Transformer center tap goes connected to chassis... the whole chassis
is grounded in my amplifiers (in many other ones too).... you see this board is attached to the chassis (ground) by a screw...so... this capacitor is a bypass that connects positive from the supply to the ground.... in my country mains outlet uses 2 pins only...only modern constructions have ground pin... this way i do not connect real ground to my chassis.... it works alike the second wire you have in your automobile.... there you have the whole car as a negative wire... we have ground into the entire chassis too... a central ground... a screw attached to the chassis.... very near the transformer center tap wiring..and there we have a central spot to distribute grounding wires.
This interesting way Alex did, does not match exactly, my schematic... Alex decided to do this way and he may have his reasons... i do think this will work too...usually we install bypass near the electrolitic condenser pins...he made that way..... and the one can answer the reasons he decide this way must be himself.
This is not the best solution in my point of view...but it is not that bad too.... and you can modify if you want.
regards,
Carlos
is grounded in my amplifiers (in many other ones too).... you see this board is attached to the chassis (ground) by a screw...so... this capacitor is a bypass that connects positive from the supply to the ground.... in my country mains outlet uses 2 pins only...only modern constructions have ground pin... this way i do not connect real ground to my chassis.... it works alike the second wire you have in your automobile.... there you have the whole car as a negative wire... we have ground into the entire chassis too... a central ground... a screw attached to the chassis.... very near the transformer center tap wiring..and there we have a central spot to distribute grounding wires.
This interesting way Alex did, does not match exactly, my schematic... Alex decided to do this way and he may have his reasons... i do think this will work too...usually we install bypass near the electrolitic condenser pins...he made that way..... and the one can answer the reasons he decide this way must be himself.
This is not the best solution in my point of view...but it is not that bad too.... and you can modify if you want.
regards,
Carlos
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There's another capacitor that produces questions... because it is strange
So.... i will explain in advance because know this question will arise son or latter.
The use of this capacitor is a tradition only...one day i had oscilations superimposed to the positive half wave in the Dx Blame ES amplifier... a very long time ago.... them i tried to stop it... oscilations where driven by high frequency burst of signals.... tones higher than 25 kilohertz, sometimes was driving the amplifier into oscilations..and a small burst of high frequency about 1 Megahertz was appearing into the positive half of the square wave inspected into the scope.... i could remove it using this small capacitor.... reason why it continue to be present in my amplifiers...it is a "just in case" capacitor... a cheap small ceramic unit.
Do not worry...do not harm...if you want you can remove it.... as i said... "just in case"
regards,
Carlos
So.... i will explain in advance because know this question will arise son or latter.
The use of this capacitor is a tradition only...one day i had oscilations superimposed to the positive half wave in the Dx Blame ES amplifier... a very long time ago.... them i tried to stop it... oscilations where driven by high frequency burst of signals.... tones higher than 25 kilohertz, sometimes was driving the amplifier into oscilations..and a small burst of high frequency about 1 Megahertz was appearing into the positive half of the square wave inspected into the scope.... i could remove it using this small capacitor.... reason why it continue to be present in my amplifiers...it is a "just in case" capacitor... a cheap small ceramic unit.
Do not worry...do not harm...if you want you can remove it.... as i said... "just in case"
regards,
Carlos
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I deeply suggest you to go to the group buy.... it is very possible this may be my
last amplifier...the last group buy, as i am turning very old..forgetting things....problems with concentration in some task..... aging effects are appearing clearly to me....no one knows how long will be doing these things.
In the future these circuits will have the value of relics ... not only mine but all amplifiers produced in small numbers within this DIY forum, they will be rarities, antiquities and treasures .... amplifiers are manufactured by the thousands .... we do 50 or less kits for each model series .. little gems for their rarity, precious by the fact that you built, which creates extra value for your descendants .. one day an amplifier may be worth a lot of money for your children and grandchildren because it will be part of DIY forums, audiophile designs, will be part of the history of audio ... I'm old ... within 10 or 20 years I will be with the angels (or demons) .. then it will be worth even more, then think about it a little bit.
regards,
Carlos
last amplifier...the last group buy, as i am turning very old..forgetting things....problems with concentration in some task..... aging effects are appearing clearly to me....no one knows how long will be doing these things.
In the future these circuits will have the value of relics ... not only mine but all amplifiers produced in small numbers within this DIY forum, they will be rarities, antiquities and treasures .... amplifiers are manufactured by the thousands .... we do 50 or less kits for each model series .. little gems for their rarity, precious by the fact that you built, which creates extra value for your descendants .. one day an amplifier may be worth a lot of money for your children and grandchildren because it will be part of DIY forums, audiophile designs, will be part of the history of audio ... I'm old ... within 10 or 20 years I will be with the angels (or demons) .. then it will be worth even more, then think about it a little bit.
regards,
Carlos
You old uncle charlie have not fell down in this forum as a parachutter
I was here learning along 8 years (aprox).... and i had the best teacher someone can have...Mr. Hugh Dean from Aspen Amplifiers...the manufacturer of great AKSA amplifiers.... since i was 9 years old (51 years ago) i was building amplifiers..they used to explode as i had not knowledge enough to realise the circuit had mistakes.... i could not detect clear errors...i had not knowledge as a kid i was...but i have learned a lot..i have studied and the main advantage i had is that i have built more then 6300 amplifiers along these years...sometimes i build one and half amplifier each day...i always had time to do these things..we find time to the things we love.
Several amplifiers exploded.... more than 25 percent i think....but i have learned listening, tweaking and i have developed a science.... "force amplifiers to run.. how to do that"...also expertise in the production of Frankstein alike things..one part from Aksa, other circuit from other brand... and let they mix for sonics!
