Vertere CALON: High-end dual-mono phono preamplifier

Touraj Moghaddam, the creator and CEO of Vertere, recently hosted a media event to introduce CALON, the inaugural Vertere dual-mono phono preamplifier. CALON ensures that the performance gains from...

Vertere CALON
Vertere CALON
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Touraj Moghaddam, the creator and CEO of Vertere, recently hosted a media event to introduce CALON, the inaugural Vertere dual-mono phono preamplifier.

CALON ensures that the performance gains from recent improvements in Vertere Record players, like the new XtraX cartridge, SG-II PTA HB, and Reference tonearms, are maximized. It provides amazing transparency and dynamics, delivering a truly great sound. A demonstration is highly recommended. CALON not only excels technically, but also has the ability to immerse the listener in the emotion and power of the music. It’s a product that speaks to both the heart and the brain.

The case is machined from non-magnetic (Austenitic) Stainless steel, which brings a high level of shielding without the ferromagnetic eddy current and field hysteresis problems iron or steel would bring. The knobs are super-polished stainless steel.

CALON high-end Phono Preamplifier in grey
CALON high-end Phono Preamplifier in grey

Each part of the circuit has been created to maximise performance and be part of a high-end whole. The gain structure has been carefully calculated, designed, and implemented to deliver the best transparency, detail resolution, and dynamics from any cartridge.

The cartridge input first enters a gain stage with user-selectable gain (default, +10dB, +20dB). Then, it is subjected to an RIAA ‘filter’ where, in an ideal manner, the HF section is passive and the LF active. After this is another user-selectable gain stage (0dB, +2dB, +4dB, +6dB, +8db) leading to the output RCAs and the balanced output line driver stage. Both outputs are on (except when muted), but connecting and using one at a time is best.

CALON high-end Phono Preamplifier
CALON high-end Phono Preamplifier

CALON includes a switchable subsonic filter to reduce the wasted energy and headroom caused by (subsonic) noise below normal audibility, which some turntable/arm/cartridges generate in excess. The circuit is linear phase and has a practically unmeasurable effect above 20Hz. In addition, the output of CALON can be 180° phase inverted for those rare records recorded/mastered with incorrect absolute phase.

CALON is user-configurable for most Moving Magnet and Moving Coil Cartridges available. The front panel knobs allow the choice of nine input impedances and nine options of capacitance together with 15 choices of gain. For example, it will enable a somewhat peaky (with a rising HF response) Moving Coil cartridge to be tamed by adding capacitance rather than by reducing input impedance. Lowering the input impedance tends to ‘slug’ the sound, reducing musical performance and drama and lowering the brightness. Adding capacitance while keeping the input impedance higher allows the entire performance to shine.

The power switch has three convenient options: Power off, Power on but output muted, and Power on output on.

CALON gets the best from any high-quality record player, with maximum transfer of dynamic range and supreme detail resolution.

Touraj commented,

“We are still learning how much info is contained in the groove. CALON allows us to get closer to getting all of it.”

CALON high-end Phono Preamplifier back panel
CALON high-end Phono Preamplifier back panel

Audio circuits

The audio circuits with their respective power supplies are on two identical four-layer gold-plated circuit boards, which is an ideal dual mono configuration. Four layers allow ideal grounding and ground planes as shields within the board itself. It provides control of the ground and power impedances to optimise signal path and ground path flow. Populated with a choice of through hole and surface mount devices using whichever is optimum for the circuit requirement. The active devices are laser-precision-trimmed high-end integrated circuits that deliver virtually identical performance statically and dynamically under differing signal levels and temperatures.

Circuit design is one thing, and circuit optimisation is another. Choice of components to achieve the required performance and neutrality is a skill that requires a massive resource of available components and almost infinite time, or it requires vast experience and skill. It’s easy to ‘throw’ loads of costly components at a circuit to get the necessary performance, but this usually means missing the target price point and not constantly hitting the target performance. Touraj has the experience and knowledge to understand the balance required between power supply and primary circuit and the choice of components wherein to deliver an accurate, musical and fun performance.

Both audio PCBs are shielded separately by Austenitic Stainless Steel shields. These shields, combined with the use of high-quality components and special solder, guarantee consistent optimum performance for the long term.

Control circuits

The control circuit includes the logic and the many relays, which means CALON is easy to use, visual, quiet in operation and stable.

Power supply

There are two toroidal transformers, one supplying low-voltage AC to the L&R Audio Boards and one supplying low-voltage AC to the logic and relay board. AC is supplied to the circuits so rectification, storage, and regulation can be as close as possible to the required circuits.

An iron shield ‘hides’ the transformers electromagnetically to maximise the overall signal-to-noise ratio.

Balanced Phono

There has been a trend among hi-fi enthusiasts in recent years to consider balanced connections as good and single-ended connections as less good. Examples are often quoted of recording studios where most audio connections are balanced. Cables in the professional world are usually very long, and noise pickup can be problematic. Balanced connections are far better at rejecting common mode noise, which is why they are ideal for long cables. Balanced connections are also hugely practical for microphones, which are often phantom-powered. There is practically no advantage to using balanced short interconnects (except if the designer has obsessed over the balanced circuits to the detriment of the single-ended ones).

Making a traditional analogue preamplifier fully balanced from input to output is practically impossible, as balanced volume controls don’t exist. Even in the unlikely event of someone making one, the channel and plus / minus tracking required would be beyond the tolerances of a volume potentiometer.

Balanced phono is even more complicated, as although a cartridge’s output is floating, it is not balanced about ground/earth. Yes, having a discrete plus and minus connection for L&R and a separate ground wire all the way back to the phono preamp is essential for optimal performance, but just putting XLRs on the cable doesn’t make it balanced.

CALON is set to hit the market in July with a price tag of £15500, €18998, or $19995.

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