DCAudioDIY.com

DC Area Audio DIYer's Community
It is currently March 28th, 2024, 6:10 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 12 posts ]  Go to page Previous  1, 2
Author Message
PostPosted: February 12th, 2014, 10:29 pm 
Offline

Joined: July 24th, 2013, 11:11 am
Posts: 21
The full schematic says at the bottom, referring to the output transformer, 'For 2k output strap B-C. For 500Ω output strap A-B & C-D.' This does not drive a speaker but rather another amp circuit.

The jack totally mystified me and made me read the accompanying text. I see it is a current metering test jack. (normally closed) This is an interesting circuit. The 1k to ground from the center tap of the filament supply, the 48k to ground at the bottom of the input transformer and the .5uf capacitor allow a out of phase signal to be applied to the tube through the cathode. This is a output section that has a parallel feed input? The 2uf capacitor from the output transformer to the filament supply allows a path for the output AC current loop.

Scott


Top
 Profile  
 
PostPosted: February 13th, 2014, 12:36 am 
Offline

Joined: April 22nd, 2013, 12:58 pm
Posts: 285
That 2uF cap from the B+ side of the OPT to the junction of the cathode bias resistor and the cathode is what later became known as "UltraPath",

Image
http://www.tubecad.com/2008/08/blog0147.htm

This is NOT the same as parafeed, IMHO.....


Jetbat wrote:
The full schematic says at the bottom, referring to the output transformer, 'For 2k output strap B-C. For 500Ω output strap A-B & C-D.' This does not drive a speaker but rather another amp circuit.

The jack totally mystified me and made me read the accompanying text. I see it is a current metering test jack. (normally closed) This is an interesting circuit. The 1k to ground from the center tap of the filament supply, the 48k to ground at the bottom of the input transformer and the .5uf capacitor allow a out of phase signal to be applied to the tube through the cathode. This is a output section that has a parallel feed input? The 2uf capacitor from the output transformer to the filament supply allows a path for the output AC current loop.

Scott


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 12 posts ]  Go to page Previous  1, 2

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 45 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group