Help. How to Triode Dynaco MKIII's?

[risingjay]

I saw it before, but can't find it. Can someone tell me how to change the Dynaco MKIII's from UL to Triode?

Thanks,

Jason

[NOSValves]

How about written instructions with a picture. email me at craigostby@comcast.net I did this file for Gary Powers a long time ago.

[Daddy Dee]

Craig,

I'd sure like to see that, too.

Thanks.

Dee

[NOSValves]

Here is the picture

[NOSValves]

Written instructions

All that is require rewiring the Dynaco Mark <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />III to Triode mode!

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Of coarse shut the amp off about ½ hour before you start poking around in there. Flip the amp over and remove the bottom cover. Locate pin 3 and 4 of each output tube (KT88). One tube will have just a single cloth lead attached to each of these 2 pins. The other tube will have the cloth leads and also a wire running from pin 4 to the front end circuit board. What you do is remove the wires connected to pin 4 on both tubes and seal them with shrink wrap. The one that has the wire connected and headed to the front end board solder the cloth lead and this wire together before you seal it with shrink wrap. Now you will need 100 Ohm ½ watt resistors and you attach these from pin 3 to pin 4 of each output tube. You will need a total of 4 100 Ohm ½ watt. Carbon film from radio shack will be fine. Make sure you get 100 Ohm not 100K. Tuck the now lose wires in a neat spot and enjoy your all done. Recheck the bias and adjust as needed once the amps warm up.

[Piranha]

VRD's just seem so much easier

[mike stehr]

That isn't difficult to do.....easy mod.

[sunnysal]

you could even install a switch to allow triode to ultralinear switching. tony

[garymd]

Larry did all of the soldering when we switched mine to triode. Although it was a 2-person effort, it would have been pretty easy if I knew what I was doing! Worked perfectly on the first try however.

[Daddy Dee]

Gary or others. What is your take on the sound triode mode?

[sunnysal]

I have the triode mod on my MkIV (which are basically one half of an ST-70 with its own PS) and I like mine set on triode. two things seem to happen when I switch to triode; 1. at high volumes I notice more cohesion in the presentation, in ultralinear the music seems to congeal at high volumes and 2. at any volume I feel the mids and highs are smoother, rounder. YMMV, IMHO, yadda, yadda. tony

[Mike Frankel]

Please forgive my ignorance,but can this technique or one similar be applied to Dynaco Mark II's?

[NOSValves]

This can basically be applied to any pentode tube some will require the change to different pin's. But to answer your exact question yes everything would be the same for your Mark II's.

Craig