“After spending thousands of hours researching, building & testing various designs, including discrete solid state, tube hybrid, and opamp phono stages, we settled on an all tube, three stage, all transformer coupled uniquely designed phono stage. One that brings something new to the analog world. Our goal was to design and built the best phono preamplifier, a unique cost no object implementation. We strongly believe we have done so.” - Stavros Danos, Designer
 
 
A phono preamplifier generally consists of three subsystems – Input Stage, RIAA Stage, Output Stage. The input stage, responsible for the main amplification of the delicate signal sourcing from the phono cartridge. This task is extremely difficult. The signal level is only a few microvolts rms, comparable to the noise level picked up in the majority of interconnect cables, along with thermal noise of some active devices.
 
The input stage must amplify the signal to the last micro detail coming from the vinyl groove, whilst rejecting noise coming from external sources, cables and the turntable electro mechanical system. The selection of the active device used for the input stage is as critical as the design of the topology used.
 
Operational amplifiers were rejected for this cost no object design. Although their performance on the benchmarks were impressive, all opamp designs failed to deliver the detail, flow and sonic bliss associated with top analog systems.
 
Many discrete JFET implementations, balanced or single ended, were more then satisfying regarding measurable performance. However none of them was quite there, and fell short of our expectations, to stand next to an absolute top system. In addition their high input capacitance presented several problems to the cartridge loading.
 
Input Stage
 
Our input stage is a proprietary topology using the E280F super tubes. The input stage is a true differential design. The signal from the cartridge is amplified as a perfectly symmetrical signal, either RCA (floating) or XLR input is used. Any noise picked anywhere in the signal chain, from the cartridge pins up to the phono preamplifier inputs are rejected. The two tube banks parallel-feed (parafeed) two mumetal transformers for complete noise rejection.
 
The input stage can be accompanied by an optional custom, balanced-to balanced step-up transformer, built to exact customer’s needs, to tailor-fit each cartridge used. The detail retrieval from our input stage is phenomenal.
 
SUT & Cartridge Loading
 
The Talos Ref comes equipped and internally pre-installed with our specially designed SUT. The SUT is 18db step up ratio, and be preordered with custom step up ratios. Our SUT transformers are also wound using fully geometrically/electrically balanced windings, thus outputting a true balanced output, thus fully benefit from our differential tube input stage.
 
Amplifiying the extremely low level signal in differential mode has the advantage of cancelling out common mode noise Common mode noise is electrical noise picked up anywhere from the cartridge body up to the inputs of the phono stage, Thus the Talos Signature has a very high SNR.
 
The unit comes with no internal loading presets, as this would predefine and limit loading combinations. Loading is thus provided by our loading modules. These are custom built on request, and tailored to a clients cartridge portofilio. Loading modules can be used for both direct and SUT inputs. Loading modules can be any value requested, and users can load any input independently.
 
RIAA Stage
 
The second stage of a phono system is the RIAA equalization circuits. Almost all phono preamplifiers use CR (capacitor-resistor) filters, usually in feedback loops for opamp designs, or between gain stages in some more expensive tube and discrete JFET circuits.
 
The Talos preamplifier had to use the best possible RIAA equalization technique, so we used a constant impedance transformer coupled LRC RIAA equalization subsystem. A small transformer loaded tube SET amplifier drives the RIAA transformer system. The RIAA equalization curve is achieved within 0.2 db in the audible range, and the ultra low constant impedance of the LCR circuit is virtually sonically transparent.
 
Output Stage
 
The third stage in the Talos Reference is the output stage, and is a transformer coupled triode stage using the E280F super tube. A step down transformer provides low output impedance, galvanic isolation and more than enough power gain (voltage and current) to drive any amplifier on the market.
 
Power Supply
 
The small SET amplifier driving the LCR RIAA and the small SET output amplifier are both powered by their own separate power supply units.
 
The external power supply is connected to the main chassis via a heavy duty umbilical chord. This ensures complete magnetic separation between the power transformer and the eight signal transformers.
 
The Talos Series phono systems are our answer to designing and building the best phono preamplifiers. Accompanied with a top analog turntable and cartridge system, we firmly believe that they are the top reference audio source today.