this is greek made
from a company called smart kit electronics
if you buy the kit its almost for sure that it will not work since its using bdv 66-67 darligtons that they are not "selected" and i dont mean matched i mean selected ....
bdv 66-67 might have diferent behaviour between company to company and also between the same company but in diferent orders ...
so if in this amplifier you have P and N transitor that they are not complementary your amp is out of balance and bias ( very critikal for this design ) will never work properly
also 100w is overestimated and will never be produced as operating these bdv 66-67 in 40 volts rails and 4 ohms loads is way out of transitors can handle .....
one option will be to get the schematic and part list of this and operate it with MJ15015-16 very nice devices from on semi
but finally you dont expect much of it sound wise no matter what transistors you use
and the best option will be to built a DX amplifier from Destroyer x
( you will get a lot of forum help if you choose to do that ) or other designs the same simple but more safe and effective to built that are discussed here in the forum
simular to DX is the P3 or P3A from rod elliot or sixtec amplifier or symasym and so on ...
search .....you will find plenty
from a company called smart kit electronics
if you buy the kit its almost for sure that it will not work since its using bdv 66-67 darligtons that they are not "selected" and i dont mean matched i mean selected ....
bdv 66-67 might have diferent behaviour between company to company and also between the same company but in diferent orders ...
so if in this amplifier you have P and N transitor that they are not complementary your amp is out of balance and bias ( very critikal for this design ) will never work properly
also 100w is overestimated and will never be produced as operating these bdv 66-67 in 40 volts rails and 4 ohms loads is way out of transitors can handle .....
one option will be to get the schematic and part list of this and operate it with MJ15015-16 very nice devices from on semi
but finally you dont expect much of it sound wise no matter what transistors you use
and the best option will be to built a DX amplifier from Destroyer x
( you will get a lot of forum help if you choose to do that ) or other designs the same simple but more safe and effective to built that are discussed here in the forum
simular to DX is the P3 or P3A from rod elliot or sixtec amplifier or symasym and so on ...
search .....you will find plenty
if looking at the circuit
there is nothing new about it
there is no improvement and good ideas, apart from very rudimentary circuit
It is, in my opinion, a very standard and simple version of Douglas Self blameless amplifier.
And if you want to build one,
I really recommend better you use the information from D. Self website here:
http://www.dself.dsl.pipex.com/ampins/dipa/dipa.htm
there is nothing new about it
there is no improvement and good ideas, apart from very rudimentary circuit
It is, in my opinion, a very standard and simple version of Douglas Self blameless amplifier.
And if you want to build one,
I really recommend better you use the information from D. Self website here:
http://www.dself.dsl.pipex.com/ampins/dipa/dipa.htm
Attachments
Re: hei line up ....
the schematic is the very one from topic starter kit!!!!
see link in first post
Now, what output transistors to use, is many choices'
if going darlington we can consider some motorola devices
http://www.onsemi.com/PowerSolutions/supportDoc.do?type=datasheets&category=798
Motorola = OnSemi
But the basic circuit is better from D.Self website
http://www.dself.dsl.pipex.com/ampins/dipa/dipa.htm
This is my basic message to the topic poster.
And good advice.
regards to friend sakis of Grekland = Greece = Hellas = Ella = The Sun
http://en.wikipedia.org/wiki/Hellen
sakis said:
the schematic is the very one from topic starter kit!!!!
see link in first post
Now, what output transistors to use, is many choices'
if going darlington we can consider some motorola devices
http://www.onsemi.com/PowerSolutions/supportDoc.do?type=datasheets&category=798
Motorola = OnSemi
But the basic circuit is better from D.Self website
http://www.dself.dsl.pipex.com/ampins/dipa/dipa.htm
This is my basic message to the topic poster.
And good advice.
regards to friend sakis of Grekland = Greece = Hellas = Ella = The Sun
http://en.wikipedia.org/wiki/Hellen
kibet85 said:
The schematic looks OK.
Conventional Lin-topology solid-state class B/AB amplifier with darlington output stage, with overcurrent & short circuit protection.
The OP stage looks a bit undersized, but for home usage with the inbuilt protection it seems enough.
However for PA usage I'd add one more pair of OP devices. Or change these BDW devices to a 200...250W rated darlington pair.
R2 must be 0.47r/5W, I'm sure that 1r/2W is a misprint.
Solder a resistor in series with P1 for safety reasons! Then I'd double C6 to 220uF.
Rail fuses are needed, use 5A fast-blow fuses /rail.
With the mentioned modifications it's a reliable and cheap project. IMHO it's not that bad as Sakis and Lineup noted. It has a correct PCB design too!
Some more comments...
P3A hasn't got public PCB design.
P3A hasn't got shortcircuit/overcurrent protection.
DX-amp hasn't got shortcircuit/overcurrent protection.
Symasym hasn't got shortcircuit/overcurrent protection.
Anyway I'm not sure that Kibet85 could find the driver/OP devices in Kenya for DX-amp/Symasym - however this project uses only cheap and easily available parts.
