Still4given and I decided to start a new thread for those building the DX Blame MkIII, an amplifier designed by Carlos (destroyerX). Although there is an existing builders thread started in 2011, it has grown to almost 2000 posts long and is difficult to navigate.
New builders are encouraged to assist each other by reading through the original builders thread and posting relevant key information here.
I will update this thread index with links to the latest schematic, board layout from recent group buy, and latest BOM.
Original thread documenting the development of the DX MkIII:
http://www.diyaudio.com/forums/soli...me-mkiii-supercharged-will-soon-released.html
Previous builders thread:
http://www.diyaudio.com/forums/solid-state/193759-dx-blame-mkiii-hx-builders-thread.html
Recent group buy:
http://www.diyaudio.com/forums/group-buys/239084-blame-mkiii-hx.html
Byron and Terry's BOM (UPDATED 21-09-13):
diyAudio
New builders are encouraged to assist each other by reading through the original builders thread and posting relevant key information here.
I will update this thread index with links to the latest schematic, board layout from recent group buy, and latest BOM.
Original thread documenting the development of the DX MkIII:
http://www.diyaudio.com/forums/soli...me-mkiii-supercharged-will-soon-released.html
Previous builders thread:
http://www.diyaudio.com/forums/solid-state/193759-dx-blame-mkiii-hx-builders-thread.html
Recent group buy:
http://www.diyaudio.com/forums/group-buys/239084-blame-mkiii-hx.html
Byron and Terry's BOM (UPDATED 21-09-13):
diyAudio
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I will be very happy to listen your evaluation in an A to B blind comparison.
How to do it:
Select a good speaker you may have... a three way unit...put it 2 to 4 meters ahead of you.... at your ears high...leveled to your ears.
Connect a switch into the power amplifiers output..also the switch (i will provide schematic) will go to the speaker, naturally...the idea is to play both amplifiers (A and B) into the same speaker.... result will be speaker dependable, speaker dependent of course...with other speaker the result can be even different.
Then select songs, various styles and rithms...drums, clarinet, bass, violin, guitar... bells..all you have..even sound effects...put all that stuff in a pen drive, or MP4 player, or Ipod or whatever you use as audio source... connect the output or your audio source to both amplifiers...of course one channel will be used..one channel for amplifier A and one channel of amplifier B...if left channel selected, then left channel to the other will be selected too.
Put them to play and hook a meter, a cheap or expensive AC rms meter, connected into the red and black wires are going to the speaker (speaker cable)...the multimeter will measure the audio.... check and adjust volume for both amplifier to read something alike 9 volts....if this is loud...then reduce to 3 or 5 volts watching the multimeter...this is not that easy..have to be adjusting volume knobs an switching and watching..takes time..not easy with a multimeter..but it is something we all have at home..or at least we should have.
Then you gonna have both amplifiers in the same condition...same song playing..same power level (aprox) and same speaker.
Ask someone from family, son, daugther, wife, friend, nephew, employee...well..the one you have to help you to operate the switch.
You cannot know the amplifier is playing..you cannot see them...no bargraph meters, no led flicking, no VU meter for you to observe..put them behind you...low light into your home... television sound off, radio sound off, engines off, air conditioning off, fan off...no noises as interferences...if you leave nearby a road..then you have to repeat several times..because noises influences evaluation.... low ligth is important..you should see the speaker only...you must sit in a confortable way... and feeling confortable..all this is very important..because mood changes evaluatons of some songs.
The switch operator will take annotations...he will write in a paper...one will be amplifier A and other will be amplifier B.... he will not know the amplifier will be playing...because he will say..playing X and playing Y and his voice can modulate because his preference and this influences... this happens a lot...empathy..the one we like the most..the one is red or the one is blue..the one is expensive and the one is cheap..you cannot know...he cannot know...so..if you made the installation.... you will mark A and B and he will decide if A will be Y or if B will be Y.... use a clever guy to do it..if you use a dumb guy... then your evaluation will not work.
Ears/brain, adjust everything....you see..we can listen bass into cell phone playing with it's tiny speaker..the self contained speaker included inside the cell phone....and we listen bass..and no bass is there...so...we "build" something..we create the illusion using our musical experience, our musical skills, our memory.... so... the switch must be operated each three seconds and the guy will say... now X...now Y...and you should vote..let's say vote is X...the switcher, the switch operator must write and fast...cannot be someone dumb... select the most clever from your sons... the fastest one.
After three seconds your brain will adjust...so...no value into the evaluation..the first three seconds you listen the real thing... after that you will listen the illusion your brain will produce..adjusted sound.
Do not believe uncle charlie?
Well...i can prove you.... one day in your life you was in a noise environment..and them a very important phone call enter and your cell phone rang....then you say hello and could not listen because noises.... trafic noises for instance..then you perceive that the person is very important..someone you miss...or some important business...someone you love...well...no more noise..you gonna listen the person..no more noise...but noise is there..and you do not listen....
