solid state Vs Tube Rectification - 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 2nd September 2004, 05:50 AM   #1
sandy is offline sandy  India
diyAudio Member
 
Join Date: May 2004
Location: Chennai
Default solid state Vs Tube Rectification

Hello,

I've build couple of Tube Preamp (one with 12AX7 and another with 6SN7)...with good results. In both these projects, i've only used solid state rectification with Chokes smoothen those curves..

I've never tried tube/valve based power supply before. Currently i'm thinking of trying out a power supply with tube recitification (5U4G). Before spending more money...i was wondering if the forum members would provide feedback on thier experience....what would be the impact on the sonic qualities.

Also, please recommend some good tubes for the rectification circuit.....got one 5U4G (NOS NEC, Made in Japan).

Cheers
Sandy.
  Reply With Quote
Old 3rd September 2004, 03:45 AM   #2
diyAudio Moderator Emeritus
 
ray_moth's Avatar
 
Join Date: Jan 2004
Location: Jakarta
If you use a tube rectifier, the results should be:

- lower noise (unless you're using Schottky diodes);

- slow turn-on, which will be kinder to the tubes in your preamp;

- higher impedance, which will give a lower output voltage.

The high impedance of a tube rectifier can cause "sag" with a variable load, such as a class AB1 amp, but not with a class A preamp.

If you change to a tube rectifier, I think you'd be better off with an indirectly-heated one, such as EZ81 (6.3v heater) or 5V4 (5v heater), because of the slower turn-on of about 15-20 secs. Your directly-heated 5U4 will deliver full voltage in only a couple of secs.
  Reply With Quote
Old 3rd September 2004, 04:08 AM   #3
diyAudio Member
 
rcavictim's Avatar
 
Join Date: Jun 2004
Location: Next to an open wormhole NW of Toronto
If you drill a hole in the amp chassis and install a vacuum tube rectifier, as a first priority place it as far away a physical layout will allow from the low level audio tubes and circuitry. Second priority is to move it as far as you can from the ouptut tube(s). Often parking it on the opposite side of a steel shielding object like a transformer is a good option.

The recifier tube can capacitively radiate mains hum noise to other tubes through the air and the wiring to the recifier tube plates on the socket underneath the chassis can also couple capacitively to low level circuit wiring.
__________________
"There are more worlds than the one you can hold in your hand." Albert Hosteen, Navajo spiritual elder and code-breaker, X-Files TV Series.
  Reply With Quote
Old 3rd September 2004, 04:20 AM   #4
SHiFTY is offline SHiFTY  New Zealand
diyAudio Member
 
SHiFTY's Avatar
 
Join Date: Jul 2002
Location: New Zealand
Depends on your power transformer. for a 5 volt rectifier(5U4, 5V4), you need a separate 5 V 3A winding. For a 6 Volt rectifier (EZ80, EZ81) you can power it off the same filament winding as the rest of the valves, as long as the total current draw is not higher than the windings rating.

Your power transformer will also need a centre tap in the high voltage secondary. This centre tap is connected to ground.

I would prefer a GZ32/5V4 or the EZ80 or EZ81 as these all have a nice slow warm up. However there is no problem with using a 5U4, they will be just coasting along with a preamp. And if you already have one then why not!
  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
Best Tube 4 Solid State Jay Tubes / Valves 17 29th March 2003 04:08 PM
solid state or tube? jaybird Solid State 5 1st February 2003 10:17 AM
The Solid State Wiki - Your solid state reference guide Jason Solid State 0 25th June 2002 05:26 PM


New To Site? Need Help?

All times are GMT. The time now is 02:32 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