Account Info
Greetings, Guest.

Reset Password
Create New Account

Browser cookies are required for these functions.

Welcome to AX84® the base camp for tube (valve) electronics hobbyists.

AX84 exists to provide:

1) A great environment to learn about music-related electronics in general. AX84 is a place where those with experience are interested in helping diligent beginners who are willing to do their homework.

2) A place where those with more experience can field their ideas to peers and get useful feedback.

3) An environment that respects the past, but is not enslaved by it. INNOVATION IS GOOD (and it didn't die in the 1950s.) There are new things under the sun every day. Move the ball forward!

Our HUGE discussion area is under 'Discussion Forum' to your left.

We are hard at work improving the site- check back often!

Recent Forum Threads
"Cathode biasing 6L6GC's?"
Posted By Alva Goldbook on 07/31/2015
I have a Fender Hot Rod Deville 410 that I've gutted. I never liked the tone very much. Plus, it is way too loud. So I've been thinking of replacing it with a blackface kind of circuit, and cathode bi...

Discuss this entry
"+9VDC PSU from DC-heater supply "
Posted By JPSH79 on 07/30/2015

I would like to make a +9V output into my amp and I was thinking of using the existing 12VDC unregulated heater- / relay-supply (or atleast the same 10,5VAC -winding) to feed the 7809 -regulato...

Discuss this entry
"DC Heater assist"
Posted By Denny Gracey on 07/25/2015
I've added the DC heater circuit from Merlin's preamp book to my UHG build - used 4001's and an 8700mf 16V cap. Getting proper DC voltage but it's still carrying 150mVpp AC which is getting coupled in...

Discuss this entry
"Discovered a little gem in my closet tonight. "
Posted By Alva Goldbook on 07/24/2015
Thought you guys might enjoy this. A few years ago my wife rescued this little combo amp for me. I never looked at it too closely. I figured it was solid state at the time and I just put it in a close...

Discuss this entry
"Thank you to this group for helping me through a successful buil"
Posted By Dave Tainer on 07/22/2015
Yes, I'm a lurker. I never wanted to use the crutch of having to ask a question of this vaunted group because I thought after so many years you probably didn't want another newbie asking the same ques...

Discuss this entry
Like us and Find us

Subscribe to me on YouTube

Site News

2014-10-21: Be sure to check out our discussion forum using the link on the left..

2014-10-20: The Treasure Fleet is on the way to Rio De La Hacha with a fortune in gold!

We're looking for media clips of recent builds... please stop by the forum and respond to the thread.

2008-10-4: Archived Projects section is functional again.

2008-9-18: RSS Feeds for the forum have been up for a while, but not advertised...
* Active Threads
* New Threads
* Recent Posts

2008-6-26: Want to participate in our discussion forums? You are welcome to read and lurk as you like. If you think you'd like to post with regularity, please sign up for an account.

AX84® is a registered trademark of Doberman Music Products, LLC. AX84.COM content may not be reproduced without the express written consent of Doberman Music Products, LLC (
For information about using the AX84® trademark, project names and designs, click here