Tonograf - A Germanium Equialiser
A fully discrete Equaliser unit with high and low shelves, the high of which has three frequency choices, and an inductive boost/cut mid-band with six frequency choices.
Our unit is heavily based on the legendary TAB W95c Equaliser module from the early 1960s. We acquired one such unit and fell in love with the sweet sound that comes out with whatever you feed into it. The discrete germanium circuit with it’s four inductors and two transformers makes a blissful impression on all that you put through it. Push it’s levels to the limit and it saturates so wonderfully, not only within it’s inductors but also within the class A transistor circuits within.
What is rather unusual about this unit is that it has all the design methods of earlier tube devices such as the V72 and V76 amplifiers, yet the designer adopted those to low voltage transistor circuitry. There was only a brief period where this seemed to be present, most likely when experienced design engineers were only becoming accustomed to designing with transistors rather than vacuum tubes. What results is a unit that produces a unique and magical sonic imprint, regardless of whether you are actually boosting or cutting any frequencies.
But it was certainly not easy to replicate this beauty. It took a number of years on and off. The inductors used within had to be analysed and custom pieces made by our transformer supplier in the UK. The mid inductor is wound in-house on our own winding machine as the tolerances here directly impact the position of those mid frequency points. The original germanium transistors are pretty much unobtanium nowadays, so we had to do extensive trials of various surrogate parts into the original TAB unit until we had something that behaved exactly as the originals did. A small number of features were added including an extra mid-band frequency, the ability to both cut or boost the mids (original is boost only), three frequency choices for the HF shelf, and a bypass switch. Other than that the original design is completely unchanged. We have also managed to employ the detented LF and HF controls as per the original which have a pleasant tactile feel to them.
The design utilises input and output transformers of the highest quality, made by Lundahl in Sweden. Panasonic, AVX and Vishay capacitors are used throughout, along with Vishay and Yageo resistors. The attention to detail in both build quality and sound quality is extensive, as is done with every Atomic Analog product.
The first batch of just ten Tonograf modules sold out very quickly and shipped in January 2025. The next batch is still at a carefully low quantity of just 20 modules, and we are now open for pre-orders on that. Please get in touch very soon if you would like to reserve one (or two!).
In the gallery you can see the product datasheet. It is not quite in it’s final, most beautiful form yet but it at least gives you all the nitty gritty numbers. One of these ships with every module.
The price per module is 155,000 ISK
This is excluding shipping cost or any local VAT or import taxes that may be payable when it arrives to your country. Purchase is done through direct email contact with Vinny, the builder himself.