i really want one that you screw or bolt to the heat sink the ones that are flat type but i need someone to suggest to me a name of the device not just general name as thier too many of these devices with the general name it gets confusing trying to choose one. Preferably like the one alex used on his dhr turbo.
MJE3055.... use this one...in the reality you can use
any NPN transistor..... the ones you have..... the biggest metal or plastic area in contact to the heatsink will be better...beeing plastic you will not need to use insulators and this is better.
You need junction, alike diodes.... base to emitter...and all power transistor have theses junctions inside.
Type NPN power transistor into E bay..the one appear is the one you may use.
Junction when hot will reduce the 600 milivolts voltage that appear there..and this will reduce the bias into the output transistors... heat control.... we need diodes, and better if diodes has a good contact area to be used.... there are diodes into To220 cases that can be used too if you prefere.... you need junction and big metal or plastic area having thermical contact with the heatsink...just that....it is not a critical application... all silicon diodes, or transistors will fit.
regards,
Carlos
any NPN transistor..... the ones you have..... the biggest metal or plastic area in contact to the heatsink will be better...beeing plastic you will not need to use insulators and this is better.
You need junction, alike diodes.... base to emitter...and all power transistor have theses junctions inside.
Type NPN power transistor into E bay..the one appear is the one you may use.
Junction when hot will reduce the 600 milivolts voltage that appear there..and this will reduce the bias into the output transistors... heat control.... we need diodes, and better if diodes has a good contact area to be used.... there are diodes into To220 cases that can be used too if you prefere.... you need junction and big metal or plastic area having thermical contact with the heatsink...just that....it is not a critical application... all silicon diodes, or transistors will fit.
regards,
Carlos
you know when you just about almiost complete well in my case i just need to attach four 1n4002(changed my mind on thermal sensor why go complicated just go the easy route). and 2 t220 type transistors 1837 and the other one. Your board really starts to add alot of weight mine weighs alot for a circuit board hav to be careful when picking it up the transistors can move out of place from the circuit board i just press them back against the board.
now talking about heatsinks they are really expesnive especially the size i need. but i have seen aluminium square blocks 300mmx300mmx50 on ebay for resonable prices. dont wnat to turn the amp on till i got the heatsink other wise trans can burn out when amp powered on just taking precautions.
Will have lot of pictures of amp when i charge the camera so everyone can see it.
THANKS CARLOS FOR ANSWERING THE QUESTIONS I ASKED AND OTHERS MEMBERS I LEARNT ALOT.
now talking about heatsinks they are really expesnive especially the size i need. but i have seen aluminium square blocks 300mmx300mmx50 on ebay for resonable prices. dont wnat to turn the amp on till i got the heatsink other wise trans can burn out when amp powered on just taking precautions.
Will have lot of pictures of amp when i charge the camera so everyone can see it.
THANKS CARLOS FOR ANSWERING THE QUESTIONS I ASKED AND OTHERS MEMBERS I LEARNT ALOT.
Will be a good idea to post some picture...we will feel happy with that
Well...heatsinks are an old and very long, long, story....and i really do not want to repeat all stuff once again...was deeply explored into the Dx Amplifier thread.... my amplifier thread.
I have a simple calculation.... to each 10 watts RMS you gonna have into your output then use an aluminium blade measuring 10 by 10 centimeter.... 100 squared centimeters if you use one side only (one face only)....or 200 squared centimeter if you decide to add both faces...
Measure your fins, and your base sides...multiply side by side and add all those numbers and them enter the simple calculation:
Example.... you found 10 fins into your heatsink... 5 X 8 centimeters fins..and base was 10 X 10 centimeters....so..... 400 to the fins added and 100 to the base...total 500.
This means you can use a 50 watts amplifier, full power, continuous into this heatsink (if calculate one face only... as metal has two sides, two faces)
This means enougth to 50 watts RMS amplifier, steady tone, 1 Kilohertz, unclipped ... the heatsink will work fine if outside the case, uncovered, unobstructed, free air circulating.
Music is not continuous...so, this heatsink may hold 2 or three times more power because music is average, not continuous...but think about... sustain music.... organs, synthetizers, guitars with reverberations, distorters, sustainers..all those things turns audio constant....no musical... we call music..but has not the average characteristic you have into the normal, standard music.
Calculation is easy:
If 100 square centimeters is enougth to 10 watts RMS
100..................10
Them we have 1850 squared centimeters..how this will result?
100........ 10
1850....... X
100X = 18500
X= 18500 divided by 100
X= 185
So.... using this heatsink you have made an "exploded view" and have calculated each fin area...and all them added you had as result a heatsink able to hold 185 watts RMS of audio power (not heat or dissipation..able to hold amplifier, class AB, putting out this sinusoidal continuous undistorted power).... and can hold musical (music) power of twice or three time this one....so....400 watts amplifier or even 600 watts amplifier can use this theorical heatsink.
Using fan...things change a lot..maybe 5 times more.
