The H&K Citation is a great tuner. Factory stock sounds very good and I prefer it over a stock Kendwood FT-990D that places 11th in audio quality in the famous fmtunerinfo shootouts.
I prefer the 50u seconds switch on the front panel engaged to push increase the high frequency sonics as I like a full range sound. Some FM tuners are a little soft on the high-end IMO.
Upgrading components could not be easier on this tuner. With the exception of the RF/IF board, the rest of the circuit boards are plug-in cards.
I have experience with Blackgate, Muse, Silmic II and a few other audio grade capacitors. I prefer the Silmic II. Digikey has these caps in many values for 25-75 cents each. Thus, the upgrade is inexpensive.
The Citation 18 schematic & physical layouts are posted at fntunerinfo.com. The various capacitor numbers are printed on the cards including polarity.
Multiplexer Card- Replace existing with Silmic II at C8, C17, C18, C19 & C20.
Output Amplifier Card- Replace existing with Silmic at C5, C10, C15, C20, C23 & C26.
Power Supply Card- It makes good sense to freshen up the power supply, however none of these capacitors were subject to high current causing heat in the capacitors unlike a SS power amplifier. I use standard Panasonic caps. Perhaps prefer FM series, but I believe all the Panasonic caps are quality parts. Replace C9, C10, C12, C13, C14, & C15.
Break-in time. Some do not believe in break-in, however I clearly hear a difference. The Silmic II are a little disorganized or scattered sounding at start up. Within a few hours this edgy sound goes away. Some say 100+ hours are needed, but 24 hours is sufficient IMO.
Be prepared, the upgrades seriously places this tuner a few levels up from stock. I do not use or need that 25u seconds switch engaged as the high frequencies are well balanced now. Voices on quality FM stations approach sounding like in my listening room talking to you.
I suspect the dual +15/-15 power supply with a discrete amplifier section vs op-amps are a plus. You may end your search with the simple upgrades to the Citation 18.
It makes me wonder if the Kenwood KT-8007 having a superior IC based multiplexer (like the Citation 18) and discrete amplifier section would also be a good upgrade candidate as well.
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Topic - Harman Kardon Citation 18 Audio Upgrades - Neff 15:44:48 10/22/11 (6)
- RE: Harman Kardon Citation 18 Audio Upgrades- IF Board - Neff 12:23:54 10/23/11 (5)
- RE: Harman Kardon Citation 18 Audio Upgrades- IF Board - HoosierAudio 16:55:34 10/23/11 (4)
- RE: Harman Kardon Citation 18 Audio Upgrades- IF Board - Baranyi 04:13:43 11/10/11 (1)
- Yes, I still love this tuner... - sherod 21:22:12 06/09/13 (0)
- RE: Harman Kardon Citation 18 Audio Upgrades- IF Board - Neff 17:10:36 10/23/11 (1)
- Where have all the 18s gone? How many were made? - openmind 10:09:25 06/10/13 (0)