Janis uses a combintation JFET and tube cascode input circuit with an Aikido-style output buffer. We use the JFET as the first stage of the input section due to the far superior low noise level than with a typical tube. This is by far a superior method especially in a lo- level stage such as a phono preamp. Gain for this version is 45dB.
Particular time and attention were given for the RIAA circuit, and we typically use a pair of resistors in series to arrive at the correct values required by the RIAA eq circuit.
Our unique cartridge impedance matching circuit consists of a number of low noise, high precision Vishay CMF series resistors, which are then combined in varying degrees via the mini DIP switches to arrive at the correct cartridge impedance used.
As with the MM/HiMC circuit, for the MC/LoMC version Janis uses a combintation JFET and tube cascode input circuit with an Aikido-style output buffer. The main difference between this version and the MM/HiMC is that we now use a solid state CCS (Constant Current Source) in the second stage rather than a standard resistive load. We chose this in order to achieve the required gain of 56dB for MC cartridges. This method of using the CCS is far superior than trying to electronically increase the gain at the input stage, which can have negative effects on the overall preamp performance.
Again particular attention and time were given for the RIAA circuit, and we typically use a pair of resistors in series in order to arrive at the correct values required by the RIAA eq circuit. To achieve the even higher gain of 65dB required for LoMC cartridges, we use the excellent Lundahl LL1678 SUT (Step Up Transformer) at the input stage, which is switched into the input circuit via a toggle switch accessible from the rear panel. As an option, we can offer the Lundahl LL1941 SUT's. Please see previous page for pricing.
Our unique cartridge impedance matching circuit consists of a number of low noise high precision Vishay CMF series resistors, which are then combined in varying degrees via the mini DIP switches in order to arrive at the correct cartridge impedance used.
Much time and care were taken in the design of the power supply as any shortcomings here will show themselves in the resulting tone of this phono preamplifier. To that end, we chose a solid state power supply, a regulated B+ high voltage and a regulated DC filament supply, one for each channel. This resulted in an ultra quiet power supply that is extremely stable with NO variations no matter what variations there may be from your household 120VAC power outlet.
Two low noise toroidal transformers, one for B+ and one for filament, housed in a fully shielded aluminum enslosure contribute to the ultra low noise environment.
A 120V/240VAC 60/50Hz selector switch on the rear panel allows Janis to be used anywhere in the world.
Only high quality components are used in the construction of Janis. Low noise, +/-1% variation Vishay CMF series metal film resistors are used throughout the signal circuit, and high quality Panasonic metal oxide resistors are used in the power supply circuit. WIMA film and Nichicon electrolytic capacitors are used throughout. Coupling capacitors are Mundorf MCap EVO series. Tube sockets are ceramic gold pin units.
The printed circuit board is designed in house and manufactured to FR4-TG standards using double layers with full ground planes on both sides to ensure complete screening of the circuits.
RCA sockets are gold plated.Tubes are a factory new, quad set of matched Genalex Gold Lion E88CC's.
Phono preamplifier gain for MM/HiMC - 45dB
Phono preamplifier gain for MC - 56dB
Phono preamplifier gain for LoMC - 65dB
RIAA response is flat across the audio band, down 0.5dB at 10Hz and 0.1dB at 40KHz
Chassis size: 14.5"W x 12"D x 8"H