The Scott 299 family of amplifiers
The 299 series of H.H. Scott amplifiers started with the original 299 which used four 12AX7 preamp tubes,
two ECF80/6BL8 phase splitter tubes four 7189 output tubes and a GZ34 rectifier tube. The original amp had it's
output transformers mounted in a row from the front of the amp to the rear. To the right of the output transformers
is a row of 7189 output tubes going from front to rear. Later 299's changed the component layout to a side to
side configuration with the four output tubes in front of the output transformers. The 299B was the second generation
and along with the 299, it put out around 20 watts of power per channel. The third, and most versatile of the 299's was
the C version. This one replaced the output tubes with the larger 7591A and could deliver around 30 watts per
channel with both channels driven. You could eek out 40 watts from a single channel if the other was idle.
The limiting factor keeping the 299C form delivering 40 watts per channel is it's power supply.
This is the only of the 299 series with an adjustable center channel control concentrically mounted on the
balance control. The 299C has two variants. One uses the 6U8 phase splitter
and the other, older version uses the 7199 as a phase splitter. This is probably
the best of the 299 series. The final 299 was the 299D. What is nice about
this amp is that it has it's output tubes behind the output transformers.
This makes for better heat dissipation and gives you more room to use tubes
other then the small 7591A. All the 299 series are stellar performers, but
due to their small physical size, they have always had problems with heat. Because of this,
most need power supply capacitors and plate resistors right off the bat. As with any amp this old,
you MUST replace the coupling capacitors and bias rectifier. The 299C should always have it's
first filter capacitor replaced. This is the can near the rectifier and power transformer. Because
of the amount of heat in that area, this capacitor likes to develop shorts.
299C schematic:
