DIY Single Ended Triode Designs - Page 2 - 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 18th March 2004, 09:46 PM   #11
diyAudio Member
 
Join Date: Jul 2003
Location: Blackstone VA
Saurav; would you share the schematic for the ECC99/ 2A3 setup? Would appreciate it.
Pete
  Reply With Quote
Old 18th March 2004, 10:05 PM   #12
diyAudio Member
 
Join Date: Sep 2002
Location: Oregon, USA
Sorry, I don't have a schematic handy, or any way to easily draw one. Here's a description, starting from the top (B+) to the bottom (ground), if that helps.

B+: 300 - 320V
CCS load set for 20mA, I used a Bottlehead C4S
ECC99 (plate), capacitor coupled to the 2A3 grid

Under the ECC99 cathode I've had the required resistor (bypassed) to get 4V at the grid with 20mA current. I replaced that with a NiMH battery, and that's what I'm using now. The +ve of the battery goes to the cathode, -ve goes to ground. I got my batteries from Radio Shack (cordless phone rechargables, 3.6V nominal, 4.1V fully charged), make sure their AH rating is high enough to be able to handle the steady state DC current through them.

Hope that helps.
  Reply With Quote
Old 18th March 2004, 10:07 PM   #13
grataku is offline grataku  United States
diyAudio Member
 
Join Date: Dec 2000
Location: -
Quote:
Originally posted by AKSA
Has anyone here ever done a 6C33C in SET?

Any comments on operating point/sonics?

Hugh

Are you referring to something like the Erno Borbley 15W SE amp? I have been curious about that.
  Reply With Quote
Old 18th March 2004, 11:10 PM   #14
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

Quote:
Any comments on operating point/sonics?
B+ 200VDC
Vg- 80VDC
Zprim ~ 600 Ohm

Should sound great, needs grunty driver to overcome Miller capacitance.

SOME SOURCES OF INSPIRATION.

Cheers,
__________________
Frank
  Reply With Quote
Old 18th March 2004, 11:41 PM   #15
AKSA is offline AKSA  Australia
diyAudio Member
 
Join Date: Sep 2001
Location: Melbourne, Australia
Hi Frank,

Thanks a lot...

They seem to rave about them in Stereophile. Is this good or bad?

I was thinking of a 6BX7 driver, with rp around 1K3. I've ordered some at $US8 each.

B+, recommended by Alex Adrianov in Kiev, is 320V, 200mA, 85V of cathode bias. This is 235V across the tube, and 47W of dissipation, with max at 60W, so running at 78%, should last well, particularly if socket is raised for ventilation. They say a bit of pencil graphite rubbed on the pins prevents the filament current starvation which is the bane of these tubes.

I was thinking of a 1K:8R transformer to reduce H2/3 to the minimum. With increased voltage at B+ I should still get a good 10W.

First stage is 6SN7.

Comments?

Cheers,

Hugh
__________________
Aspen Amplifiers P/L (Australia)
www.aksaonline.com
  Reply With Quote
Old 18th March 2004, 11:53 PM   #16
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

Quote:
They seem to rave about them in Stereophile. Is this good or bad?
Depends on what side of the fence you're sitting, I suppose.

Quote:
They say a bit of pencil graphite rubbed on the pins prevents the filament current starvation which is the bane of these tubes.
A fellow member, 316A I think, once offered the following tip to prevent carbonised heater pins: when wiring up the heater connection at the socket, just wrap the wire around it a few times than solder it. This should provide for some extra metal surface to help pass current and keep things a tad cooler.

If it were for my own use, I'd find myself some NOS Johnson septar sockets. They're the most reliable I've ever used.

Hadn't heard the graphite trick before...I wonder how that actually works.

Quote:
Comments?
Sounds fine by me.

Cheers,
__________________
Frank
  Reply With Quote
Old 20th March 2004, 09:37 AM   #17
grataku is offline grataku  United States
diyAudio Member
 
Join Date: Dec 2000
Location: -
Quote:
Originally posted by fdegrove
Hadn't heard the graphite trick before...I wonder how that actually works.
Graphite is greasy and conducting plus it has an inverse temperature coefficient (becomes more conducting as it's heated).
Could that help reduce the hot spots, hi resistance spots on the socket/pin interface??
I'll try that on my 300W halogen lamp contacts.
  Reply With Quote
Old 20th March 2004, 12:28 PM   #18
morfeas is offline morfeas  Greece
diyAudio Member
 
Join Date: Jun 2003
Location: Athens
As for the sonics of the 6C33 I would say a good mix between SS, SET. Still missing the energy of my PP 6550.

Runs on 235V, 200mA. Long time to burn in. The first 100 hours the bias comes after 30-40 minutes! After the burn in period 15 minutes are OK. Driver 6N1P.

A lot of HEAT that should be taken in to account seriously!
  Reply With Quote
Old 20th March 2004, 03:19 PM   #19
diyAudio Member
 
Join Date: Oct 2002
Location: Munich, Germany
Default 6C33B

Hi,
one more source for inspiration.
  Reply With Quote
Old 20th March 2004, 03:20 PM   #20
diyAudio Member
 
Join Date: Oct 2002
Location: Munich, Germany
Attachment does not show up, will try later again.
  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
Power cord for single ended triode kimobuddy Tubes / Valves 1 11th April 2009 07:47 PM
Running Single Ended 6V6 in Triode Mode WRyan Tubes / Valves 19 10th February 2009 06:09 PM
Best Cheap Speaker for Single Ended Triode Patrick Bateman Multi-Way 16 22nd December 2006 10:17 PM
single-ended bipolar designs? el`Ol Solid State 1 13th May 2005 08:22 PM
Single Ended Triode (SET) amp friendly design GaryF Multi-Way 5 30th May 2004 05:30 AM


New To Site? Need Help?

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