build power amplifier class ab

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ardi79

Member
2016-04-12 9:01 am
hello everybody, im from indonesia. im beginner in building diy kit. i have try to get more information about amplifier and i found this forum.

i have plan to build power amplifier class ab and i confused to choose which one is suittable for me ong ljm l12, ljm l15, ljm l20, ma9s2. i have a pair of speaker 10 inch 350 watt. maybe someone can help me to choose which suitable for me. thanks
 
mosfet54

mosfet54

Banned
2016-02-24 5:29 pm
Varna, Bulgaria
try this sounds very good :)
but there are not any protections

R2 must be 5W and T3 must be on a small heatsink.
T6 and T7 need no heatsink but its good to mount them to one ;p

R10 must be one 560 and one 5k trim pot in series for tuning standby current.

this offers class A input stage + class AB output ;p
 

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Bob Richards

Bob Richards

Member
2011-02-22 6:37 am
Portland Oregon, USA
www.opalcreekaudio.com
I'd replace R9, R10 and/or R11 with a pot, so I could adjust the bias of the output stage. Different FETs of the same part number might need a different bias voltage. FETs usually run a higher quiescent current than bipolars, but you want to get that right. When a solid state power amp blows up, it can also blow out the speakers. If you're really new at building amplifiers I might recommend instead a LM3886 class AB chip amp. I built one of those and I'm gettin 50watts rms into 8 ohms and it sounds great. There are 3886 kits on the web that you can buy.
 
mosfet54

mosfet54

Banned
2016-02-24 5:29 pm
Varna, Bulgaria
your comments doesnt make sense since i already mentioned that.
->
mosfet54 said:
try this sounds very good :)
R10 must be one 560 and one 5k trim pot in series for tuning standby current.
Click to expand...

its tested, the only problem is the limited output voltage by the output stage.
i will fix that with dynamic changing resistances -> bootstrapping. just need to think about it.

Even limited its enough high ;p

here is the proof its triple tested ->

http://www.diyaudio.com/forums/solid-state/290004-irf530-9530-amplifier-simulated-multisim-tina.html

in three simulation programs -> multisim, tina and reality
 
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vzaichenko

vzaichenko

R.I.P.
2010-01-11 1:31 pm
Moscow, Russia
VHex

Hi Ardi79,

I can recommend you a rather simple, inexpensive, however - high quality VHex amplifier. It's successfully built by a number of members here.

Schematic: VHex schematic
Final layout: VHex PCB layout

I can also offer the manufactured PCBs for VHex+ (same schematic, but 2 pairs of output HexFETs, although you can use just one pair if you like). They look like this: VHex+ PCBs

Cheers,
Valery
 
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ilimzn

Member
2005-02-11 1:25 pm
Zagreb
mosfet54 said:
try this sounds very good :)
Click to expand...

Try it at full power at 20kHz into a dummy load. That's a test, not 3W into recycled PC speakers.
And 'tripple tested' because it's 'tested' in 3 different simulators? If you knew anything about simulators, you would know all of these use the same basic simulation engine and given the same models will give the exact same results. Neither of which are real world because a simulator and a model is not the real world. Amplifiers are tested in the real world and with real world instruments.
Stop trolling and start learning, and stop accusing anyone who critiques your half-designs of 'not making sense' especially people who have ben designing amplifiers longer than you have been alive, because as it is you just come off as an idiot. And moderators, feel free to censor me, but I'd bet you most here don't think I'm not telling the truth.

And to the original poster:
Ignore this guy's posts. Or don't - if you feel like beta-testing someone else's guesswork designs.
 
cumbb

cumbb

Member
2005-05-03 8:15 pm
different/relative
Do you want listen very very very loud? How sensitive are your speakers (dB/W/m) and what is the impedance? May be, you do need just 2 x 5 "Watt".-)
All your listed amps are toooo complex to sound good. In my mind. Tooo much stages, x-complementary-parts-stages, toooo complex inputs: a lot of noise and rumbling and scratching. Good to drive multiwayspeakers with complex crossovers and big rumbling, roaring wooden casings,-)
I would recommend you, as a "beginner", cheaper and easier to build, clean and clear sounding amps. As example a little quasicomplementary or, better, a little se. About 10 parts, psu, good heatsink and you will be happy for ever.
In my mind,-)
 
