Yes... strange numbers on the board.
A long time without news from Nordic...i am afraid he is very sick.
About condensers Igreen...comments not exactly to you only..but for all thread readers.... the image shows some confusion about condensers.
Avoid ceramic condensers if possible..... the small values should be silver mica if possible ...they are better, and also expensive too.
You can use poliester or other material, but avoid condensers that are coiled inside... the ones with two plates and dieletric are better...dieletric can be made of poliester or other material.
Ceramic works better if you have a stable frequency crossing it...when you have variable frequencies and levels it may not work so good as some more advanced folks have explained me.
So, into oscilators, where frequency is stable, ceramic may be excelent...but into variable frequencies, alike frequency modulation of SSB radio transmissions, will not be so good compared to other materials.
I am very ashamed about those pictures..dirty boards needing cleaning...but those are the ones i have.
This amplifier is very old.... a long time ago we started the thread about it.. a lot of comments are into the Nordic group buy... about HRII there are a lot of tips and tricks there.
regards,
http://www.diyaudio.com/forums/showthread.php?s=&threadid=108456&perpage=25&highlight=&pagenumber=30
A long time without news from Nordic...i am afraid he is very sick.
About condensers Igreen...comments not exactly to you only..but for all thread readers.... the image shows some confusion about condensers.
Avoid ceramic condensers if possible..... the small values should be silver mica if possible ...they are better, and also expensive too.
You can use poliester or other material, but avoid condensers that are coiled inside... the ones with two plates and dieletric are better...dieletric can be made of poliester or other material.
Ceramic works better if you have a stable frequency crossing it...when you have variable frequencies and levels it may not work so good as some more advanced folks have explained me.
So, into oscilators, where frequency is stable, ceramic may be excelent...but into variable frequencies, alike frequency modulation of SSB radio transmissions, will not be so good compared to other materials.
I am very ashamed about those pictures..dirty boards needing cleaning...but those are the ones i have.
This amplifier is very old.... a long time ago we started the thread about it.. a lot of comments are into the Nordic group buy... about HRII there are a lot of tips and tricks there.
regards,
http://www.diyaudio.com/forums/showthread.php?s=&threadid=108456&perpage=25&highlight=&pagenumber=30
The threads used by the "Corporation" to advertise amplifiers.
...a non profit amplifiers, all DIY units..nothing for sale... all them tuned "by ears", and made to offer forum folks a nice souding amplifier... absolutelly for free!
The HRII debug thread started too late...so...it is very small:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=133108
Here you have the Precision 1 thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=114033&perpage=25&pagenumber=52
Here the DHR, the Destroyer High Resolution Turbo thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=124931&perpage=25&pagenumber=12
And here the HRII thread (High Resolution II) that was called HDII by Nordic...here you have some tips about the HRII, not only group buy... the thread is a group buy, but i have posted something interesting to builders too.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=108456&perpage=25&highlight=&pagenumber=30
And Greg Erskine web site, having pages about the Dx Amplifier, very helpfull, very usefull, a nice cooperation from Greg. (Gerskine in our forum):
Be happy, was very pleasant to me to see friends building my amplifiers, i am still happy because or that...proud because of that, gratefull and deeply honored by your preference into the Dx Corporation (exists only in my dreams) products.
Greg's pages:
http://users.tpg.com.au/users/gerskine/dxamp/
...a non profit amplifiers, all DIY units..nothing for sale... all them tuned "by ears", and made to offer forum folks a nice souding amplifier... absolutelly for free!
The HRII debug thread started too late...so...it is very small:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=133108
Here you have the Precision 1 thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=114033&perpage=25&pagenumber=52
Here the DHR, the Destroyer High Resolution Turbo thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=124931&perpage=25&pagenumber=12
And here the HRII thread (High Resolution II) that was called HDII by Nordic...here you have some tips about the HRII, not only group buy... the thread is a group buy, but i have posted something interesting to builders too.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=108456&perpage=25&highlight=&pagenumber=30
And Greg Erskine web site, having pages about the Dx Amplifier, very helpfull, very usefull, a nice cooperation from Greg. (Gerskine in our forum):
Be happy, was very pleasant to me to see friends building my amplifiers, i am still happy because or that...proud because of that, gratefull and deeply honored by your preference into the Dx Corporation (exists only in my dreams) products.
Greg's pages:
http://users.tpg.com.au/users/gerskine/dxamp/
Hi Carlos,
Your amplifiers are VERY YOUNG, not old. Compare them to Marshall Leach's amplifiers, which are still very popular. He still sells his DIY boards for the Low TIM amp, after all these years -- at least he did in 2006 when I bought boards from him. First published when?
Your amplifiers will remain in public view until DIYaudio and all the other sources of your information disappear from the Internet. I doubt it will ever disappear Carlos. It is your legacy. Be proud.
I know you are bored with them already. But they will always be new to some people. So stick around and talk about your amplifiers and advise DIY builders for as many years as you can. Another 30-40 years would be nice. 😉
Yes, Nico has disappeared. He did not respond to emails I sent a long time ago. His domain is expired now. Graham Maynard's domain has also expired now. I hope he's okay.
..Todd
Your amplifiers are VERY YOUNG, not old. Compare them to Marshall Leach's amplifiers, which are still very popular. He still sells his DIY boards for the Low TIM amp, after all these years -- at least he did in 2006 when I bought boards from him. First published when?
Your amplifiers will remain in public view until DIYaudio and all the other sources of your information disappear from the Internet. I doubt it will ever disappear Carlos. It is your legacy. Be proud.
I know you are bored with them already. But they will always be new to some people. So stick around and talk about your amplifiers and advise DIY builders for as many years as you can. Another 30-40 years would be nice. 😉
Yes, Nico has disappeared. He did not respond to emails I sent a long time ago. His domain is expired now. Graham Maynard's domain has also expired now. I hope he's okay.
..Todd
Thank you Todd.
It is strange that Nico have disappeared...will ask someone from South Africa about him.
regards,
Carlos
It is strange that Nico have disappeared...will ask someone from South Africa about him.
regards,
Carlos
Dx Amplifier using advanced bias point (500ma) is beeing tested
It is not a class A...but has advanced bias point...some AB with more bias than normal.
Distortion, total THD is 0.00123497
But i found other numbers too:
More real i think:
20W...............0.003%
30W...............0.005%
40W...............0.1%
Was not assembled (for a while) but will be tested soon.
Also a class AB with very small distortion....something alike 0.002% at maximum power is under testing.
Sounding fine..but i cannot say nothing as i have not compared those three ones...one of them was not even assembled.
Just playing with simulators..but i really do not think this can result much better...only nice numbers that may produce some passion in some folks.
regards,
Carlos
It is not a class A...but has advanced bias point...some AB with more bias than normal.
Distortion, total THD is 0.00123497
But i found other numbers too:
More real i think:
20W...............0.003%
30W...............0.005%
40W...............0.1%
Was not assembled (for a while) but will be tested soon.
Also a class AB with very small distortion....something alike 0.002% at maximum power is under testing.
Sounding fine..but i cannot say nothing as i have not compared those three ones...one of them was not even assembled.
Just playing with simulators..but i really do not think this can result much better...only nice numbers that may produce some passion in some folks.
regards,
Carlos
Attachments
Numbers are nice..they can be a very good advertising
I wish it represents good sound into the real world too.
Well... with speaker distorting 100 percent more... i have troubles to believe this means something.
At least will make some folks happy...nice numbers to instruments.
regards,
Carlos
I wish it represents good sound into the real world too.
Well... with speaker distorting 100 percent more... i have troubles to believe this means something.
At least will make some folks happy...nice numbers to instruments.
regards,
Carlos
Attachments
There's nothing special, only three CCS into the circuit
This have produced nice numbers together some tweaking for numbers.
Let's see near future how this unit will sound..for a while the prototype is sounding nice (mufled alike all class A)
Not ready.... under testing.
regards,
Carlos
This have produced nice numbers together some tweaking for numbers.
Let's see near future how this unit will sound..for a while the prototype is sounding nice (mufled alike all class A)
Not ready.... under testing.
regards,
Carlos
Now i am starting to understand why people loves simulators
It is so easy to arrange the circuit to nice distortion readings that may stimulate...it is nice for sure..but hard is to make those things sound fine.
This measurement (simulator) is full power... THD is the measurement.... under standard simulator analisis arrangement (multisim 10)
This is the main problem....real things.
regards,
Carlos
It is so easy to arrange the circuit to nice distortion readings that may stimulate...it is nice for sure..but hard is to make those things sound fine.
This measurement (simulator) is full power... THD is the measurement.... under standard simulator analisis arrangement (multisim 10)
This is the main problem....real things.
regards,
Carlos
Attachments
I will ask brazilian folks, from the Orkut, to assemble this unit to me
As i will delay twice more time compared to the time they may spend to assemble this one.
Some transistors, into the CCS power position will need replacement to TIP41 and TIP42 for safety reasons.
regards,
Carlos
As i will delay twice more time compared to the time they may spend to assemble this one.
