The combo you see here – one BOZ 216 control unit and two BOZ 2200 digital amplifiers were products way beyond their time. They are to a certain extend, incredibly complex units and so over engineered, there is almost none like it in the market. You can read up more from the online manual (too much to condense it here!) but to put it in real layman terms, the 216 is the preamp and also the power supply to the 2200 amps. The 216 can power up to eight 2200 amps for sixteen channel of amplification if you ever want to go the full boat on it. But in this combo, it will just power up the 2200 amps (which the previous owner used to biamp his speakers). The 2200 digital amp, to put it in real loose terms is a powered DAC. As in a DAC with the ability to drive speakers. The BOZ-2200 modules are an ultra high precision D/A converters operating in PWM mode with a master clock set at a speed 2,222 times higher than the CD format, 1,024 times higher than DVD-Audio and 35 times higher than the SACD format. In contrast to conventional D/A converters, it operates at a switching voltage of more than 60 Volts, delivering the equivalent of 400 Watts per channel in 4 Ohms. All internal signal processing is performed at 96Kz. Being that the setup is all digital, it only accepts digital inputs from a digital source. So the digital source unit will send its digital output to the 2200 where it converts (via its 24 bit/ 384 KHz DAC) and amplifies the signal where it will transmit out through its speaker binding post into your speakers. This greatly reduces the complex chain found in conventional amps. The 216 on the other hand is involved in powering up the 2200 and controlling the volume and functionality of the 2200. Each 2200 is capable of 200W in 8 ohms or 400W in 4 ohms. Both the 216 and 2200 cannot work on its own or with other brands. Each 2200 is hooked up to the 216 via its speakon connector cords (which is how the 2200 is powered up) and instructions/communications are exchanged between units via the RJ11 cables. Between the 2200 units, a second digital cable (other than the one from the digital source) is needed to “share” the incoming digital signal (via daisy link) from the digital source so both 2200 will output the same signal to the speaker. The 2200 powered DAC’s display can be switched to show volume level or incoming sampling frequency which we have set separately for each 2200 in the pics. So you can either set for both to show volume level or sampling frequency.
Once all the above is done, you are ready to enjoy this groundbreaking combo. What to expect? Probably the most neutral sounding system found anywhere. And because it cuts through and simplifies how signals are converted to sound, the resolution they are capable off is incredible. It doesn’t pick certain frequency range to emphasize but rather, tackles it from zero to whatever the signal extends to. All in full resolution. From its manual – “The BOZ-2200 modules are an ultra high precision D/A converters operating in PWM mode with a master clock set at a speed 2,222 times higher than the CD format, 1,024 times higher than DVD-Audio and 35 times higher than the SACD format. In contrast to conventional D/A converters, it operates at a switching voltage of more than 60 Volts, delivering the equivalent of 400 Watts per channel in 4 Ohms. All internal signal processing is performed at 96Kz.” Truly some spectacular stuff in there and that is just skimming the surface on what is inside those units.
Cosmetically, there are some minor scuff marks here and there but nothing major. The 216 weighs as much as some power amps at 73 lbs and each 2200 is about 25 lbs. We don’t have the original boxes but will securely pack them in two boxes for shipping – the 216 in one and the two 2200 in another. These are very hard to find pieces especially one in this condition and completeness. In terms of digital technology in audio, they are at the forefront of it all. For under $5,000 now, you are getting two very powerful amps with onboard DAC, preamp and an outboard power supply that will compete against some of the best out there at any price point.