Rare, and in fine condition, H. H. Scott model LK-150 Stereo HiFi Vacuum Tube Power Amplifier in perfect working order.
This amplifier is, by may HiFi aficionados, considered the pinnacle of HiFi gear designed by legendary designer H. H. Scott. Sold as a kit, these amplifiers were built by skilled amateurs. This particular one is built nicely with good soldering skills. This particular amp is in very clean condition and all original with the exception of the upgrade of two electrolytic capacitors. The replacement capacitors are, like the original ones, Mallory type FP capacitors.
This amplifier comes with the original Instruction Book (25 pages), the book has some markings inside to check off parts while the kit was assembled; three pages instructions how to unpack; a try-fold titled "H.H. Scott takes pride in reprinting this article from THE Atlantic.";folder "SCOTT KIT WARRANTY"; large folded "CHART AM-1", original schematics with service bulletin for Lk-150 STEREO POWER AMPLIFIER on the back; and also a part change notice.
Condition:
The chassis is straight and to keep it this way, I will ship this in a wooden box made ot 3/4" plywood in case the package is being dropped. All components of this amplifier are original, except the tubes which have been replaced. The two electrolytic capacitors in the power supply and named C202 and C203 in the original schematics (included!) have been replaced with NOS Mallory type FP capacitors with two times 40uF instead of the original two times 30uF. The two new capacitors are shown in pictures 20 and 21. Try to find two of these, they are scares as hens teeth! Both capacitors have been reformed with a DC power-supply and a 1.2 K Ohm resistor to limit the current that is needed to reform the insulation. Each capacitor was reformed over a period of 24 hours and the voltage over the resistor kept below 20 Volt during the process. I did the same procedure with the two capacitors in the front which are kept original; on the schematics they are named C201, C202, C205, and C206. Interestingly the can with C201 and C202 has the plus as the common on the can!
One of the capacitor fiber mounting plates was broken and I replaced it with an original Mallory part with the same color. Usually such a repair is done using screws where the original one were fastened using aluminum rivets. Being a perfectionist, I obtained rivets with the right diameter and used rivets to keep it original (I will include a bunch of spare rivets in case the potential buyer will need some in the future).
The upgrade from 30uF to 40uF is helping with the demand of current at the low end of the frequency spectrum and is limiting peak loads on the rectifier tubes. The pictures show the amp with two Sylvania 5U4 tubes. This amplifier actually was designed for two 5AR4 or GZ34 rectifier tubes. I will include two brand new 5AR4 recitfier tubes as well.
All tubes have been tested on my Hickok TV-7 tube tester (see picture 23) and are at, or above 100%. The two type 7199 tubes are original E.H.Scott tubes and measure:
Pentode system, 58 and 60, a reading of 50 is 100%.
Triode system, 42 and 48, a reading ot 42 is 100%.
The 6550 measured 60, 60, 72, and 84, a reading of 45 is 100%.
As you can see in the pictures, the chassis is clean, free of corrosion and free of scratches! The pictures show some dust particles as the pictures are magnified as if you look through a magnifying glass!. There are some slight scratches on the transformers but no dents or any other imperfections. The Aluminum bottom aluminum cover is attached with the original screws and they all still have a strong grip and have not been overtightened by some individual who does not know the difference between a wheel log and a screw holding the bottom cover on an amplifier...
In case you noticed that the fuse-cap is not shown in the picture showing the back of the amplifier. I just removed the cap to prevent damage when I put it on its back to take pictures of the underside of the amp. The fuse and fuse cap are original and are included!
History:
This amplifier is a beast, the increadible frequency range, especially on the low end, has its weight in the form of iron! The transformers are larger than the trnasformers on an MC-275 or a Citation! If you are not satified with your MC-275 or Citation, try an LK-150 and you will never look back!
Inventory Number 01003;
Price: Sold!