FINISHED: JKSN-U67

[JessJackson]

Nice that you didn't overdo the value of the output cap to get "more bass".
I've done a similar mod and got a PIO cap in there.

I was under the impression that on the u67 the output cap actually worked opposite in terms of higher value less bass, due to the feedback circuit, is this not the case?

 

[JessJackson]

Whats really quite interesting about the 67 is the what happens when you change the coupling cap value.

I started with the 1uf and the mic sounded even, when i went down to a 0.5uf the top end seemed to get more restricted and it feels like the de emphasis circuit is kicking in a lot more than before.

Anyone else experience this phenomena

 

[bockaudio]

Nice that you didn't overdo the value of the output cap to get "more bass".
I've done a similar mod and got a PIO cap in there.

I was under the impression that on the u67 the output cap actually worked opposite in terms of higher value less bass, due to the feedback circuit, is this not the case?

Unrelated.
The relationship between the output cap and a transformer in this circuit is like a port in a speaker box. You can change the slope of the LF, and the resonance at the crossover point. If you don't measure the electronics only when you make a change like  that, you are only guessing at what happened.

 

[weiss]

nice one! i like the self made pcb

 

[JessJackson]

Thank you Weiss, The Mic has been getting used every day. I wanted to see what effect I would have by changing out the green MKT cap for the blue square MKP thats in the Sony-C800G board. The mic instantly became harsh and top end became like sandpaper. Changed it back immediately.

This is probably whats causing the harsh top end myself and everyone else in the industry who owns a Sony complains about. So interesting how a the MKP destroyed the sound instantly.

The only complaint I have would be that my mic sounds a little TOO smooth. 67's that I compare it to sound a little more transient rich and spitty. Which I would put forward as being due to the electrolytic capacitor.

I don't have much space in there and the original u67 use a Seimens + Halske electrolytic. (Elektrolyt Kondensator 0,5uF +50-10% 250v B 43711-0)

Ive searched far and wide, i even brought two big boxes of nos S&H caps hoping to find the right value but no go. I'm trying to figure out what the modern alternative would be.

Cheers.

J

 

[JessJackson]

I was under the impression that on the u67 the output cap actually worked opposite in terms of higher value less bass, due to the feedback circuit, is this not the case?
Unrelated.
The relationship between the output cap and a transformer in this circuit is like a port in a speaker box. You can change the slope of the LF, and the resonance at the crossover point. If you don't measure the electronics only when you make a change like  that, you are only guessing at what happened.

yeah I feel you.

anyway my friend lost my mic so if anyone see's it anywhere , probably LA area. let me know.

trying to get a board from max so I can build another one without having to do it on perf board.

Cheers

Jess