Noise floor of Tubelab SE - Page 4 - diyAudio
Go Back   Home > Forums > Commercial Sector > Vendor Forums > Tubelab

Tubelab Discussion and support of Tubelab products, prototypes and experiments

Reply
 
Thread Tools Search this Thread
Old 29th November 2012, 08:38 AM   #31
victorm is offline victorm  Australia
diyAudio Member
 
Join Date: Apr 2012
Hello all, could use a recommendation/advice here,

My 300B based TSE is humming a little and I'd like to get rid of the hum, so started looking at the heater voltages and their shapes. First I noticed that 5842 heaters are getting about 4V, with 100 Hz ripple, so I shorted the R3 and added 10000 uF cap in parallel with C1. That helped a little, but not enough. The 5842 heaters are now getting DC with ripple (Vmin=4.64V, Vmax=5.44V). Obviously, these voltages above are also found at the input of the regulator.
The output of the regulator shows (Vmin=4.48V, Vmax=4.96V, 100Hz ripple), AC voltage at the 6.3V transformer winding under load is 5.5V RMS. Looks like NOT enough to get a stable 5V DC out of the regulator ;-(
So here is the question - I am planning to add another 2x15000uF in parallel with C1 and implement the trick George suggested for Davide, i.e. replace R1 with a trimmer and decrease the regulator output voltage a little to get rid of the ripple. Since my Vmin at the regulator input is 4.64V, I will probably end up with around 4V DC on the 300B filaments.

Will this affect anything in a negative way? Any other suggestions (before I start looking at the transformer replacement)?

Really appreciate your help here guys,

Cheers,
-Victor
  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
noise floor analyser vincent_brient Vendor's Bazaar 6 19th September 2011 08:57 AM
Warm up noise from Tubelab SE? Evenharmonics Tubelab 8 15th December 2010 03:38 AM
tripath noise floor. lbstyling Class D 10 23rd September 2010 04:54 AM
Tubelab SE buzzing noise from the speaker Evenharmonics Tubes / Valves 7 18th July 2009 02:08 AM
noise floor problem johndiy Solid State 12 31st August 2006 01:32 AM


New To Site? Need Help?

All times are GMT. The time now is 05:32 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