PAS phono. (curcio) - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 15th December 2004, 12:31 PM   #1
GeirW is offline GeirW  Norway
diyAudio Member
 
GeirW's Avatar
 
Join Date: Jan 2004
Location: Trondheim, Norway
Default PAS phono. (curcio)

Gday.

Just some quick questions regarding this stage.

1. Do anyone of you happen to know, the commponent values?
(they have been kind enough to distribute the moded. schem.
at dynaco doctor, but none values. it can`t be that simple
that they use old pas values. (turned operation point)

2. Is my humble attemt on the schematic right.
Opinions on the usage of 6922 !? ,
most phono stages/preamp`s i seen, uses ECC83/12AX7.
From what i can read about the 6922, it`s a very good performer,
but is it right in here.

Attached Images
File Type: png caspas.png (16.8 KB, 438 views)
  Reply With Quote
Old 15th December 2004, 12:56 PM   #2
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
6922-oids are an excellent choice for a phono input. Though their gain is lower than a 12AX7, they have (when run properly) much lower noise and suffer much less from Miller effects. The surrounding component values will be quite a bit different between these tubes (12AX7 usually runs at ca. 1ma, 6922 at ca. 8-10ma, and the plate resistances and transconductances are an order of magnitude different).

In my own phono preamp, I use a high transconductance FET at the bottom of a cascode with a 6922-like tube on top. Works a charm, and I get the best of both worlds- the low noise and low gate current of the FET with the swing, linearity, and overload resistance of the tube.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 15th December 2004, 01:51 PM   #3
alejo is offline alejo  Argentina
diyAudio Member
 
Join Date: Jun 2004
Location: bs.as.
Default SY schematic

Hello, SY IŽn search for Phono preamp, plese atach your schematic to see your desing.

thanks
alejo
  Reply With Quote
Old 15th December 2004, 05:13 PM   #4
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Default Re: PAS phono. (curcio)

Quote:
Originally posted by GeirW
Gday.

Just some quick questions regarding this stage.

1. Do anyone of you happen to know, the commponent values?
(they have been kind enough to distribute the moded. schem.
at dynaco doctor, but none values. it can`t be that simple
that they use old pas values. (turned operation point)

2. Is my humble attemt on the schematic right.
Opinions on the usage of 6922 !? ,
most phono stages/preamp`s i seen, uses ECC83/12AX7.
From what i can read about the 6922, it`s a very good performer,
but is it right in here.


The Curcio design (copyrighted) is available as a reprint from www.audioXpress.com

Jan Didden
__________________
I won't make the tactical error to try to dislodge with rational arguments a conviction that is beyond reason - Daniel Dennett
Check out Linear Audio Vol 7!
  Reply With Quote
Old 15th December 2004, 06:24 PM   #5
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
I haven't posted my full preamp design yet because it uses some tubes and FETs which are no longer commonly available (I built it nearly 20 years ago). But Curcio's design is likely to be quite fine.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 15th December 2004, 08:28 PM   #6
GeirW is offline GeirW  Norway
diyAudio Member
 
GeirW's Avatar
 
Join Date: Jan 2004
Location: Trondheim, Norway
Gday.

ouch.
Quote:
The Curcio design (copyrighted)
didn`t notice, that isn`t fair play.
  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
Curcio Daniel II builders? djmike Tubes / Valves 3 14th November 2013 11:17 AM
Curcio daniel Sarge Tubes / Valves 36 29th June 2012 11:48 AM
FS: Dynaco PAS with full Curcio mods beeah Swap Meet 9 17th December 2007 07:56 PM
Curcio Sarah Phono stage: opinions? ad010685 Tubes / Valves 4 8th August 2006 12:30 PM
Curcio or Triode Elec for ST-70 hot rod parts? ultrachrome Tubes / Valves 7 7th November 2003 02:23 AM


New To Site? Need Help?

All times are GMT. The time now is 02:25 PM.


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