Dear friends...we have group buy for boards.
Join us.... we have two group buys, one for the International High Level International audiophile community and other for High Leval audiophile brazilian comunity.
A high level design (Dr. Self) that had high level of effort my Dx on development and tweaking for nice sonics, with high level boards, high level parts, high level sonics and high level of LOW distortions.
Wanna the best possible?....join us!
Here you have the group buy.... 10 orders in 24 hours!..... in Brazil there are more guys that have informed their interest:
http://www.diyaudio.com/forums/grou...kii-mkii-supercharged-groub-buy-interest.html
The DIY, amateur amplifier, with the highest level of spreading around the world..the Dx Corporation amplifiers...made to sound good to human ears..your ears!
Dx Corporation is constituted by you!.... the ones had interest and have assembled Dx amplifiers..we are an association of good audiophiles, the ones does not mind (too much) with numbers and are interested in the real emotion of nice sonics (despite our amplifier measure very well too!)
Dx Corporation is a virtual non profit organization, a real DIY ruled by a fanatic..supported by amateurs... the Corporation's Osciloscope, Function Generator, Multimeters, Transistors, Fets, Resistances, capacitors, electrolitic condensers, diodes, rectifiers, heatsinks and all stuff used where gifts from audiophile friends that decided to help me to produce more and more amplifiers...all donation alike the DIY forum.... My Osciloscope travelled from unit states in the hands of a very famous Acoustic Engineer, the one is called world wide to produce Acoustics projects..the one gives enormous value and support to the Corporation....you can donate too!..... building Dx amplifiers and helping me to spread it around the world....be one more to join this peacefull army that is whilling to destroy bad sonics, high prices, selfish and bad mood.... etch a board man!.... use a piece of wood with nails.... find some junk in the junkyard.... clean it..test the parts and assemble a beautifull amplifier with ZERO cost...and beating MILLIONS of others that did not came from junk yard..but in the reality should -- there.
ahahahahahah!
regards,
Carlos
Join us.... we have two group buys, one for the International High Level International audiophile community and other for High Leval audiophile brazilian comunity.
A high level design (Dr. Self) that had high level of effort my Dx on development and tweaking for nice sonics, with high level boards, high level parts, high level sonics and high level of LOW distortions.
Wanna the best possible?....join us!
Here you have the group buy.... 10 orders in 24 hours!..... in Brazil there are more guys that have informed their interest:
http://www.diyaudio.com/forums/grou...kii-mkii-supercharged-groub-buy-interest.html
The DIY, amateur amplifier, with the highest level of spreading around the world..the Dx Corporation amplifiers...made to sound good to human ears..your ears!
Dx Corporation is constituted by you!.... the ones had interest and have assembled Dx amplifiers..we are an association of good audiophiles, the ones does not mind (too much) with numbers and are interested in the real emotion of nice sonics (despite our amplifier measure very well too!)
Dx Corporation is a virtual non profit organization, a real DIY ruled by a fanatic..supported by amateurs... the Corporation's Osciloscope, Function Generator, Multimeters, Transistors, Fets, Resistances, capacitors, electrolitic condensers, diodes, rectifiers, heatsinks and all stuff used where gifts from audiophile friends that decided to help me to produce more and more amplifiers...all donation alike the DIY forum.... My Osciloscope travelled from unit states in the hands of a very famous Acoustic Engineer, the one is called world wide to produce Acoustics projects..the one gives enormous value and support to the Corporation....you can donate too!..... building Dx amplifiers and helping me to spread it around the world....be one more to join this peacefull army that is whilling to destroy bad sonics, high prices, selfish and bad mood.... etch a board man!.... use a piece of wood with nails.... find some junk in the junkyard.... clean it..test the parts and assemble a beautifull amplifier with ZERO cost...and beating MILLIONS of others that did not came from junk yard..but in the reality should -- there.
ahahahahahah!
regards,
Carlos
Attachments
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Very sad right now.Was listening to music on my vintage B&W DM14 speakers.Everthing OK increased volume a lot overload and DC protection of the speakers kicks in lower the volume protection turns off only of one speaker the other one stay on.This could mean only one thing DC at the output.Used a multimeter there was a short at the output trannies.Disasampled the pcb and toke my transistor tester and they were OK.With this tester I could test trannies on board but to be shure soldered them out and also then OK and no more shorts between the legs.Soldered the trannies back in and the amp stays dead.Again shorts between the legs disasampled the board toke my trannie tester OK.Is it possible that when the trannies are cold they are OK and when they are warm are bad?
