I fetched the components today.... now we are just waiting for some sunshine to get the photopositives done.....I believe tommorrow may be partly cloudy.... who knows. 
cost is about ZAR111 excluding the ouput pair... per channel, so about USD 31 per 2 channels... these are non-boutique types.... and standard 1% metal film resistor... and wirewound resistors for the big ones....
cost is about ZAR111 excluding the ouput pair... per channel, so about USD 31 per 2 channels... these are non-boutique types.... and standard 1% metal film resistor... and wirewound resistors for the big ones....
During the loading of condensers into the long tail, the voltage will increase
Slowly....because of that, transistors will pass from the state off to state on ...will conduct, and them the voltage will increase.
Till all condensers are charged, the sittuation is unstable..voltage is increasing and condensers are loading..this happens in half second or less than that...some miliseconds.
The output line will follow this charge sequence...voltage will go from zero to some volts, and some circuits you have some damping...the speaker move forward and backward...and this has the switching pulse..when the transistors start to conduct.. also the switch off.... the noise can be heard.
When you have small condensers and zener.... condensers fast charge from zero to the nominal current of the zener..and you do not perceive...so fast those things happens...when the speaker decide to move forward, the positive peak already disappeared...than the oposite polarity happens also fast and speaker move sligtly.
Speaker do not react so fast as some small signal peak...when enter the coil and transform into mechanical energy and start to push the speaker suspension..the pulse already gone.
This is the reason why i use to make comments about small signals, small errors.... they do not appear...not only those ones but many others..speakers are sonic killers, the best we have till our days..but still some "steam locomotive"
There are signals, because speed, or frequency if you prefer..pulses, because small and short in time the speaker ignore..reason why the worries about micro electronics have no sense into my mind.
I can pay a good money to the one will perceive two tones..one with overshot and other without...so...people worrying with things do not need to worry...we have to increase speaker quality, to develop other media to transform audio into air compression.
There's also a delay when the brain receive some audio...let's imagine a square wave...let's believe that was perfectly reproduced.... when enter ear you will have diafragm (also wax and hairs inside), a duct that will increase some frequencies and decrease others..exponential cone you have inside the ear....some mechanical parts with bonds..the hammer and the counter part... cels that perceive pressure..vibrations on them start chemical reactions that are transformed into electrical signals...all those things...in special the chemical reaction, takes long time..so...the square wave will be tranformed int a mountain... and sinusoidal will be a very flat, not high hill...so... slew rate..hi speed..all this have no sense inside our perception system.
regards,
Carlos
Slowly....because of that, transistors will pass from the state off to state on ...will conduct, and them the voltage will increase.
Till all condensers are charged, the sittuation is unstable..voltage is increasing and condensers are loading..this happens in half second or less than that...some miliseconds.
The output line will follow this charge sequence...voltage will go from zero to some volts, and some circuits you have some damping...the speaker move forward and backward...and this has the switching pulse..when the transistors start to conduct.. also the switch off.... the noise can be heard.
When you have small condensers and zener.... condensers fast charge from zero to the nominal current of the zener..and you do not perceive...so fast those things happens...when the speaker decide to move forward, the positive peak already disappeared...than the oposite polarity happens also fast and speaker move sligtly.
Speaker do not react so fast as some small signal peak...when enter the coil and transform into mechanical energy and start to push the speaker suspension..the pulse already gone.
This is the reason why i use to make comments about small signals, small errors.... they do not appear...not only those ones but many others..speakers are sonic killers, the best we have till our days..but still some "steam locomotive"
There are signals, because speed, or frequency if you prefer..pulses, because small and short in time the speaker ignore..reason why the worries about micro electronics have no sense into my mind.
I can pay a good money to the one will perceive two tones..one with overshot and other without...so...people worrying with things do not need to worry...we have to increase speaker quality, to develop other media to transform audio into air compression.
There's also a delay when the brain receive some audio...let's imagine a square wave...let's believe that was perfectly reproduced.... when enter ear you will have diafragm (also wax and hairs inside), a duct that will increase some frequencies and decrease others..exponential cone you have inside the ear....some mechanical parts with bonds..the hammer and the counter part... cels that perceive pressure..vibrations on them start chemical reactions that are transformed into electrical signals...all those things...in special the chemical reaction, takes long time..so...the square wave will be tranformed int a mountain... and sinusoidal will be a very flat, not high hill...so... slew rate..hi speed..all this have no sense inside our perception system.
regards,
Carlos
The overshot.... i found an overshot into the HRII when creating the unit
Based into the Standard Dx...into try an error basis, trying sub circuits and parts..playing with them till i found a good sonics...than i stopped..no more change.... sound was good enougth, better than the Dx standard.
But had an overshot.
A friend loved, asked me to construct.... i told him....
- "For a while, has an overshot...not perfect...this will not sound..but not perfect for a while"
And he wanted...and there the amplifier gone with him... the first early prototype, i had to make another dirty board construction.
But next day he called me by phone:
- " I never have listened so nice sound, but i was thinking...that oversomething you told...not perfect...i was thinking..the sound is already good...i am imagining how better could be without the defect"
I said...not really a defect, and also not an effect, because has no effect into sonics...but i told him.... when he knew had overshot, he started to wonder how could be without the overshot...that things was now "killing" the sonics.
I asked the amplifier back to introduce the damn output coil...no more overshot..also the amplifier lost some brigth.... not so nice.
I am telling you folks, that we have to understand people's psychologie.... because this matters..and a lot...now he is happy...his HDII, first prototype, awfull construction, using enormous coil into the output (10 uH)... very big to kill the overshot...the overshot he do not know what really is (he works as salesman...understand nothing of electronics)....but he had the belief that non perfect has to sound non perfect....
Now his unit is perfect....no overshot...sounding less perfect.
And he is happy.
So.... this happens...the coil is used into the HR-II design.... i hate that coil and i made it smaller in value, only to reduce the overshot...but if someone construct and decide to inspect waves..will see the small overshot... will start to think.
- "how could be this sound without overshot"...
The one will complain...i will tell him to increase coil...sound will loose the brigth a little and the guy will be happy.
Because of that, many practices exists... to produce perfect waveshapes... and sometimes, we pay a lot in audio performance to follow those rules.
regards,
Carlos
Based into the Standard Dx...into try an error basis, trying sub circuits and parts..playing with them till i found a good sonics...than i stopped..no more change.... sound was good enougth, better than the Dx standard.
But had an overshot.
A friend loved, asked me to construct.... i told him....
- "For a while, has an overshot...not perfect...this will not sound..but not perfect for a while"
And he wanted...and there the amplifier gone with him... the first early prototype, i had to make another dirty board construction.
But next day he called me by phone:
- " I never have listened so nice sound, but i was thinking...that oversomething you told...not perfect...i was thinking..the sound is already good...i am imagining how better could be without the defect"
I said...not really a defect, and also not an effect, because has no effect into sonics...but i told him.... when he knew had overshot, he started to wonder how could be without the overshot...that things was now "killing" the sonics.
I asked the amplifier back to introduce the damn output coil...no more overshot..also the amplifier lost some brigth.... not so nice.
I am telling you folks, that we have to understand people's psychologie.... because this matters..and a lot...now he is happy...his HDII, first prototype, awfull construction, using enormous coil into the output (10 uH)... very big to kill the overshot...the overshot he do not know what really is (he works as salesman...understand nothing of electronics)....but he had the belief that non perfect has to sound non perfect....
Now his unit is perfect....no overshot...sounding less perfect.
And he is happy.
So.... this happens...the coil is used into the HR-II design.... i hate that coil and i made it smaller in value, only to reduce the overshot...but if someone construct and decide to inspect waves..will see the small overshot... will start to think.
- "how could be this sound without overshot"...
The one will complain...i will tell him to increase coil...sound will loose the brigth a little and the guy will be happy.
Because of that, many practices exists... to produce perfect waveshapes... and sometimes, we pay a lot in audio performance to follow those rules.
regards,
Carlos
Bootstrapping
"In my (not simple) amplifiers I also parallel the bootstrap capacitor with lesser values, for we do not want reactive impedance in the bootstrap circuit."
Hallelujah !
At last somebody has addressed my personal concerns about bootstrapping. This is also not addressed by Douglas Self (and others) when used in the front end of an amplifier.
Thank you, Graham.
SandyK
"In my (not simple) amplifiers I also parallel the bootstrap capacitor with lesser values, for we do not want reactive impedance in the bootstrap circuit."
Hallelujah !
At last somebody has addressed my personal concerns about bootstrapping. This is also not addressed by Douglas Self (and others) when used in the front end of an amplifier.
Thank you, Graham.
SandyK
Hi Sandy,
I think the term would be to 'cascade' capacitors, and this is especially relevant when using electrolytics.
There are many who say that electrolytics should not be used in AF because hysteresis can be demonstrated.
However, good quality ones are fine as long as they cannot dynamically upset stage biases, and values are suitably cascaded downwards to between 470 and 100nF to minimise effects through mid/treble, and to ensure NFB stability.
But try to tell this to someone who's mind is already made up about electrolytics !!!
However, some radial sub-mins should not be let anywhere near audio.
One easy way to check an electrolytic is in series with a LS. Yes this test is unbiased but still relevent because biasing improves linearity, not reduce the series impedance.
Listen for bass loss with high values, and mid/treble loss with 47uF downwards. Some types can be good, whilst others lose so much mid/treble you won't think twice about throwing them in the bin, even if brand new.
Simple bridge and multi-meter measuring of capacitors will not show up this kind of series loss.
I see many audio pcbs populated by sub-min radials, and wonder whether the ones fitted were batch purchased by accountants, or designer purchased for known specification !!!
Cheers ............. Graham.
I think the term would be to 'cascade' capacitors, and this is especially relevant when using electrolytics.
There are many who say that electrolytics should not be used in AF because hysteresis can be demonstrated.
However, good quality ones are fine as long as they cannot dynamically upset stage biases, and values are suitably cascaded downwards to between 470 and 100nF to minimise effects through mid/treble, and to ensure NFB stability.
But try to tell this to someone who's mind is already made up about electrolytics !!!
However, some radial sub-mins should not be let anywhere near audio.
One easy way to check an electrolytic is in series with a LS. Yes this test is unbiased but still relevent because biasing improves linearity, not reduce the series impedance.
Listen for bass loss with high values, and mid/treble loss with 47uF downwards. Some types can be good, whilst others lose so much mid/treble you won't think twice about throwing them in the bin, even if brand new.
Simple bridge and multi-meter measuring of capacitors will not show up this kind of series loss.
I see many audio pcbs populated by sub-min radials, and wonder whether the ones fitted were batch purchased by accountants, or designer purchased for known specification !!!
Cheers ............. Graham.
Hey!!! I got a bag full of those cheap elcos yesterday I will no have to call my amp the DXIII to overcome what you just said, mentaly.
Found a sheet of blue press and peel paper I bought who knows when, this morning... so me off to printing shop now to see if te stuff works..... went through the parts last night... all seems ok.. except they packed 1uf instead of 10nf caps.. there is always a screwup with orders from that shop...so I have learned to precheck before building.... the caps don't bother me, as I normaly measure them for matching before installing.
I will no have to call my amp the DXIII to overcome what you just said, mentaly.Found a sheet of blue press and peel paper I bought who knows when, this morning... so me off to printing shop now to see if te stuff works..... went through the parts last night... all seems ok.. except they packed 1uf instead of 10nf caps.. there is always a screwup with orders from that shop...so I have learned to precheck before building.... the caps don't bother me, as I normaly measure them for matching before installing.
Hi again Sandy,
Yes a CCS can overcome the phase shift within bootstrapping and is more compact, but CCS currents are much less stable with temperature and can themselves become distorted by semiconductor related capacitance and device/junction slew induced voltage/current variation.
Like Carlos, I prefer simple resistor bootstrap.
Cheers ............ Graham.
Yes a CCS can overcome the phase shift within bootstrapping and is more compact, but CCS currents are much less stable with temperature and can themselves become distorted by semiconductor related capacitance and device/junction slew induced voltage/current variation.
Like Carlos, I prefer simple resistor bootstrap.
Cheers ............ Graham.
Ohms law use to be secret in many places...that was good Graham, lol
I am also addicted to electrolitic condensers, and in my mind, the non defective ones are very good, almost all them....My problem against electrolitic condensers are connected to their size..enormous whales...i use to avoid them when possible.
The ones dried, that had leakage of electrolitic, or the ones worked under very high temperature, or installed inverted...those ones are bad to me.
Speaker factories used electrolitics in series inside the speaker enclosure, they were used into the passive crossover, the idea was to smooth the bass...but i could not perceive this smoothing.... in the reality, in my mind, they protected their speaker against DC and included reactance, resistance and inductance in series only.
I do not think amplifiers that use electrolitic condensers into the output, sounds not good.... they sound fine.
High Resolution II is much more acceptable by our communitty than the standard Dx...but i prefer resistances into the differential colectors..... sounds less precise, but warm and nice.
For sure, many folks will apreciate the transistorized version that is the official one...into the schematic...but to try resistance is very easy...just remove the transistors in install 2K resistances into the colector-emitter places.
I will be very happy to listen what people perceive...will be delicious to see humans listen almost the same things.
regards,
Carlos
I am also addicted to electrolitic condensers, and in my mind, the non defective ones are very good, almost all them....My problem against electrolitic condensers are connected to their size..enormous whales...i use to avoid them when possible.
The ones dried, that had leakage of electrolitic, or the ones worked under very high temperature, or installed inverted...those ones are bad to me.
Speaker factories used electrolitics in series inside the speaker enclosure, they were used into the passive crossover, the idea was to smooth the bass...but i could not perceive this smoothing.... in the reality, in my mind, they protected their speaker against DC and included reactance, resistance and inductance in series only.
I do not think amplifiers that use electrolitic condensers into the output, sounds not good.... they sound fine.
High Resolution II is much more acceptable by our communitty than the standard Dx...but i prefer resistances into the differential colectors..... sounds less precise, but warm and nice.
For sure, many folks will apreciate the transistorized version that is the official one...into the schematic...but to try resistance is very easy...just remove the transistors in install 2K resistances into the colector-emitter places.
I will be very happy to listen what people perceive...will be delicious to see humans listen almost the same things.
regards,
Carlos
Hi Carlos,
Re your differential-mirror.
The mirror gives better control for output zero and lower distortion, but the resistors give better phase linearity within the closed NFB loop and thus a more acceptable reproduction.
So you have one amplifier with a mirror, and one with circa 1k resistors.
How's about trying to split the difference ?
Keep the mirror, but try say 4k7 to 10k across each half between the differential collectors and the -ve rail.
I can't say that I've seen anyone else try this yet, but it might retain the best aspects of both types of differential loading !
Re capacitors. Some of the latest digital gear is 50% by volume of capacitors, to 2% chips !
Cheers ........... Graham.
Re your differential-mirror.
The mirror gives better control for output zero and lower distortion, but the resistors give better phase linearity within the closed NFB loop and thus a more acceptable reproduction.
So you have one amplifier with a mirror, and one with circa 1k resistors.
How's about trying to split the difference ?
Keep the mirror, but try say 4k7 to 10k across each half between the differential collectors and the -ve rail.
I can't say that I've seen anyone else try this yet, but it might retain the best aspects of both types of differential loading !
Re capacitors. Some of the latest digital gear is 50% by volume of capacitors, to 2% chips !
Cheers ........... Graham.
I always end up singing the makeing christmas song when I'm makeing stuff...
Yep... I know the transparency is upside down... but it is just a spare incase the blue stuff doesn't work...
Yep... I know the transparency is upside down... but it is just a spare incase the blue stuff doesn't work...
Attachments
It is the first time I used it.... Way too good to be true.....
Guess I'll be getting more of the expensive papers then.... maybe just cut and paste some to an a4 sheet next time... to strech it a bit...
You be the judge...
I'm just glad the part I hate most is done.....now for drilling....
27 resistors =54 holes... + caps etc. and that's just one channel
Guess I'll be getting more of the expensive papers then.... maybe just cut and paste some to an a4 sheet next time... to strech it a bit...
You be the judge...
I'm just glad the part I hate most is done.....now for drilling....
27 resistors =54 holes... + caps etc.
and that's just one channelAttachments
I think was a message for you..but the edit function is behaving strange
I think the part of message deleted was an edit inclusion i tried to make using forum edit function that did not entered the system.
I am having problems with my computer, also using our forum to edit as i told.
Texts are disappearing...forum is behaving very slow...i am having problems with my computer is suppose.
If something was deleted was because those bugs i am having.
Also Microsoft is bothering me because my XP professional is not original...i have to find another one, or another option or to buy the Vista Windows.
Nothing was deleted "on purpose" basis.... forum program, or my computer is producing a mess... and creating me a lot of work... i have to click refresh before each movement.... it is a kick between the patience.
Sorry Pavel....i made some comment to you...but something nothing important and really, in this moment i do not remember.... ah!.. was about bootstrapp...agreeing with you and telling the options i have used..mirror, VAS with CCS, Mirror in place of the bootstrapp and mirror using CCS...well..i have tried many things after the decision to keep the bootstrapp there.
regards,
Carlos
I think the part of message deleted was an edit inclusion i tried to make using forum edit function that did not entered the system.
I am having problems with my computer, also using our forum to edit as i told.
Texts are disappearing...forum is behaving very slow...i am having problems with my computer is suppose.
If something was deleted was because those bugs i am having.
Also Microsoft is bothering me because my XP professional is not original...i have to find another one, or another option or to buy the Vista Windows.
Nothing was deleted "on purpose" basis.... forum program, or my computer is producing a mess... and creating me a lot of work... i have to click refresh before each movement.... it is a kick between the patience.
Sorry Pavel....i made some comment to you...but something nothing important and really, in this moment i do not remember.... ah!.. was about bootstrapp...agreeing with you and telling the options i have used..mirror, VAS with CCS, Mirror in place of the bootstrapp and mirror using CCS...well..i have tried many things after the decision to keep the bootstrapp there.
regards,
Carlos
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