Various MC Step-Up Units Utilizing the HM-3

The HM-3 is a simply amazing step-up transformer for MC cartridges.  We are not quite sure if it's appropriate to mention the HM-3 on this Web site because this step-up transformer can be a treasure not only for tube amps, but also for any audio systems that equips with a MM phono stage.  The basic idea of the MC transformers is to amplify the MC cartridge output signal to the acceptable voltage level for MM phono equalizers through a transformer - without an active amplifier.  With the HM-3, the sound image becomes very wide and deep with three dimensional representation.  The low sound is very tight and the high frequency is crisp clear.  In essence, the vinyl sound through the HM-3 is the closest to the real live music.              

There are so many different MC cartridges in the market with wide variety of internal impedance and output levels.  The HM-3 is specifically designed for those MC cartridges whose internal impedance is between 2 and 40 Ohms with the gain of either 26 or 32 dB (x20 or x40 amplification).  Typical examples of MC cartridges work well with the HM-3 include Denon DL-103 and various Ortofon MC cartridges.   

No matter how good a MC step-up transformer is, it's worthless if the transformer is not properly mounted on a right chassis.  This is because we are dealing with a very low voltage signal, typically less than milli-volt, which is prone to picking up hum and noises.  With such a low signal level, even slight vibrations on hook up wires will alter the sound quality.  Therefore, for more than one year, we have been designing various chassis to mount the HM-3.  After many experiments, we have finally come up with two basic styles with four different models.  One of styles we have chosen uses a commercially prepared 2mm thickness aluminum chassis from Japan.  Another style is a very unique, milled metal chassis prepared by a professional machinist.

Each of these style has own strengths and weaknesses.  For example, 2mm aluminum chassis needs some modifications and reinforcements to withstand against hum and noises.  But, it's cheaper to build and allows to have switches to choose impedance.  On the other hand, milled metal chassis are heavy and free from hum and noises.  However, they are expensive and need careful engineering to finalize the sound.  This is because the chassis and hookup wires become almost a part of transformer that determines the final sound.  Because of this characteristic, milled metal chassis needs to be fixed for either 3 Ohms (between 2 and 7 Ohms) or 12 Ohms (7 to 40 Ohms) cartridge impedance.

Generally speaking, MC step-up transformers are like fine musical instruments.  With a commercial 2mm aluminum chassis, it's relatively forgiving on decent audio systems as if average musical instruments are for average players.  With milled metal chassis, even minor faults on your system will stand out like a sore thumb.  However, if you have a top quality well designed flawless system, you have to have the milled metal chassis simply because you can definitely hear the differences.

Being more specific, currently, we have four MC step-up units utilizing the HM-3, and one model is still under development (the milled OFHC copper model is in a proto-type stage).

Among them, the most basic model is called the Live! MC-10.  This model uses a 2mm thick commercial aluminum chassis imported from Japan. RCA connectors on this model consist of the WBT-0244, which is rated as a midrange WBT connector.  All internal hookup wires are made of silver plated copper wires.

 One step up model from the Live! MC-10 is called the Live! MC-10 HC (no photo is shown).  This model uses the same aluminum chassis as the Live! MC-10, but RCA connectors are the WBT NextGen 0210Cu Ms, which uses gold plated 99.99% pure cupper for both positive and negative conductive materials.  All hookup wires on this models use sliver plated 99.99% pure OFHC (Oxygen Free High Conductive) copper wires.  As the result, the sound of this model is a little smoother than that of the Live! MC-10.

 In addition, we have two upper class models, the Live MC-1 Supreme and the Live MC-10 Supreme.  These supreme models use a hard coat anodized milled aluminum chassis instead of the 2mm aluminum chassis.  As the result, these models are by-far free from hum and noises compared with standard MC-10 models.  Also, heavy weight of milled aluminum chassis prevents vibration and improves channel separation.  Consequently, Supreme models have wider and more three dimensional sound stage than standard MC-10 models have.  These supreme models use the WBT NextGen 0210Cu Ms RCA connectors as well as sliver plated 99.99% pure OFHC (Oxygen Free High Conductive) copper hookup wires.

The difference between the Live! MC-1 Supreme and the MC-10 Supreme is that the MC-10 Supreme has switches for low or high impedance settings, but the MC-1 Supreme does not use any switches.  In theory, the MC-1 Supreme should yield better sound than the MC-10 Supreme does because the MC-1 Supreme has the shortest hookup wires without switches which might potentially degrade the sound.  This could be said that the convenience of impedance switches is the trade off for the slightest deterioration (if any) of its sound quality.

Should you be interested in any of our MC Step-Up units, please contact us at support@obsinc.us, or call 269-624-4681 Ext-112, or 269-657-8738.

The "Live! MC-10" - with the 2mm Commercial Aluminum Chassis

The "Live! MC-1 Supreme" - with the Hard Anodized Milled Aluminum Chassis.  This model uses the WBT 0210CuMs NextGen RCA connectors as well as 4N (99.99% pure) OFHC silver plated copper wires for its internal hookup wires (these photos are showed with the WBT 0244 RCA connectors.)

The "Live! MC-1 Ultimate" - with the Milled OFHC Copper Chassis with 24K Gold Plated by Anderson Silver Plating in Indiana, US

This model is still in a proto-typing stage.

Our latest model, the "Live! MC-10 Supreme" - this model is equipped with the low and the high impedance switches, so that users can use wide variety of MC cartridges.  This model uses the WBT 0210CuMs NextGen RCA connectors as well as 4N (99.99% pure) OFHC silver plated copper wires for its internal hookup wires.

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Last changed: 02/01/15