Carlos are there other trannies to use for testing like the TIP142-147?
I do have spare 5200-1943 but to not want to use them if isn't necessary.
Carlos are there other trannies to use for testing like the TIP142-147?
I do have spare 5200-1943 but to not want to use them if isn't necessary.
Really a very sad thing...i am very sorry by that
i ensure i have tested the amplifier deeply, suffered torture and several guys assembled..no one reported damage.... i also have tested and anything wrong happened.
Well... something is wrong dear Meanman...there is a component or some parts wrong in value...maybe written one value and the reality the value can be other...you have assembled several of our amplifiers and you could see they use to be very reliable.
Do not try other output transistors if you had troubles...i had troubles with a toroidal transformer if you remember...i could not even discover why.... there are things uncle charlie does not know.
Better to check the amplifier...both channels damaged?... if both channels then speaker cable and speaker is the one to have suspection....one channel damaged?, then the board should be checked observing the other one..using the other one as reference.
I cannot be with you..if i could..for sure i would be to fix your amplifier by myself...i feel very, very, very, very sad to be YOU to face these troubles because you are with me for a very long time..always building my amplifiers..so..you are Dx Corporation from the feet nails to the extreme point of your hairs.
Be calm.... relax and go checking ....if you want, send me the damaged board and uncle charlie gonna check it and fix it to you for free.
Carlos Eugênio Mergulhão
Rua Dona Balbina Menelau 56 - 1601
Candeias - Jaboatão dos Guararapes
Pernambuco - Brazil
South America
Zip code: 54440-515
Heatsinks are very important.... in stand by mode, the output goes cold...really cold..almost the same environment temperature.... playing loud it became hot..around 42 degrees celsius (high human fever) to average, non distorted levels..of course if you force the amplifier to operate into distortions, then you will have it hot..almost 52 degrées celsius in the heatsink.... the transistor should have, the top of the transistor, almost the same temperature you have in the heatsink..if you have it too much hot at the top, two things may be happening...first the bad thermal transference to heatsink or transistor loosen (screw loosen) or heatsink too much small or oscilations..and oscilations in this amplifier can happens if you have, from your DVD, CD player or other audio source having spurious signal from the internal oscilators, clock and so on.... Ipod, the MP3 and MP4 players, these hell things uses to have these spurious signal that are filtered by the earphones (coil)..but when people plug the output jack to amplifiers usually send spurious signals.
Make pictures..let uncle charlie see your system..your heatsink size..your source.... measure your speaker to see if the resistance to DC is normal or if you have a semi-burned speaker coil with a very low resistance on it..... must check everything...now everything is under suspection...since the amplifier..the most obvious guilty to blame, but also audio source, supply, heatsinks and speaker itself.
regards,
Carlos
i ensure i have tested the amplifier deeply, suffered torture and several guys assembled..no one reported damage.... i also have tested and anything wrong happened.
Well... something is wrong dear Meanman...there is a component or some parts wrong in value...maybe written one value and the reality the value can be other...you have assembled several of our amplifiers and you could see they use to be very reliable.
Do not try other output transistors if you had troubles...i had troubles with a toroidal transformer if you remember...i could not even discover why.... there are things uncle charlie does not know.
Better to check the amplifier...both channels damaged?... if both channels then speaker cable and speaker is the one to have suspection....one channel damaged?, then the board should be checked observing the other one..using the other one as reference.
I cannot be with you..if i could..for sure i would be to fix your amplifier by myself...i feel very, very, very, very sad to be YOU to face these troubles because you are with me for a very long time..always building my amplifiers..so..you are Dx Corporation from the feet nails to the extreme point of your hairs.
Be calm.... relax and go checking ....if you want, send me the damaged board and uncle charlie gonna check it and fix it to you for free.
Carlos Eugênio Mergulhão
Rua Dona Balbina Menelau 56 - 1601
Candeias - Jaboatão dos Guararapes
Pernambuco - Brazil
South America
Zip code: 54440-515
Heatsinks are very important.... in stand by mode, the output goes cold...really cold..almost the same environment temperature.... playing loud it became hot..around 42 degrees celsius (high human fever) to average, non distorted levels..of course if you force the amplifier to operate into distortions, then you will have it hot..almost 52 degrées celsius in the heatsink.... the transistor should have, the top of the transistor, almost the same temperature you have in the heatsink..if you have it too much hot at the top, two things may be happening...first the bad thermal transference to heatsink or transistor loosen (screw loosen) or heatsink too much small or oscilations..and oscilations in this amplifier can happens if you have, from your DVD, CD player or other audio source having spurious signal from the internal oscilators, clock and so on.... Ipod, the MP3 and MP4 players, these hell things uses to have these spurious signal that are filtered by the earphones (coil)..but when people plug the output jack to amplifiers usually send spurious signals.
