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Harman Kardon Citation 19 Recap

Discussion in 'DIY' started by AmCan, Dec 14, 2011.

  1. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    I am getting ready to start my recap on my Citation 19 and I was hoping to get some opinions on a few capacitor selections. I still need to select the main power caps, the main output caps on the Assay Board, and a replacement for these 1000uF 25V axials in the under carriage of the chassis. 1st what purpose do these axials serve? Are they only supplying the LEDs and how important are they? 2nd, I am torn between getting some Teflon V-Caps or some Mundorf Silver Oils for the Assay Board. I have never heard the V-caps but I have heard the sweet treble extension and sparkle of the silver oils. The rated capacitance for this cap is .1uF and if I went with the silver oils I could afford to double the capacitance here and hope to catch some extra air & open space in the presentation of the music. 3rd, as far as the main power caps go I can fit either the 10,000uF / 80V, KG Series, Super Through or 15,000uF / 100V, KG Series, Gold Tune. The limiting factor here are the 63x80 mm dimensions. I have been told that the power supply can handle as much as 22k but I can't find any that will fit. Also I have been told that with uping the capacitance I may have to upgrade the bridge rectifier but I do not even know where that is on the board or what to select to replace it. All opinions are welcome. So far my recap projects have been cake next to what I anticipate with this one.

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    Attached Files:

    Last edited: Mar 15, 2012
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  2. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    Capacitors for Transistors

    These Mundorf M-Caps fit in here nicely. I took the opportunity to re-grease all the transistors. Word of advice. Just go ahead and replace the resistors while you are back there because it is a pain to take the driver boards off.

    [​IMG][​IMG]
     

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    Last edited: Mar 15, 2012
  3. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    Main Caps Under Carriage

    I wasn't expecting to have to change the rig but it makes sense thinking about it now. This amp was made back in the day when Harman Kardon still hand assembled all their gear in the good old U.S.of A.

    Another word of advice; just go ahead and replace the bridge rectifier you see right there when you are changing the rig because everything gets soldered to it.

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    Last edited: Mar 15, 2012
  4. Westy56

    Westy56 A symphony of paradox

    Messages:
    6,612
    Location:
    Abq, NM
    Nice. :yes:
    Some day these amplifiers will get the respect they deserve.


    Steve
     
  5. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    Thanks. :) I agree that this period of HK, the 70's solid state, does not get the respect it deserves. At the time HK rivalled McIntosh for the most expensive Hi-Fi on the market. I hope to have 2 of these one day running in bridged mode, one amplifier per speaker.

    I will post more pics tonight. It would appear that I didn't take a complete set of finished pictures from the top. Must of been because I was too tired, excited, and nervous to turn it on. Making the rig was the most adventurous task that I have taken on but I was already committed having spent $55 on each can. Somehow, I thought that since the Nichicons were solder lugs that they would just magically screw in too. I ended up improvising and making the rig out of 10 & 14 gauge Romex, which worked real well because the 14 gauge can bend into place and it stays where you want it. I used the 10 gauge as a terminal strip. It is a vast improvement from the steel and massive amounts of solder that were used previously. I was so nervous that the rectifier bridge wouldn't handle the upgrade to the power supply but it did no problem. Still I might want to upgrade the rectifier bridge one day just to see if there are better parts out there today. I need to investigate that a little.
     
  6. Westy56

    Westy56 A symphony of paradox

    Messages:
    6,612
    Location:
    Abq, NM
    I ran two of them until I switched to the II's. :music:
    The only time I bridged them was when I wanted to blow an 8 ohm speaker.

    Just one 19 will drive a pair of maggies at 150 watts without sweating.


    Steve
     
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  7. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    LOL! You're right. It's probably not necessary. Right now I am running 4ohm 93 db efficient 200W PSB Imagine T's without any problem ... and I am thinking I may want to make the move to more efficient horns.
     
  8. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    Here are a few more pictures. The person who owned this before me decided to cheap out on his upgrade and purchased the wrong size Mallory caps. Look how bad this looks not to mention unsupported. In the end I went with the 15k 100V Gold Tunes with a rated ripple of 8.7

    [​IMG][​IMG]
    [​IMG]

    Wire hooked up before soldering
    [​IMG]
     

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    Last edited: Mar 15, 2012
  9. avatar

    avatar New Member

    Messages:
    12
    Location:
    Belgrade,Serbia
    Hi,
    Nice work AmCan, keep it going.
    While you're at it, you could change the wiring of the amp.Both signal and power.
    I would suggest solid core for the power supply, it makes alot of difference.As for bridge recitifier I would use discrete schottky diodes.
    Happy restoring
     
  10. Sir.Byrd

    Sir.Byrd Lunatic Member

    Messages:
    15,254
    Location:
    Seattle, WA
    Another option would be 68 amp IXYS bridge rectifiers, similar package to the original rectifier, but you will need to improvise the mounting. Only $23 each or so.
     
