6W6 as a driver - 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 14th September 2005, 11:29 AM   #1
Cassiel is offline Cassiel  Libya
diyAudio Member
 
Cassiel's Avatar
 
Join Date: Sep 2004
Location: Madrid
Default 6w6 as a driver

Hi guys:

I did a SE amp with NOS GE 6w6's and like the sound a lot. Now they are wired as triode with a 100 ohm resistor, there's a little blue glow in both valves, is this a problem?

Operating point is: 320v anode, 27mA dropping 38 volts in the cathode. About 8,5 watts dissp.: maximun is 10. I know 320 is over the maximun for this valve(300) but i've heard American NOS are tough and can stand the abuse. But not sure so i ask.

Another question concerning this valve. I saw the Karma amplifier wich uses this valve as a driver, saying is a sleeper? tube, very linear and very low distortion. Now could somebody provided me with operating points to use this tube as a driver? Very similar as a 45 i've read. But don't know.

Thanks in advance,

al
  Reply With Quote
Old 14th September 2005, 03:59 PM   #2
amperex is offline amperex  United States
diyAudio Member
 
Join Date: Feb 2005
Location: MI
I did not review voltages, but a blue glow is not an issue. I read triode connected 6W6GT are linear & good sounding. You may wish to try some other manufactures as well. I seen these tubes sell for NOS at $2.50 each on epay.
  Reply With Quote
Old 14th September 2005, 11:48 PM   #3
diyAudio Member
 
Sch3mat1c's Avatar
 
Join Date: Jan 2003
Location: Milwaukee, WI
Send a message via ICQ to Sch3mat1c Send a message via AIM to Sch3mat1c
6W6's only shortcoming is low plate dissipation. Next to that it's a great tube with high current capacity, especially given the low screen voltage. The perfect vertical sweep tetrode, but then, linearity isn't bad when brought over to audio either!

Triode mode is just fine for tubes with really low Vs ratings because the plate still attracts more electrons than the screen and excess screen dissipation isn't a concern.

Tim
__________________
Seven Transistor Labs
Projects and Resources
  Reply With Quote
Old 15th September 2005, 03:36 AM   #4
diyAudio Member
 
Join Date: Mar 2005
Location: KCMO
So would 6W6 make a good driver tube? I ask because I have at least a dozen NOS ones and they would look nice driving a pair of EL-34s.
John.....
  Reply With Quote
Old 15th September 2005, 10:06 AM   #5
amperex is offline amperex  United States
diyAudio Member
 
Join Date: Feb 2005
Location: MI
Default Yes.....

Triode connected 6W6 are very good & linear- excellent driver tube overlooked by many audiophiles..
  Reply With Quote
Old 15th September 2005, 04:56 PM   #6
Cassiel is offline Cassiel  Libya
diyAudio Member
 
Cassiel's Avatar
 
Join Date: Sep 2004
Location: Madrid
Thanks for the answers.

Ok, i will find the correct operating points in some schematic in which the 45 drives a 300b or something, have read that 6w6 can replace the 45 as a driver with no need for adjustments, other than the filament voltage.

About the blue glow...it went worse so i did some tests. It happens that when i remove the capacitor and leave the cathode unbypassed the blue dissappears I'm using a 220uf 100 volts cap. Really confused here, any ideas?

Thanks,


Al
  Reply With Quote
Old 15th September 2005, 09:05 PM   #7
diyAudio Member
 
Sch3mat1c's Avatar
 
Join Date: Jan 2003
Location: Milwaukee, WI
Send a message via ICQ to Sch3mat1c Send a message via AIM to Sch3mat1c
Geez, WTH you need a tube half as big as the output for?! Even a 100MHz transmitter, using an EL34, which doesn't really even handle 100MHz (hence my point) doesn't need anywhere near that much drive!

I've whipped 6W6s before and never noticed any blue glow, it might be parasitic oscillation? That would possibly explain the cathode bypass response. You put in a screen grid stopper resistor, right?

Tim
__________________
Seven Transistor Labs
Projects and Resources
  Reply With Quote
Old 16th September 2005, 12:43 AM   #8
diyAudio Member
 
astouffer's Avatar
 
Join Date: Jun 2004
Location: Pittsburgh, crumbling wasteland
Hey Tim, guess you never looked at what Sakuma did Used an 845 to drive another 845. The preamp might have been an 801, not sure. This gets me thinking about the 6W6s in my collection...
  Reply With Quote
Old 16th September 2005, 06:52 AM   #9
Colt45 is offline Colt45  Serbia
diyAudio Member
 
Join Date: Feb 2002
Location: Canada
Send a message via ICQ to Colt45
320 - 38 = 282, 282 < 300

anyways, they can probably take a fair bit more than 300 without blowing up.

but max plate voltage is in reference to the cathode, not ground.
  Reply With Quote
Old 17th September 2005, 05:35 PM   #10
Cassiel is offline Cassiel  Libya
diyAudio Member
 
Cassiel's Avatar
 
Join Date: Sep 2004
Location: Madrid
The SE6W6 is finally completed, i had a bad solder which was causing me headaches, now it's doing fine. In the future i'll try 6v6īs to compare.

Quote:
Geez, WTH you need a tube half as big as the output for?! Even a 100MHz transmitter, using an EL34, which doesn't really even handle 100MHz (hence my point) doesn't need anywhere near that much drive!
Well a 6dj8 is driving the 6w6 in my amp. But i like experimenting and i thought about the possibility of using the 6w6 as a driver for another project , thatīs all.

Quote:
but max plate voltage is in reference to the cathode, not ground
This sentence clears many doubts i had.

This is all, i'll post the pic of my amp soon. Thanks to all who helped.

Al.
  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
L-pad attenuator for midrange driver 6 1/4 inch driver rhythmdiy Multi-Way 0 4th November 2007 03:32 PM
Base driver to suit ESS Heil driver gerado Planars & Exotics 6 1st August 2007 07:56 PM
FS: Silver Iris Coaxial 15" driver pair (sans XO and compression driver) theAnonymous1 Swap Meet 0 24th April 2007 12:09 AM
Driver/ driver configuration improve soundstage width andy2 Multi-Way 6 16th June 2005 08:47 PM
mtm versus tm driver recommendations on project with $500 driver and xo part limit gsattler Multi-Way 4 20th May 2002 05:54 PM


New To Site? Need Help?

All times are GMT. The time now is 12:24 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright Đ1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2