Some transistors, into the CCS power position will need replacement to TIP41 and TIP42 for safety reasons.
regards,
Carlos
We have a massive activity into the Brazilian Orkut
around 100 millions use the Orkut in Brazil.
regards,
Carlos
around 100 millions use the Orkut in Brazil.
regards,
Carlos
An externally hosted image should be here but it was not working when we last tested it.
I am still playing with the simulator
And i think i will change something.
Well.... it is virtual for a while...when finished i will post pictures and final schematic
regards,
Carlos
And i think i will change something.
Well.... it is virtual for a while...when finished i will post pictures and final schematic
regards,
Carlos
Now we have automatic bias...from class A to class AB
Input impedance - 39k
THD - 0.0029%
Output power 50 watts RMS into 8 ohms
Sensitivity - full power with 1 volt into the input
audio bandwith - from 20 hertz to 100 kilohertz full power no losses
audio bandwidth - 3db - 5 hertz to 200 kilohertz
full power distortion into 20 Hertz - 0.038%
full power distortion into 20 kilohertz - 0.989%
full power distortion into 1 kilohertz - 0.004%
full power distortion into 5 kilohertz - 0.038%
1 watt into 1 Kilohertz - 0.001%
1 watt into 10 kilohertz - 0.004%
10 watts into 1 kilohertz - 0.01%
10 watts into 10 kilohertz - 0.013%
Stand by bias is 757 miliamperes each rail... this goes reducing depending to the audio level going to the drivers... it is sensed and changes the bias circuit internal resistance...sensors are actuacting both rails audio polarities simultaneously.
This amplifier was not assembled and tested..some transistors may change and some options may be included as current sinks and current mirrors as optional to comparison.
If results fine listening them a thread will be opened with Dx Evolution name...based into the Dx Standard having some features from the Precision and from the HRII.
Bias control was inspired, copied, adjusted and tweaked from a Brazilian Gradiente amplifier from the eigthies..considered the best amplifier made in Brazil.
Intentions are..beat forum amplifiers (some of them).... produce something that may sound good and also measure reasonably good... one idea is to create an amplifier than can be a Dx Corporation legacy, because my health is turning complicated and beeing an impeachment to do those things... my last try i think.
regards,
Carlos
Input impedance - 39k
THD - 0.0029%
Output power 50 watts RMS into 8 ohms
Sensitivity - full power with 1 volt into the input
audio bandwith - from 20 hertz to 100 kilohertz full power no losses
audio bandwidth - 3db - 5 hertz to 200 kilohertz
full power distortion into 20 Hertz - 0.038%
full power distortion into 20 kilohertz - 0.989%
full power distortion into 1 kilohertz - 0.004%
full power distortion into 5 kilohertz - 0.038%
1 watt into 1 Kilohertz - 0.001%
1 watt into 10 kilohertz - 0.004%
10 watts into 1 kilohertz - 0.01%
10 watts into 10 kilohertz - 0.013%
Stand by bias is 757 miliamperes each rail... this goes reducing depending to the audio level going to the drivers... it is sensed and changes the bias circuit internal resistance...sensors are actuacting both rails audio polarities simultaneously.
This amplifier was not assembled and tested..some transistors may change and some options may be included as current sinks and current mirrors as optional to comparison.
If results fine listening them a thread will be opened with Dx Evolution name...based into the Dx Standard having some features from the Precision and from the HRII.
Bias control was inspired, copied, adjusted and tweaked from a Brazilian Gradiente amplifier from the eigthies..considered the best amplifier made in Brazil.
Intentions are..beat forum amplifiers (some of them).... produce something that may sound good and also measure reasonably good... one idea is to create an amplifier than can be a Dx Corporation legacy, because my health is turning complicated and beeing an impeachment to do those things... my last try i think.
regards,
Carlos
How this auto bias works?
It is not complicated.
Watch the diagram attached.
You see that current comes from a CCS and will develop voltage over the series of resistances represented by the upper NPN transistor (left), the fixed resistance (that is the VBE multiplier) and the lower (PNP) transistor.....
This series of resistances is have a resultant that is three resistances added one each other in series..first i the resistance from the NPN upper left transistor, it is not saturated.... second is the fixed resistance from the VBE multiplier circuit pré adjusted into stand by mode...third is the PNP transistor that is not saturated.
Those resistances will develop the voltage needed to bias the output darlington transistors (alike darlington, those two emitter followers)... and into stand by mode the bias will be big..around 780 miliamperes each rail.
