Ultrapath - Advantages? - 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 24th April 2010, 04:44 AM   #1
batsong is offline batsong  United States
diyAudio Member
 
Join Date: Jan 2008
Location: St. Louis
Default Ultrapath - Advantages?

What are the sonic advantages of Ultrapath?
  Reply With Quote
Old 24th April 2010, 08:48 AM   #2
Arnulf is offline Arnulf  Europe
diyAudio Member
 
Join Date: Feb 2009
It introduces PSU noise to cathode, awesome sonic advantage if your stage has too much PSRR to begin with.
__________________
mod verb, transitive /mod/ to state that one is utterly clueless about the operation of device to be "modded" and into "fixing" things that are not broken; "My new amplifier sounds great so I want to mod it."
  Reply With Quote
Old 24th April 2010, 05:55 PM   #3
diyAudio Member
 
dsavitsk's Avatar
 
Join Date: Jan 2005
Location: Hartford
Arguably it allows you to keep the final PS cap out of the signal current loop. Some people think it works well, others don't.

ETF Presentation
  Reply With Quote
Old 24th April 2010, 08:05 PM   #4
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Quote:
Originally Posted by Arnulf View Post
It introduces PSU noise to cathode, awesome sonic advantage if your stage has too much PSRR to begin with.


However the addition of a capacitor across the cathode bias resistor in conjunction with an ultrapath cap produces an interesting benefit if you get the ratio right - you get greatly improved psrr. That cathode bypass cap should be ~ (mu +1) x C_ultrapath although it usually is not too critical in my experience. This technique appears to have originated in Western Electric amplifiers sometime in the 1920s.

I've used the technique successfully in the output stage of a cathode biased (!) 2A3 amp I designed a few years back, it reduced 120Hz buzz on the output of the amplifier in question by more than 6dB.
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan

Last edited by kevinkr; 24th April 2010 at 08:10 PM.
  Reply With Quote
Old 24th April 2010, 08:22 PM   #5
batsong is offline batsong  United States
diyAudio Member
 
Join Date: Jan 2008
Location: St. Louis
Thanks for all of the replies.
What I was looking at was using a capacitor in conjunction with the bypass cap on a 2A3.
I had removed the bypass cap because I felt it has resulted in more bass and treble, though it also gave the bass a little extra 'flabbiness'.
I'm guessing that if I put the bypass cap back in with an Ultrapath, I would lose this. I wonder if switching to a film capacitor for the bypass would help. Although, with this amp, even with 105db speakers the hum is not bad.
  Reply With Quote
Old 24th April 2010, 08:56 PM   #6
diyAudio Member
 
Sch3mat1c's Avatar
 
Join Date: Jan 2003
Location: Milwaukee, WI
Send a message via ICQ to Sch3mat1c Send a message via AIM to Sch3mat1c
Considering a triode is "0%" PSRR, anything you can do to help it is a great idea.

*That includes using pentodes instead.

Tim
__________________
Seven Transistor Labs
Projects and Resources
  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
Q............PP Ultrapath pointy Tubes / Valves 2 25th November 2009 07:13 PM
Fixed Bias v Ultrapath dsavitsk Tubes / Valves 6 28th October 2007 07:33 PM
Ultrapath line amp tinitus Tubes / Valves 10 28th June 2007 11:54 AM
Ultrapath output transformers bequerel Tubes / Valves 10 31st October 2006 10:45 PM
Ultrapath Cap Diy martin Tubes / Valves 1 23rd October 2005 09:46 PM


New To Site? Need Help?

All times are GMT. The time now is 09:39 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