BOSC - HiFi Monoblock Class-D GaN Amp

[stretchneck]

What external ac/dc power supply do you use?

 

[orchardaudio]

What external ac/dc power supply do you use?

56V:
https://www.arrow.com/en/products/sdi250-56-u-p219/cui-inc

48V:
https://www.arrow.com/en/products/sdi250-48-u-p219/cui-inc

 

[GreatLaBroski]

And just to be clear we're talking about 56v DC, not 56v+- DC, right?

 

[orchardaudio]

And just to be clear we're talking about 56v DC, not 56v+- DC, right?

Yes. Only +56V.

 

[GreatLaBroski]

Thanks, that's an important detail no doubt

 

[orchardaudio]

Thanks, that's an important detail no doubt

For the pinout you can use the one from the CUI datasheets above.

 

[kipman725]

Nice project, looks like the integrated TI GaN half bridges? have you considered a higher power version? I have had good results with GaN Systems 650V parts in other applications.

Is its a self oscillating design?

 

[GreatLaBroski]

For the pinout you can use the one from the CUI datasheets above.

Super simple. I'll most likely end up bypassing the Molex connectors anyway since I'm looking to do a 10-channel.

 

[orchardaudio]

I just placed the order for the bare circuit boards. So those of you who are purchasing parts on your own feel free to do so. Typical turn around on these is 4-6 weeks.

Looks like the bare boards will be arriving next week.

 

[orchardaudio]

Is its a self oscillating design?

Yes.

 

[GreatLaBroski]

Looks like the bare boards will be arriving next week.

Nice, that's exciting!

 

[GreatLaBroski]

I'm about to place an order for SMD stencils. Just to confirm, this is a one-sided board?

 

[orchardaudio]

I'm about to place an order for SMD stencils. Just to confirm, this is a one-sided board?

Yes single sided.

 

[orchardaudio]

BOSC has reached 40 orders. The $999 price is available until November 5th. After that, the price will go to $1249.

Order here:
Shop | Orchard Audio

This is the last chance to get these amazing amplifiers at this price.

Manufacturing of the BOSC amps will kick off on November 6th. Deliveries will start taking place 8-12 weeks after that.

 

[orchardaudio]

Also, fully assembled boards are available for $250 each. If you are intesrested please let me know before Nov 6th.

 

[orchardaudio]

Looks like the bare boards will be arriving next week.

There was a delay due to customs, it looks like they should be at my place on Friday, so I will be shipping them out the following week.

Also please take a close look at the larger inductors and the datasheet for the op-amps:

• Depending on how you plan on cleaning the board, the inductors cannot be washed as they are not sealed parts.
• The op-amps if washed need to be backed for 30 minutes at 85C to get rid of the moisture.

If you have any questionsconfused you can send me an email.

 

[pinnocchio]

Received my PCBs last week, thanks!

@GreatLaBroski : Did you ever made the stencil order? If yes, do you have some spares to sell?

Thanks
Do

 

[orchardaudio]

The BOSC amps made The Audio Beatnik's best of 2019 list:
https://bit.ly/2tt38Nd

 

[U101222]

I have a few questions:
1. Are you planning to continue selling modules for DIY?
2. Also, it seems that the amp needs only a +56V, so a simple but regulated SMPS with one output should be enough, right?
3a. Why are the the 4Ohm and 8Ohm models different? Gain, even input impedance and voltage are different.
3b. What would be the downside of using the 8Ohm (optimised?) model wth 4Ohm speakers, and viceversa?
4. The input impedance seems a bit low, so a buffer may be advisable in some circumstances, esp. without active preamp (as in my case). Would a buffer like Neurochrome's Universal Buffer a good complement?

Roberto

 

[U101222]

The power supply can be between 48 and 60V. The max output power of the amplifier will depend on the power supply voltage and load. You have to ensure that output power does not exceed 200W.

Interesting, the output power of the SMPS? What happens if the SMPS *can* deliver more?