P3A hasn't got public PCB design.
P3A hasn't got shortcircuit/overcurrent protection.
DX-amp hasn't got shortcircuit/overcurrent protection.
Symasym hasn't got shortcircuit/overcurrent protection.
Anyway I'm not sure that Kibet85 could find the driver/OP devices in Kenya for DX-amp/Symasym - however this project uses only cheap and easily available parts.
Re: Re: Re: Re: 100 watt audio amplifier
if you look at my sgnature below this post
this is supposed to make all think before posting!!!
but i do not mind too much .. i have said some worse things
than is put into my own mouth at times .. at this board
no problems mate
Andy L. Francis said:OMG! I need a coffee.
Awfully sorry!!! [/B]
if you look at my sgnature below this post
this is supposed to make all think before posting!!!
but i do not mind too much .. i have said some worse things
than is put into my own mouth at times .. at this board
no problems mate
some times we read posts too fast
i have nothing against the circuit as a kit though is the cra***piest you can buy ......
the bdv 66-67 inside make might be one Philips and one SGS that is a guarantee that the amp will not work .....
also the rest of the material inside the kit is the cheapest available
also the statment 100w is not real so yes thats a bad amp
andy ...something else
from the way the starter of the thread writes i think he is a rookie ( no effence hopefully )
so if he buys a kit and then start to change this and that may be he ends up in the wrong situation
the conclusion is that may be the schematic is good or very good but this has nothing to do with what the kit provides .....
this is what i always scream about ...... stick to the subject ....otherwise posts are getting too long without a reason ....hell this poor guy kibet85 probably cannot understand all this we talk about .....
excuse my tone but often somebody asks a simple thing in the forum and he might get directions on how to built a space ship to go to mars except a simple answer or opinion of someone with a bit more expirience ....
since this greek made you dont want to know how many i had to mod or repair since i was 14 and this kit was allready in the market and until today no update at all ....... now days i am 42 ...thats a long time
i have nothing against the circuit as a kit though is the cra***piest you can buy ......
the bdv 66-67 inside make might be one Philips and one SGS that is a guarantee that the amp will not work .....
also the rest of the material inside the kit is the cheapest available
also the statment 100w is not real so yes thats a bad amp
andy ...something else
from the way the starter of the thread writes i think he is a rookie ( no effence hopefully )
so if he buys a kit and then start to change this and that may be he ends up in the wrong situation
the conclusion is that may be the schematic is good or very good but this has nothing to do with what the kit provides .....
this is what i always scream about ...... stick to the subject ....otherwise posts are getting too long without a reason ....hell this poor guy kibet85 probably cannot understand all this we talk about .....
excuse my tone but often somebody asks a simple thing in the forum and he might get directions on how to built a space ship to go to mars except a simple answer or opinion of someone with a bit more expirience ....
since this greek made you dont want to know how many i had to mod or repair since i was 14 and this kit was allready in the market and until today no update at all ....... now days i am 42 ...thats a long time
Thanks guys..first,m a rookie....i just love loud sound..now,this amp has already been made..its intended use is a subwoofer amplifier(actually,m using it right now)..the thing is,its not responding to those low bas notes...e.g..i hope you guys know this song'get ur walk on'by xzibit..it has some deep bass..this amp is not responding to those kind of beats..could u guys tel me wats the problem is...
M using a +-38 transformer with 4700 microfarad caps rated 100 watts..for the outputs,1 pair of darlingtons...mj2500 and 2n6388...thught of adding another pair and increasing the caps to like 15000.... my sub is a pioneer 800 wats rated 4ohms...
M using a +-38 transformer with 4700 microfarad caps rated 100 watts..for the outputs,1 pair of darlingtons...mj2500 and 2n6388...thught of adding another pair and increasing the caps to like 15000.... my sub is a pioneer 800 wats rated 4ohms...
questions
are you using 38+38 ac ????? so your rails are something like 50+50 volts ????
then in this case what is your idle ????
did you managed to set the idle as was or you made any mods???
also mj 2500 and 2n6388 are they complementary ????? can they be complementery ????? do they share the same specs ????
have you checked the device with a scope ????is it symmetrical ???is clipping symetrical ????
are you using 38+38 ac ????? so your rails are something like 50+50 volts ????
then in this case what is your idle ????
did you managed to set the idle as was or you made any mods???
also mj 2500 and 2n6388 are they complementary ????? can they be complementery ????? do they share the same specs ????
have you checked the device with a scope ????is it symmetrical ???is clipping symetrical ????
