PICS of DC-3 bias mod with bias test points

[talltxguy]

Like anybody else's DC-3, mine was running way too hot - 154% max plate dissipation with Mesa green EL84's. My local Mesa tech in Austin, Anthony the "Audio Monk," installed the following:



I'm still working on finding the optimal bias, but it's fun experimenting with things. And now, if I find a good deal on some tubes that may or most likely are not in the Mesa bias range, I can get them! 8)

 

[O==00==O]

Very nice! My DC-2 studio caliber ran waaaaay too hot for today's production tubes so I know where you're coming from.

 

[bendo]

Any chance you can pull the chassis and post some pics of the internal work?

 

[talltxguy]

If you have any questions, please contact Anthony, the Mesa tech in Austin who did the work. His website can be found at the following addy: http://audiomonknyc.com/index.html
His work phone & work addy can be found on the Mesa website under authorized repair in the U.S.

 

[bendo]

Thanks! Much appreciated.

 

[D2dark]

Like anybody else's DC-3, mine was running way too hot - 154% max plate dissipation with Mesa green EL84's. My local Mesa tech in Austin, Anthony the "Audio Monk," installed the following:



I'm still working on finding the optimal bias, but it's fun experimenting with things. And now, if I find a good deal on some tubes that may or most likely are not in the Mesa bias range, I can get them! 8)

Why on the picture your amps say 'DYNO-watts' and not Dyna-watts ???

 

[talltxguy]

Well, "Dyno-Watt" appears on the back of my amp because...to quote JJ from "Good Times," my amp is "dyyyyyyynooo-mite!" Yeah, perhaps it was an allusion to one of my favorite shows?

I would encourage anybody to read the "Dyna-Watt Patent" - U.S. Patent #4713624, which is one of Randall Smith's many patents. In the patent, the word "dynamic" appears many times. Not once did I see a word with the prefix "dyno."

The only word with the prefix "dyno" that has to do with amplifiers is the word "dynode," which refers to an electrode for the transmission of secondary electrons in a vacuum tube. I did not see dynode in Smith's "Dyno-Watt Patent."

The DC-3 manual uses the word "Dyna-Watt." And as most of us know, the word "Dyna-Watt" and not "Dyna-Watt" appears on post DC-3 amps.

I believe some copywriter at Mesa misunderstood "Dyna-Watt" and spelled it incorrectly, then gave the instructions to the dudes who do the printing on the chassis. Perhaps quite a few amps left the factory with "Dyno-Watt," and nobody thought anything of it because that's what was written in the copy. And since Mesa is very detail-oriented and has many quality controls, I can't believe that "Dyno-Watt" just slipped by when people in the shop knew it should have been "Dyna-Watt." I think Randall Smith, or somebody who had read the patent and was familiar with it, let the copywriter or the dude who does the printing know that "Dyno-Watt" was an incorrect spelling of what Smith was referring to in his patent.

"Dyno-Watt" is not exclusive to my amp; it does appear on other DC-3's as well from what I've heard. I don't know if there are more DC-3's with "Dyno-Watt" or "Dyna-Watt" though. I am curious though. I've never heard any talk or read anything where one is more valuable than the other or has different circuitry.

http://www.freepatentsonline.com/4713624.html

 

[bendo]

Since I will be in Austin all next week for VMware training, I am going to have the Monk perform this work on my DC3 as well.

Looking forward to the after.

 

[talltxguy]

Sounds good! 8)

I was stunned to see how bias really does affect loudness.

What kind of output tubes will you be running? Right now I'm running JJ's at 27.5 ma per tube, which is leaving me pretty happy with the cleans as well as with the distorted stuff.

 

[bendo]

Same. It has JJs in it right now.