900W H-class PA Amp with Limiter

[NMOS]

I dont know work stable or not,

not have built

good DIY Support not available

I have decide spend time class D,

DIY member in class D does much more help and share expierience

with High Voltage SIC in class D amplifier

no need class TD anymore

 

[masood251]

In my h900 2sa1943 heated and suply is as following
Positive side.67dc(high side)1.3vdc(lower side)
Negative side 27vdc(higher side)31vdc (lower ) please solve me

 

[NMOS]

In my h900 2sa1943 heated and suply is as following
Positive side.67dc(high side)1.3vdc(lower side)
Negative side 27vdc(higher side)31vdc (lower ) please solve me

I think oscillation,

I remember there are no capacitor in scheamatic at drivers transistor between b and C

Try 500 pf for each and look again

 

[masood251]

Please see my ampl.
There is 100pf collector to base both driver transistors.

 

[starbala18]

Apex audio can I ask a favor can I get complete PDF of h900 into my email account balovesbalabat@gmail.com

 

[deo]

Join the input ground (sgnd) with the output ground(gnd).
Anyway I didn't see anything concrete, just words ...

 

[deo]

First TD1800,second Labgruppen.

 

[NMOS]

First TD1800,second Labgruppen.

Any idea why TD1800 look worse ?


Long time already and I cant see positive feedback working DIY TD1800 without issues

 

[deo]

The amplification must be smaller and I think it is a mistake when designing the wiring.
Anyway, I'm just an amateur and I don't know much.
I repaired a yamaha p7000s, and the output signal looks perfect with no artifacts.
I'll try to take some pictures with the P7000s output.
Post # 3806 was for masood251.

 

[deo]

P7000s out,the same principle like TD1800,with minor modification.All tests with 4ohm and approx.half power.

 

[sajti]

Any idea why TD1800 look worse ?


Long time already and I cant see positive feedback working DIY TD1800 without issues

Because the VAS stage is connected to the modulated voltage. It must be connected to directly to the HV.

Sajti

 

[NMOS]

Because the VAS stage is connected to the modulated voltage. It must be connected to directly to the HV.

Sajti

ok, but I dont understand,...why APEX not fix with a update ?

Exerybody will get frustration when build ant final test will be a nightmare

 

[masood251]

Please see my wiring

 

[sajti]

ok, but I dont understand,...why APEX not fix with a update ?

Exerybody will get frustration when build ant final test will be a nightmare

Same for me. It would be a very small change, and big improvement.

Sajti

 

[NMOS]

Same for me. It would be a very small change, and big improvement.

Sajti

For me, I need to know, does TD driver circuit work reliablle ?

I want TD driver add to reliable proven class AB PA amp design

I want only use TD driver circuit, APEX TD1800 circuit amp I dont use

 

[deo]

For Sajti.
I tried and as you said, but no results.
I this scheme the amplification part is about the same as the TD1800, but it still works.
I remember about 10 years ago I repaired something like this (Mackie).

 

[deo]

For NMOS,
I think the Labgruppen auto-oscillator is the best.It's more complicated, but it's much more efficient and it works for sure.
The rest of the scheme exists on the net (right here on the forum).A little mistake PWMNATD=PNP,PWMNPATD=NPN transistor.You can also try the downconverter from yamaha, it's much simpler.

 

[NMOS]

For NMOS,
I think the Labgruppen auto-oscillator is the best.It's more complicated, but it's much more efficient and it works for sure.
The rest of the scheme exists on the net (right here on the forum).A little mistake PWMNATD=PNP,PWMNPATD=NPN transistor.You can also try the downconverter from yamaha, it's much simpler.

Fron which Labgruppen Model are the pics ?

Downconverter from which Yamaha Model ?

 

[deo]

Labgruppen fp10000 or fp14ooo,Yamaha P5000, P7000 or either one EEEengine amplifier.I'll try to change the TD1800 (Mackie) downconverter to the Yamaha model.
It's just that I don't have much time and I don't know how it will be.

 

[sajti]

For Sajti.
I tried and as you said, but no results.
I this scheme the amplification part is about the same as the TD1800, but it still works.
I remember about 10 years ago I repaired something like this (Mackie).

OK. For me it is not logical to use the VAS from the noisy modulated psu, instead of clear 140V DC. I see how Mackie did, but I would still give it a try with TD1800...

Sajti,