How?.... brain adjusts.
Please Terry, you look to be a very nice guy, i am asking you please to do this test... i will be very happy to know your evaluation..and this will be a helpful hand as a north to new designs to be made in the future..i know the differences...i like one of them the most...i want to know if you perceived the same way.
It was made in portuguese..but electricity and electronics has no language... the switch is an old style guitar switch.
The one that gonna operate the switch cannot know the amplifier is A and B...or his voice will modulate, will show preference and will be a strong influence on you...you do not know what is X and Y and he do not know what is A and B
regards,
Carlos
How to do it:
Select a good speaker you may have... a three way unit...put it 2 to 4 meters ahead of you.... at your ears high...leveled to your ears.
Connect a switch into the power amplifiers output..also the switch (i will provide schematic) will go to the speaker, naturally...the idea is to play both amplifiers (A and B) into the same speaker.... result will be speaker dependable, speaker dependent of course...with other speaker the result can be even different.
Then select songs, various styles and rithms...drums, clarinet, bass, violin, guitar... bells..all you have..even sound effects...put all that stuff in a pen drive, or MP4 player, or Ipod or whatever you use as audio source... connect the output or your audio source to both amplifiers...of course one channel will be used..one channel for amplifier A and one channel of amplifier B...if left channel selected, then left channel to the other will be selected too.
Put them to play and hook a meter, a cheap or expensive AC rms meter, connected into the red and black wires are going to the speaker (speaker cable)...the multimeter will measure the audio.... check and adjust volume for both amplifier to read something alike 9 volts....if this is loud...then reduce to 3 or 5 volts watching the multimeter...this is not that easy..have to be adjusting volume knobs an switching and watching..takes time..not easy with a multimeter..but it is something we all have at home..or at least we should have.
Then you gonna have both amplifiers in the same condition...same song playing..same power level (aprox) and same speaker.
Ask someone from family, son, daugther, wife, friend, nephew, employee...well..the one you have to help you to operate the switch.
You cannot know the amplifier is playing..you cannot see them...no bargraph meters, no led flicking, no VU meter for you to observe..put them behind you...low light into your home... television sound off, radio sound off, engines off, air conditioning off, fan off...no noises as interferences...if you leave nearby a road..then you have to repeat several times..because noises influences evaluation.... low ligth is important..you should see the speaker only...you must sit in a confortable way... and feeling confortable..all this is very important..because mood changes evaluatons of some songs.
The switch operator will take annotations...he will write in a paper...one will be amplifier A and other will be amplifier B.... he will not know the amplifier will be playing...because he will say..playing X and playing Y and his voice can modulate because his preference and this influences... this happens a lot...empathy..the one we like the most..the one is red or the one is blue..the one is expensive and the one is cheap..you cannot know...he cannot know...so..if you made the installation.... you will mark A and B and he will decide if A will be Y or if B will be Y.... use a clever guy to do it..if you use a dumb guy... then your evaluation will not work.
Ears/brain, adjust everything....you see..we can listen bass into cell phone playing with it's tiny speaker..the self contained speaker included inside the cell phone....and we listen bass..and no bass is there...so...we "build" something..we create the illusion using our musical experience, our musical skills, our memory.... so... the switch must be operated each three seconds and the guy will say... now X...now Y...and you should vote..let's say vote is X...the switcher, the switch operator must write and fast...cannot be someone dumb... select the most clever from your sons... the fastest one.
After three seconds your brain will adjust...so...no value into the evaluation..the first three seconds you listen the real thing... after that you will listen the illusion your brain will produce..adjusted sound.
Do not believe uncle charlie?
Well...i can prove you.... one day in your life you was in a noise environment..and them a very important phone call enter and your cell phone rang....then you say hello and could not listen because noises.... trafic noises for instance..then you perceive that the person is very important..someone you miss...or some important business...someone you love...well...no more noise..you gonna listen the person..no more noise...but noise is there..and you do not listen....
How?.... brain adjusts.
Please Terry, you look to be a very nice guy, i am asking you please to do this test... i will be very happy to know your evaluation..and this will be a helpful hand as a north to new designs to be made in the future..i know the differences...i like one of them the most...i want to know if you perceived the same way.
It was made in portuguese..but electricity and electronics has no language... the switch is an old style guitar switch.
The one that gonna operate the switch cannot know the amplifier is A and B...or his voice will modulate, will show preference and will be a strong influence on you...you do not know what is X and Y and he do not know what is A and B
regards,
Carlos
Attachments
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A to B comparison method - a video
Comparação de A para B comparison from A to B - YouTube
I would like to listen evaluation of anyone, not only from Terry.... but he was invited because of special empathy in between us.
Also you can evaluate other amplifiers against a Dx Amplifier, and your evaluation is important too.
