Rectifier tube 5AR4 vs. 5U4GB? - 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 11th October 2011, 12:19 AM   #31
diyAudio Member
 
hartze11's Avatar
 
Join Date: Nov 2008
Location: Boulder, CO
Quote:
Originally Posted by kmaier View Post
You're correct on both counts... and yes, the B+ will come up before the input and output tubes heat up. This will give you a surge on the filter caps (no load) so be sure the caps can handle the surge. I prefer to use either a 5V4G or 5AR4/GZ34 as they typically have a good 10 second delay before B+ builds up and it builds slowly. Your current draw is high for a 5V4G so I'd stick with the 5AR4.
Sorry to resurrect this thread, but I had my last 5AR4 do weird things (too much hum), so I'm thinking about using the solid-state rectifiers that I built in...

Won't the solid-state rectifiers also put a lot of B+ out before the tubes warm-up?

Any recommendations? Thanks! Dave
  Reply With Quote
Old 11th October 2011, 04:57 AM   #32
работник
diyAudio Member
 
Rod Coleman's Avatar
 
Join Date: Jul 2004
Location: Warwickshire UK
Yes, the SS rectifiers will apply B+ instantly, and this may give problems.

The modern-production GZ34/5AR4 seems to be less than perfectly reliable, too - so many of us here use "damper" (efficiency) diodes - either 2 tubes in a full-wave rectifier, or paired with (eg) UF4007 SS rectifiers in a hybrid bridge.

The 6CJ3 and PY500A are examples of good rectifiers in this position. They not only delay the application of B+, but also cause it to appear very slowly across 30 seconds - meaning you don't get unpleasant surge currents, as well as protecting the signal-valves while their heaters/filaments warm up.

There's lots of different dampers to choose from - but please use Duncan's PSUD2 to find out the repetitive peak current in your power supply, to make sure the damper can handle it. But suffice to say, the diodes named above can cope with 500Vdc supplies with 50uF directly after the rectifier, and still be working years later. The reliability of dampers is much better than 5AR4s!
  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
5AR4 Tube trade IFixAudio Swap Meet 0 28th January 2007 08:41 AM
Perplexed by 5AR4 Tube Socket? Picture Included ted777ted Tubes / Valves 4 26th September 2005 10:04 PM
Anybody heard about Tarzian Silicon Rectifier for Tube Rectifier Replacement? zxx123 Tubes / Valves 4 21st February 2005 04:02 AM
Tube rectifier for VDIGC tube psu ebijma Chip Amps 2 11th March 2004 04:02 PM
5AR4 & 5U4G Rectifier Questions... Guiness Tubes / Valves 6 29th April 2003 10:37 PM


New To Site? Need Help?

All times are GMT. The time now is 02:19 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