diyAudio - Audiohobby.com
Go Back   Home > Forums > Blogs
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
DIY Audio & Electronics
Old

V-FETRON 75 UPDATE #1

Posted 6th March 2016 at 03:05 PM by Michael Rothacher (Audiohobby.com)
Updated 6th March 2016 at 10:34 PM by Michael Rothacher

Achievement Unlocked: 75 Watt Class A Zero Feedback SIT Circlotron

Click the image to open in full size.
Soft clipping at 75W

Because of the high input capacitance of the 2SK180’s and the gain of this circuit, we have to pull out all the stops to get our 75W beast to make audio bandwidth. Here you can see that each SIT is getting its own transformer and buffer.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.
diyAudio Member
Views 510 Comments 0 Michael Rothacher is offline
Old

Nelson Pass Presentation

Posted 26th October 2015 at 04:50 PM by Michael Rothacher (Audiohobby.com)
Updated 26th October 2015 at 04:53 PM by Michael Rothacher

Here's the link to Nelson's presentation at BAF 2015:

Pass Presentation BAF 2015

Slides are available in pdf. See the video description for the link.
diyAudio Member
Posted in Uncategorized
Views 554 Comments 0 Michael Rothacher is offline
Old

Video Blog#1 Posted

Posted 7th May 2014 at 10:16 PM by Michael Rothacher (Audiohobby.com)

Video Blog #1 is posted here:

https://www.youtube.com/watch?v=mWTy...KhQ2ow&index=2
diyAudio Member
Posted in Uncategorized
Views 1026 Comments 1 Michael Rothacher is offline
Old

Ironamp Project Video Posted

Posted 1st November 2013 at 12:56 AM by Michael Rothacher (Audiohobby.com)
Updated 2nd November 2013 at 05:52 PM by Michael Rothacher

Ironamp project video posted here:

https://www.youtube.com/watch?v=FZymAeaVsAg

I hope you enjoy it.

I updated the captions if you want to try Youtube's translation option - should be funny
diyAudio Member
Posted in Uncategorized
Views 921 Comments 0 Michael Rothacher is offline
Old

Matching Stuff

Posted 26th November 2011 at 11:24 PM by Michael Rothacher (Audiohobby.com)

The topic of JFET and MOSFET matching comes up often in the forums, so I thought I'd show you the jigs I use.

First up, is my trusty old JFET IDSS matcher.

Click the image to open in full size.

There's a 9V battery inside, and the meter probes are conneted across a 10 Ohm resistor which is connected to the JFET drain. I included a polarity switch for convenience when testing P channel parts.

It's pretty easy to connect the microclips, count to five, and take a reading.

Click the image to open in full size.

And here's what I use for the big stuff. This is my MOSFET Vgs matcher.

Click the image to open in full size.

First, I install a sample part and let it warm up for about an hour. There's a thermistor hot-glued to the heat sink,...
diyAudio Member
Posted in Uncategorized
Views 1182 Comments 0 Michael Rothacher is offline
Old

Compact PCB For All JFET Circlotron

Posted 24th January 2011 at 11:59 PM by Michael Rothacher (Audiohobby.com)
Updated 2nd October 2011 at 11:59 AM by Michael Rothacher

This is the artwork for the PCB in the pictures. It fits into the ExpressPCB miniboard profile so it's a little cheaper to have made.

It will be necessary to check the orientation of the bias pots (I can't remember). I wouldn't want you to blow-up your $30 JFETs.
Attached Files
File Type: zip amplifiercompact.zip (8.4 KB, 639 views)
diyAudio Member
Posted in Uncategorized
Views 3269 Comments 5 Michael Rothacher is offline
Old

All JFET Circlotron

Posted 22nd January 2011 at 10:29 PM by Michael Rothacher (Audiohobby.com)

I've been mostly out of the audio hobby for a while, but I've had a few inquiries about the SemiSouth version of the Amazing FET Circlotron as of late. So, I wanted to post the performance graphs here before I lose them.
Attached Thumbnails
Click image for larger version

Name:	thdvfrq.gif
Views:	1264
Size:	10.7 KB
ID:	311   Click image for larger version

Name:	thdvpwr.gif
Views:	1184
Size:	10.3 KB
ID:	312   Click image for larger version

Name:	IMG_0944.jpg
Views:	2252
Size:	205.2 KB
ID:	313   Click image for larger version

Name:	IMG_0948.jpg
Views:	2200
Size:	249.6 KB
ID:	314  
Attached Files
diyAudio Member
Posted in Uncategorized
Views 3805 Comments 0 Michael Rothacher is offline
Hide this!Advertise here!

New To Site? Need Help?

All times are GMT. The time now is 03:49 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2
Wiki