Well Carlos, after a year, I still enjoy your contributions and the spirit in which you share your ideas.
I just came back from the shop now with all the components and also something extra that I saw you needed... it wil be a tiny suprise for you... I just forgot to get a bubblewrap envelope... so you'll have to wait a day extra for your stuff.
PS is the 47J component a capacitor? I have wima's or cog caps in 47p I think...
I just came back from the shop now with all the components and also something extra that I saw you needed... it wil be a tiny suprise for you... I just forgot to get a bubblewrap envelope... so you'll have to wait a day extra for your stuff.
PS is the 47J component a capacitor? I have wima's or cog caps in 47p I think...
Sounding remarkable for one transistor... (this was my first transistor based amp)...
Is there another solution to using the 1000uf cap (I used 2200) in series with the output (could I use a series resistor?)... it does make it sound a little muddy/veiled but the boost in bass power is there... the earphones that came with the Ipod Shuffle can hardly keep up with the bass now, but it sounds very nice on my Audiotechnica earphones.
Now quickly going to build the other channel.. but first need to search my stuff for another 47p cap, as I only found one COG one this morning.
Is there another solution to using the 1000uf cap (I used 2200) in series with the output (could I use a series resistor?)... it does make it sound a little muddy/veiled but the boost in bass power is there... the earphones that came with the Ipod Shuffle can hardly keep up with the bass now, but it sounds very nice on my Audiotechnica earphones.
Now quickly going to build the other channel.. but first need to search my stuff for another 47p cap, as I only found one COG one this morning.
Yes dear Nordic, the 47pf is a capacitor.
But i made another amplifier...with more power...class A...simple with astonishingly 1000 miliwatts of power over 8 ohms...ahahahahah!
here is some comments about it:
I made it today...i wanna to have fun with something class A...
something simple, small, and very Hot (this is could obtain!)
Audio quality is class A quality….nothing needed to comment,
as everybody knows class A sonic qualities.
This one can be plugged into a speaker, like I did and you can
see in the images.
The current is around 1 amperes….. consumption is around 10 watts,
power, off course, beeing a class A single ended, it is not better than
1 watt over 8 ohms…..2 watts over 4 ohms
Well, it can serve you as a Headphone amplifier, can be your desktop
amplifier to MP3 players near your Bed, can work alike a pré amplifier
with the quality of low output impedance, that can drive almost anyi
input load without problem.
And better…can produce a lot of fun to you.
Having a darlington power transistor, an NPN that can hold more than 2
amperes continuously….that can dissipate over 20 watts, and them you
can assemble this one.
It is called “Hot Spot”…because if you touch the heatsinks or touch the
enormous 10 ohms resistor, the bubble produced in your finger will
make you understand what I mean with this name.
I made it this morning..and a pair of hours was all we need to assemble a
simple amplifier…was listened and sounded good….it has much more power
than the other one published here….and can drive difficult headphones.
The output electrolitic condenser is 10000uF to present a very low resistance
when transfering audio to 4 ohms or even 2 ohms speakers.
The Darlington normally have informed gain of 1000….and I have used
1 ampere from colector to emitter….this means that something alike 1 miliamp
will be needed to cross base to emitter junction to bias…also 1.2 volts will be
needed…… but normally we force 10 times more current into the voltage divider
that is used to bias the base….. so….10 miliamps will be the current.
This result in 120 ohms resistor from base to ground…it will develop 1.2 volts
over it extremes…. The needed voltage to force the darlington into conduction.
The complemetary voltage…to reach 24 volts (22.8V) will be keept over the upper
base resistor….reason why the value is 2280 ohms.
As I told you..around 1 ampere will cross the 10 ohms resistor…creating around
10 volts of voltage over this load resistor extremes….adjusting the base trimpot, you
can drive the transistor into the condition to measure around 12 Volts in its colector.
