Beast with 1000 JFETs redux?

[lastnamenelson]

A novice builder stumbles onto this thread and says:

Nelson's circuit board reminds me of an IC, with duplicated transistors and resistors. Could a circuit like this be put on a chip, or would the voltage/current be too high, causing too much heat?

 

[rayma]

Single devices can be made of small monolithic, interconnected transistors, while the beast is made with discrete parts.
The power device die is thermally limited at some point, while the beast can just have more parts added.

 

[Biosonar]

Following Nelson’s introduction, here is the finished Mini Beast headphone amplifier. It puts out 5 watts, with zero feedback, low distortion and drives low impedances.

Pictured behind the Mini Beast is an electrostatic headphone transformer and bias supply for driving electrostatic headphones. The transformers were designed and built by Dave Slagle. Both are run by 24 DC volt supplies.

These will be demoed this weekend in the Refined Audio room at Capitol Audiofest.

 

[Zen Mod]

 

[stretchneck]

Interesting - can you get 10w into 8/4ohms running mono balanced? Looking forward to the technical paper on this one…

 

[BRN]

Had a chance to listen to the Mini Beast with Cube speakers in the Refine Audio room. This was one, if not, my favorites at show. The Cube speakers sound great.

 

[stretchneck]

Cool - was there anymore feedback on when we can expect to see further details?

I’ve heard Cube audio as well, they were nearly my ideal speaker - but at the time they sounded slightly too forward for my liking (I’ve now realised that it was likely the DAC they were paired with). I need to try them again at some point…

 

[lastnamenelson]

@BRN: Any chance you can post a photo of the Mini Beast with speakers?

 

[BRN]

Sorry, I did not take a picture with both. I believe the speakers were the Nenupher Mini.

 

[adason]

Here ya go...

 

[lastnamenelson]

@adason: Perfecto!

@adason & @BRN: How did the setup sound? What was playing?

 

[adason]

I am not a fullrange person. Was trying to listen to headphones, but it was not available.

 

[lastnamenelson]

Gotcha. Thanks.

 

[BRN]

@adason & @BRN: How did the setup sound? What was playing?

The base was extended and the sound is cohesive and natural sounding throughout. That is something that I like and single drives seem to do so well. They were playing some blues. The speakers were a great match with the Mini Beast.