[Freo-1]

Wanted to start a thread for one of the all time great pieces of audio equipment, the HK Citation II

There are tons of mods out there for this amplifier. Numerous power supply mod/upgrades, front end changes, bias circuit modifications,  re-wiring for triode output, you name it.

So, for those of who own one, how is yours configured, and what have you done to it?

For mine, I switched out the front end to triode, using 5687/7119 triode input, and left the output ultralinear. I wanted to open up the sound stage, while retaining the 60 WPC output, as I have them connected to a pair of Polk LSI 15's.  The Polk LSI's are one of the best buys in audio IMHO (the vifa ring tweeter is tremendous).  They do need some power, so that's why I left it in ultralinear.

The bias circuit was upgraded to make it more stable (including a very cool NOS Simpson ammeter). My Citation was a very early one, which had a large round meter vs. the rectangle.  The power supply was beefed up by a factor of ten, and HEXFREDS were used vs standard diodes.

How is yours configured, and what do you think gives the best sound? 

[doodlebug]

Bringing this one back, I've rebuilt a Citation II using Jim McShane's recommended approaches:

- Power Supply updates including all the capacitors, and diodes bridge.

- Also added increased capacitance for the first-stage voltage amp to more fully decouple it from the power supply rails.

- Bias Supply:  full rebuild of all components with increased capacitance.

- Cleaned and rerouted all the grounding into a Star Ground setup including a large buss bar along the power supply.

- Interstage coupling caps all replaced including the feedback loop caps on all stages.

- Swapped RCA connectors while I was at it.

I'm still running mine with the full ultralinear wiring of the final stage, but will likely rewire it for triode operation as a next step.

This is one fine amp that goes head-to-head with my McIntosh tube amps of the same vintage.

Cheers,

David