Posted by Francisco Gutierrez

November 28, 2012 - 06:35 pm

Terrific technical article ! I've been in tubes until recently ( 2wo and a half years and what a trip ! ) I've an electronics aficionado since childhood and reading onto something new about this technology is so refreshing ; most people regard us as " retro " but it only tells on their lack of knowledge about the matter ; many thanks , you gave me something to think and work “bout. Sure I will !

Posted by Steve L.

October 23, 2011 - 03:12 pm

Hi Steve K., I'm excited to hear that! Please stay in close touch about what you find. If you run into trouble, I will be happy to help!

Posted by Steve K

October 23, 2011 - 02:52 pm

I've decided to give the hotrod procedure a try on my backup ST-70. As a first step, I've replaced all the original caps and am now balancing and biasing the channels. (Also found a cold solder joint on one cap that may explain some old behavior that occurred when I tried to power this thing up a couple of years ago.)

Posted by johm

October 10, 2011 - 11:38 pm

Great£”;£”;Should be studied£¬;This is also good£”;www.diyhifishop.com

Posted by Steve L.

October 08, 2011 - 10:16 pm

Hi Steve K, Thank you for your kind words. I must point out, though, that Dave and I have not heard the amp, because Andres lives in Venezuela. I am working with Andres now to get information on subjective impressions of the sound. Will be adding those to the article, soon. From the performance data so far, and from engineering considerations, one would expect it to have approximately the excellent sound of the ST-70A mods, at least at levels up to half power.

Posted by Andres

October 08, 2011 - 08:39 pm

Thank you for your comments is very gratifying to know that this project is of interest to you. Thanks to Steve for writing the article