Anistardi Peletuk

[thimios]

Good find, Thimios, these tiny mistakes are very hard to find........

Hugh

Thanks Hugh,too many projects in the same time....
I will post the circuit diagram as built and measurements for easy troubleshooting if any interesting...

 

[thimios]

Is tis your first job done with PCB ?

I did a lot of work with PCB yours is great ... but try to reduce the diameter of the holes in the copper foil .... as small as you can only to give a center to start the drill bit, then you will keep as much copper as possible ... soldering will be easier and stronger.

Yes,it is absolutely necessary to increase pads diameter.

Just checked Anistardi´s site to check the schematic.

I find it weird and counterintuitive that the thermal sensor is a mid power transistor (BD139) but power transistor drivers are flimsy TO92 low current transistors such as 2N5401/5551 , quite unsuitable for the task.

Yes these TO92 run realy hot.

 

[thimios]

YouTube

 

[Vrystaat]

Well done Thimios, sounds good !!

 

[bimo]

YouTube

What is your impression?

I'm sorry i'm late because I take a holiday from 6 June until now.
Please take measurements of this amplifier.

 

[thimios]

Yes bimo, i will.

 

[bimo]

Yes bimo, i will.

I want to see FFT of low level ex. at 1W/8Ohm and high level near clipping.
I found in simulation, OITPC compensation always make harmonic profile almost monotonic at low level, and sometime at high level too.

 

[thimios]

I have prepare a scope test just now.
The fft measurements will be in the afternoon or tomorrow, sorry i can't do faster.

 

[bimo]

I have prepare a scope test just now.
The fft measurements will be in the afternoon or tomorrow, sorry i can't do faster.

No need to hurry.
Whatever you have time, I can wait.

 

[thimios]

As built measurments

Here are measurments for easy troubleshooting.
Power Supply=+/-33v
Bias=20mA
Offset=3mV.
Sensivity.input signal=700mv Out=15.7v just before clip.
gain =22
Power out=35W RMS/7 ohm.

 

[thimios]

Scope test

Here is the scope measurements.
Clearly shown a little overshot.

 

[thimios]

No comments?

 

[thimios]

I want to see FFT of low level ex. at 1W/8Ohm and high level near clipping.
I found in simulation, OITPC compensation always make harmonic profile almost monotonic at low level, and sometime at high level too.

Here is the fft analyze.

 

[thimios]

The rest

 

[AKSA]

Hi Thimios,
After seeing the schematic I was interested, and when I saw the harmonic profile I was VERY interested.......
So, I ask you now a day or so later when you've had a listen, what do you hear with the sonics? Does it sound as good you expected?
Cheers,
Hugh

 

[bimo]

Just checked Anistardi´s site to check the schematic.

I find it weird and counterintuitive that the thermal sensor is a mid power transistor (BD139) but power transistor drivers are flimsy TO92 low current transistors such as 2N5401/5551 , quite unsuitable for the task.

I use transistor TO92 transistor driver only for amplifier with PSU 25VDC maximum. With optimal bias class AB, it is OK. It is verify on simulator, and many people was built them. Of course, it is can not use higher bias.

BD139 for thermal sensor, because it easy to mount and cheap

 

[bimo]

Hi Thimios,
After seeing the schematic I was interested, and when I saw the harmonic profile I was VERY interested.......
So, I ask you now a day or so later when you've had a listen, what do you hear with the sonics? Does it sound as good you expected?
Cheers,
Hugh

I'am afraid Thimios can not review of listening test, because as he said, he do not have proper speaker.

Hi, Mr. Hugh, I think you like harmonic profile of this amplifier
I think, the distortion can be reduce a bit if he use higher bias for the mosfet.

 

[thimios]

I'am afraid Thimios can not review of listening test, because as he said, he do not have proper speaker.

Hi, Mr. Hugh, I think you like harmonic profile of this amplifier
I think, the distortion can be reduce a bit if he use higher bias for the mosfet.

Sure, but now i have a pair of full range FANE 12-250TC and i'm looking for a proper box.
I can't review of listening test using one chanel only!
I will do this when the second chanel is done.

 

[AKSA]

Yes, Bimo, very nice profile, but I would be quite happy with higher THD as long as the profile is just the same.

It's a very good amp, with good manners in all the difficult tests.

Congratulations to you, and to Thimios!

Hugh

 

[bimo]

Yes, Bimo, very nice profile, but I would be quite happy with higher THD as long as the profile is just the same.

It's a very good amp, with good manners in all the difficult tests.

Congratulations to you, and to Thimios!

Hugh

Thank you to Dadod, who invented OITPC compensation.
With some topology, wider loop gain can have monotonic harmonic profile.
Class AB which sounded like class A?