Yes Wayne....it is interesting
Dear Bigun.... i am glad to see you around.
I hope you are doing fine my dear.... i am working together Zimmer.... a SMPS.... this hell thing is needed to high power amplifiers... sadly we have to use..or the transformer will be too much big... too much heavy...too much expensive.
Parts exploding everywhere..... well...name is destroyer..... it is normal...was that way in the early beginning.....and SMPS is an early begining to me
regards,
Carlos
Dear Bigun.... i am glad to see you around.
I hope you are doing fine my dear.... i am working together Zimmer.... a SMPS.... this hell thing is needed to high power amplifiers... sadly we have to use..or the transformer will be too much big... too much heavy...too much expensive.
Parts exploding everywhere..... well...name is destroyer..... it is normal...was that way in the early beginning.....and SMPS is an early begining to me
regards,
Carlos
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Well I finally got it working. I used the modifications suggested by Carlos in post 29. The only thing different is the 3300R resistor. I had to use 820R there in order to be able to set the bias. With 3K3 there the pot did nothing. That 47R resistor did the trick for reducing heat in the VAS. I made a really short video of it playing. I kept it short because I don't have it hooked up to a proper heatsink yet. I have it hooked up to two different speakers because I hooked up my Honey Badger to the other two on the left so I could do a blind test with my son. He picked the MKIII which is great since the Honey Badger is one of my favorite amps and the MKIII is just hooked up breadboard style.
Here's the video.
Blessings, Terry
DX Blameless MKIII initial test. - YouTube
Here's the video.
Blessings, Terry
DX Blameless MKIII initial test. - YouTube
To look in the scope you must inject a very low level
of a sinusoidal wave to see the crossover distortion, that makes a knee into the waveform...but you do not even need to use the scope.
Watch this video below..... follow the instructions, increase current to 30 miliamperes (aproximately) to each power transistor and be happy into your test and comparison.... after that, reduce because of heat..this is for optimization to a duel...but after that..better to keep heat under control and accept that sometimes, in very low volumes (you will not play these volumes all time long) you may perceive something because your golden ears...average listeners cannot perceive..they may say they perceived for you not to be ashamed (the King new clothes).
My amplifier is very good in performance within the normal power range....after you surpasses and goes above the threshold of clipping it may clip in a very ugly way and may loose comparison of the type "What is the amplifiers that annoys rats the most"...you know..some harmonics can go to mouse ears and banish them from your home...mine one..when distorting hard, saturated...may banish rats and mice..... i really had no worries about this stuff...my concern is inside the usefull range..from 1 watt to the threshold of clipping only.
Optimizing bias to the MKIII for competition - YouTube
regards,
Carlos
of a sinusoidal wave to see the crossover distortion, that makes a knee into the waveform...but you do not even need to use the scope.
Watch this video below..... follow the instructions, increase current to 30 miliamperes (aproximately) to each power transistor and be happy into your test and comparison.... after that, reduce because of heat..this is for optimization to a duel...but after that..better to keep heat under control and accept that sometimes, in very low volumes (you will not play these volumes all time long) you may perceive something because your golden ears...average listeners cannot perceive..they may say they perceived for you not to be ashamed (the King new clothes).
My amplifier is very good in performance within the normal power range....after you surpasses and goes above the threshold of clipping it may clip in a very ugly way and may loose comparison of the type "What is the amplifiers that annoys rats the most"...you know..some harmonics can go to mouse ears and banish them from your home...mine one..when distorting hard, saturated...may banish rats and mice..... i really had no worries about this stuff...my concern is inside the usefull range..from 1 watt to the threshold of clipping only.
Optimizing bias to the MKIII for competition - YouTube
regards,
Carlos
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Hi Carlos,
I tried watching you video but the harsh language is too much for me. There is a reason I select forums with filters. The MKIII is playing fine and I will make further adjustments once I have it mounted to it's final heatsink. After that I will attempt comparisons to some of my other amps. Thanks for all your help.
Blessings, Terry
I tried watching you video but the harsh language is too much for me. There is a reason I select forums with filters. The MKIII is playing fine and I will make further adjustments once I have it mounted to it's final heatsink. After that I will attempt comparisons to some of my other amps. Thanks for all your help.
Blessings, Terry
Hi Carlos,
FYI, I will not be using "L" brackets on the final install. Those were just for testing so I could attach to my big test heatsink. I will have to order some new heatsinks for this since the PCB is so long. Once I have them I will try increasing the bias. Long heatsinks are getting rarer, at least for a good price. I may try to find some shorter ones and attach them together.
On the drivers. Do they generate much heat on their own? If I put them on a separate heatsink, how big does it meed to be and do they need to share one or could they each have their own?
