The Black Hole......

[Bonsai]

From Croatia.🙂

 

[31697B]

Damir,

I changed the power supply to +/-35vdc at 5A total idle, 24 OP devices and fixed a HF osc with RC at each FET; Improved SOA.

Here is max power THD+N at 2 Ohms.





-Richard

 

[dadod]

Damir,

I changed the power supply to +/-35vdc at 5A total idle, 24 OP devices and fixed a HF osc with RC at each FET; Improved SOA.

Here is max power THD+N at 2 Ohms.

View attachment 829273



-Richard

So, it's about 80W at 8 Ohm?

Thx, Damir

 

[31697B]

So, it's about 80W at 8 Ohm?

Thx, Damir

A little more than 100W into 8 Ohms.




and 200W with 4 Ohm...



[@ 1% THD+N]


-Richard

 

[billshurv]

Not many of us are brave enough for an upgrade to include a 10dB reduction in output power!

 

[Zung]

Perfect for a flat at Sukhumvit road; 10dB more would mean trouble. 🙂

 

[Hans Polak]

A little more than 100W into 8 Ohms.

-Richard

0.5Watt into 8 Ohm is 2 Volt rms out.
Assume that the specified 20ppm at 0.5 Watt is just white noise.
20 ppm of 2Volt is 40uV at the output or circa 1,3 uV RTI.
Not knowing the BW that was used, but when taking a usual 80Khz, this translates into ca 5nV/rtHz.

Sorry, but I find this a bit hard to believe.

Hans

 

[dadod]

A little more than 100W into 8 Ohms.


View attachment 829320

and 200W with 4 Ohm...

View attachment 829321

[@ 1% THD+N]


-Richard

Richard you can't get 100W at 8 Ohm with +-35V DC, some of this is wrong.
Damir

 

[vacuphile]

Hans, the slope triggered an alarm with me, thanks for putting a label on it!

 

[Hans Polak]

Richard you can't get 100W at 8 Ohm with +-35V DC, some of this is wrong.
Damir

When bridging amps you can achieve 100Watt in 8 Ohm with +/-35Volt.
With the 5 amps idle current per single amp, it will mean 20 Amp for a stereo set.
This will be approx 2000 Watt fom the mains.
For each CD that is played, the Power Plant Operator will charge you for ca. $ 0,40 😀 😀

Hans

 

[dadod]

When bridging amps you can achieve 100Watt in 8 Ohm with +/-35Volt.
With the 5 amps idle current per single amp, it will mean 20 Amp for a stereo set.
This will be approx 2000 Watt fom the mains.
For each CD that is played, the Power Plant Operator will charge you for ca. $ 0,40 😀 😀

Hans

Bridged amp with +-35V power supply can deliver 200W/8 ohm but nobody said it's bridged.

 

[31697B]

I'll ask EE who did the tests to check the PS voltages.

My speaker sens is 92db/W/m so it doesnt take too much power.

THx-Richard

 

[jjasniew]

Cute young woman always cheers me up.

You must've done (or been) something very right in this life - or still are!

 

[31697B]

Bridged amp with +-35V power supply can deliver 200W/8 ohm but nobody said it's bridged.

Not bridged.

he said.... "Use standard (Vdc) x (Vdc)/2Rload'

Might be THD and not THD+N. he will use another instrument to double check the numbers. label at top of screen may be wrong.

PS voltage is actually +/- 42vdc


THx-RNMarsh

 

[vacuphile]

Good managers don't waste anybodies time like that.

 

[31697B]

Good managers don't waste anybodies time like that.

hahaha Cute. He is closet to factory. I cant get there. Maybe you've heard something about a virus?

I would much rather do all the tests I am interested in myself.



-RNM

 

[billshurv]

OK looks like I missed some fun again!

 

[Hans Polak]

OK looks like I missed some fun again!

It seems that Richard Marsh has now morphed into Mr Sin Bin in Thailand.
A Sin Bin is a Penalty Box, so is he punishing himself ??

Hans

 

[billshurv]

Ah, I see my confusion There is a forum glitch so under the new name his homepage has no posting history but all old posts can be found under 'show more posts'.

 

[hhoyt]

Sorry for the off topic post, but it seems appropriate to now.

There is a group of people on Groups.io that is designing a ventilator as an open source project with what appears to be a qualified group of engineers and medical people.

ref: Circuit Board for Bare-Bones Ventilator Moves Toward Production with Radio Amateurs’ Help

VentilatorDevelopers@groups.io | Home

if you can be of service to this activity, or you can adapt it to your part of the world...
I think the rest is self evident.

Go in good health
Alan

Hi Alan,
I am working with the group on that ventilator project, it is progressing rapidly...I am peripheral to the group and actually just doing machining for the microfluidic mixer, nothing electronic...
From what I have been told production quantities of parts should be available within a few weeks...of course there are a few legal hurdles to jump...from FDA to patent clearances...

Cheers!
Howie / WA4PSC