Hi sakis..what u have just asked is too technical..but anyway,lemmie give it a try...when u ask about complementary,i guess ur asking if they pair up wel?i can say they do..i adjusted the current to 50milliamps as stated..one thing i'v discorved is that its gain is low..i was testing it today at my friends place..we were using a boschman eq and had to put tha sub gain to half...with his amp,u can feel the dedication to respond to deep beats... His amp is the cheap 150 wat amp!!i knw,crap amp..anyway,if u have any suggestions,holla back..it would be much appreciated...then,i was thinking of my next project as the lynx amp..v2.1...cuz it uses darlington outputs which are available here..is it ok?
listen mike
facts
- this amp is designed to operate in 40+40 volts
- increase the rails of the amp is almost 53 volts thats out of specs
- will effect the gain
-will effect the bias
-will effect the protection circuit
-will effect safety
then .....
one amplifier to operate properly in this class has to be symmetric IE the transitors used have to be complementary IE same make brand and cahracteristics ....
for example 2n6388 is 80 volt .....too litle for operating at 53+53 volts then 10 ampere and can dissipate 65w totaly ..... you are asking to more than 100w...thats not right ......b1000 is the grade of amplification you get from this transistor and finally this transistor is not designed to use for audio is for small switching application or power supply
now mj 2500 is even worst only 60 volt .....cannot operate at 53+53 volts 10 ampere and then 150w ( thats the only good but very diferent from 2n6388 ) and atleast can go up to 3mhz that makes it a transistor that can work for audio .....
more facts
they way this amp is built it will fail any minute now and its disuster waiting to happen .... unless all these is a mistake and you have 38+ 38 volts DC ...in this case transistors are barely enough but will not work as long as their not complemetary ......first it will fail the 2n6388 then will also destroy the mj2500 and then your speaker .....even if you have fuses on this will not be fast enough to save your speaker ...
in case you have 53+53 volts rails the protection circuit needs to be redesigned to be able to operate at this voltage .....
also the idle you state of 50ma is totally wrong and the only way to calculate bias properly for this configuration is to measure the voltage drop acroos every emiter resistor 0.47R 5W for every transistor respectively .and then calculate with ohms law
..... i bet you that if you do you will see that the one has like 10 mv and the other has 50 mv since this is coming from the diference of the transistors .....
the only possible solution is to get the brother of mj 2500 that is the mj 3000 or any other set of complementary transistors .... for example mj 11015-16 that are 160 volts devices and then either remove totaly the protection circuit or recalculate it for the specific application ....
in this case you will almost make at least 120w of solid power and also very stable
ALso somewhere you state something like 100w power if this your transformer is not enough for this application if you have an amplifier that you expect to produce 100 w you need a minimoum of 200w to make operate properly .....
amplifier lesson one finished ( there is probably more but i just told you the basics )
good luckprobably your amp is working but out of balance and since you have to much rail voltage probably there is a lot of power but protection circuit will allow enough drive cause of too high rails voltage ...... if you remove the protection for a minute you will have about 120 w of power for about 1/4 of a second ,...... then it will blow
facts
- this amp is designed to operate in 40+40 volts
- increase the rails of the amp is almost 53 volts thats out of specs
- will effect the gain
-will effect the bias
-will effect the protection circuit
-will effect safety
then .....
one amplifier to operate properly in this class has to be symmetric IE the transitors used have to be complementary IE same make brand and cahracteristics ....
for example 2n6388 is 80 volt .....too litle for operating at 53+53 volts then 10 ampere and can dissipate 65w totaly ..... you are asking to more than 100w...thats not right ......b1000 is the grade of amplification you get from this transistor and finally this transistor is not designed to use for audio is for small switching application or power supply
now mj 2500 is even worst only 60 volt .....cannot operate at 53+53 volts 10 ampere and then 150w ( thats the only good but very diferent from 2n6388 ) and atleast can go up to 3mhz that makes it a transistor that can work for audio .....
more facts
they way this amp is built it will fail any minute now and its disuster waiting to happen .... unless all these is a mistake and you have 38+ 38 volts DC ...in this case transistors are barely enough but will not work as long as their not complemetary ......first it will fail the 2n6388 then will also destroy the mj2500 and then your speaker .....even if you have fuses on this will not be fast enough to save your speaker ...
in case you have 53+53 volts rails the protection circuit needs to be redesigned to be able to operate at this voltage .....
also the idle you state of 50ma is totally wrong and the only way to calculate bias properly for this configuration is to measure the voltage drop acroos every emiter resistor 0.47R 5W for every transistor respectively .and then calculate with ohms law
..... i bet you that if you do you will see that the one has like 10 mv and the other has 50 mv since this is coming from the diference of the transistors .....
the only possible solution is to get the brother of mj 2500 that is the mj 3000 or any other set of complementary transistors .... for example mj 11015-16 that are 160 volts devices and then either remove totaly the protection circuit or recalculate it for the specific application ....
in this case you will almost make at least 120w of solid power and also very stable
ALso somewhere you state something like 100w power if this your transformer is not enough for this application if you have an amplifier that you expect to produce 100 w you need a minimoum of 200w to make operate properly .....
amplifier lesson one finished ( there is probably more but i just told you the basics )
good luckprobably your amp is working but out of balance and since you have to much rail voltage probably there is a lot of power but protection circuit will allow enough drive cause of too high rails voltage ...... if you remove the protection for a minute you will have about 120 w of power for about 1/4 of a second ,...... then it will blow
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