6V6/12AX7 Project Question/Help - 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 27th February 2011, 02:16 AM   #1
diyAudio Member
 
Join Date: Jan 2004
Location: Indiana
Default 6V6/12AX7 Project Question/Help

I am working on a tinker/junkbox project and am getting a little over my head. Its really my first scratch build so be nice, I have built a lot of kits and I know just enough to get in trouble and certainly don't mind throwing it together to see what happens!

I am working off of the attached schematic that I put together stealing bits and pieces from other projects I have seen.

Click the image to open in full size.

And am looking at adding in a stereo to mono summing stage in front of this setup. I found this on the aikenamps page:

Click the image to open in full size.

I'm not sure how to determine if this will work with my B+ or not, but I think I am going to throw it together and see. This is going to drive a small mono system from an iPod to just a mom speaker or a paralleled pair of speakers for a desktop type system.

Thoughts, comments, suggestions?

Thanks!

Tim
  Reply With Quote
Old 27th February 2011, 03:31 AM   #2
diyAudio Member
 
Tom Bavis's Avatar
 
Join Date: Jun 2002
Location: Macedon NY
Assuming you have enough gain already, you just need two resistors for the summing function - one per channel, joined at the input. Value should be several times the output impedance of the iPod - 1K or more should do.
  Reply With Quote
Old 27th February 2011, 01:29 PM   #3
Cassiel is offline Cassiel  Libya
diyAudio Member
 
Cassiel's Avatar
 
Join Date: Sep 2004
Location: Madrid
Why not use a proven schematic? If you're output transformers are cheap best one is RH84. It works with the 6v6 just as well. Kitic's design sounds good with cheap parts - others don't. Anyway, if you insist going your way you'll need a feedback loop for that pentode and the 6v6 cathode resistor should be around 470 Ohms.
  Reply With Quote
Old 27th February 2011, 04:02 PM   #4
diyAudio Member
 
Join Date: Jan 2004
Location: Indiana
Thanks for the info on the summing, I was really stretching for a use for the other half of the 12ax7 and just thought I would give it a try.

The RH84 project does look pretty interesting, I might bench that up first and see how it sounds with the iron I have on hand.

Thanks
  Reply With Quote
Old 27th February 2011, 09:25 PM   #5
diyAudio Member
 
Join Date: Jun 2004
Location: Indiana
You could run the two sides of the 12AX7 in parallel to provide more drive. You could also run the 6V6 in triode mode if the output level would be high enough to suit your needs. This would allow you to avoid the need for feedback (simpler) and would give you a use for some of the excess gain of the 12AX7 to drive the higher voltage swing requirements of the triode mode. Just a thought.
__________________
If We The People refuse to hear the truth we will be ruled by liars.
  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
Guitar amp with 6P6S (6V6) and probably 12AX7 klopsson Instruments and Amps 17 31st December 2012 11:05 PM
6v6 PP biasing question mor2bz Tubes / Valves 1 24th November 2010 06:46 PM
12AX7 Tube Question duanestorey Tubes / Valves 7 12th April 2010 03:34 AM
12AX7/12BH7 Hammond Tube Preamp Project jordankersten Tubes / Valves 4 5th April 2009 02:49 AM
12AX7 preamp project Mrpong Tubes / Valves 0 24th January 2006 11:47 AM


New To Site? Need Help?

All times are GMT. The time now is 02:47 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