"Like" AX84 on facebook

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
"Ideas on noise source"
Posted By boogieboom on 02/12/2016
Hi, folks.

A while back, I built a Hi Octane with an effects loop, octal socket, adjustable bias, and relay switching on the 3rd gain stage. Great recording amp for a classic Eagles/Clapton thing....

Discuss this entry
"Identifying OT secondary taps"
Posted By Audiosalvage on 02/11/2016
I have an OT with 3 taps a yellow, green and white. I've applied 20 VAC to each of these and got 570v,433v and 312v respectively. How do I determine what speaker impedance goes with which wire? ...

Discuss this entry
"Supply filtering with VVR"
Posted By Tim Hall on 02/11/2016
I'm down to the last little design details for my current project - determining RC values for B+ nodes.

(For those of you who find this stuff elementary, please pardon me, if I talk out loud a bit....

Discuss this entry
"Source for Humdinger & Other Small Value Trimpots"
Posted By FreshStart on 02/11/2016
I've found a 250 ohm 1/4 watt trimpot on Mouser. Is that a high enough power rating to use as a "humdinger" on the virtual center tap for AC heaters? (5E3 if that matters)

What I can't seem to find...

Discuss this entry
"Preamp Design Review & switching option help"
Posted By tristanc on 02/10/2016
I've continued modifying my L2L-style build following learnings from LTSPICE modelling / posts to this forum / prototyping / lots of Googling etc.

Here is a portion of the schematic focussing on th...

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 (sales@dobermanamps.com).
For information about using the AX84® trademark, project names and designs, click here