  11. Westy56

    Westy56 A symphony of paradox

    Messages:
    6,612
    Location:
    Abq, NM
    Hey AmCam, I sent this thread to a fellow AK member who just came into a pair of 19's.

    "cool thread ,I am extremely happy with mine .I constantly compare them
    to my much more expensive Mitsubishi and they stand up well except for
    cosmetics which really never mattered to me ,my wife thinks they are
    ugly but they will probably be buried with me when I go ...LOL
    interesting thread I will keep my eyes on that one"

    Keep us posted. :thmbsp:


    Steve
     

     

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  12. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    Thanks. I wasn't sure what size amp to get since i increased the capacitance of the main caps. Does it pay to go any bigger? These are rated at 600V. I assume that since the rails are 55 that this is more than adequate, just like the rating on a capacitor, or is it a little different? It would be easy to mount these IXYS bridge rectifiers with metal screw through the chassis as there doesn't appear to be anything in the way. I saw these on Parts Connexion. I will check out the discrete schottky diodes as well just to compare and learn.
     
  13. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    I did buy some analog terminals to install already from the Shack - I am not paying for over priced gold plated terminals. I'd rather buy over priced capacitors :yes:. I am going to use a left over piece of my Audioquest Type 4 speaker cable, which is LGC, at least to go from the analog terminals to the driver boards. I think there is a paired 17 & 20 gauge wire in there and since they are what I use for speaker cables I though that would be pretty cool. Then I am going to make some interconnects out of the type 4 cable too. I read an article about how it makes for good jumpers http://www.soundstage.com/revequip/greg15.htm Now that would be cool don't you think? To have the same wire running from pre to and through your amp to your speakers.:thmbsp:
     
  14. Sir.Byrd

    Sir.Byrd Lunatic Member

    Messages:
    15,254
    Location:
    Seattle, WA
    I'm not sure what the significance of the amperage of the rectifiers is, but the 68A units are barely more expensive so I always just use those, I use 4 of them in my amplifier which is only 25 watts per channel.
     
  15. avatar

    avatar New Member

    Messages:
    12
    Location:
    Belgrade,Serbia
    AmCan,
    Go for it!
     
    Last edited: Feb 8, 2012
  16. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    O.k. Thanks. I will see if I can find an answer as to the significance of the wattage ratings when i go to upgrade them. I wish I would have done it at the same time as the rig but I will get to it when I replace the internal wiring to all LGC.

    I will post on the Driver Boards next.
     

     

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  17. sfox52

    sfox52 AK Subscriber Subscriber

    Messages:
    3,857
    Location:
    Maryland
    Has anyone added a speaker protection circuit to one of these? I'm considering an outboard unit that could be used with other amps, maybe Elliot Sound's version?
     
  18. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    I considered it but in the end decided that it wasn't really necessary. A speaker protection circuit is going to protect against DC leakage from the output stage but in my amateur opinion if you recap everything and measure DC at the terminals prior to hooking up for the first time you are unlikely to suffer any mishaps unless you are driving the amp into clipping all the time. At a 100W at 8ohms or 200W at 4ohms you are unlikely to need circuit protection. I certainly wouldn't want to hook this amp up to a pair of Vintage Ditton's though. :no:
     
  19. Westy56

    Westy56 A symphony of paradox

    Messages:
    6,612
    Location:
    Abq, NM
    I agree, except your rating on the 4 ohm taps [150 watts].


    Steve
     
  20. AmCan

    AmCan Active Member

    Messages:
    196
    Location:
    Toronto, Canada
    Steve, you may be right about the power ratings but my assumption was based on the power meter LEDs, which shows 4ohms up to 200W. I don't see it rated in the manual at 4ohms. Here are the specs - how do you know it's only 150W at 4? Although i am probably not even reading this meter correctly either knowing my math skills.

    Power Output : 100 watts per channel @ 8 ohms
    Amperage : 3.7 amps @ 8 ohms, 6.3 amps @ 4 ohms
    Total Harmonic Distortion : 0.08% @ 8 ohms
    0.08%
    Frequency Response : 5Hz - 140kHz -3dB
    Slew Rate : > 40 volts/microsecond
    Rise Time : better than 2 microseconds
    Transient Intermodulation Distortion (TIM) : < 0.08%
    Damping Factor : > 125:1
    Signal-to-Noise Ratio : CD, VIDEO, etc - 95dB
    Input Level/Impedance : CD, VIDEO, etc - 200mv/32k ohms

    Edit: Note: I have seen a review were someone measured the output at 110W at 8 Ohms. I'll have to see if I can find that again.
     

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    Last edited: Feb 23, 2012

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