Assembled board PCB Fisher TR-1 clone phono preamp MM / GE transistors

MM phono stage, entirely based on domestic USSR Germanium GE transistors P416B.

Corrector, according to mentions in the Western press, is the very first serial corrector based on transistors, 1958. The correction is divided into 2 cascades. The circuit itself is most likely an RCA design; a very similar circuit was published in the RCA reference book for 1957. (Correction close to RIAA)

The sound of the phono stage is detailed, bright - similar to “tube sound”. The sound as a whole is very clear and soft, the scene is localized. Pleasant sound, with good soft, deep bass, good lower “middle”, a certain fusion of transistor detail and lamp warmth.

Draw your attention !

You must have soldering skills and understand electronics!

The phono stage board is made according to the “vs music” version of the circuit. The circuit has been redesigned to use domestic germanium transistors. Special thanks to “vs music” for the work done. The corrector board has its own voltage stabilizer. The possibility of supplying supply voltage, both alternating and constant, is also implemented. The corrector's power supply circuit is based on developments from the late 50s and early 60s. In the corrector, it is possible to change the output gain (40dB / 44dB) by rearranging (jumper). The power plus is connected to ground. Therefore, to power the corrector, you need to use a separate power supply or transformer. It is highly desirable to place the corrector board in a separate aluminum or metal case, which serves as a screen (“ground”).

Main characteristics:

Cartridge type: MM

Design – phono corrector based on GE transistor;

Frequency range, Hz: 20 Hz ... 20 kHz (frequency response +/- 2.0 dB);

Nominal sensitivity input voltage: 3 ... 5 mV;

Output voltage: 0.450 V; (800 mV) / 0.450V (800 mV)

Gain, dB: 40dB / 44dB

DC power supply (U): -23…-35 V

DC power supply (U): ~23…-~33 V

Current consumption (I): no more than 20 mA

Deviation of frequency response from the standard is no more than +/- 3 dB

Signal to noise ratio (unweighted) (SNR) > ~70 dB

Harmonic distortion (THD) no more than 0.3%

Dimensions (W x D x H): 70x100x30 mm;

The scheme and recommendations for assembly and connection are included in the kit.