Inside case.... things change a lot...maybe 3 times less!
If black the heatsink will be better...not painted..anodized
Heatsink thickness is not important..important is the area in contact with the air.... thin fins works fine too.
Well... this is the best i can do....if not enougth..them search those detailed informations you have into the Dx Amplifier, my amplifier thread.
Be happy.
Carlos
..................................................................................................
With heatsinks that obbey this practical rule i found testing, into an environment of 28 degrées celsius the heatsink will not be hot above 50 degrées celsius (and this is safe..cannot go above 52 degrées celsius...better if work into 42 degrees celsius)
So...maximum is 22 degrees celsius above environment temperature.
Well...heatsinks are an old and very long, long, story....and i really do not want to repeat all stuff once again...was deeply explored into the Dx Amplifier thread.... my amplifier thread.
I have a simple calculation.... to each 10 watts RMS you gonna have into your output then use an aluminium blade measuring 10 by 10 centimeter.... 100 squared centimeters if you use one side only (one face only)....or 200 squared centimeter if you decide to add both faces...
Measure your fins, and your base sides...multiply side by side and add all those numbers and them enter the simple calculation:
Example.... you found 10 fins into your heatsink... 5 X 8 centimeters fins..and base was 10 X 10 centimeters....so..... 400 to the fins added and 100 to the base...total 500.
This means you can use a 50 watts amplifier, full power, continuous into this heatsink (if calculate one face only... as metal has two sides, two faces)
This means enougth to 50 watts RMS amplifier, steady tone, 1 Kilohertz, unclipped ... the heatsink will work fine if outside the case, uncovered, unobstructed, free air circulating.
Music is not continuous...so, this heatsink may hold 2 or three times more power because music is average, not continuous...but think about... sustain music.... organs, synthetizers, guitars with reverberations, distorters, sustainers..all those things turns audio constant....no musical... we call music..but has not the average characteristic you have into the normal, standard music.
Calculation is easy:
If 100 square centimeters is enougth to 10 watts RMS
100..................10
Them we have 1850 squared centimeters..how this will result?
100........ 10
1850....... X
100X = 18500
X= 18500 divided by 100
X= 185
So.... using this heatsink you have made an "exploded view" and have calculated each fin area...and all them added you had as result a heatsink able to hold 185 watts RMS of audio power (not heat or dissipation..able to hold amplifier, class AB, putting out this sinusoidal continuous undistorted power).... and can hold musical (music) power of twice or three time this one....so....400 watts amplifier or even 600 watts amplifier can use this theorical heatsink.
Using fan...things change a lot..maybe 5 times more.
Inside case.... things change a lot...maybe 3 times less!
If black the heatsink will be better...not painted..anodized
Heatsink thickness is not important..important is the area in contact with the air.... thin fins works fine too.
Well... this is the best i can do....if not enougth..them search those detailed informations you have into the Dx Amplifier, my amplifier thread.
Be happy.
Carlos
..................................................................................................
With heatsinks that obbey this practical rule i found testing, into an environment of 28 degrées celsius the heatsink will not be hot above 50 degrées celsius (and this is safe..cannot go above 52 degrées celsius...better if work into 42 degrees celsius)
So...maximum is 22 degrees celsius above environment temperature.
I am sorry Norazmi...i do not use pré amplifier
I use CD output directly into power amplifier input.... a trimpot into the input controls the signal level if needed when we have not volume control into the CD player.
The amplifier sensitivity can be adjusted to match the CD player line output level, and impedance is having a reasonable matching.
We have a resistance into the feedback line (the one in series with an electrolitic condenser that has it's negative lead connected to the input ground) that can be changed... when you reduce you gonna have more sensitivity..... increasing you gonna have less sensitivity.
The amplifier is adjusted to 750 milivolts RMS into the input..with this signal level you gonna have full output power...but you can reduce that resistance to lower input voltages and you can increase to allow you to enter your amplifier with higher level audio sources (some CD players can put out more than 2 volts)
I use to adjust controling the speaker passive crossover....levels are adjusted to my home...so...not needed to increase bass or decrease bass.... and not needed to increase treble or decrease treble... the audio goes from the CD to the amplifier and them to the speaker having internally the passive crossover that controls the whole situation....in the reality i have wire potentiometers (reostatos) in series with midrange and tweeter...so... reducing tweeter and midrange level i can have more bass (ratio, proportion, relative level, perceived ballance of audio)
Well.... others love pré amplifiers...i really think they are not needed to me..i have not to switch from CD to turntable...so..not even the switching function we have into pré amplifier is used by me.
I cannot suggest you a pré amplifier, i know nothing about them, as you see, i do not use them.
regards,
Carlos
I use CD output directly into power amplifier input.... a trimpot into the input controls the signal level if needed when we have not volume control into the CD player.
The amplifier sensitivity can be adjusted to match the CD player line output level, and impedance is having a reasonable matching.
