Simple SE with EL34 and 600v B+ - 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 26th February 2011, 09:49 PM   #1
diyAudio Member
 
Join Date: Feb 2009
Default Simple SE with EL34 and 600v B+

While my red board is on hold, i did an inventory of what i got. I have 1 extra "ten pounder" power transformer that does 310 or 620ish b+ and some new winged C el34's. Could i make this work with the simpleSE?

The power supply will be external and supply the b+. So would have to change RK to something like 1.2k to match the extra 100 or so volts extra. Im Not sure if i need to increase r14/r22 10k.


http://www.diyaudio.com/forums/attac...-15-supply.gif
  Reply With Quote
Old 27th February 2011, 01:17 PM   #2
diyAudio Member
 
tubelab.com's Avatar
 
Join Date: Jul 2005
Location: South Florida
Quote:
Could i make this work with the simpleSE?
I doubt it. The 800 volt plate rating on the EL34 might have applied to the original Mullard tubes, but todays tubes would probably explode!

Lets assume for a minute that the tube would withstand 800 volts on the plate. The screen grid can't. It is rated for 500 volts maximum and todays tubes have alignment problems making some glow in an SSE at normal voltage (about 450 volts). This means that triode or UL are not going to work, so you would need to run pentode with the screen at a lower voltage. Pentode would require some negative feedback to lower the output impedance.

Another issue with all of the popular audio tubes is the fact that the plate is on pin 3 and the heater is on pin 2. If the plate voltage is 600 volts the peak of the audio signal will swing up to 1200 volts (higher if the amp is overdriven). An arc can develop in the socket or the base of the tube between these two pins. I have seen it happen, but it is usually in guitar amp applications. When the plate voltage jumps into the heater supply, parts are going to blow!

The most that I have fed my SSE is 525 volts and the only tubes that would work were EH KT88's.
__________________
Too much power is almost enough! Turn it up till it explodes - then back up just a little.
  Reply With Quote
Old 27th February 2011, 05:53 PM   #3
diyAudio Member
 
boywonder's Avatar
 
Join Date: Jan 2008
Location: So.Cal.
Quote:
Originally Posted by nightanole View Post
I have 1 extra "ten pounder" power transformer that does 310 or 620ish b+ and some new winged C el34's. Could i make this work with the simpleSE?
Is it 620 CT? ie 310-0-310?
  Reply With Quote
Old 27th February 2011, 06:15 PM   #4
diyAudio Member
 
Ty_Bower's Avatar
 
Join Date: Mar 2007
Location: Newark, DE
Quote:
Originally Posted by boywonder View Post
Is it 620 CT?
There's no center tap on the "Ten Pounder". You either need to build the doubler or use a full wave bridge.

Of course, if you had two extra Ten Pounders around, you could series the HV secondaries together to create a virtual center tap...

Last edited by Ty_Bower; 27th February 2011 at 06:19 PM.
  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
Simple SE and EL34 Ty_Bower Tubelab 25 26th July 2009 05:34 AM
El34 Se Jean-Paul_2 Tubes / Valves 2 11th June 2009 05:33 PM
EL34 SE in 430V? zxx123 Tubes / Valves 6 29th November 2005 08:55 PM
se el34 finally karma Tubes / Valves 8 3rd November 2005 08:40 PM
se 6c33c or se el34 schematic karma Tubes / Valves 10 2nd July 2005 05:40 PM


New To Site? Need Help?

All times are GMT. The time now is 01:26 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