Make pictures..let uncle charlie see your system..your heatsink size..your source.... measure your speaker to see if the resistance to DC is normal or if you have a semi-burned speaker coil with a very low resistance on it..... must check everything...now everything is under suspection...since the amplifier..the most obvious guilty to blame, but also audio source, supply, heatsinks and speaker itself.
regards,
Carlos
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The amplifier cannot work with more than 42 volts at full power
In special if the speaker has low impedance....some of them have "strange" crazy crossovers inside...and them you have very low impedance because capacitors, resistances and coils inside.... low impedance in some frequency..not DC resistance..the impedance!
The amplifier can operate with a sustained 42 volts supply.... but it may be endangered by higher voltage..... in your case, dear Meanman... you had one channel burned... this is confused because the other could be burned too or could survive.
I am still thinking the supply may not be the problem..because even using higher voltage, when playing full power, the voltage may drop.
You should measure your voltage..the supply DC voltage, with your amplifier playing loud..to see the real voltage is feeding the amplifier while operating and draining energy.
An electrical bicicle, non loaded, can measure 100 MPH in their wheel if their wheels are not touching the ground (unloaded)..but loaded, some of them cannot run at higher speed than 50 miles an hour (the real good ones)...so..you should check your voltage LOADED..with your amplifier screaming loud!
All this depends on your speaker DC resistance (measure with a multimeter) and your impedance... and this is more complicated, needs a generator and a variable resistance in series with the speaker..and adjustable wire potentiometer.. a power potentiometer we call here Reostato...when you adjust the variable resistance to split the voltage in two, means half to the speaker and half to the load...with 1 Khz entering the power amplifier and being reproduce into the speaker..then..when you have half and half..voltage splitted in two parts.... the resistance after adjustment to allow you to measure exactly this half and half..will be your indicator...it will inform you the real impedance..but to THAT specific frequency..this does not guarantee you should not have lower impedance in other frequencies.... and this may happens..it is a hell hard work to measure that....i do not know better way without pink or white noise and spectrum analiser and some other tools..but these tools we usually do not have.
Heatsink size is important...drivers CANNOT operate without heatsinks... well..there are many causes but the amplifier.
This amplifier...with small heatsinks...and no driver's heatsink.... and crazy speaker loads...and full volume..and more than 42 volts...well.... will burn of course.
The trouble can be inside the amplifier board..but you should check other things too..and first..because it could die by itself or could be murdered too!
Take your automobile... and remove the oil (means you have removed heatsinks from drivers)..them remove the water from the cooling system (this means small heatsinks)..then overdrive your motor acelerating maximum without engage a speed....(excess of voltage).... your engine will melt.
regards,
Carlos
In special if the speaker has low impedance....some of them have "strange" crazy crossovers inside...and them you have very low impedance because capacitors, resistances and coils inside.... low impedance in some frequency..not DC resistance..the impedance!
The amplifier can operate with a sustained 42 volts supply.... but it may be endangered by higher voltage..... in your case, dear Meanman... you had one channel burned... this is confused because the other could be burned too or could survive.
I am still thinking the supply may not be the problem..because even using higher voltage, when playing full power, the voltage may drop.
You should measure your voltage..the supply DC voltage, with your amplifier playing loud..to see the real voltage is feeding the amplifier while operating and draining energy.
An electrical bicicle, non loaded, can measure 100 MPH in their wheel if their wheels are not touching the ground (unloaded)..but loaded, some of them cannot run at higher speed than 50 miles an hour (the real good ones)...so..you should check your voltage LOADED..with your amplifier screaming loud!
All this depends on your speaker DC resistance (measure with a multimeter) and your impedance... and this is more complicated, needs a generator and a variable resistance in series with the speaker..and adjustable wire potentiometer.. a power potentiometer we call here Reostato...when you adjust the variable resistance to split the voltage in two, means half to the speaker and half to the load...with 1 Khz entering the power amplifier and being reproduce into the speaker..then..when you have half and half..voltage splitted in two parts.... the resistance after adjustment to allow you to measure exactly this half and half..will be your indicator...it will inform you the real impedance..but to THAT specific frequency..this does not guarantee you should not have lower impedance in other frequencies.... and this may happens..it is a hell hard work to measure that....i do not know better way without pink or white noise and spectrum analiser and some other tools..but these tools we usually do not have.