Observe that audio enters the drivers...also observe that we have diodes to the output line that is zero volts...so... you have a zener regulation effect into those diodes that will try to keep 1.2 to 1.8 volts measured from drivers base to ground.
Audio entering, if large enougth, will develop more than 1.2 volts into the diodes and this will trigger the red circuit (-1.2 volts will trigger the green circuit) that will drive the left transistor (in series with the bias current..the ones have a fixed resistance into the middle that represents a pre adjusted VBE multiplier resistance) into saturation...when those transistors, not only the NPN but also the PNP are driven into saturation, the colector to emitter resistance is reduced..so, the series resistance will also reduces as an effect..and this will reduce bias...this way, having high power, the amplifier will work into AB.... having small audio, or no audio level it will work into class A.
I hope this is clear enougth... i tried to make is simple to be easy understandable.
regards,
Carlos
It is not complicated.
Watch the diagram attached.
You see that current comes from a CCS and will develop voltage over the series of resistances represented by the upper NPN transistor (left), the fixed resistance (that is the VBE multiplier) and the lower (PNP) transistor.....
This series of resistances is have a resultant that is three resistances added one each other in series..first i the resistance from the NPN upper left transistor, it is not saturated.... second is the fixed resistance from the VBE multiplier circuit pré adjusted into stand by mode...third is the PNP transistor that is not saturated.
Those resistances will develop the voltage needed to bias the output darlington transistors (alike darlington, those two emitter followers)... and into stand by mode the bias will be big..around 780 miliamperes each rail.
Observe that audio enters the drivers...also observe that we have diodes to the output line that is zero volts...so... you have a zener regulation effect into those diodes that will try to keep 1.2 to 1.8 volts measured from drivers base to ground.
Audio entering, if large enougth, will develop more than 1.2 volts into the diodes and this will trigger the red circuit (-1.2 volts will trigger the green circuit) that will drive the left transistor (in series with the bias current..the ones have a fixed resistance into the middle that represents a pre adjusted VBE multiplier resistance) into saturation...when those transistors, not only the NPN but also the PNP are driven into saturation, the colector to emitter resistance is reduced..so, the series resistance will also reduces as an effect..and this will reduce bias...this way, having high power, the amplifier will work into AB.... having small audio, or no audio level it will work into class A.
I hope this is clear enougth... i tried to make is simple to be easy understandable.
regards,
Carlos
The circuit is not complicated... hard is to tune all those things
to avoid distortions (numbers) and to sound fine...this is the real hard work.
Circuit was published by JVC in 1979.... Brazilian Gradiente used into 1981 (licensed)...and i have tweaked down 2005.
Now i will build and adjust the whole thing.
give me some time.
will keep Dx crew informed about what is going on.
regards,
Carlos
to avoid distortions (numbers) and to sound fine...this is the real hard work.
Circuit was published by JVC in 1979.... Brazilian Gradiente used into 1981 (licensed)...and i have tweaked down 2005.
Now i will build and adjust the whole thing.
give me some time.
will keep Dx crew informed about what is going on.
regards,
Carlos
An externally hosted image should be here but it was not working when we last tested it.
I will make a board today...my style of boards..nothing pretty
just to produce a prototype.
The circuit is not ready to go..even the main thread was opened..for a while this is a study and i will keep you informed..
Friends that wants to produce boards must wait...the amplifier was not tested real life..it can sound awfull..do not trust in numbers..they say nothing..just numbers and not more than numbers...they indicate possible good sound..but does not guarantee nothing..guarantee is something built, tested and beeing listened.
regards,
Carlos
just to produce a prototype.
The circuit is not ready to go..even the main thread was opened..for a while this is a study and i will keep you informed..
Friends that wants to produce boards must wait...the amplifier was not tested real life..it can sound awfull..do not trust in numbers..they say nothing..just numbers and not more than numbers...they indicate possible good sound..but does not guarantee nothing..guarantee is something built, tested and beeing listened.
regards,
Carlos
An externally hosted image should be here but it was not working when we last tested it.
Hurrahh!! Carlos Destroyer you are back! Back in doing what you do best...thanks for the continuation of your legacy. I may admit that I do not fully understand yet how the electrons are scrambling on your new circuit amp, but sure it will take a little bit more time to absorb your explanation. It's nice to imagine how you control and force those tiny electrons to flow. 🙂
Hopefully you will fully recover with some afflictions you're having and make alot of people much happier again!
Regards,
mannycc
Hopefully you will fully recover with some afflictions you're having and make alot of people much happier again!
Regards,
mannycc
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