The Compactron Phono Preamplifier - part 2

 Hi!

The variable EQ Compactron Phono Stage is finished.

Some photos of the initial construction steps were shown in part 1. Here the finished unit.

Besides adjustability of input impedance and input capacitance, there are selector switches for different bass turn over frequencies and different amounts of treble roll off to adapt to the recording curves of vintage records labels.

In addition the absolute phase of the output can be switched.

The phono stage is meant to be used with MM cartridges or MC with external step up transformer. However in its highest gain setting it is useable with MC cartridges directly in if they are not loo low in output. That is how I am testing it right now.

Gain is selectable in 4 steps via a switch on the back side. More details about this in the post about the Compactron Preamplifier. The outputs are available as RCA as well as XLR sockets. The outputs are transformer coupled and have very low output impedance.

Knobs can be chosen to taste.

More colors available soon.

My favourite is the all orange front.

Here a pic of the inside. Some of the wiring still not final in this photo as it just was an initial test run.

All power supplies including the DC heater supply are choke filtered.

Vents directly above and below the tubes.

The feet are stainless steel as well as their counterparts on which they are supposed to sit to avoid damaging the surface below.

Other feet are available on request.

Stay tuned for more new developments in the Compactron series. An entire line of electronics is planned with Compactron tubes and in this chassis style, including DACs and power amps as well as an integrated.

Best regards

Thomas