Heatsink size is important...drivers CANNOT operate without heatsinks... well..there are many causes but the amplifier.
This amplifier...with small heatsinks...and no driver's heatsink.... and crazy speaker loads...and full volume..and more than 42 volts...well.... will burn of course.
The trouble can be inside the amplifier board..but you should check other things too..and first..because it could die by itself or could be murdered too!
Take your automobile... and remove the oil (means you have removed heatsinks from drivers)..them remove the water from the cooling system (this means small heatsinks)..then overdrive your motor acelerating maximum without engage a speed....(excess of voltage).... your engine will melt.
regards,
Carlos
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The rail voltage under load I mean playing music very loud never drops under the 40 Volts in idle 42 Volts.Did use the speaker on the other channel no problem.Did measure every resistor before solder them in.Maybe the tolererance of the other trannies or bad output trannies.I could measure my speakers impedance with my Clio 7 loudspeaker measurement system.I must say did use a pre-Amp maybe the output of this pre to high?
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What is your voltage without load....iddle voltage...in stand by mode?
regards,
If i understood correctly, your supply keeps voltage stable, around 42 volts while you're playing very loud...what kind of supply is this?.. is it a SMPS?
Can you produce some pictures to Uncle Charlie?..... have you measured your vintage speaker?...what as the resistance measured?
Sometimes the coil goes burning slowly.... some coil turns goes carbonized and short one wind with the other..reducing the impedance and the resistance... this happens..and it is not rare to happens..in the morning the speaker can be good and in the evening it can be bad.
Carlos
regards,
If i understood correctly, your supply keeps voltage stable, around 42 volts while you're playing very loud...what kind of supply is this?.. is it a SMPS?
Can you produce some pictures to Uncle Charlie?..... have you measured your vintage speaker?...what as the resistance measured?
Sometimes the coil goes burning slowly.... some coil turns goes carbonized and short one wind with the other..reducing the impedance and the resistance... this happens..and it is not rare to happens..in the morning the speaker can be good and in the evening it can be bad.
Carlos
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So, your amplifier is not the trouble
It is perfect.
I am uploading a video to Youtube explaining how to measure/check impedances in speaker..the poor man's method.
I am in a hurry, i will go out to vote for President...but soon the link will be here:
http://www.youtube.com/watch?v=i-Jkw0MtuyI
regards,
Carlos
It is perfect.
I am uploading a video to Youtube explaining how to measure/check impedances in speaker..the poor man's method.
I am in a hurry, i will go out to vote for President...but soon the link will be here:
http://www.youtube.com/watch?v=i-Jkw0MtuyI
regards,
Carlos
Without pre amp and using the other speaker is a very good idea
We never know what sources can have in the output.
If your DVD has some 36 khz tones, or other frequencies below 100 Megahertz...the amplifier will capture and will amplify and will send to the output..everybody will overheat and some transistors may burn.
High frequencies in high levels entering amplifiers is alike poison applied directly inside vains!
regards,
Carlos
We never know what sources can have in the output.
If your DVD has some 36 khz tones, or other frequencies below 100 Megahertz...the amplifier will capture and will amplify and will send to the output..everybody will overheat and some transistors may burn.
High frequencies in high levels entering amplifiers is alike poison applied directly inside vains!
regards,
Carlos
Hello...everybody...i im new to this forum.
I have PCB DX ST Amp and DX PSU (Many, many thanks for Nabuco)
I im now ordering components for DX PSU. I Want components to be high quality.
So i im currently making looking at Parts ConneXion - The authority on hi-fi DIY parts and components
I have questions before order:
Can i use for Each rail for bigcapacitor (2x 10,000uF per rail)? in your schematic is one 10,000uF and other is 4700uF? I ask becuse Nabuco make diameter for both capacitors 35mm. 10,000uF has diameter 35 but 4700uF has 25mm mm so may i use 10,000uF instead of 4700uf without lossing any sound quality? I have selected Nichicon 10,000uF / 50V, KG Series, 35X80 is Nichicon high quality cap for power supply??
For Diodes MUR860 i have selected ON SEMI manufacturer...i think thats ok..
