State of the art Phono stage from Jim Fosgate!
Story of the F 159: The author of the F159 is Jim Fosgate. Foz’s
electronic design experience and excellence spans decades and coupled
with Jolida’s decades of manufacturing experience, results in a unit
which can provide our customers with a distinct improvement in turntable
sound reproduction at an affordable price. In addition the phono
pre-amplifier has a Fosgate designed Crosstalk Reduction Circuit (XT-R)
which represents a distinctive electronic approach to solving crosstalk
caused by a turntable’s cartridge and acoustic problems due to axial
tilt. We have placed the name F159 to honor the designer who has built
and tested 158 prototypes until finalizing his work in the 159th
has used an upgrade to the classic Cascode circuit design and added a
MOSFET to give the musical performance of tubes with the speed and
detail of current solid state designs. Unlike most tube equipment it can
product a perfect square wave and uses zero negative feedback when the
tone controls are off.
Ice’s Audio F159 Phonograph Stage Tube Pre-Amplifier is an example of
state-of-the-art vacuum-tube technology as it exists today. This product was
designed to provide:
1) a Phono Stage that would deliver musical accuracy
2) a significant value based on a high
performance to price ratio
3) a vacuum tube unit that would exceed the
reliability of solid state units.
The F159 is housed in a heli-arc welded
chassis and uses 2 6922/6DJ8 tubes. Parts quality is the best
currently available, and the overall circuit layout is maximized for sonic
Another major feature of the
phono stage is the inclusion of the XTR circuit or Cross Talk Reduction
circuit. To obtain high performance from a modern phonograph system, the
tonearm and pickup cartridge must be properly adjusted to within a few
thousands of an inch to minimize the effect of axial tilt. Axial tilt is when
the cartridge needle of the turntable is not perpendicular to the record
groove. In addition, a low dB channel separation of the cartridge can result in
crosstalk. Crosstalk is simply the stereo signal from the left side leaking
into the right side, and the stereo signal from the right side leaking into the
left side. Jim Fosgate, has designed an elegant electronic circuit to
compensate for crosstalk and axial tilt. The XT-R represents a breakthrough
since axial tilt and crosstalk is not mitigated thru the traditional method of
physical adjustment, the compensation of the XT-R is electronic. The XT-R
incorporates signal cancellation to reduce inter channel crosstalk. This is the
same technique that is used in high separation surround processors. The XT-R
corrects for a misaligned stylus or cantilever, misaligned generator,
misaligned tone arm azimuth (axial tilt). It also reduces crosstalk from cross
coupling of the generator coils or tone arm wiring. This circuit works with moving magnet, moving iron, and
moving coil cartridges. The XT-R will compensate for up to 7 degrees of axial
tilt and can improve channel separation to a maximum of 48 dB. The result will
be an improvement in stereo imaging and clarity without any sacrifice in
1- Gain @ 1KHZ in low gain position 40DB with 47K input.
2- Gain @ 1KHZ in high gain position 60DB with 47K input.
3- Noise floor in high gain position approx -70 DB with input load set
to 10 ohms, noise floor will be lower with gain set in low position.
4- Frequency response with RIAA EQ is Plus/Minus 1/4 DB from 250 HZ to 20KHZ, + 3DB at 20 HZ (Bass Boost)
5- Distortion .05% @ 1 KHZ 1V RMS out.
6- Plate voltages APPROX 90V on input stage, 70V on second stage.
7- The calibrate meters work the same way as the XTR.
8- Rear panel Adjustable loading
Includes both Two 6922 & two 6DJ8 tubes
For more information, please visit this product's webpage.