We have a resistance into the feedback line (the one in series with an electrolitic condenser that has it's negative lead connected to the input ground) that can be changed... when you reduce you gonna have more sensitivity..... increasing you gonna have less sensitivity.
The amplifier is adjusted to 750 milivolts RMS into the input..with this signal level you gonna have full output power...but you can reduce that resistance to lower input voltages and you can increase to allow you to enter your amplifier with higher level audio sources (some CD players can put out more than 2 volts)
I use to adjust controling the speaker passive crossover....levels are adjusted to my home...so...not needed to increase bass or decrease bass.... and not needed to increase treble or decrease treble... the audio goes from the CD to the amplifier and them to the speaker having internally the passive crossover that controls the whole situation....in the reality i have wire potentiometers (reostatos) in series with midrange and tweeter...so... reducing tweeter and midrange level i can have more bass (ratio, proportion, relative level, perceived ballance of audio)
Well.... others love pré amplifiers...i really think they are not needed to me..i have not to switch from CD to turntable...so..not even the switching function we have into pré amplifier is used by me.
I cannot suggest you a pré amplifier, i know nothing about them, as you see, i do not use them.
regards,
Carlos
Member
Joined 2009
Paid Member
joka22 said:
with all the innovation in this forum there are probably some clever ideas for DIY heatsinks. Here's one option:
http://sound.westhost.com/articles/diy-heatsink.htm
Thanks i already been on that site, too much work and need machinery i just have hole tapper, dremel drill, cutter disc etc. but not any type of millin machinery. but no problem will sell off my old gainclone amp housed in tank type housing solid machine contruction with solid handles and is bullet proof yes i have shot it with well a air rifle gun it is rock solid. one board is blown due to crapy heatsink and other is making motorboating type sound maybe due to ground problems but i had my fun now it dhr turbo turn. with the money from the gainclone i buy nice black heatsink from ebay.
Avoiding stages into the audio chain we use to obtain better results
Adjusting the speaker to your home/environment/musical taste/musical style, will produce nice result with good recordings, in special the style you use as reference to adjust.
Personal tastes can enter into this job... sounding the way you like, as you are not into some kind of standard equalization, universal thing, competition.... so..... beeing nice to your ears will be nice to your soul.
Be happy, listen good music, dance and sing some songs....kiss you wife many times a day and say you love here... and your life will be rich of good moments.
There are pre amplifier with a lot of knobs...and usually you use volume, maybe some tone...but the other switches stay there just decorating, unused.
regards,
Carlos
Adjusting the speaker to your home/environment/musical taste/musical style, will produce nice result with good recordings, in special the style you use as reference to adjust.
Personal tastes can enter into this job... sounding the way you like, as you are not into some kind of standard equalization, universal thing, competition.... so..... beeing nice to your ears will be nice to your soul.
Be happy, listen good music, dance and sing some songs....kiss you wife many times a day and say you love here... and your life will be rich of good moments.
There are pre amplifier with a lot of knobs...and usually you use volume, maybe some tone...but the other switches stay there just decorating, unused.
regards,
Carlos
Hi Carlos,
My plan is to start building DX HR Turbo as soon as my new amp workshop (room) is finished in the next few weeks, and I move all my crap in.
A question for everyone/anyone...
As usual, I will be building this for a permanent amp, not a just a temporary project to disassemble later. I need to buy output transistors for it. I'll be running ~75v rails.
2SC5200/1943 are nicely priced, fast, but don't handle as much power.
MJ21194/93 have great SOA but are slower and almost twice the price.
MJL4281/4302 are very expensive, but fast and good SOA.
Sankens are expensive, but not readily available in Canada.
(Good, fast or cheap: pick any two.)
Am I missing any other reasonable options?
..Todd
My plan is to start building DX HR Turbo as soon as my new amp workshop (room) is finished in the next few weeks, and I move all my crap in.
A question for everyone/anyone...
As usual, I will be building this for a permanent amp, not a just a temporary project to disassemble later. I need to buy output transistors for it. I'll be running ~75v rails.
2SC5200/1943 are nicely priced, fast, but don't handle as much power.
MJ21194/93 have great SOA but are slower and almost twice the price.
MJL4281/4302 are very expensive, but fast and good SOA.
Sankens are expensive, but not readily available in Canada.
(Good, fast or cheap: pick any two.)
Am I missing any other reasonable options?
..Todd
No Todd... i think you have explored the main options we have
at least the most used and reliable ones.
I hope you decide for something having reasonable price and performance.
regards,
Carlos
..........................................
There's another one....but do not remember the number.. J4215 and J4315 maybe are those the numbers.... they are a good option too... alike 2SC5200
will check this number latter and will send you the correct number if this one was wrong.
regards,
Carlos
at least the most used and reliable ones.
I hope you decide for something having reasonable price and performance.
regards,
Carlos
..........................................
There's another one....but do not remember the number.. J4215 and J4315 maybe are those the numbers.... they are a good option too... alike 2SC5200
will check this number latter and will send you the correct number if this one was wrong.
regards,
Carlos
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