The "Caffeine" Headphone Amplifier

The "Caffeine Ultra" Amp is truely a high fidelity amp at the lowest price possible. It uses the amazing AD8397 opamp and two TLE2426 railsplitter to create the virtual ground. Furthermore, it includes two slide switches for gain and bass boost (8dB). Advanced customers agree: If this amp would be housed in a "commercial" enclosure the price could be raised up to $200!

Superior Sound Quality

The amp is equipped with the newest generation of high performance audio amplifiers--the AD8397 opamp. Standard "CMOY" based amplifiers use the OPA2134 or OP2277 opamps which are capable of providing 25mA output current only (without buffers). The AD8397 is capable to provide 310mA output current with excellent linearity. Could you imaging how much better this opamp sounds? If you had compared this amp to the standard CMOY amp you would never want to hear a CMOY amp again!

Superior Build Design

The design of this amp is superior to others as it uses a professional circuit with two Keystone battery connectors. There are no loose cables to clutter the inside of the amp, and the Keystone connector holds the battery securely. Even when the amp is moved or flipped over the battery stays in place.

Powering the Amp

The amp needs one 9V battery for powering. You can expect 40-60 hours of battery life using alkaline batteries. Rechargeable batteries will last about 20 hours (depends on the battery type, music and headphones). Optionally a 9-18V DC external wall adaptor can be used to power the amp.

Battery Charging

The amp charges all 7.4 or 8.4V rechargebale batteries with a so-called trickle charging that forces a constant current (30mA) into the battery. A completely flat 250mA rechargeable NiMH battery will be charged in 8-12 hours and will last more than 20 hours using Sennheiser's HD650 at very load play back.

Attaching the Amp

The amp comes with four pair velcro dots. Four "Loop" dots are already sticked at the bottom. They look very nicely on the amp, safe the buttom from getting scratched and they can be used to attach the amp to any surface (player, laptor, desk etc.).

Key Features and Components

- AD8397 high performance opamp
- 2x TLE2426 railsplitter
- detachable bass boost (8dB)
- gain adjustment (3x/8x)
- trickle charging using LM317 constant current (30mA)
- black circuit board with chemical nickel-gold letters (no silk print!)
- toggle switch by NKK Nikkai
- 1/8'' (3.5mm) audio jacks
- blue low current LED in a silver housing
- Alps volume potentiometer (very low noise)
- solid aluminium volume knob with rubber rings
- 1% SMT resitors thin film type
- low-ESR 1500µF power cap (FC Panasonic series)
- 9V battery connectors by Keystone
- size with knob: 2.44" wide X 4.45" long X .95" thick (6.2 x 11.3 x 2.4 cm)


Currently sold out. Will be available in February again.