Thanks, Terry
FYI, I will not be using "L" brackets on the final install. Those were just for testing so I could attach to my big test heatsink. I will have to order some new heatsinks for this since the PCB is so long. Once I have them I will try increasing the bias. Long heatsinks are getting rarer, at least for a good price. I may try to find some shorter ones and attach them together.
On the drivers. Do they generate much heat on their own? If I put them on a separate heatsink, how big does it meed to be and do they need to share one or could they each have their own?
Thanks, Terry
3 watt heatsinks, the ones Juan Vargas is using...
....in his Dx Super A blue boards...check with Juan the model..these gonna fit the drivers.
3 Watt minimum...if you manage to install a 5 watt gonna be even better.
Voltage amplifier transistor, the big one and the drivers should be in separate heatsinks if you increase the current in order to optimize performance.
16 to 30 milivolts you measure into the power emitter resistors extremes, atop of these resistors, measuring the leads...you decide depending your heatsinks if you will go to 16 or 30 milivolts or any voltage in between these ones...the higher the better...but the heat generated will increase a lot..it is dangerous when you put your finger atop of the transistor case and cannot keep it ther for more than 4 seconds. (finger-o-meter)
If you adjust 16 milivolts, at 64 volts supplies..then your current will be 200 mA iddle, this means you gonna be dissipating 12 watts to each rail....or 24 watts total... a good heat...need a huge heatsink.
If you adjust 30 milivolts, at 64 volts supplies.. the your current will be aprox. 340 mA to each rail (iddle...or in stand by mode, no signal entering)... this current is to each rail... this means you gonna me dissipating aprox. 22 watts per rail or 44 watts total... this is a very huge heat...looks alike two JLH class A power amplifiers.... a really huge heat.
Naturally with your 55 supplies the heat will be a little bit less...but even this way a really big heat.
The output power depends on your transformer...65 percent of its VA rating or Watts rating will be audio...so...if your transformer is 1000 watts..then you will have 650 watts RMS of total power...325 to each channel.... naturally this is an example only... you gonna have less...the iddle current is too big..and this reduces the efficiency a lot.... this ratio of power is not dependent of load..... you can reduce to 1 ohms and even this way you gonna have the limitation of output power that depends on the transformer power..no magic on that.... 100 watts transformer will put out 65 watt RMS no matter what you do.
I use to do this stuff listening.... pianissimo moments of orchestra.... i can listen and you can listen the harsh sound that reduces of transistor crossover distortion at low power levels...this way i can save some power and avoid some heat...if you can listen the stuff..then adjust it while listening..but be aware of current...go monitoring with ampere meter, not to go to much high in current or your output can be destroyed.
You cannot exceed 12 amperes to each rail if your supply remains in 64 volts...naturally if your voltage drop to 40 volts, then you can go to 22.5A per rail
In my home amplifiers i accept some harshing into low levels of audio..the pianissimo of an orchestra..because i do not listen the style of music that goes to these low levels..so....i got rid of the current..in my amplifiers, the stand by current is lower than 60 mA each rail...dissipation in my home is less than 4 watts each rail..total of 10 watts.... or 6 mA to each power transistor... 3 mV voltage drop at the power emitter resistors (0.47 ohms)
regards,
Carlos
....in his Dx Super A blue boards...check with Juan the model..these gonna fit the drivers.
3 Watt minimum...if you manage to install a 5 watt gonna be even better.
Voltage amplifier transistor, the big one and the drivers should be in separate heatsinks if you increase the current in order to optimize performance.
16 to 30 milivolts you measure into the power emitter resistors extremes, atop of these resistors, measuring the leads...you decide depending your heatsinks if you will go to 16 or 30 milivolts or any voltage in between these ones...the higher the better...but the heat generated will increase a lot..it is dangerous when you put your finger atop of the transistor case and cannot keep it ther for more than 4 seconds. (finger-o-meter)
If you adjust 16 milivolts, at 64 volts supplies..then your current will be 200 mA iddle, this means you gonna be dissipating 12 watts to each rail....or 24 watts total... a good heat...need a huge heatsink.
If you adjust 30 milivolts, at 64 volts supplies.. the your current will be aprox. 340 mA to each rail (iddle...or in stand by mode, no signal entering)... this current is to each rail... this means you gonna me dissipating aprox. 22 watts per rail or 44 watts total... this is a very huge heat...looks alike two JLH class A power amplifiers.... a really huge heat.
Naturally with your 55 supplies the heat will be a little bit less...but even this way a really big heat.
The output power depends on your transformer...65 percent of its VA rating or Watts rating will be audio...so...if your transformer is 1000 watts..then you will have 650 watts RMS of total power...325 to each channel.... naturally this is an example only... you gonna have less...the iddle current is too big..and this reduces the efficiency a lot.... this ratio of power is not dependent of load..... you can reduce to 1 ohms and even this way you gonna have the limitation of output power that depends on the transformer power..no magic on that.... 100 watts transformer will put out 65 watt RMS no matter what you do.
I use to do this stuff listening.... pianissimo moments of orchestra.... i can listen and you can listen the harsh sound that reduces of transistor crossover distortion at low power levels...this way i can save some power and avoid some heat...if you can listen the stuff..then adjust it while listening..but be aware of current...go monitoring with ampere meter, not to go to much high in current or your output can be destroyed.
You cannot exceed 12 amperes to each rail if your supply remains in 64 volts...naturally if your voltage drop to 40 volts, then you can go to 22.5A per rail
In my home amplifiers i accept some harshing into low levels of audio..the pianissimo of an orchestra..because i do not listen the style of music that goes to these low levels..so....i got rid of the current..in my amplifiers, the stand by current is lower than 60 mA each rail...dissipation in my home is less than 4 watts each rail..total of 10 watts.... or 6 mA to each power transistor... 3 mV voltage drop at the power emitter resistors (0.47 ohms)
regards,
Carlos
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To the ones does not know...very few guys i believe
The power amplifier performance depends on the supply power.
Every amplifier that is powered by 64 volts supplies will produce the same ammount of power if they are using the same power transformer..differences are but they are small..if not bridged, the power gonna be the same.
What can change this stuff is the audio transference..the Back EMF, the coupling and, or the amplifier output impedance..the level of mismatch.
For the supplies you can have more power if you insert more capacitors..but this power is form small time..just of a peak, while the capacitors discharge...more dinamic than continuous power.
The power of an audio amplifier is the power it's supply can deliver...naturally the amplifier efficiency says the result...usually our amplifiers, in Class AB, have 65 percent of efficiency.
No magic on that..very simple..have power into the supply?.. then you gonna have power into your output.
5 or 10 percent..even 15 percent is something that does not change anything..we cannot listen these differences of power..the voice coil can perceive..but not us!..so..if a genius designer can have "all the juice" on an amplifier and can put out 15 percent more..... well... he waste his time..you will not perceive..... you have to double, for some people you have to multiply power by four to perceive something different.
What may confuse some guys are speakers..some of them cannot work fine with 50 watts...and if you plug a 80 watts amplifier it can put some bass out..then the guy may think he can notice this difference in power... he could because the speaker wake up..just that.
You see the specification below..when reached the power supply limit....not matter what you do, even reducing impedance, the power will remains the same..... and that power is the maximum power delivered from the supply to your class of amplifier.... the image is not a Dx amplifier..it is just an image i have captures into the internet.
regards,
Carlos
The power amplifier performance depends on the supply power.
Every amplifier that is powered by 64 volts supplies will produce the same ammount of power if they are using the same power transformer..differences are but they are small..if not bridged, the power gonna be the same.
What can change this stuff is the audio transference..the Back EMF, the coupling and, or the amplifier output impedance..the level of mismatch.
For the supplies you can have more power if you insert more capacitors..but this power is form small time..just of a peak, while the capacitors discharge...more dinamic than continuous power.
The power of an audio amplifier is the power it's supply can deliver...naturally the amplifier efficiency says the result...usually our amplifiers, in Class AB, have 65 percent of efficiency.
No magic on that..very simple..have power into the supply?.. then you gonna have power into your output.
5 or 10 percent..even 15 percent is something that does not change anything..we cannot listen these differences of power..the voice coil can perceive..but not us!..so..if a genius designer can have "all the juice" on an amplifier and can put out 15 percent more..... well... he waste his time..you will not perceive..... you have to double, for some people you have to multiply power by four to perceive something different.
What may confuse some guys are speakers..some of them cannot work fine with 50 watts...and if you plug a 80 watts amplifier it can put some bass out..then the guy may think he can notice this difference in power... he could because the speaker wake up..just that.
You see the specification below..when reached the power supply limit....not matter what you do, even reducing impedance, the power will remains the same..... and that power is the maximum power delivered from the supply to your class of amplifier.... the image is not a Dx amplifier..it is just an image i have captures into the internet.
regards,
Carlos
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Hey A.
I have been working on finishing up the Super A and a peeceebee. I still need to buy some decent size heatsinks for the MKIII. The boards are so long it is hard to find long enough heatsinks. I may have to go with Conrad but the shipping if very expensive. I've had my Super A and peeceebee playing sind by side now for two days. Both sound very very good.
I have been working on finishing up the Super A and a peeceebee. I still need to buy some decent size heatsinks for the MKIII. The boards are so long it is hard to find long enough heatsinks. I may have to go with Conrad but the shipping if very expensive. I've had my Super A and peeceebee playing sind by side now for two days. Both sound very very good.
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