Resistors 5k6, 0R47, 3R3(3W) and 2k2 are 2W power rated in schematic...i will use PRP resistors for amplifier board later, so PRP resistors exist only 1/2, 1/4 and 1W. Can i use on amplifier board PRP resistors and for DX PSU board Caddock resistors?? Or in other therm can i mix two resistors manufacturers without sound quality loss? Caddock and PRP resistors? If yes, Caddock resistors are rated for 2,25W so then i can put 2,25W instead of 3W for 3R3? 0R47 does not exist in Caddock, next clostest value is 0R5 is this oK?
I use for 100nF VISHAY-RODERSTEIN MKP-1837 Film Capacitor 0.1uf 100VAC / 160VDC 1% witch is MKP capacitor (Metal Polypoline) hiqh quality, but for 1,5nF does not exist MKP VISHAY-RODERSTEIN. Only 10nF, what is your suggesstions to use? MKT?
And LED's on DX PSU board - they don't make noise in voltage?
Soory for this long post...i want to ask before ordering...
many, many thanks..
I have PCB DX ST Amp and DX PSU (Many, many thanks for Nabuco)
I im now ordering components for DX PSU. I Want components to be high quality.
So i im currently making looking at Parts ConneXion - The authority on hi-fi DIY parts and components
I have questions before order:
Can i use for Each rail for bigcapacitor (2x 10,000uF per rail)? in your schematic is one 10,000uF and other is 4700uF? I ask becuse Nabuco make diameter for both capacitors 35mm. 10,000uF has diameter 35 but 4700uF has 25mm mm so may i use 10,000uF instead of 4700uf without lossing any sound quality? I have selected Nichicon 10,000uF / 50V, KG Series, 35X80 is Nichicon high quality cap for power supply??
For Diodes MUR860 i have selected ON SEMI manufacturer...i think thats ok..
Resistors 5k6, 0R47, 3R3(3W) and 2k2 are 2W power rated in schematic...i will use PRP resistors for amplifier board later, so PRP resistors exist only 1/2, 1/4 and 1W. Can i use on amplifier board PRP resistors and for DX PSU board Caddock resistors?? Or in other therm can i mix two resistors manufacturers without sound quality loss? Caddock and PRP resistors? If yes, Caddock resistors are rated for 2,25W so then i can put 2,25W instead of 3W for 3R3? 0R47 does not exist in Caddock, next clostest value is 0R5 is this oK?
I use for 100nF VISHAY-RODERSTEIN MKP-1837 Film Capacitor 0.1uf 100VAC / 160VDC 1% witch is MKP capacitor (Metal Polypoline) hiqh quality, but for 1,5nF does not exist MKP VISHAY-RODERSTEIN. Only 10nF, what is your suggesstions to use? MKT?
And LED's on DX PSU board - they don't make noise in voltage?
Soory for this long post...i want to ask before ordering...
many, many thanks..
Hi roby,
I am using 2X 10,000uF with no problems. This amp is well designed so quality of parts may not be that critical. (except for power transistors).
Mix and match the resistors if you like - it will do no harm. You may end up with a fine culinary dish instead. I do believe that the values of parts are quite critical so try and use the exact ones. My 1.5nF is a 15cent ceramic type.
If you really want to use high quality parts, then buy some extra PCB boards to do tests. First board cheap generic parts, and the second one with Turkish jewels. =)
Without a reference, how would you even know that the expensive parts really sound better?
@ Rudi : thanks to Rudi for suggesting to NOT use the Sankens (which I did use anyway) and the most involving and fluid amplifier is playing right in front of me.
@meanman - DX corp members feel pain when one member's amp malfunctions. I hope you managed to resolve it.
I am using 2X 10,000uF with no problems. This amp is well designed so quality of parts may not be that critical. (except for power transistors).
Mix and match the resistors if you like - it will do no harm. You may end up with a fine culinary dish instead. I do believe that the values of parts are quite critical so try and use the exact ones. My 1.5nF is a 15cent ceramic type.
If you really want to use high quality parts, then buy some extra PCB boards to do tests. First board cheap generic parts, and the second one with Turkish jewels. =)
Without a reference, how would you even know that the expensive parts really sound better?
@ Rudi : thanks to Rudi for suggesting to NOT use the Sankens (which I did use anyway) and the most involving and fluid amplifier is playing right in front of me.
@meanman - DX corp members feel pain when one member's amp malfunctions. I hope you managed to resolve it.
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