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new arrival [message #9390] Fri, 02 December 2005 17:10 Go to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
Hey-Hey!!!,
My Harmon-Kardon Citation II just came in the mail. What a heavy beast!

I took a close look underneath and found it complete. The meter is intact and no evidence of fire. Going to rebuild it and see if it lives up to expectations. Been wanting one of these for a while...:)

If it lives up to its billing, I may have to borrow its output Iron for another project.

I love the looks of this, it runs the outputs at 46 Watts of dissipation each, and allegedly is only happy with EI KT90's. Fortunately I do have a quad of those. The outputs are big, far larger than the can the Peerless S-265-Q came in. Guess that's the diff between a 40W and a 60+ Watt.

Oh, didn't I have another project in the works...so easy to get distracted.
cheers,
Douglas

Re: new arrival [message #9392 is a reply to message #9390] Sat, 03 December 2005 06:41 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Stu Hegeman designed that amp; no? I have a friend who owns several as well as the Citation I pre-amp and a Citation V. He won't buy anything else and I do think that is some of the best sounding vintage stuff around. Ballsy.

yep... [message #9393 is a reply to message #9392] Sat, 03 December 2005 07:09 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
That is Stu's amp. It is going to need some serious rehab. The plastic insulation is breaking down into a sticky gooey mess. The cloth covered stuff is not so bad, but I am not moving it back and forth much while I am under the hood.

And then there is all of the rest of the circuit. Most of the values on the bigger resistors are marginal. It was just painted on the big brown bodies.

Fortunately the replacements are already gathered up in kit form. Just need to get a few minutes so I can fix it all up. Going to go and model the PS, I have some 1k2v SiC diodes from Cree that should do a bit better than the ancient originals. I suspect that the doubler circuit is going to have some big spikes of current delivery. No sense toasting them...
cheers,
Douglas

Re: new arrival [message #9394 is a reply to message #9390] Thu, 08 December 2005 17:48 Go to previous messageGo to next message
Tre' is currently offline  Tre'
Messages: 34
Registered: May 2009
Baron
"I may have to borrow its output Iron for another project."

Douglas, I just built PP 300b with those transformers. Sounds good. I have my 8 ohm speakers connected to the 4 ohm tap. The loss of bass due to the lower relative inductance doesn't bother me as I am bi-amping into my subs at 100hz.

Have Fun...Tre'

Picture [message #9395 is a reply to message #9394] Thu, 08 December 2005 17:52 Go to previous messageGo to next message
Tre' is currently offline  Tre'
Messages: 34
Registered: May 2009
Baron
http://www.dock.net/tre/300bPP.jpg

drool-drool!!! [message #9396 is a reply to message #9395] Thu, 08 December 2005 18:20 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
Those are some *SWEET* looking pieces of ndustrial Art. Very pretty. Are those the 3k8 or 3k2 a-a ones? I have the 3k2, and they ratio out near perfectly at 3k1 on 4, 8, and 16.

Draw a 1k6 load line on an 813 with 30% U-L, and B+ of 650-700V. Idle at ~140 mA and I am off to the races with this pair of Iron. I am figuring about 75W or so and being Class A all the way. I have some special power Iron on the boards with Heyboer. Half an amp DC from 500 to 700V with a few stops in the middle.

None of this Class A to Max-Power/N( with N being an integer larger than 1 ), and Class AB1 at Max-Power pile of Marketing beefalo-chipz....:)

I am first getting a kit from Jim so I can resurrect the amp and listen to it. Got a few pairs of Tektronix matched 12BY7A's in the stash to try on that one.

Re: drool-drool!!! [message #9397 is a reply to message #9396] Thu, 08 December 2005 19:18 Go to previous messageGo to next message
Tre' is currently offline  Tre'
Messages: 34
Registered: May 2009
Baron
They are the FT3273671A. In 1990 John Atwood tested them at 3K5 on the 8 ohm tap.

Tre'


Re: drool-drool!!! [message #9398 is a reply to message #9397] Thu, 08 December 2005 20:16 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
hey-Hey!!!,
My Citation II manual says that same part number applies to a 3k2 a-a. I heard there were two a-a loads, and mine ratio out at 3k1. Add DCR and we're *REALLY* close to 3k2.

I don't suppose you'd care to check voltage ratio's with some 60 cps from a variac, would you? I am quite curious as to the exact details of the other version. If you do decide to get into it, could you also check the U-L tap location?
cheers,
Douglas

Re: drool-drool!!! [message #9399 is a reply to message #9398] Thu, 08 December 2005 20:39 Go to previous messageGo to next message
Tre' is currently offline  Tre'
Messages: 34
Registered: May 2009
Baron
Next time they are on the bench, I'll check them.
Howard Sams says 3K2 for that part number.

Tre'



Re: drool-drool!!! [message #9400 is a reply to message #9399] Fri, 09 December 2005 03:25 Go to previous messageGo to previous message
Damir is currently offline  Damir
Messages: 1005
Registered: May 2009
Illuminati (2nd Degree)
Hi, Tre` - glad to see you here! Interesting amps - feel free to post a schematic/description in "Group Build" department.

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