So you have your fancy turntable, tonearm, cartridge, and you are good to go right? Not so fast. You see… the signals from your cartridge are really small and weak. How small you ask? 0.2mV for a MC cartridge. They are useless until they are amplified. And the first step in this process is the phono amp or phono stage. What it does is boost the signal (increases the amplitude) to a line level signal, which in turn is usually amplified again before it is directed to the speakers. The phono stage will also need to be of a design that is compatible with your cartridge; either MM or MC. Fortunately most phono stages will have circuitry for both types. (Although some do not)
And as you have probably already guessed from my other articles on this topic the remainder of this one will be highlighting some of the esoteric products available at the higher end of the price scale. And, as with other high end audio equipment, it goes from the sublime to the ridiculous…
I’ve always liked the classic look of McIntosh. Plus they know a thing or two about tube amps. This reasonably priced unit is no exception. It has 4 tubes with 2 tubes per channel making it a fully balanced configuration. It has 3 sets of RCA inputs which is very handy if you have multiple tonearms or turntables. All of the inputs can have both resistance and capacitance adjusted and comes with pre-programmed profiles for MM and MC cartridges. Additionally there are 5 other fully customizable profiles. Plus there are 78 analog equalization curves included.
A Rumble Filter is included that helps remove noise that may have seeped into a song during the recording process; while a Scratch Filter can help restore the sound of frequently-played records that may have become worn.
To help combat noise, the MP1100 features a dual mono design with the left and right audio channels electrically and mechanically isolated from each other while the power supplies are electronically separated.
This unit is probably getting in the air of being not reasonably priced.
Much of the PhonoBlock’s effortless musicality can be attributed to power supply capability. The power available to the amplifier section is a bedrock solid foundation. Precisely defined by fixed current regulators, shunt voltage regulators right at the load and over 100,000 microfarads (per mono chassis) for energy storage. It takes nearly 20 seconds for this huge reservoir to fill up when AC power is applied.
The base of the unit is laser machined 12 gage cold rolled steel. That robust platform is protected epoxy power coat finish. The theme of sturdy construction is also evident in the circuit boards. At 1/8” thickness, the PhonoBlock Fiberglass FR-4 circuit boards are twice as thick as normally seen. Individual components are isolated from any mechanical movement.
Sometimes ground loops can cause hum in a sound system, at these can be frustrating to isolate and eliminate. On the PhonoBlock however there are options on the audio circuit’s ground reference. Each mono chassis has three grounding options. They are selectable by moving a gold-plated shunt: Audio ground can float with respect to the chassis | Audio ground can tie directly to the chassis | Audio ground ‘softly’ connected to the chassis thru a 50 Ohm resistor
There will be only one gain/load configuration will be optimum for a given system. Whilst there are a variety of ways of accomplishing this what the PhonoBlock does is to keep the signal path tight and uncluttered. They do this by using gold plated plug in configuration boards. Signal path length is kept very short and direct. Only the one, optimum value component is applied to the signal path.
The PhonoBlock comes with 4 gain options and 7 cartridge loading values. In addition, blank plug-in boards are included for fine tuning with custom values
Pure Swiss esoterica. It comes as two boxes. One contains two mono-block amplifiers, the other the power supply. The power supply alone weighs in at 23kg!
The L10 is a fully discrete, and balanced design, with ultra-short signal paths and heavily regulated and filtered, multi-stage power supplies, wide-bandwidth, high slew-rate and DC coupled topology that incorporates R-2R ladder volume control, sophisticated DC detection and cancellation circuitry and software control. Signal path routing is refined, to reduce induced noise and distortion. The external power supply is a dedicated design, optimized for the L10. Feedback topology can be user selected between local and global settings to suit musical preferences and system requirements.
The result of all of this is the most musically sophisticated line preamplifier that money can buy: A lower noise-floor, increased transparency, harmonic layers and textures (especially at low frequencies), wider dynamic range, greater dimensionality and a more natural tonal palette.
Versatility, upgradability (to full four-chassis, true monaural topology) user configurable operation and a full-function control interface come as standard.
Next up…. POWER amps….