Go Back   Home > Forums > > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubelab Discussion and support of Tubelab products, prototypes and experiments

Thread Tools Search this Thread
Old 3rd September 2011, 04:29 AM   #11
dagerman is offline dagerman  United States
diyAudio Member
dagerman's Avatar
Join Date: Feb 2011
Location: Greater Seattle Area
Originally Posted by Jpeg View Post
Well, it looks like you have a scope, you are ahead of me on that one Did you wind up with a pair of "5842 compatable" russian tubes? I have seen posts about those not being very compatable... Have you tried just hooking up one channel on your RCAs and swapping both driver and output tubes back and forth to see if you can detect a bad tube? Just a thought, but it's easy to check.
Well, not sure about the 'ahead' part... You know how they say "a fool's a fool independent of tool"... Right now I wold trade a thorough understanding of how the circuit works for my scope. I haven't figured out how to scope the driver stage. As soon as I hook up the scope probe to either end of the coupling cap, I get real bad static and the bias current goes through the roof.

Anyway, my 5842's are Raytheon and RCA (I have two pairs) and swapping them hasn't have any effect. The 45s however do seem to be different. On one channel I can't get the bias current under 45mA and if I swap the tubes, the issue follows.
Initially I had set the board up for my pair of new 300Bs and I was able to adjust all operating points as expected, but it still sounded off and distorted at higher volume.
I decided to 'park' the board and revisit after
A) I learned how to use my scope properly (I thought I did, but...) and
B) I read up on the theory, so I know where and how to measure

One day, there will be light (and sound)!
For the next couple of days I'll focus on Salmon fishing in the San Juans anyway.

Happy Labor Day,
There are 10 types of people: Those who understand binary and those who don't.
  Reply With Quote


Unplanned TSE mod, letting out the smokeHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
TSE redone..working well..but :) Green77 Tubelab 6 29th June 2011 08:00 PM
Running a TSE with 5u4g? discomonkey Tubelab 6 30th April 2011 04:30 PM
TSE c4 question evanc Tubelab 4 20th April 2011 03:31 AM
Motor Run vs. Solen in TSE jeffx Tubelab 8 5th March 2011 08:00 PM
Lost a channel in my TSE oldmanStrat Tubelab 4 26th August 2009 01:13 AM

New To Site? Need Help?

All times are GMT. The time now is 05:14 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio