Lafayette KT550 !! Holy Cow!!!!!

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topround

Lafayette KT550 !! Holy Cow!!!!!
« on: 8 May 2008, 09:46 pm »
My friend bought an old KT 550, He brought it over for me to hear , it had some problems...so.. I took it to my friend Vinny,a great tube repair guy on Long Island, what came back after he rebuilt it with new caps,is one of the best amps I ever heard in my LIFE!

Weighs about 60 or 70 pounds, 55 watts , huge transformers.
The musicians came out of my speakers and decided to play in my room last night
I was dancing and swearing and sweating it was friggin great.
Pure power and music, throbbing live music that you could listen to forever, your pulse changes with the music, it is sick, makes a dancer out of a wallflower :lol: :dance:
I have this one disc of Michael Brook"Cobalt Blue" I would listen to this and it would lull me to sleep sometimes, last night it was another world, the music popped out of the speakers ,, huge, every note gripping and important and necessary I am still excited

Sorry to gush, but I gotta tell someone

giantsteps

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #1 on: 9 May 2008, 12:13 am »
My friend bought an old KT 550, He brought it over for me to hear , it had some problems...so.. I took it to my friend Vinny,a great tube repair guy on Long Island, what came back after he rebuilt it with new caps,is one of the best amps I ever heard in my LIFE!

Weighs about 60 or 70 pounds, 55 watts , huge transformers.
The musicians came out of my speakers and decided to play in my room last night
I was dancing and swearing and sweating it was friggin great.
Pure power and music, throbbing live music that you could listen to forever, your pulse changes with the music, it is sick, makes a dancer out of a wallflower :lol: :dance:
I have this one disc of Michael Brook"Cobalt Blue" I would listen to this and it would lull me to sleep sometimes, last night it was another world, the music popped out of the speakers ,, huge, every note gripping and important and necessary I am still excited

Sorry to gush, but I gotta tell someone

 I'm enjoying your Eico 81...no shootout w/ my 500c yet. They just don't make 'em like they used to. :D


 Frank

Derockster

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #2 on: 9 May 2008, 03:02 am »
Hi,i am using a pair of Altec 1568 amplifiers to drive my Spendor sp 100s.These amps sound wonderful definitely keepers.Regards derockster :thumb:

lonewolfny42

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Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #3 on: 9 May 2008, 03:25 am »
topround....
Quote
The musicians came out of my speakers and decided to play in my room last night
I was dancing and swearing and sweating it was friggin great.
Ahhh....Mike....come on,lay off the wine, will ya.... :jester:

For those that may not know....
Lafayette Radio was a radio manufacturer and retailer based in Syosset, New York. The company sold radio sets, amateur radio equipment, citizen's band (CB) radios, and other communications equipment, as well as electronic components and even tools, through retail outlets as well as by mail-order. I use to shop at the store in Jamaica, NY. More info here...

As for the kit KT-550...... Lafayette introduced the KT-550 in late 1960. The KT-550 was actually designed by Stewart Hegeman and featured push-pull 7027As generating 50 watts per channel continuous.

Enjoy Mike..... :dance: :wine:




topround

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #4 on: 9 May 2008, 09:37 pm »
 :D

topround

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #5 on: 9 May 2008, 09:37 pm »
OK
Wineless for 2 days now and still this amp rocks :wine:
It has new caps so it still has to burn in a lot, its got Russian paper in oil so it should settle in very nicely I hope.
One of the things I notice is that you can keep turning up the volume( it just wants to play loud)
and it doesn't bother you, the music gets louder and more dynamic but no fatigue

I love it

Maybe I just got some real good synergy here but man it works

OK it's Friday so I am going to open a bottle now
Cheers all
see ya tomorrow at the rave

rajacat

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Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #6 on: 9 May 2008, 09:41 pm »
Photos please! :)

topround

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #7 on: 9 May 2008, 10:00 pm »
OK everyone loves pictures





TheChairGuy

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #8 on: 9 May 2008, 10:04 pm »
10 minutes with my 50 year old/50 watt Push/Pull 6CD6 Dukane's (old caps and all) and I had my Odyssey Khartago Mono Extreme's up for sale.

With the right easy-driving speakers...some of the old gear is just fantastic stuff  :thumb:

The service center that updated caps and wiring (MacIntosh authorized) said they often tell ebay buyers of purchased tube gear it's not worth fixing...they said the iron in mine was as good as anything made today.  I think I paid $800 for the mono amps and service in total and I blissfully love them everyday. 

I haven't had a SS amp here for 2 years now....the only other amp I have is a dual mono, integrated Bell amp recently serviced by Jim (dang - I can't remember his moniker, but rajacat/Roy used him as well :scratch:) in the Tacoma, WA area.

I know part of the reason is their coloration - who cares - I am absolutely smitten with their sound regularly.

Enjoy Mike/topround!  John

topround

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #9 on: 9 May 2008, 10:09 pm »
John,
If dancing is a sign of success I have it in spades
I am a wallflower by nature and I have no choice but to dance and be musically, emotionally involved,
it is not coloured at all it is so real>>>>>>>>>
Welcome to the holodeck..please have a seat!!!

mike

topround

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #10 on: 9 May 2008, 10:24 pm »
Woo Hoo

 :dance:

SET Man

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #11 on: 9 May 2008, 10:30 pm »
Hey!
 
   There is something special about tube isn't it? :wink:

   C'mon Mike! I want to see photo of that amp topless!  aa

Take care,
Buddy :thumb:

topround

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #12 on: 9 May 2008, 10:45 pm »
Buddy

Tubes rule!! Dogs Drool!!

giantsteps

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #13 on: 9 May 2008, 10:51 pm »
Woo Hoo

 :dance:

  :dance: Wa hoo!! I know the feeling Dr. Prat!! Just hooked up the 500c, poured myself a Drambuie and the joint is jumpin'!! :dance: I was going to drop by and take some pictures for Rajacat but you already did it. BTW do some  :weights: 'cause I might need your help w/ the Roland. :thumb:


 Frank

Whitese

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #14 on: 10 May 2008, 01:37 am »
i just sold my Lafayette KT-550 which is 100% original and it was fantastic!!!!  quiet as the dead of night!!!

Only sold it as I am moving and am happy with my Pilot SA-260 and SA-232 driving my speaks...

Awesome find there, cherish it!!

slbender

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Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #15 on: 10 May 2008, 05:49 am »

The Lafayette KT-550 stereo amp is quite similar to the Harman-Kardon Citation power amp, both were all-out designs by the one and only Stu Hegeman.  Both are perhaps one slight step superior to the Fisher 500c with its 7591's.

The primary difference between the KT-550 and Citation II, I think the Citation II was the later improved model a couple of years later, made using ultra-wide bandwidth video tubes for the input gain and driver stages (12BY7's) and using the just newly released KT-88's by GEC of England, instead of the 7027's.  The 7027 had a 25 watt Pd. versus the 35 watt Pd of the KT-88; later the 7027A tubes eventually matched the 6550 / KT-88 Pd at 35 Watts of Plate dissipation per tube, but using those in the KT-550 would not improve any characteristic of the KT-550.

So, the pair of 7027's produced 50 wpc in the KT-550, while the KT-88's in the Citation II managed 60 wpc. and perhaps even a little bit more.  In both amplifiers the output transformers were very nearly the same, the power transformer however, appears to be somewhat smaller in size in the Lafayette amp limiting the power to the original 7027 levels. 

Both the Citation II and the Lafayette KT-550 are at their sonic best when pricey Polypropylene or Teflon coupling caps are installed to let their full clarity and tube transparency through.

Of course, the vintage stereo amp, circa 1960 to die for is the Acrosound Stereo 120 with original GEC KT-77's in it....  :icon_twisted:

It would be interesting to compare a modded KT-550, against a souped up, rebuilt Citation II against an Acrosound Stereo 120 ( or its identical twin - the Realistic HK-210 ) all with new pricey caps and Hexfred diodes.  All three are power-house amps, yes.  Nice sounding amps all of them, but hither, still using the flawed push-pull topology... ultralinear on the screens and etc,. so none of them possesses the true sonic purity of a really well designed SET Amp.


--Steven L. Bender, Designer of Vintage Audio Equipment


Buddy

Tubes rule!! Dogs Drool!!

JimJ

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Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #16 on: 11 May 2008, 03:20 pm »
Hot :)

audiobasics

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Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #17 on: 9 Jul 2008, 07:36 pm »
That is truly a gorgeous amp!

I've only seen one other, a refugee from long storage in a damp cellar.

It was a but furry with corrosion to say the least.

MontyMo

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Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #18 on: 30 Jul 2020, 11:07 pm »

I have used both the Lafayette and Citation II. Both rebuild! I am currently using a Citation II. I totally love the sound of the Citation with my  Magnepan LRS speakers. The image and depth of soundstage is like nothing I have ever owned. (Or for the most part heard)

These old amps, if properly rebuild are something special!
Monty











The Lafayette KT-550 stereo amp is quite similar to the Harman-Kardon Citation power amp, both were all-out designs by the one and only Stu Hegeman.  Both are perhaps one slight step superior to the Fisher 500c with its 7591's.

The primary difference between the KT-550 and Citation II, I think the Citation II was the later improved model a couple of years later, made using ultra-wide bandwidth video tubes for the input gain and driver stages (12BY7's) and using the just newly released KT-88's by GEC of England, instead of the 7027's.  The 7027 had a 25 watt Pd. versus the 35 watt Pd of the KT-88; later the 7027A tubes eventually matched the 6550 / KT-88 Pd at 35 Watts of Plate dissipation per tube, but using those in the KT-550 would not improve any characteristic of the KT-550.

So, the pair of 7027's produced 50 wpc in the KT-550, while the KT-88's in the Citation II managed 60 wpc. and perhaps even a little bit more.  In both amplifiers the output transformers were very nearly the same, the power transformer however, appears to be somewhat smaller in size in the Lafayette amp limiting the power to the original 7027 levels. 

Both the Citation II and the Lafayette KT-550 are at their sonic best when pricey Polypropylene or Teflon coupling caps are installed to let their full clarity and tube transparency through.

Of course, the vintage stereo amp, circa 1960 to die for is the Acrosound Stereo 120 with original GEC KT-77's in it....  :icon_twisted:

It would be interesting to compare a modded KT-550, against a souped up, rebuilt Citation II against an Acrosound Stereo 120 ( or its identical twin - the Realistic HK-210 ) all with new pricey caps and Hexfred diodes.  All three are power-house amps, yes.  Nice sounding amps all of them, but hither, still using the flawed push-pull topology... ultralinear on the screens and etc,. so none of them possesses the true sonic purity of a really well designed SET Amp.


--Steven L. Bender, Designer of Vintage Audio Equipment

SlushPuppy

Re: Lafayette KT550 !! Holy Cow!!!!!
« Reply #19 on: 30 Jul 2020, 11:40 pm »
Talk about a topic that has risen from the dead!  :lol: