Decreasing the stop resistor would go on the opposite side of the solution I want to apply.
The first issue I had is explained in post 1172.
Bonfis had similar issues in his post 1241. He solved it his by increasing the stop resistor to 56 Ohms (post 1291).
In the simulator, I get instability as soon as I reach 3/4 the power with the 22 Ohms resistor. Increasing the stop resistor solves it, decreasing it to 10 Ohms get things worse.
Of course increasing Cdom a bit won't hurt.
There's a screenshot if simulator oscillations with stop resistor to 10 Ohms.
The first issue I had is explained in post 1172.
Bonfis had similar issues in his post 1241. He solved it his by increasing the stop resistor to 56 Ohms (post 1291).
In the simulator, I get instability as soon as I reach 3/4 the power with the 22 Ohms resistor. Increasing the stop resistor solves it, decreasing it to 10 Ohms get things worse.
Of course increasing Cdom a bit won't hurt.
There's a screenshot if simulator oscillations with stop resistor to 10 Ohms.
Attachments
I see...your main targed is stability (more) and my primary targed
is audio quality (more)...then we are going in different directions, but both are very nice.
Go ahead man..do it and come here and say what you have perceived.
I will say something in advance...lifeless sound will be the result...loss of bright and realism.
Let's see what you will observe while listening....but do it one channel to make comparison..because if you do both channels you will be fooled.... and will think/believe/imagine the modification had improved..but this is more connected to our own psychological self than to sound reproduction.
Believe me...we are masters of fooling ourselves.... we humans delirate a lot...we do think we are beautifull when we are not...we do think we are more intelligent than some others..when we are not...we do think our wife is the best...when we have not tested all others to be sure about that...so...all is a matter of belief... something fanatic and non rational..be aware you already decided to evaluate your result as better...and i am sure it will not be better.
We humans, we are all fundamentalists.
regards,
Carlos
is audio quality (more)...then we are going in different directions, but both are very nice.
Go ahead man..do it and come here and say what you have perceived.
I will say something in advance...lifeless sound will be the result...loss of bright and realism.
Let's see what you will observe while listening....but do it one channel to make comparison..because if you do both channels you will be fooled.... and will think/believe/imagine the modification had improved..but this is more connected to our own psychological self than to sound reproduction.
Believe me...we are masters of fooling ourselves.... we humans delirate a lot...we do think we are beautifull when we are not...we do think we are more intelligent than some others..when we are not...we do think our wife is the best...when we have not tested all others to be sure about that...so...all is a matter of belief... something fanatic and non rational..be aware you already decided to evaluate your result as better...and i am sure it will not be better.
We humans, we are all fundamentalists.
regards,
Carlos
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Yes I will post my observations.
What will make it sound dull, the increase of the miller cap, or the increase of stop resistor value?
In Self's documentation, the stop resistors are 100 Ohms in value. When I try such values in the simulator, I can lower significantly the value of Cdom without compromising stability.
My question is, If I go to a high value for the stop resistor, and a lower value for Cdom... What could be the result, sonically?
What will make it sound dull, the increase of the miller cap, or the increase of stop resistor value?
In Self's documentation, the stop resistors are 100 Ohms in value. When I try such values in the simulator, I can lower significantly the value of Cdom without compromising stability.
My question is, If I go to a high value for the stop resistor, and a lower value for Cdom... What could be the result, sonically?
Home Made MKIII
Uncle Charlie,
I would like to thank you for this Dx MKIII, been setup and tested this amp last night and bias was set on .23mV, Wow I really like the quality and very punchy amp... i'll take more update photo tonight and post it here.
Many thanks....
Regards,
Uncle Charlie,
I would like to thank you for this Dx MKIII, been setup and tested this amp last night and bias was set on .23mV, Wow I really like the quality and very punchy amp... i'll take more update photo tonight and post it here.
Many thanks....
Regards,
Attachments
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Thank you dear friend....yes...it is very good
I like it too..... was tuned for sonics, but mainly into the simulator...i have made small touches into the workbench searching for more and more stability because some novices have decided to build..then i was very carefull.
People, these old days, where addicted to simulators and numbers...some came to me because of small distortion numbers...this way i have made for them...with good numbers and special stability...at least i could find any issue in my home.
This last amplifiers was made mainly for sonics.....more close to the threshold of oscilation, tuned sharp as a razor's edge
Your pictures are very good...is it a Sony Camera?
regards,
Carlos
I like it too..... was tuned for sonics, but mainly into the simulator...i have made small touches into the workbench searching for more and more stability because some novices have decided to build..then i was very carefull.
People, these old days, where addicted to simulators and numbers...some came to me because of small distortion numbers...this way i have made for them...with good numbers and special stability...at least i could find any issue in my home.
This last amplifiers was made mainly for sonics.....more close to the threshold of oscilation, tuned sharp as a razor's edge
Your pictures are very good...is it a Sony Camera?
regards,
Carlos
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How many mv maximal can the bias up with this amplifier?
And if the bias quickly goes up (example from 30mv to 70 mv or higher) how many mv I must stay under the 30mv, so that the amplifier remains stable, is 20mv than a good choise to test the amplifier with music.
What are the benefits if if the bias go upwards, I mean is there also a difference in sound quality if the bias go upwards?
And no, I test with the bias not myself, first I need answers
Regards,
Rudy
And if the bias quickly goes up (example from 30mv to 70 mv or higher) how many mv I must stay under the 30mv, so that the amplifier remains stable, is 20mv than a good choise to test the amplifier with music.
What are the benefits if if the bias go upwards, I mean is there also a difference in sound quality if the bias go upwards?
And no, I test with the bias not myself, first I need answers
Regards,
Rudy
Yes...yes and no and yes
It is good to increase bias...but it is bad because of heat.... also it is very good because we guarantee all transistor are "on"...but as you have a lot of transistors you gonna have a lot of waste in heat.
To know exactly the "point" you should simulate...i do not have this schematic in my simulator (this computer) and the job computer was formated last thursday...so, i cannot answer you this question...how much you should increase i do not know.
I have strong suspection by the work i have made in the Dx Super A, that you will have to increase a lot...and the point will be forcing power transistors to dissipate 5 watts each one..... i do not remember, but it seems you have 4 or 5 pairs.... so.... multiply and imagine the hell heat...if you are in Siberia...well..this gonna be great for you..but this heat in Brasil may cook my low countries and sterilise uncle charlie for ever.
So, the answer is yes, is no, is more or less and i do not know...also a suggestion, put it into simulator and give it a try to see the point.
I know and i knew this amplifier is a hell hot.... this way i have suggested people to just check if all transistors are conducting...less than 1 milivolt measured over the power emitter resistors.
Guarantee is void if you increase.
Good luck...has fire extinguisher?
regards,
Carlos
............................................
By the way dear BMW, it is so hot today here, that i am nude and going to the shower to cool down my body.... you see over the sofa the water...it is a hell hot....i will buy Air conditioning machine next monday...and you thinking in increase heat..... oh pain!
It is good to increase bias...but it is bad because of heat.... also it is very good because we guarantee all transistor are "on"...but as you have a lot of transistors you gonna have a lot of waste in heat.
To know exactly the "point" you should simulate...i do not have this schematic in my simulator (this computer) and the job computer was formated last thursday...so, i cannot answer you this question...how much you should increase i do not know.
I have strong suspection by the work i have made in the Dx Super A, that you will have to increase a lot...and the point will be forcing power transistors to dissipate 5 watts each one..... i do not remember, but it seems you have 4 or 5 pairs.... so.... multiply and imagine the hell heat...if you are in Siberia...well..this gonna be great for you..but this heat in Brasil may cook my low countries and sterilise uncle charlie for ever.
So, the answer is yes, is no, is more or less and i do not know...also a suggestion, put it into simulator and give it a try to see the point.
I know and i knew this amplifier is a hell hot.... this way i have suggested people to just check if all transistors are conducting...less than 1 milivolt measured over the power emitter resistors.
Guarantee is void if you increase.
Good luck...has fire extinguisher?
regards,
Carlos
............................................
By the way dear BMW, it is so hot today here, that i am nude and going to the shower to cool down my body.... you see over the sofa the water...it is a hell hot....i will buy Air conditioning machine next monday...and you thinking in increase heat..... oh pain!
Attachments
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I have no file to simulate..... and i will not assemble once again
Sorry.
Too much hot here to work...no way to move my fat from this sit i am rigth now.
Also i am satisfied with this amplifier sound..the ones wants to change it, then they should work hard for it....i have no motivation...satisfied, happy with the amplifier, as i said.
I am melting as an ice cream.... 32 degrées and no wind today...it is crazy hot..no clouds, only the sun doing all he can to kill me!
BMW will not need only a fire extinguisher...to put all these output trainees to operate tuned to the best (lowering distortion), he will need a fire soldier Batallion.
If i remember this happens more or less with 110 miliamps to each power transistor..now multiply 0.11 by 64 and them multiply by the number of transistors.
Hehehehehehehehehehe!
regards,
Carlos
Sorry.Too much hot here to work...no way to move my fat from this sit i am rigth now.
Also i am satisfied with this amplifier sound..the ones wants to change it, then they should work hard for it....i have no motivation...satisfied, happy with the amplifier, as i said.
I am melting as an ice cream.... 32 degrées and no wind today...it is crazy hot..no clouds, only the sun doing all he can to kill me!
BMW will not need only a fire extinguisher...to put all these output trainees to operate tuned to the best (lowering distortion), he will need a fire soldier Batallion.
If i remember this happens more or less with 110 miliamps to each power transistor..now multiply 0.11 by 64 and them multiply by the number of transistors.
Hehehehehehehehehehe!
regards,
Carlos
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I understand Carlos , you have moved on , unfortunately the mk3 is the top amplifier representing the corporation, its by far the largest and most expensive and has the maxium capability. The boards are capable of using 1/2/3/4/5 pr of outputs , making them more flexable and capable than any previous or present Dx build...
The minor attention necessary to make it better or live up to its full potential is more than worthwhile ....IMO
More so that current super-a , Just saying .....
The minor attention necessary to make it better or live up to its full potential is more than worthwhile ....IMO
More so that current super-a , Just saying .....
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Next year, dear Wayne, i will release a low power Mako
It is the "big bang" amplifier..... maybe because something alike it produced all that Universe...ahahahahahah!
Mako is something crazy...can go above 2 Kilowatts each channel, i will reduce it to make the baby Mako to publish next year.
It will come together the Dx Zim power supply, a 1.4 Kw SMPS supply that has something different you gonna be surprised...but this is a secret..no SMPS have this feature i will put on it.
I have moved on....this is real.... despite MKIII Hx is excellent, my attention now turned to other side... i will not go back or return to the past.
Attention now is focused on new models....when this one was created i gave all attention to it even having people asking me to upgrade the previous model...and i said no... saying no, the same way, once again.
regards,
Carlos
It is the "big bang" amplifier..... maybe because something alike it produced all that Universe...ahahahahahah!
Mako is something crazy...can go above 2 Kilowatts each channel, i will reduce it to make the baby Mako to publish next year.
It will come together the Dx Zim power supply, a 1.4 Kw SMPS supply that has something different you gonna be surprised...but this is a secret..no SMPS have this feature i will put on it.
I have moved on....this is real.... despite MKIII Hx is excellent, my attention now turned to other side... i will not go back or return to the past.
Attention now is focused on new models....when this one was created i gave all attention to it even having people asking me to upgrade the previous model...and i said no... saying no, the same way, once again.
regards,
Carlos
My MKIII and PSU
Uncle Charlie,
This is the update pictures of my build, driving my nano ipod the amp works perfect, but when i change my player to Asus notebook and adjust my media player equalizer i surprise after 3 minutes playing music my output tranies turns very very hot and when i check the bias is incresing to 185mV and so on...
hhmmmm... i wonder what could be the reason?
My supply is +/-80VDC using those 4 toroidal transformer.
I know uncle charlie your too much busy to answer but i'll just post my question and experience hoping anyone who experience the same can give their inputs and that would be much appreciated.
Regards,
Uncle Charlie,
This is the update pictures of my build, driving my nano ipod the amp works perfect, but when i change my player to Asus notebook and adjust my media player equalizer i surprise after 3 minutes playing music my output tranies turns very very hot and when i check the bias is incresing to 185mV and so on...
hhmmmm... i wonder what could be the reason?
My supply is +/-80VDC using those 4 toroidal transformer.
I know uncle charlie your too much busy to answer but i'll just post my question and experience hoping anyone who experience the same can give their inputs and that would be much appreciated.
Regards,
Attachments
Watch out folks, I think i've found a mistake
Please someone confirm... If it's really a mistake, it's present both on the official schematic AND on the PCB...
Please refer to the attached pics...
I think the base-stopping resistor of the positive side driver is not connected properly to the biasing circuit.
I can't believe i didn't see this before (and that nobody did).
On the schematic: the purple line is what I think to be correct junction.
On the PCB: the red path shows that the connection to the biasing transistor's collector is made through both the 22R and the 10R. I think it should be done only through the 22R only.
Please friends verify and tell us!!
Martin.
Please someone confirm... If it's really a mistake, it's present both on the official schematic AND on the PCB...
Please refer to the attached pics...
I think the base-stopping resistor of the positive side driver is not connected properly to the biasing circuit.
I can't believe i didn't see this before (and that nobody did).
On the schematic: the purple line is what I think to be correct junction.
On the PCB: the red path shows that the connection to the biasing transistor's collector is made through both the 22R and the 10R. I think it should be done only through the 22R only.
Please friends verify and tell us!!
Martin.
Attachments
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