100W Hi-Fi audio amplifier!

radio · 2011-09-12 4:17 pm

Hi all!

After a long time whose resih to design a 100W amplifier that is very simple, economical, but it is very good for beginners and the other for home use! :shhh:

For starters here's schematic (Figure 1).
thanks and cheers ! :smash:

east electronics · 2011-09-12 5:49 pm

are you placing this schematic for evaluation?
if you do please say so so people understand .

if you claim that this is a working schematic you need to say more about the construction ,listening impressions, details and fotos of prototype and so on and on ...

if you expect people to construct the ampliier in order to debug any mistakes i think this is a bad practice ..

CBS240 · 2011-09-12 6:15 pm

A quick evaluation shows me this is a poor attempt to modify a quasi-comp output amp to a complementary OPS. The output Z and thus gain will not be the same for positive and negative output swings because Re for T11 is missing. :shhh:

DF96 · 2011-09-12 6:29 pm

Yes, it looks like a poor attempt to modify an already weak circuit. The VI limiting for T11 has not been swapped to the opposite polarity! The input LTP will be unbalanced due to a simple resistive load. Best ignored.

kikikaka · 2011-09-12 7:00 pm

And the low-side "over-current protecting" circuit is actually not protecting against anything, just drives the low-side output transistor into death...

radio · 2011-09-13 6:22 am

Hi all!!
I'm sorry I put the wrong schematic of this amplifier.

The original is this!!

Technical parameters:
Supply voltage: Uccmax=+/- 42V
Output power: Pomax=100W/4R
Frequency response: fo=10 to 83kHz/-3dB
Harmonic Distortion:THD 0.12% for 100W/1kHz; 0.013% at 100W/10kHz
Intermodulation distortion: 0.28% at 80W / 80 +7 kHz
Input sensitivity: approx. 1V
Current protection: 2x3,15A fast fuses
Speed during SR: 14V/us
Min. impedance: 4R

thanks and cheers

44250 · 2011-09-13 8:13 am

hmm...

If he is who I think he is... I'd like that I'm wrong. Time will show. Here in Serbia there was a guy that used to do things at forums just like radio,and behaved the same way. Not just in Serbia,he was active at all forums in ex-YU countries (Croatia diyaudio.com.rh ,Bosnia and Herzegovinia elektronika.ba ,Serbia www.elitesecurity) using diferent nicks:ZX-O,slavko and a few others always offering changed and "impruved" schematics of boraomega's designes and people like him. A few people tried to cooperate with him but soon they all quit. I don't say that the radio is the same person,but they have a same approach to the forums. Hope I'm wrong,but time will tell.

radio · 2011-09-13 9:04 am

44250 said:
If he is who I think he is... I'd like that I'm wrong. Time will show. Here in Serbia there was a guy that used to do things at forums just like radio,and behaved the same way. Not just in Serbia,he was active at all forums in ex-YU countries (Croatia diyaudio.com.rh ,Bosnia and Herzegovinia elektronika.ba ,Serbia www.elitesecurity) using diferent nicks:ZX-O,slavko and a few others always offering changed and "impruved" schematics of boraomega's designes and people like him. A few people tried to cooperate with him but soon they all quit. I don't say that the radio is the same person,but they have a same approach to the forums. Hope I'm wrong,but time will tell.

I do not know what is the thing here that is mentioned?
Here is 100W Hi-Fi amplifier, so that we focus on the subject!
And for this type of research as you say you have other forums!? :worried:

Regars

Johno · 2011-09-13 10:30 am

The protection circuit will turn the drivers hard on, but not me I'm afraid....

lineup · 2011-09-13 10:43 am

radio said:
Hi all!!
I'm sorry I put the wrong schematic of this amplifier.
The original is this!!

R19 and R20 should change place in your schematic.
The amplifier may work alright.
Of course there are a lot of practical things to add.

radio · 2011-09-13 11:36 am

lineup said:
R19 and R20 should change place in your schematic.
The amplifier may work alright.
Of course there are a lot of practical things to add.

Hi lineup! :wave:

Notes with the R19 and R20 is just fine!
Do not worry,.... you just add that all your practical solutions, and I'll be good if they are immediately put into the project!? :shhh:

thanks and cheers ! :cheers:

P.S.
Now design a schematic for a given PCB!
So give suggestions what needs to change the schematic?!

radio · 2011-09-13 4:14 pm

Hi !
Here is the schematic stepped up with the changes.
If anyone has any comments about this amplifier let you go let them out!?
My comment: Otherwise i'm very pleased by this amplifier, having given a very deep and powerful bass, defined the mid-range and high range is very soft and friendly to the ear!
thanks

ingenieus · 2011-09-13 4:43 pm

The circuit looks fine. However, if you read the books by Bob Cordell and Douglas Self you will see quite a number of improvements that can be made.

