Pass Citation 12

[TJ]

hi , can anyone kindly tell me this circuit working or not base on discussion ? tqvm

 

[Zen Mod]

http://passdiy.com/pdf/citation.pdf

 

[Nelson Pass]

hi , can anyone kindly tell me this circuit working or not base on discussion ? tqvm

If the supply voltage doesn't vary, and it is carefully biased at warmup,
it will work.

Otherwise the bias will wander around a lot.

 

[Rax]

Hi all,
Just grabbed a Citation 12, and am exploring completing this MOSFET-based rebuild. From a cursory - this far - review, it seems both vertical and lateral MOSFETs are suitable with different circuitry attached.

I understand Nelson uses verticals for this, but I'm leaning towards laterals as it seems the additional circuitry may be simpler.

What would be some easily available MOSFETs for each scenario? It's not trivial - at least to me - to discern which MOSFETs are of which kind when looking at parts (and their datasheets) from the usual distributors, but it seems a shorthand criteria may be that the pinout is different and maybe also the typical packages.

Thank you in advance for your help with this.

 

[a1095us]

What if any is the minimum rail voltage to operate this properly?
I have a power supply that works at about +36 / -36 VDC.

 

[Nelson Pass]

There's no particular minimum, just tradeoffs of voltage vs bias current. 23v rails is a start and 36v is not out of bounds. You just have to watch the bias currents and maybe adjust the front end resistors a bit.

 

[OnAudio]

There's no particular minimum, just tradeoffs of voltage vs bias current. 23v rails is a start and 36v is not out of bounds. You just have to watch the bias currents and maybe adjust the front end resistors a bit.

Happy holidays and many happy returns. That's true higher rails increase the bias and it has to be readjusted

 

[pascalfr]

Hello
i have in all my devices an old Kenwood KA7020 100W 8 ohms dead, i think to recycle it in a Citation 12 mosfet N. Pass. This amplifier has 2 transformers with 45V secondary output and a heatsink 29cm/11,41in x 11cm/4,33in x 6,5cm/2,56in. Do you think it is a good idea ? I don't want to repair it but improve it by a new output stage and a very good preamp because the original class B amplifier is not the best they made (2SD1717/2SB1162 and opamp in preamp). It could be a nice project to keep same box and options but with a better conception
Thank you in advance for your opinions
Cordially
Pascal

 

[pascalfr]

45V is without charge, original SM say 42V charged for 56V rail