I have some pictures of the Trion 8000 and the Cascade Elroy (same circuit).

The first mic on the left has been rewired for a 6AU6 tube and is using an AMI T49 transformer. This mic has the same circuit as the Sony C800g mic with a 213vdc B+ voltage. I used a 1uf paper in oil coupling capacitor.

The PCBs had to be cut to fit the larger transformer in both the CAD and the Elroy.

The mic in the center has the same circuit and the transformer is the same as our Akita microphone.

The Elroy has an improved plate follower circuit design. I rewired the transformer so that a 1uf Polypropylene capacitor was added between the plate resistor and the transformer. C2 was omitted and a wire put in its place so the transformer is connected directly to ground.

The transformer is a German BV8 with a Telefunken 6ak5 tube.

Size wise the AMI T8 works well in these mics.













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I guess there's no shootout audio vs the unmodded Trion available huh? (or plots of modded mic?)
Also, do you ever sell the parts in kit form (with some informal support/instructions)?

No I'm sorry... good intentions but no time. the mic now resides at The Boom Labs (dot net) in Nashville and all I can say for sure every mic JJ Audio has done mods on have become got to mics at the studio and all are in use.

quick must do fix is a tube change. 5 bucks. I have extra's if you need one. good ones. i bought an extra batch by mistake.

Rich

meant to title to say Jim Jacobsen

Would you recommend a NOS TELEFUNKEN 6AK5 5654 6AK5W or a Siemens Halske 6AK5W / 5654 for this mic? I am planning on upgrading the tube, and I'm not sure which tube to choose. If there are any other suggestions that would be great...

NOS TELEFUNKEN 6AK5 5654 6AK5W

Siemens Halske 6AK5W / 5654

***added note> the Telefunken link looks like a nice tube. I almost bought one myself but remembered i have a pair of NOS Mullards I picked up at "thetuberoom" on ebay. ###

From what I've read I've not heard anybody knock the Telefunken and surely has to be better that the $5.00 RCA tube I put in. But that $5 tube did WONDERS. Only bad thing is I don't know what else you can use this tube in if you don't like it.

If you get a Telefunken I'll send you a RCA to compare and then maybe I'll buy one too. That's the only way to find out. Short smooth black plate triple mica tubes are the way to go. Get it from a reputable dealer so if there's ringing or noise you can get it exchanged. Do NOT buy from China. It'll cost you 70 dollars to send it back because of tracking. Jim would know more than me. All I know is I'm happy with the RCA tubes, JANS and any other USA made ones I've gotten my hands on.

Hope that helps. rich

GE 5star, Sylvania Gold Brand, Tung Sol, RCA, Mullard, Telefunken.
All good tubes. These tubes are cheap enough to buy many tubes and see what you like.

The Mullard and Tele's are going for high prices.

The only tubes that I found noisy were the Western Electric 403a tubes.









Jim Jacobsen
JJ Audio

Would it be the best choice?
https://www.riverstoneaudio.com/pair...w-vacuum-tubes
Does it mean the same as "add a capacitor in parallel to R9"?