Waste of power….yeah!...class A is always that waste of power… sometimes.better
than tube amplifiers but terrible to our electricity bills.
Well..single ended…class A…is the worst possible wast of energy…. 10 watts
will be needed, will be consumed, to produce around 10 percent of clear audio
You can have more power…but it will be distorted…1 watt is
something you can have with 8 ohms speaker and using this small amp,
you will apreciate the class A nice bass.
About the treble….not needed comments, as it is cristal clear.
Yes…I also think that class A produces some audio compression…but
the audio quality largely compensates us related this problem.
The 33 ohms in the input….. and the base to emitter junction resistance
will produce a nice load to the MP3 player…the capacitor in the input
is there to avoid RF pick up…the series resistor is because of sensitivity,
the 470 picofarads capacitor, from Base to Colector, in the Darlington
transistor is to avoid oscilations….the output zobel is also because of
the danger of oscilations when you have hi gain transistors.
The diode, from the positive supply to ground is there to protect the whole
thing if you made a mistake, as the supply invertion….and you cannot
imagine how many guys do that everyday…but they do not tell us..hehe.
The Hot Spot is simple…sounds good, and will be usefull, at least to produce
some fun.
I am not an Enginner…I am a “changeneer”,….i use to change, to replace parts
till I have the amplifier working the way I want…the basic calculations I know,
but to produce this one we need only basic knowledge.
regards,
Carlos
But i made another amplifier...with more power...class A...simple with astonishingly 1000 miliwatts of power over 8 ohms...ahahahahah!
here is some comments about it:
I made it today...i wanna to have fun with something class A...
something simple, small, and very Hot (this is could obtain!)
Audio quality is class A quality….nothing needed to comment,
as everybody knows class A sonic qualities.
This one can be plugged into a speaker, like I did and you can
see in the images.
The current is around 1 amperes….. consumption is around 10 watts,
power, off course, beeing a class A single ended, it is not better than
1 watt over 8 ohms…..2 watts over 4 ohms
Well, it can serve you as a Headphone amplifier, can be your desktop
amplifier to MP3 players near your Bed, can work alike a pré amplifier
with the quality of low output impedance, that can drive almost anyi
input load without problem.
And better…can produce a lot of fun to you.
Having a darlington power transistor, an NPN that can hold more than 2
amperes continuously….that can dissipate over 20 watts, and them you
can assemble this one.
It is called “Hot Spot”…because if you touch the heatsinks or touch the
enormous 10 ohms resistor, the bubble produced in your finger will
make you understand what I mean with this name.
I made it this morning..and a pair of hours was all we need to assemble a
simple amplifier…was listened and sounded good….it has much more power
than the other one published here….and can drive difficult headphones.
The output electrolitic condenser is 10000uF to present a very low resistance
when transfering audio to 4 ohms or even 2 ohms speakers.
The Darlington normally have informed gain of 1000….and I have used
1 ampere from colector to emitter….this means that something alike 1 miliamp
will be needed to cross base to emitter junction to bias…also 1.2 volts will be
needed…… but normally we force 10 times more current into the voltage divider
that is used to bias the base….. so….10 miliamps will be the current.
This result in 120 ohms resistor from base to ground…it will develop 1.2 volts
over it extremes…. The needed voltage to force the darlington into conduction.
The complemetary voltage…to reach 24 volts (22.8V) will be keept over the upper
base resistor….reason why the value is 2280 ohms.
As I told you..around 1 ampere will cross the 10 ohms resistor…creating around
10 volts of voltage over this load resistor extremes….adjusting the base trimpot, you
can drive the transistor into the condition to measure around 12 Volts in its colector.
Waste of power….yeah!...class A is always that waste of power… sometimes.better
than tube amplifiers but terrible to our electricity bills.
Well..single ended…class A…is the worst possible wast of energy…. 10 watts
will be needed, will be consumed, to produce around 10 percent of clear audio
You can have more power…but it will be distorted…1 watt is
something you can have with 8 ohms speaker and using this small amp,
you will apreciate the class A nice bass.
