchone; 10th May 2012 at 07:17 AM.
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need some help with RIAA Preamp david77 Tubes / Valves 50 14th May 2010 12:12 PM
My own RIAA tube preamp ronned2tm Tubes / Valves 7 11th December 2009 01:49 AM
Suggestions for RIAA preamp? coldcathode Tubes / Valves 17 7th March 2009 07:32 PM
RIAA Preamp Justcallmedad Solid State 4 2nd September 2005 01:52 AM
Another Simple RIAA preamp ? CheffDeGaar Analogue Source 7 10th February 2004 10:34 AM


New To Site? Need Help?

All times are GMT. The time now is 05:24 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