You gonna be surprised with the results..sometimes different from your expectancy
regards,
Carlos
Comparação de A para B comparison from A to B - YouTube
I would like to listen evaluation of anyone, not only from Terry.... but he was invited because of special empathy in between us.
Also you can evaluate other amplifiers against a Dx Amplifier, and your evaluation is important too.
You gonna be surprised with the results..sometimes different from your expectancy
regards,
Carlos
Hi Carlos. I A/B my amps all the time. I will for sure do that with these. I am still awaiting caps to finish the Super A. I also need to acquire some long heatsinks for this amp. I do have one long heatsink I can test one channel at a time. I may do that just to make sure all is ok while I wait.
Blessings, Terry
Here are my test speakers and some of my DIY amps
Blessings, Terry
Here are my test speakers and some of my DIY amps
I hope that room is a basement level room with a concrete floor, 'cause I'd be afraid of causing structural collapse with that much mass in one place!
Hi Carlos. I A/B my amps all the time. I will for sure do that with these. I am still awaiting caps to finish the Super A. I also need to acquire some long heatsinks for this amp. I do have one long heatsink I can test one channel at a time. I may do that just to make sure all is ok while I wait.
Blessings, Terry
Here are my test speakers and some of my DIY amps
Sure you don't get confused when switching ....
I have been planning to build a switch of some sort for a long time. It is difficult to change source and speaker at the same time without a period of silence. It doesn't take much to fool your ear. I also find it is very difficult to truthfully gauge without it being in stereo. It takes some work to get everything set up so it flows. I should build one now while I am waiting to get the components I need to finish these amps. I have some pretty nice amps already to give things a good run. In the picture you see on the left, top to bottom; Mezmerize BI buffer, Twisted Pair X-BosoZ, Jen's 6 pair Leach Low TIM, Leach Superamp, Symasym, three channel P101. On the right top to bottom, Dynaco PAS III, TO-3 Krell KSA50, 6 pair plastic output KSA50, APEPH-X, and in lower right in front a Honey Badger. Right now I am working to finish this DX MKIII, DX Super A, SKA GB150 and a Peeceebee. Looking forward to having a lot of fun comparing all them. I have 6 different sets of nearfield speakers I want to try them on as well. Life is good!
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Symasym is a great amplifier
Krell has nice bass tones....you have good ones.. i have assembled almost all them (not the Alephx) and these ones i do think are strong in a competition.
First model of Symasym had some harsh in the treble.... some noise..but i do think this was fixed.
regards,
Carlos
Krell has nice bass tones....you have good ones.. i have assembled almost all them (not the Alephx) and these ones i do think are strong in a competition.
First model of Symasym had some harsh in the treble.... some noise..but i do think this was fixed.
regards,
Carlos
OK, I have one channel playing. The first channel I hooked up has a problem. It was pulling way too much current on the + rail and started smoking the 47R resistor that replaced D1. I just unbolted it and bolted up the second channel and it didn't have a problem. I powered it up through a lightbulb and my Capacitor multiplier with a 25-0-25vac 500VA transformer. I have the the CM set for one volt drop which gives me +/-37Vdc. I have about 33mv offset. I set the bias to 250mA using a 10R 10W resistor on the - rail and and ammeter on the + rail. They agreed nicely. This give me 27mv across one emitter resistor as you can see in the picture. When I took the picture it was playing some Gerry Mulligan through a JBL 4312. Sounding pretty sweet. Now that I have this one working I can start researching why the other isn't. I'm sure it is something simple. Once I get that solved I will get busy building the PSU for it. I plan to use a 55-0-55 400VA transformer for it. Probably go with a CRC setup.
Blessings, Terry
Blessings, Terry
Thanks crispy.
The cap multiplier is from a group buy that PMI held for the Mr Evil Finished Capacitor Multiplier.
A very nice unit but it is limited to about 45V rails so I will need something bigger for the transformer I plan to use with this.
That heatsink came from a telephone system power supply that I dug out of a dumpster. It is meant to be mounted vertically or have a fan but it works well for testing as I can just bolt angle to it. It's too big to actually place in a cabinet. Handy to have around.
I will post more pics as things progress. I hope to get the other channel working this morning. I never can tell how good an amp sounds until I can play it in stereo.
Blessings, Terry
The cap multiplier is from a group buy that PMI held for the Mr Evil Finished Capacitor Multiplier.
A very nice unit but it is limited to about 45V rails so I will need something bigger for the transformer I plan to use with this.
That heatsink came from a telephone system power supply that I dug out of a dumpster. It is meant to be mounted vertically or have a fan but it works well for testing as I can just bolt angle to it. It's too big to actually place in a cabinet. Handy to have around.
I will post more pics as things progress. I hope to get the other channel working this morning. I never can tell how good an amp sounds until I can play it in stereo.
Blessings, Terry
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