Finished up the rebuild/upgrade on my original HK Citation 11. It really is a great piece of equipment to work on. My intensions were at first to upgrade all components I could, but as I got more and more familiar with it's components I decided to leave much of it in place. First up was C6 for the power supply which can be seen as the big blue cap. it is disconnected and a like valued Nichicon PW(M) is under the chassis keeping the appearance.
Bottom right is the Phono preamp board. Only two electrolytic capacitors were available to replace. I used Nichicon UFG Caps. The two red film caps were replaced as one of the originals was broken. As well as both resistors of this critical filter circuit. I tested each resistor and replaced these two. One was out of specs and I replaced the mated channel as well.
The power distribution board is above that. All the electrolytic were replaced with Nichicon PW(M). The two axial caps were also replaced, as well as the three Diodes used for regulation. Each resistor was tested for tolerance.
Upper left is the preamp output board. The problem child. Originally I used another AK'ers suggested replacements for the caps which were all radial caps which were never going to work so I had to do a lot of research to find suitable axial caps which would fit at all. As can be seen, the two on top, are extended past the mounting hole. Actually all the axial caps available were tough fits but the electrical values are correct. There were other resistors I intended to replace but i found the original were of such high quality there are no replacements for them. So I left them in place. All resistors were tested for tolerance. A couple were replaced. There was a problem with some switching noises when the tone boards were engaged but it turned out to be a power/up charging timing scenario which was solved with patience and board swapping.
I was lucky to have two units to switch and test. I still ended up replacing some jfets on suspicion. Cant hurt.
Both tone boards had new electrolytic replaced as well.
This was a worthy project as the results are evident. There are no strange sounds coming from this unit and it sounds great and very clean at volume levels beyond pleasurable levels. I used it to replace the second Citation 11 I acquired. It needs much work. But trial and errors are over. Yes I ordered parts for it as well.
I found between the two HK 11's there are differences in components as well as the boards themselves. Maybe 3 years difference in build times. The second one has a pre amp level adjustment which will be interesting to address. I buttoned this up fast to protect it as it is used daily. Will have more pictures for the next one.