Harman Kardon Citation II Rebuild

[Death by Uberschall]

They sure don't build them like that anymore.  :icon_thumright:

 

[SlingBass]

I've only just now stumbled onto this  :doh:  Facinating, and also (I'm sure) very interesting for you.  A labor of love...cool  :glasses10:

 

[Dan025]

Out with the old harness:

In with the new:

The system is stable and runs at  full power.  I had it running for over an hour into dummy loads, just playing with it.  Mains current never rose above 2A.

I offer the following two images:

only a little bit of phase distortion - but check out the frequency it's running at!

I ran it up to 50KHz with no loss of power.  This thing could be an AM radio transmitter!

harmon kardon did always like to build thing that reproduce a full spectrum. i wish i could hear it when you fire it up with those custom speaker for the first time.

 

[mayfly]

Gentlepeople,

It now plays music.  I've only been running one side at a time since I only have one working set of input tubes (NOS ones are on order for the other side), but the sound is very very detailed and accurate.  Even through a crappy PA monitor (which I made 15 years ago) it sounds highly detailed.  Many times I heard stuff in recordings that I did not hear previously - even for material that I was very familiar with.  In this regard, it does not really have a 'tube' sound.  It instead sounds like a very very good solid state amp.  It is so detailed that it could be used in a mastering suite.

I like it.  I'll probably like it more when I can run both channels.  :glasses10:

 

[blue313]

So you've resisted the urge to hook up the Tonelab to it so far?

 

[Dan025]

in hatchenohe japan there was a little shop that sold this kind of stuff. it all went for big $

they had alot of macintosh stuff i'm not sure if i spelled that right  :icon_scratch:

one of these days i'd like to find something like that and do exactly what you did. i love hifi. all this 5.1 and 7.1 stuff is way over rated these days most studio engineers don't have the creativity to make it sound seemless and spacious. a good stereo mix can give all the 3-D effect you need.

 

[mayfly]

So you've resisted the urge to hook up the Tonelab to it so far?

Yeeeeea - not gonna do that  :icon_jokercolor:

 

[mayfly]

spent the last hour listening.  Still sounds great.  Bias stable, things are running good.

 

[mayfly]

Update - got the second set of input tube.  A nice matched pair of NOS RCA, and a single JAN.

Both channels are now working, but I could only get in about half a song of listening in before boy #2 woke up and needed attention.

 

[kboman]

You've numbered your kids?! :icon_biggrin:

 

[mayfly]

You've numbered your kids?! :icon_biggrin:

Yep.  Beats calling them "hey you"

 

[Death by Uberschall]

You've numbered your kids?! :icon_biggrin:

Yep.  Beats calling them "hey you"

Mayfly, "These are my kids. This is Junior, this is Junior Jr, and this is Oh Crap Not Another One."

:icon_jokercolor: :laughing7: :icon_jokercolor:

 

[Super Turbo Deluxe Custom]

You've numbered your kids?! :icon_biggrin:

Yep.  Beats calling them "hey you"

Seems to work.  I've never met your kids, and knew immediately to which you were referring.

 

[ByteFrenzy]

You've numbered your kids?! :icon_biggrin:

Yep.  Beats calling them "hey you"

Seth sounds identical to the French 'Sept'. So we call him #7. 'Well, we had to try six times before you came along'...

 

[mayfly]

ok, it's pretty much done.  The plan is to put about 10 hours on it on the bench, then dub it ready for a hi-fi speaker listening session.

Here's some good photos (the previous set were taken with the iPhone and are kinda crappy)

I'm not saying they're the best HiFi speakers in the world...

it looks better in real life:

Those diodes are running nice and cool.  Very glad that I insulated the cathodes!

Glad that I could find the original type capacitors.

A bit of the new harness

and some more

The most important new part:

Test source - it survived a gig-related guitar stunt incident!

A shot showing under the cards and the tubes.  The preamp tubes are NOS (as there are no currently produced tubes of this type).  The 6550s are a matched quad of winged-Cs

Speaking of tubes, here are the ones that were in the amp when I got it.  Sadly, they are junk:

But kinda interesting...

With a full load, it pulls the supply down a bit.

And here it is assembled and flipped over.  Flipping this sucker over takes a fair amount of effort!

 

[Death by Uberschall]

Great job!!  :icon_thumright:

Does the amp have a tone stack or volume controls, or is it only a stereo slave?

 

[mayfly]

It's just an amp.  It's not an "integrated amplifier" as those HiFi guys like to say.

 

[blue313]

That must have been a ton of work, not to mention very neat and tidy.  :icon_thumright:

How much of the original amp is left?

 

[Death by Uberschall]

How much of the original amp is left?

Chassis, trannies and turret boards.  :icon_thumright:

 

[mayfly]

How much of the original amp is left?

Chassis, trannies and turret boards.  :icon_thumright:

Pretty much!  I even replaced the RCA jacks with gold ones.  :icon_thumright:

However, it's those transformers that are the important parts.  It would not be worth doing if they were not working or missing.  They are also responsible for the astounding frequency response.

BTW, tubes in I spent about $300.  However, I did have some parts in the bin - maybe about $50 worth.  Still worth doing IMHO.