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 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.
IN addition, many modern phono preamplifiers although provide a built-in MC phono cartridge support inside but the implementation is frequently just a boost of gain within the RIAA equalization stage. Such MC solution is a compromise of performance. It usually suffers from reduced bandwidth, stability and dynamic range, degraded S/N figure, inaccurate RIAA equalization, insufficient gain and elevated harmonic distortion. For optimal LP audio playback with LOMC* cartridges, such preamps if configured to MM/MI mode and use an external LOMC head amplifier, such as our MPA-1a, will improve the overall performance to a much unprecedented level.
MPA-1a is a MC step up solution that offers superior S/N figure, completely transparent sound reproduction, no sound colorization, extremely low harmonic distortion and wide input dynamic range.
* LOMC stands for low output moving coil.
Musicality and fidelity are two most important attributes to audiophile enjoyment. While musicality is the music itself of artistic beauty of music, the fidelity of the audio equipment is to faithfully reproduce, reveal and enhance the musicality of the music. MPA-1a is a LOMC solution that delivers the highest musicality and fidelity of musics recorded on vinyl records. The production is very limited. Don't miss the opportunity to collect one when it is still being made.
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) do. 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 owning superior LOMC phono cartridges for vinyl record playback.
Powered by two 9 volt DC batteries*, effectively eliminating 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 low signal level amplifier
. It's not like any conventional voltage amplification preamp which usually uses a low value shunt resistor at the input that is essentially a kludge implementation of MC support within a RIAA phono preamp.
MPA-1a operates on its input current rather than the input voltage. But it does not amplify the input current. There is no current amplification by MPA-1a. MPA-1a achieves the desired output voltage level by impedance transformation.
MPA-1a uses a pair of complimentary low emitter spread resistance NPN/PNP transistors for achieving 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 simple basic design without effort in dealing with odd number (3rd, 5th, etc.) order harmonics of the push-pull circuit
.
MPA-1a is significantly different from Dr. Leach's original design. MPA-1a is implemented with a solution to address the distortion issue effectively which results in a ultra low distortion and a completely transparent sound reproduction.
In technical terms, the distortion caused by the transistor beta difference between the PNP and NPN transistors is effectively minimized to a unmeasurable level.
MPA-1a uses a pair of DC battery to power the entire amp. It effectively eliminate AC hum from otherwise an AC 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 otherwise 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 request for 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.
Shipping:
We will ship your order within two business days, same day whenever possible on the day of receiving your payment.