Here are the ones that I can spot:

Replace R3 with a current mirror
Replace with a Darlington pair
Replace R10 and R11 with a current source
R15 and R16 do not need to be tied to the output - replace with a single resistor with bypass cap in parallel
T10 and T11 can be doubled up with another pair
Add additional bypass caps in parallel with C3 and C4, as is done with C6/C7

And that's just the start. You could also add cascodes etc. Some would say that you can lose the VI limiters as it does not help much when a real disaster happens and negatively affects sound quality for the rest of the time. But if you make all of these changes you will have a completely different design. Not sure if that is what you were looking for.

radio · 2011-09-13 5:04 pm

ingenieus said:
The circuit looks fine. However, if you read the books by Bob Cordell and Douglas Self you will see quite a number of improvements that can be made.

Here are the ones that I can spot:

Replace R3 with a current mirror

Replace with a Darlington pair

Replace R10 and R11 with a current source

R15 and R16 do not need to be tied to the output - replace with a single resistor with bypass cap in parallel

T10 and T11 can be doubled up with another pair

Add additional bypass caps in parallel with C3 and C4, as is done with C6/C7

And that's just the start. You could also add cascodes etc. Some would say that you can lose the VI limiters as it does not help much when a real disaster happens and negatively affects sound quality for the rest of the time. But if you make all of these changes you will have a completely different design. Not sure if that is what you were looking for.

It's OK to everything you said.
The question now is: what comes with all these changes?
thanks and cheers

44250 · 2011-09-13 5:36 pm

heh

radio said:
I do not know what is the thing here that is mentioned?
Here is 100W Hi-Fi amplifier, so that we focus on the subject!
And for this type of research as you say you have other forums!?
Regars

You will say everything for yourself,and time will help.

radio said:
...as you say you have other forums!?
Regars

?

radio · 2011-09-13 6:02 pm

Hi 44250!
I thought that you give a comment about this amplifier?!

Cheers

44250 · 2011-09-13 6:34 pm

I can not comment the scheme that You have posted because I don´t have knowledge to do so. Also I can not comment something that I haven´t heard - that is something i appreacheate the most. My ears have a hard ear-drums and it is so hard to impress me,only a few amplifiers have succeded that.

richie00boy · 2011-09-13 6:55 pm

44250 said:
If he is who I think he is... I'd like that I'm wrong. Time will show. Here in Serbia there was a guy that used to do things at forums just like radio,and behaved the same way. Not just in Serbia,he was active at all forums in ex-YU countries (Croatia diyaudio.com.rh ,Bosnia and Herzegovinia elektronika.ba ,Serbia www.elitesecurity) using diferent nicks:ZX-O,slavko and a few others always offering changed and "impruved" schematics of boraomega's designes and people like him. A few people tried to cooperate with him but soon they all quit. I don't say that the radio is the same person,but they have a same approach to the forums. Hope I'm wrong,but time will tell.

Ah that explains it. About a month ago on here he was posting a design that he had ripped off one of my designs without giving any credit. The modifications simply introduced problems to the design and when I asked him a few simple questions he did not answer.

44250 · 2011-09-13 7:11 pm

richie00boy said:
Ah that explains it. About a month ago on here he was posting a design that he had ripped off one of my designs without giving any credit. The modifications simply introduced problems to the design and when I asked him a few simple questions he did not answer.

As I said before,time will tell.

I myself do not have knowledge to enter even small theory conversation,and that is a reason I rather spend my time reading posts from people that do know what are they talking about. Sometimes something even catches my memory

and that is my point of being on many forums world wide;just to learn something at my free time. I have meet people like him (ZX-0,slavko54 and similar) here and there and this approach reminded me on that person. I don´t say that this is him 100% but that is similar behaveing that ZX-0 aka slavko54 made BANNED on those forums that he spend his time. I´ll say it again,I do not claim that this is the same person. Time,all of you and him self will say the whole trooth. Hope for the best...

ingenieus · 2011-09-13 10:06 pm

radio said:
It's OK to everything you said.
The question now is: what comes with all these changes?

The short answer is "less distortion."

The long answer:

An externally hosted image should be here but it was not working when we last tested it.

100W Hi-Fi audio amplifier!

Banned

Attachments

Member

Member

R.I.P.

Member

Banned

Attachments

Member

Banned

Member

Member

Banned

Banned

Attachments

Member

Banned

Member

Banned

Member

Member

Member

Member