adydula
Headphoneus Supremus
- Joined
- Dec 14, 2010
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I just completed a new Cmoy amp using TI speciffically designed for headphones op amp the 1688. AGDR just designed a circuit based on the cmoy with TI 1688.
A mint-tin CMOY headphone amp like no other! Uses the brand new Texas Instruments OPA1688 and (optionally) OPA1622 headphone driver chips. Ultra low distortion with extremely low idle current for long battery life. Uses either throw-away 9V batteries or lithium rechargeable batteries.
Texas Instruments has just released a brand new generation of headphone chips, available only in surface-mount packages. These chips have many benefits over the older chips:
The lowest Total Harmonic Distortion and Noise (THD+N) of any headphone chip to date
Extremely low quiescent (idle) current for low power draw and long battery life. Up to 1/6 the draw of some older op-amps.
High output current levels. The OPA1688 is rated for a maximum of 75mA per channel, while the OPA1622 is good for 150mA per channel. Most older op-amps in CMOYs are only rated at 20-25mA.
High capacitive load drive with no output resistor. Most op-amps used in CMOYs were never intended to drive the levels of capacitance found in headphones and headphone cables, resulting in oscillations unless series output resistors are used tp isolate the load. The new TI chips are designed to drive headphone CLOADs directly, with no output resistor.
So if you ever had a penchant to muck with some DIY...take a look!
Alex
A mint-tin CMOY headphone amp like no other! Uses the brand new Texas Instruments OPA1688 and (optionally) OPA1622 headphone driver chips. Ultra low distortion with extremely low idle current for long battery life. Uses either throw-away 9V batteries or lithium rechargeable batteries.
Texas Instruments has just released a brand new generation of headphone chips, available only in surface-mount packages. These chips have many benefits over the older chips:
The lowest Total Harmonic Distortion and Noise (THD+N) of any headphone chip to date
Extremely low quiescent (idle) current for low power draw and long battery life. Up to 1/6 the draw of some older op-amps.
High output current levels. The OPA1688 is rated for a maximum of 75mA per channel, while the OPA1622 is good for 150mA per channel. Most older op-amps in CMOYs are only rated at 20-25mA.
High capacitive load drive with no output resistor. Most op-amps used in CMOYs were never intended to drive the levels of capacitance found in headphones and headphone cables, resulting in oscillations unless series output resistors are used tp isolate the load. The new TI chips are designed to drive headphone CLOADs directly, with no output resistor.
So if you ever had a penchant to muck with some DIY...take a look!
Alex