Harmonious Audio MPA-1a Moving Coil MC Head Amplifier Preamplifier

Description

Untitled Document
Moving Coil Phono Cartridge Head Amplifier
MPA-1a
The item listed for sale is a
HMS Audio
MPA-1a
moving coil phono cartridge head amplifier, a MC pre-preamplifier or more commonly called a
MC Head Amplifier
.
Most quality vintage RIAA phono preamps were made without a moving coil phono cartridge support. MPA-1a is exactly designed for filling the missing part of such vintage RIAA phono preamps without a MC stage inside.
Many newer phono preamplifiers may indeed provide a built-in MC phono cartridge support inside but unfortunately the implementation is usually just a boost of gain within the RIAA equalization stage. Such MC solution is a compromise of performance. They mostly suffer from reduced bandwidth, stability and dynamic range, degraded S/N figure, inaccurate RIAA equalization, insufficient gain and elevated harmonic distortion. For optimal LP audio reproduction with LOMC* cartridges, it is best to configure such preamps to MM/MI mode and leave the LOMC step up function to an individual external LOMC head amplifier such as our MPA-1a.
MPA-1a is a MC step up solution that offers superior S/N figure, completely transparent sound, no sound colorization, extremely low harmonic distortion and wide input dynamic range. Your phono preamp configured in MM/MI RIAA equalization mode will work much nicer with an external MC support.
* LOMC stands for low output moving coil.
Musicality and fidelity are two most important attributes of audiophile enjoyment. While musicality is the music itself that provides the beauty and art of music the fidelity part really relies on the audio equipment to faithfully reproduce and enhance the musicality of the music. MPA-1a is a high quality MC solution that delivers the highest musicality and fidelity at a unthinkable low price. The production is very limited. Don't miss to collect one while it's still being made. You will not be disappointed.
Design Highlight:
High gain, wide bandwidth, ultra low noise and distortion.
Single ended, AC coupled input and output,
Class A, complementary push-pull with harmonic distortion nullifying optimization.
Constant 100 ohm input impedance at 32 db gain.
No loading effect like SUTs (step up transformers). No SUT gain/impedance matching issues.
Built-in bypass switch, no re-cabling needed when switching between MC and MM/MI phono cartridges.
Low entry cost barrier for utilizing the superior LOMC phono cartridge for vinyl record playback.
Powered by two 9 volt DC batteries*, one per channel, effectively eliminate AC hum pick up from the power supply.
Micro power consumption at 0.0018 watt per channel. A pair of fresh battery can last over a year.
Designed and manufactured in California, USA
* Please note: 9 volt DC batteries are not included
Performance Facts:
MPA-1a is a trans-conductance ultra small signal amplifier. It's not like any conventional voltage amplification preamp with a low value shunt resistor at the input which is essentially a kludge implementation of MC support of a RIAA phono preamp.
MPA-1a operates on its input current rather than the input voltage. In fact, MPA-1a does not amplify the input current nor the input voltage. There is no voltage nor current amplification by MPA-1a. MPA-1a works by the principle of converting impedance electronically.
MPA-1a uses a pair of complimentary low emitter spread resistance NPN/PNP transistors for achieving a ultra low thermal noise figure. Very few FET, tube or operational amplifier based designs can match the low thermal noise performance of MPA-1a.
MPA-1a is a latest evolution of the design by Dr. Marshall Leach of Georgia Institute of Technology published in the 60's. Dr. Leach's design was a plain basic design without effort in optimizing its performance, especially in terms of harmonic distortion.
MPA-1a is significantly different from Dr. Leach's original design. It adds a circuit that applies exactly 100% equal amount of feedback to both positive and negative phase of the complimentary circuit which minimizes/eliminates the harmonic distortion so effectively that it results in a completely transparent sound reproduction due to the effectiveness in the harmonic distortion reduction. This is a significant improvement over the original basic design by Dr. Leach.
MPA-1a uses a pair of DC battery to effectively eliminate AC hum from an AC powered power supply. MPA-1a is a design with a minuscule power consumption. A pair of DC 9 volt Alkaline batteries can last over a year. Users of MPA-1a can virtually forget about the batteries for a year. Since the amplifier consumes so little electricity no power indicator (such as use of a LED) is implemented which would have consumed far more electricity and reduced the service life of the batteries.
Specification
:
Application:
For all low output moving coil phono cartridges.
The output of MPA-1a should be connected to the input of a MM/MI RIAA phono preamplifier with a standard 22 - 100K ohm input impedance.
Voltage Gain:
32 db.
Input Impedance:
100 ohm at 32 db.
Output Impedance:
~ 4K ohms
Output Driver
Class A complementary push-pull
Input/output coupling
AC coupled.
Bandwidth:
5 Hz ~ 100 KHz +/- 3db.
S/N figure:
Greater than 70 db.
THD:
Less than 0.002%.
Power Supply:
Two 9 volt alkaline batteries (
not included
), one for each channel. The batteries will last from 6 month to over one year with typical moderate use.
Warranty:
In addition to our eBay return policy our MPA-1a MC head amplifiers are sold with a free one year warranty. The warranty covers the electronics of its materials, functionality and workmanship. All wear and tear of the chassis is not covered under the warranty.
If within one year of your purchase of MPA-1a the amplifier stops working simply contact us to send it back to us for a free repair. We will repair or replace the amplifier for you for free. Please note that it will be the customer's responsibility for the small cost of shipping. The warranty repair will be totally free otherwise.
Shipping:
We will ship your order within two business days, one day whenever possible upon receiving your payment.