A Heretical Unity gain line stage - Page 9 - 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 20th June 2005, 01:59 AM   #81
diyAudio Member
 
Join Date: Jan 2004
Location: malaysia
Quote:
In any case, the f3 of the specified transformer is 80-100kHz. Here's the datasheet:
In that case, its fine.

Keep the updates on the listening results!
  Reply With Quote
Old 20th June 2005, 02:37 AM   #82
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
I had this version in my living room system for a week or so; it sounded fine. If it did anything other than silently and effortlessly raise and lower the volume, I could not hear it. Getting the system silent unless spoken to was quite worthwhile.

Since than, I've been living with the Mark 2 version (article coming soon), with an output servo, but identical signal and regulator circuitry to what I'm showing here. I've spent this afternoon with a glass of something alcoholic (ok, maybe more than a glass), kd lang, They Might Be Giants, and of course, Tony Rice, as my wife has given me an afternoon off to celebrate Father's Day in the US. The preamp does its job with effortless grace.

Version two, also with a servo, but with RCRC filtration on the plates and some Ampex input transformers, is running my garage/lab system. That's been getting some workout as I try and get the Mark 3 (with novel servo) boxed up and ready for some extended listening.

I should mention that, claiming moderator's privilege, I've been incorporating revisions in the original posts.
__________________
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 20th June 2005, 08:23 AM   #83
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
boxed up and ready for some extended listening.
If i may be brave and jump the gun with a prediction - it will "silently and effortlessly raise and lower the volume" and be otherwise utterly indistinguishable from any other well designed preamp

Mark 3? Just giving the silver wire pushers more business.
  Reply With Quote
Old 20th June 2005, 11:51 AM   #84
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Quote:
Originally posted by analog_sa


If i may be brave and jump the gun with a prediction - it will "silently and effortlessly raise and lower the volume" and be otherwise utterly indistinguishable from any other well designed preamp
If all goes well, yes. Novelty can have negative consequences... But the version I'm listening to is quite distinguishable from several others I've tried- it doesn't pass along the buzzes, bamgs, and burbles from the lousy grounds that I can't control.
__________________
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 22nd June 2005, 06:04 AM   #85
diyAudio Member
 
wrenchone's Avatar
 
Join Date: Feb 2004
Location: Silicon Valley
Not a rag at all, just an innocent question - why did you choose your current approach rather than something like a White follower? I've used both the White-type follower and a simple current source loaded follower with JFETs and gotten decent results.
  Reply With Quote
Old 22nd June 2005, 11:37 AM   #86
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Don't worry about the rag!

A White follower, done correctly, will work fine. It will require twice as many tubes and elevated heater supplies, while giving essentially no better performance. And it is much tougher to direct couple- which will be the next chapter in this saga.

My previous preamp also used JFETs as cathode loads. It worked well enough for me to use it for 20 years or so.
__________________
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 26th April 2013, 10:18 AM   #87
Gost22 is offline Gost22  Bolivia
Banned
 
Join Date: Sep 2012
Location: San Ignatio de Velasco
Hi Sy and all!
For this schemetics to connect the power supply to the heater and power supply catode tube follower on her well done differently or should that be done?
Thank you for your cooperation and assistance!
P.S.
My previous preamp also used JFETs as cathode loads. It worked well enough for me to use it for 20 years or so.
SY, where is the schematics??
thank you!
Attached Images
File Type: png Complet schematics-2.png (179.3 KB, 111 views)

Last edited by Gost22; 26th April 2013 at 10:37 AM. Reason: Help!
  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
A Heretical Unity Gain Line Stage part III SY Tubes / Valves 253 9th October 2013 02:35 PM


New To Site? Need Help?

All times are GMT. The time now is 08:43 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