A

ardi79

Member
2016-04-12 9:01 am
cumbb said:
Do you want listen very very very loud? How sensitive are your speakers (dB/W/m) and what is the impedance? May be, you do need just 2 x 5 "Watt".-)
All your listed amps are toooo complex to sound good. In my mind. Tooo much stages, x-complementary-parts-stages, toooo complex inputs: a lot of noise and rumbling and scratching. Good to drive multiwayspeakers with complex crossovers and big rumbling, roaring wooden casings,-)
I would recommend you, as a "beginner", cheaper and easier to build, clean and clear sounding amps. As example a little quasicomplementary or, better, a little se. About 10 parts, psu, good heatsink and you will be happy for ever.
In my mind,-)
Click to expand...

my speaker branch sellus (hyundai) its use for karaoke. not standing speaker. he4 my old amplifier pioner v210. sorry my english it not good.
 
mosfet54

mosfet54

Banned
2016-02-24 5:29 pm
Varna, Bulgaria
ilimzn said:
Try it at full power at 20kHz into a dummy load. That's a test, not 3W into recycled PC speakers.
And 'tripple tested' because it's 'tested' in 3 different simulators? If you knew anything about simulators, you would know all of these use the same basic simulation engine and given the same models will give the exact same results. Neither of which are real world because a simulator and a model is not the real world. Amplifiers are tested in the real world and with real world instruments.
Stop trolling and start learning, and stop accusing anyone who critiques your half-designs of 'not making sense' especially people who have ben designing amplifiers longer than you have been alive, because as it is you just come off as an idiot. And moderators, feel free to censor me, but I'd bet you most here don't think I'm not telling the truth.

And to the original poster:
Ignore this guy's posts. Or don't - if you feel like beta-testing someone else's guesswork designs.
Click to expand...

The 3rd simulator as i mentioned is REALITY and IM SURE YOU ALREADY READT THIS !

Tried with good speaker at very good power and its surprising clean good and simple amp better than complex ones ! I learned what i needed, nothing more to learn, more is more than more and its dangerous /!\

This is not crappy PC speaker. This is big powerful speaker ->150W 6ohm 90db 40Hz-20kHz. with two basses, big middle and highs.

They use same engine but they're using different data.
for example offset in multisim is -108mV where in TINA is 37mV.

They are not reality but they're reality too ;)

Dont think i am not having imagination because im not an OLD HUMAN -> TROLL (AND I WILL BE IMMORTAL AND FRESH)(WILL LIVE SOME 200-300 years)(maybe more)(maybe infinite).(who knows)(me;p)
This means that you are not trusting the spread of knowledge (magic) and you are just a bad ego. I bet this design is the future . And the key is injecting signal in the middle. You dont know why people are not using this ? They dont use it because it has limited output. My fix is using bootstrapping. Why people not use bootstrapping ? Because there are trap too. They use it one side only and this is not working because its work is to lift the bottom side up when the upper is up. (and vice versa) evb use some classic standart "recipe" with a poisonous spice in it.

We are immortals and we have the whole time of the earth, but we learn faster than you think.(like we're not having any time).
we have time and in same time we have no time to lose.

:warped:

Chill bro -> https://soundcloud.com/drob-it-mnml/drobit-banica-original-mix
You have that need ;)

https://soundcloud.com/drob-it-mnml/drobit-windows-xperiment
https://soundcloud.com/drob-it-mnml/drobit-memory-implant-original-mix
https://soundcloud.com/dimor/dimor-drobit-stereo-confusion-original-mix
https://soundcloud.com/drob-it-mnml/drobit-teach-me-in-progress
https://soundcloud.com/drob-it-mnml/drobit-fruity-madness-original-mix-cut
and yes
chorbominator -> (has nice bass)
https://soundcloud.com/drob-it-mnml/drobit-chorbominator-original-mix
https://soundcloud.com/drob-it-mnml/drobit-be-careful-in-progress

listen to these and im sure you'll sync to my opinion ;)
 

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bimo

bimo

Member
2010-09-16 2:07 pm
Depok, West of Java
anistardi.wordpress.com
Simple amplifier with easy to find components in Indonesia :) https://anistardi.wordpress.com/2016/02/02/amplifier-perkutut-pro/

I think it is enough for your amplifier and it is very good in mid frequency because H2 distortion dominant. If you change Q3 with 2SC3503, it will more better (slew rate will increase and slightly lower distortion). If you difficult to find 2SC3503, I have some friends who sell it.
 
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