There's history.... several amplifiers built and shared in this forum...more than 600 builders and several group buys opened and 80 percent of them had more than 30 orders... some brazilian groups reached 100 orders...so..i have learned burning my fingertips.
The MKIII-Hx, is now a days the best one..the most modern ones and the result of all this long time research... you have the chance to have it...without any trick... it is cost price..the lowest price you can have for the quality offered...join us!..it is almost for free...give yourself a chance to be happy.
Of course you gonna have my support life long (well...some years more..i am old)
regards,
Carlos
I was here learning along 8 years (aprox).... and i had the best teacher someone can have...Mr. Hugh Dean from Aspen Amplifiers...the manufacturer of great AKSA amplifiers.... since i was 9 years old (51 years ago) i was building amplifiers..they used to explode as i had not knowledge enough to realise the circuit had mistakes.... i could not detect clear errors...i had not knowledge as a kid i was...but i have learned a lot..i have studied and the main advantage i had is that i have built more then 6300 amplifiers along these years...sometimes i build one and half amplifier each day...i always had time to do these things..we find time to the things we love.
Several amplifiers exploded.... more than 25 percent i think....but i have learned listening, tweaking and i have developed a science.... "force amplifiers to run.. how to do that"...also expertise in the production of Frankstein alike things..one part from Aksa, other circuit from other brand... and let they mix for sonics!
There's history.... several amplifiers built and shared in this forum...more than 600 builders and several group buys opened and 80 percent of them had more than 30 orders... some brazilian groups reached 100 orders...so..i have learned burning my fingertips.
The MKIII-Hx, is now a days the best one..the most modern ones and the result of all this long time research... you have the chance to have it...without any trick... it is cost price..the lowest price you can have for the quality offered...join us!..it is almost for free...give yourself a chance to be happy.
Of course you gonna have my support life long (well...some years more..i am old)
regards,
Carlos
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Customized, modified, arranged, adapted...my own MKIII-Hx version... can I?
Yeeeees!...you can.
Can i use other voltages?
- for sure you can buddy.... from 4.5 volts to 64 plus 64 i can guarantee it will work and fine...we can also arrange it to higher voltages....it is a multivoltage amplifier.... kind amplifier...friendly amplifier.
regards,
Carlos
Yeeeees!...you can.
Can i use other voltages?
- for sure you can buddy.... from 4.5 volts to 64 plus 64 i can guarantee it will work and fine...we can also arrange it to higher voltages....it is a multivoltage amplifier.... kind amplifier...friendly amplifier.
regards,
Carlos
I want to tweak...can I?
yes you can!.... tweak it a lot man... some tweak may burn something but you may be skilled enough not to make too much big mistakes... try it by yourself.
Can i increase deep bass?
Yep... the input capacitor can be increased till 100uf.... to more you increase the more you gonna "modify" bass character and performance.... sound may become blurry and undefined...but you can.
Only the input?
No!...the gain and sensitivity capacitor (condenser) can be increased too..then you will have full power in 1 hertz and will waste a lot of energy if you like... well.... do what you want....sound will be blurred.... 47uf is the best tuning there..checked in several amplifiers.
regards,
Carlos
yes you can!.... tweak it a lot man... some tweak may burn something but you may be skilled enough not to make too much big mistakes... try it by yourself.
Can i increase deep bass?
Yep... the input capacitor can be increased till 100uf.... to more you increase the more you gonna "modify" bass character and performance.... sound may become blurry and undefined...but you can.
Only the input?
No!...the gain and sensitivity capacitor (condenser) can be increased too..then you will have full power in 1 hertz and will waste a lot of energy if you like... well.... do what you want....sound will be blurred.... 47uf is the best tuning there..checked in several amplifiers.
regards,
Carlos
I have here a small transformer...can i use it?
Yes..you can..if your secondary is three wires....so..have a center tap, and voltage measure from center tap to the extremes is almost the same..then you can.
Power output will depend on your transformer power.... 100 watts transformer will give you 60 watts (aprox) of power.... 200 watts transformer will give you 100 watts, 300 watts transformer will give you 150 watts...and this is TOTAL...means left and rigth channel playing together and sharing this power..in the last example.... 150 watts of power will be split in two..shared by two channels...75 plus 75 watts is what you may have.... do not even try to reduce impedance to 1 ohms to increase.... you will continue having the same power because there's no magic on that thing.
regards,
Carlos
Yes..you can..if your secondary is three wires....so..have a center tap, and voltage measure from center tap to the extremes is almost the same..then you can.
Power output will depend on your transformer power.... 100 watts transformer will give you 60 watts (aprox) of power.... 200 watts transformer will give you 100 watts, 300 watts transformer will give you 150 watts...and this is TOTAL...means left and rigth channel playing together and sharing this power..in the last example.... 150 watts of power will be split in two..shared by two channels...75 plus 75 watts is what you may have.... do not even try to reduce impedance to 1 ohms to increase.... you will continue having the same power because there's no magic on that thing.
regards,
Carlos
Can i use other transistors?
Yes, you can!... but you have to select them because of the voltage you gonna use...the idea is to select devices that are able to face rail plus rail voltage... also the current must be studied..... respecting PNP and NPN..using matched, or complementary pairs..then everything gonna be all right.
regards,
Carlos
Yes, you can!... but you have to select them because of the voltage you gonna use...the idea is to select devices that are able to face rail plus rail voltage... also the current must be studied..... respecting PNP and NPN..using matched, or complementary pairs..then everything gonna be all right.
regards,
Carlos
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