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For Sale: AMB M3 Stereo Headphone Amplifier and Preamp + Sigma 25 Regulated Power Supply

post #1 of 4
Thread Starter 
This Classified is Closed

For Sale:
AMB M3 Stereo Headphone Amplifier and Preamp + Sigma 25 Regulated Power Supply

Will Ship To: US - Lower 48 States

AMB M³ Stereo Headphone Amplifier with a σ25 Regulated Power Supply. Built with parts sourced from AMB and Mouser.

 

As per AMB: "The M³ is a high-end DIY stereo amplifier for dynamic headphones. It includes a number of distinctive features, carefully considered to maximize performance."

 

I built it myself to the recommended specs on the AMB website with the Variable Gain (range of 2 to 13.75) option you can use it with a wide range of headphone impedances, giving you fine control over the volume. It has two Alps "Blue Velvet" pots for the Volume and Variable Gain controls. It also has Vishay resistors, as well as Nichion and Wima capacitors throughout. It comes with OPA627AP opamps installed and 3 AD8610AR opamps for rolling.

 

I added a pre-amplifier function that can be implemented via the toggle switch on the front panel.

 

As per AMB: "The low-noise performance and moderate voltage gain of the M³ also makes it an excellent line-stage pre-amplifier."

 

The M3 is built into an aluminum Hammond case that measures 8.66" x 6.3" x 2.1".

 

It is in perfect working condition, sounds excellent, has no dings or blemishes.

 

I have listened to the Sennheiser HD 650, Alessandro MS-1, ATH-M50, Sony MDR-V6, and Koss Porta Pros. All sound great with this amp.

 

It comes with an outboard σ25 Regulated Power Supply (110/120V input).

 

The σ25 is built into an aluminum Hammond case that measures 6.3" x 4.06" x 2.09".

 

As per AMB: "The recommended configuration for the M³ is to use an outboard power supply. This allows the power transformer and other AC components to be located far away from the sensitive amplification circuitry for minimum induced hum and noise."

 

Details:

 

- Nichion electrolytic capacitors (low ESR, low impedance, low noise, high ripple current, high temperature, and long life).
- Wima Metal film caps.
- Vishay precision resistors and rectifiers.
- Alps Blue Velvet potentiometers for Volume and Variable Gain.
- Neutrik locking 1/4" headphone jack.
- Gold plated chassis-mount RCA jacks.
- Separate aluminum enclosures for M³ Stereo Headphone Amplifier and σ25 Regulated Power Supply.

- Toroidal power transformer for PSU.

- IEC AC inlet with built in fuse chamber and switch.
- Gold plated DIP sockets.
- Blue chassis-mount LEDs.
- Knurled aluminum knobs.

- Silver plated, Teflon insulated copper hookup wire used throughout.

- Preamp option via toggle switch.
  

Please see these reviews for additional information and listening impressions.

 

$20 shipping via USPS Priority Mail. Payment via PayPal. Or Local Pick up in New York City.

The M3 will ship on the next business day following payment. It will be shipped USPS Priority Mail (2-3 business days).

 

Please see eBay feedback @ eBay My World - blingblingdr

PM me for high resolution pics of the complete build process.


Edited by BlingBlingDr - 10/24/14 at 7:28am
post #2 of 4
Thread Starter 

Price Drop!

post #3 of 4
Thread Starter 

Bump and Price Drop!

post #4 of 4
Thread Starter 

$OLD!!!

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