About the treble….not needed comments, as it is cristal clear.
Yes…I also think that class A produces some audio compression…but
the audio quality largely compensates us related this problem.
The 33 ohms in the input….. and the base to emitter junction resistance
will produce a nice load to the MP3 player…the capacitor in the input
is there to avoid RF pick up…the series resistor is because of sensitivity,
the 470 picofarads capacitor, from Base to Colector, in the Darlington
transistor is to avoid oscilations….the output zobel is also because of
the danger of oscilations when you have hi gain transistors.
The diode, from the positive supply to ground is there to protect the whole
thing if you made a mistake, as the supply invertion….and you cannot
imagine how many guys do that everyday…but they do not tell us..hehe.
The Hot Spot is simple…sounds good, and will be usefull, at least to produce
some fun.
I am not an Enginner…I am a “changeneer”,….i use to change, to replace parts
till I have the amplifier working the way I want…the basic calculations I know,
but to produce this one we need only basic knowledge.
regards,
Carlos
Attachments
Here is the maximum voltage output measured under dinamic loaded conditions
The music was playing...measurement was made over the speaker terminals when playing music with bass....because my meter measure only from 30 hertz to 400 hertz..
This audio was distorted....it works fine when the reading is around 2 volts.
regards,
Carlos
The music was playing...measurement was made over the speaker terminals when playing music with bass....because my meter measure only from 30 hertz to 400 hertz..
This audio was distorted....it works fine when the reading is around 2 volts.
regards,
Carlos
Attachments
Unlce Carlos (we call everyone unle and aunty thats older than us) this sounds so good I don't want to give my wife's ipod back.
Sharp man, this is so neat... now to get it in a case....
I see its current hungry... one 9V battery distorts the bass a bit under high volume... Two in parallel are better... scratching around for a third now....
Could I swap the bd139 for a 135 without changeing anything else to use less batteries?
Sharp man, this is so neat... now to get it in a case....
I see its current hungry... one 9V battery distorts the bass a bit under high volume... Two in parallel are better... scratching around for a third now....
Could I swap the bd139 for a 135 without changeing anything else to use less batteries?
Nordic, have you observed that i have posted one more circuit...the last one, the Hot
Spot, that was posted here, in this thread, cannot use headphones in series with the positive supply, as the current is too high...the power there is 10 watts, and of course, the headphone will be instantaneously destroyed.
I know that you are happy with you low powered version..... the battery one....but, take a look in this other.... the hot one is very interesting too.
You have asked about short circuit in the input to make measurements...yes, this is a very good idea.
Also you have asked about the increase of the electrolitic condenser to 2200uF....also a good idea.
About the Op chip i cannot say nothing, as i did not listen to it...i suppose it will perform better than this simple amplifier...but i am not sure, as i did not have tested.
Yes, you have replaced the batteries, and now using two units in parallell..hehe...sucking a lot of miliamps.
Have you installed it inside some case..... can you produce some images for us?
Older guys are called uncle here too.
regards,
Carlos
Spot, that was posted here, in this thread, cannot use headphones in series with the positive supply, as the current is too high...the power there is 10 watts, and of course, the headphone will be instantaneously destroyed.
I know that you are happy with you low powered version..... the battery one....but, take a look in this other.... the hot one is very interesting too.
You have asked about short circuit in the input to make measurements...yes, this is a very good idea.
Also you have asked about the increase of the electrolitic condenser to 2200uF....also a good idea.
About the Op chip i cannot say nothing, as i did not listen to it...i suppose it will perform better than this simple amplifier...but i am not sure, as i did not have tested.
Yes, you have replaced the batteries, and now using two units in parallell..hehe...sucking a lot of miliamps.
Have you installed it inside some case..... can you produce some images for us?
Older guys are called uncle here too.
regards,
Carlos
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