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

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Parallel SE output
Parallel SE output
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
Thread Tools Search this Thread
Old 4th January 2012, 06:28 PM   #1
razorrick1293 is offline razorrick1293  United Kingdom
diyAudio Member
Join Date: Nov 2010
Location: England Hertfordshire
Default Parallel SE output

Hi guys,

I know its common to have 2 of the same tube in a SE design, or even similar ones like el84s and 6v6s. but what about different kinds of tubes such as a pentode and a triode? or el84 and 6k6gt? or any thing else if anyone can think of something wilder!

From what i understand the output transformer would see the 2 as one big tube, and as long as they were biased right, everything should be fine, maybe with a 10 ohm resistor connecting the 2 together?

Any comments welcome!

  Reply With Quote
Old 4th January 2012, 06:48 PM   #2
the_manta is offline the_manta  Germany
diyAudio Member
the_manta's Avatar
Join Date: Nov 2006
Location: Munich, Bavaria
Regarding CD conditions, you're right.
But more important are the dynamic parameters !
The tubes have for sure very different Ri(Rout) since one is a pentode the other a triode. Differences in transconductance are also a huge problem. The tube with the higher gm will conduct more and more with higher positive drive signal and the other way round with less drive signal. this imbalance in AC-current sharing will cause distortion etc.
The AUDIO-SCULPTURE MAJUSCULE had a related circuit. When big amounts of power were needed, a pentode is "switched" in parallel to the triode with the help of a special circuit. This points into the direction of Class-G/H
Терпенье и труд все перетрут
  Reply With Quote
Old 4th January 2012, 09:08 PM   #3
razorrick1293 is offline razorrick1293  United Kingdom
diyAudio Member
Join Date: Nov 2010
Location: England Hertfordshire
Thanks for your reply!

ive just built a circuit which has both el84 and 6v6 output options (including both in parallel) and i switched triode and pentode on both simultaneously. i wasnt sure if i could get away with a t/p switch for each individually.

Ive also just got a 6k6gt to experiment with, and it seemed like it could be a low power replacement for the 6v6.

Distortion is a factor im interested in (for guitar amps) though im also interested in the character it might have in playing music.
  Reply With Quote


Parallel SE outputHide 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
SE to parallel SE? Carlp Solid State 0 23rd September 2010 02:46 AM
Tubelab SE in parallel? Mazuki Tubelab 31 20th February 2009 09:32 PM
parallel SE 2A3 sunrise Tubes / Valves 20 29th August 2008 07:41 PM
SE parallel output questions Richard Ellis Tubes / Valves 3 18th May 2008 12:33 PM
Parallel SE vs. Single SE Output Question valveitude Tubes / Valves 19 4th May 2005 05:36 PM

New To Site? Need Help?

All times are GMT. The time now is 10:02 AM.

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