The Antique Collector Installment 4 - More on H.H. Scott

Posted by: Steven Stone at 1:01 pm, June 21st, 2009

 
SCOTT 299 SERIES AMPLIFIERS
 
The Scott 299A was the first stereo integrated amplifier.  It was introduced in September 1959.  Its list price was $199.95, the equivalent of about $675 in 1988 dollars.  Its' touted features included provisions for connecting stereo cartridges and tape heads, D.C. filament supply, and a third channel output.  The front panel sported rumble and scratch filters, contour switch, phase reverse switch, separate dual concentric treble and bass controls, an input switch with provisions for not only RIAA curves, but also European 78s, and Ortho curves.  Inputs were also supplied for a tape amp, NARTB tape head, and tuner.  The stereo selector has provisions for mono, reverse stereo, channels A and B alone, and something called Bal A and Bal B for checking levels on each side.  This last feature is especially handy when troubleshooting for uneven output levels.  It is perhaps a bit excessive on an integrated amp, but with separates, you can find out instantly whether the output discrepancy occurs before or after the power amplifier. The 299A was initially rated at 20 watts a side. By 1961, the 299B had crept up to 25 watts per side. The 299C was 36 watts per side and finally the 299D, introduced in July 1963, was 40 watts per side.  The 299 tube layout featured four 12 AX7s in the front, just like the Scott 130 preamp, and two 6GH8 driver tubes with four 7591 power tubes.  The tube rectifier was the ubiquitous 5AR4.  One might wonder how an amplifier with the same tube layout and topology could "grow" from 25 watts to 40 watts.  Less feedback, increase in the stack density of the power transformer, and lower-noise parts are the reasons for the 299s added beef; either that or Steroids.  

        
 
The 299A was soon replaced by the 299B, 299C, 299D, 299T (T stands for transistor), and lastly the 299 F (for final?) in 1969.  The 299 versions with tubes enjoyed a long and fruitful lifetime, starting in 1959; the 299D finally went out of production in December 1964.  Scott made a whole mess of 299s.  If any used component could be said to be as common as cockroaches, it's the 299.

         In HiFi/Stereo Reviews' tests of integrated amplifiers in August 1961, the 299C met its specifications of 30 watts RMS from 20 to 15,000 cycles.  At 20,000 cycles the amplifier could only put out 28 watts, displaying the classic Scott top end roll-off. This reduction of power capabilities at high frequencies was characteristic of most contemporary integrated amplifiers due to their output transformers.  In HiFI/Stereo Reviews' tests only the Sherwood s©5000 II had better signal to noise figures.  In a 1959 ad, Scott hyped the 299 as "The Stereo Amplifier that sets Standards for the Next Decade", and in fact these advertising claims turned out to be true as it did lead its' class over the next ten years.

 
SCOTT LK-72

        
 
My personal experience with Scott integrated amplifiers has been principally with the LK©72, a kit version of the 299 design.  The LK©72 is identical to the 299 in every way except one.  In the December 1960 issue of HiFi/Stereo Review, a Scott ad lists the 25 watt per channel LK©72 tube complement as 4 7591 output tubes, 2 7199 splitter/inverters, 4 12AX7 preamp tubes, and 1 5AR4 rectifier.  You'll notice the LK©72s' tube complement differs from the 299 in that it uses 7199s instead of 6gh8s as driver tubes.  Actually 7199s are the industrial version of a 6GH8. While their specs vary slightly, they are essentially "plug-compatible".  Later Kits used 6GH8s instead of 7199s as Scotts' source for 7199s dried up.  

        
 
There are probably even more LK©72s in the world than 299s, since they were relatively easy to build, competitively priced, and ridiculously reliable.  While the sound of these units does vary from unit to unit, depending on the soldering abilities of their builders, and the age of each unit, there is still a readily identifiable "sound" to these beasts.  If some manufacturers' products, for example the Conrad Johnson Premier 2, can be described by reviewers as "caramel colored", the Scott integrated amplifiers could best be described as "fudge colored".  The upper frequencies are hooded, while the midrange and upper bass predominate.  This creates an overall balance that is very sweet, and very dark.  Inner detail is buried under gobs of euphonic darkness, the edge of transient attacks are melted like a marshmallow plopped into hot chocolate.