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BOSC - HiFi Monoblock Class-D GaN Amp

Hello.

My company will shortly be launching a GaN Class-D amp - BOSC.

If there is enough interest from this community I can offer just the circuit board.

The modulator is a completely custom proprietary dual feedback design with switching frequency up to 900kHz.

Preliminary Specifications:
  • Gain: 16.8dB or 6.92 (For 8 and 6ohm speakers)
  • Gain: 13.8dB or 4.89 (For 4 and 3ohm speakers)
  • Signal to Noise Ratio (SNR): 121dB (A-weighted)
  • Total Harmonic Distortion (THD): <0.0003% (-110dB) @ 9W
  • Frequency Response: DC - 60kHz+
  • Sensitivity: 2.5Vin for 37.5W
  • Input Impedance: 5kohm fully balanced for 8ohm amp
  • Input Impedance: 7.1kohm fully balanced for 4ohm amp
  • Output Power: 150W into 4ohm
  • Output Power: 150W into 8ohm
  • Board Size: 3.64'' x 3.3''

More info:
BOSC | Orchard Audio

Tour Participation:
1. pinnocchio
2.
3.
4.
 

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Am keen and have some questions.

Why the low input impedance of 5k ohm?

What's a suitable PSU to drive them without noise when powering compression drivers actively?

Low input impedance to maximize noise performance.

For the 4 ohm version you need 48V 250W minimum.
For the 8 ohm version you need 56V 250W minimum.

I use off the shelf SMPS supplies as the amplifiers have very good PSRR and all specs listed are with the SMPS supplies.
 
Any chances of getting a demo going around Canada and USA so we can test it?

I've got so many amps and I'd like to first know if the amp works well with my speakers and equipment and if the sound signature is what I like. Then I would commit to PCBs

Thanks
Do

I am already planning to do this. I will start a list in the orinal post of people who are interested.
 
See attached images for some additional test results.
 

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An awesome review for the BOSC amp:

"Class-D amplifiers generally trigger reactions and opinions of a generic, mass-market sound. And I’ll admit, I tend to not be too curious about anything based around that amplification method. But Leonid (Leo) Ayzenshtat’s Class-D amplifiers continually force me to think differently. They prove that it isn’t about the type of thing, but rather about how skillfully a thing is made."*

"I wanted to stop my heart so I could hear the music better. I was being sucked in, pushed out, and unable to focus on anything else but the music. There were all the little bird-like chimes, dancing between clicks and pings and bongs of xylophone harmonics with dry reed raspy sounds zooming in and out, floating on top of deep rolling strings and organ-like bass. I didn’t want to miss a moment of it."*

Read the full review here:
https://theaudiobeatnik.com/reviewing-the-orchard-audio-bosc-monoblocks/
 
I recognize that, but you said earlier in the thread that you’d consider selling PCBs if there was sufficient interest. I’d probably be interested in buying 10 PCBs depending on the BOM price, if you were to offer it. However at the current completed board cost it’s not within budget for me.