Yes.... this is the better way i found to face those things.
I use to let the board "rest"..also i use to take a rest.
Happened, many times, after that, when i watch the board and them i perceive the transistor there is PNP...when the correct is NPN.
So.... have a good breath.... a nice hot Cappuccino Coffee and when you return, the bug will be dancing over the board..your eyes will see the one clearly.
Removion or those BC546 into the differential colectors is a very good idea.... difference in sonics exists of course, and them, you will have the chance to perceive that because debugging the unit..when fixed...you will listen it without those transistors, and them you will try them once more...so.... this bug will help you a lot...you will see...having not doubts...will perceive...in the best possible way...how those things behave.
Thanks the bug you will be able to say, with sure, the one sound better for you.... and better for you..... has a good chance to be better for everybody, as humans are almost the same.
You see...Hugh does the same...and he is the best related those things.
regards,
Carlos
I use to let the board "rest"..also i use to take a rest.
Happened, many times, after that, when i watch the board and them i perceive the transistor there is PNP...when the correct is NPN.
So.... have a good breath.... a nice hot Cappuccino Coffee and when you return, the bug will be dancing over the board..your eyes will see the one clearly.
Removion or those BC546 into the differential colectors is a very good idea.... difference in sonics exists of course, and them, you will have the chance to perceive that because debugging the unit..when fixed...you will listen it without those transistors, and them you will try them once more...so.... this bug will help you a lot...you will see...having not doubts...will perceive...in the best possible way...how those things behave.
Thanks the bug you will be able to say, with sure, the one sound better for you.... and better for you..... has a good chance to be better for everybody, as humans are almost the same.
You see...Hugh does the same...and he is the best related those things.
regards,
Carlos
Once happened that i made a new supply...and circuit covered, into a case
Wires travelling out..... i had not my traditional red for positive, blue for negative and black for ground....i had not those wires....and because of that, other colours were used....not exactly other colours...but other type of red (violet) were used.
But you see that violet and red is easy to select, easy to find.
Also the blue was different...was a ligth blue....not a problem too.
the black one was changed for dark brown...well...dark brow and black not hard to select too.
And then i started to construct an amplifier... was in 2004, my first beloved Aksa.... a very old model and anything worked.
And Hugh said:
Impossible to have 4 volts from base to emitter into the VAS Carlos...check your circuit.
And theres the voltage...also the off set was big....but how those folks(transistors) could hold that voltage without burn?...and were's the heat?..... even today i cannot believe i could be so stupid.
The problem was my belief that my supply was fine....i have not measured the supply into the board.....of course i have measured the supply separated from the board when constructed.....but i could not perceive something strange, off course the digital voltmeter show me the negative sign when positive should appear in that moment, but...as i use to understand (my error) voltage without polarities... i could go on with the mistake....the wires were wrong inside the case...positive was negative...inverted!
Hugh circuits has protections....invertion do not burn Aksa modules (clever...more clever), because of that, strange voltages appeared into VBE junctions, as not direclty biased, bigger voltages were there, and not conducting....no junction diode zener effect...no 600 milivolts (650 milivolts others accept as standard) there.... and i was removing transistors alike an idiot...not alike an idiot...i was an idiot!
This is the problem...very obvious...very simple..so simple that you will never realise (I did not) that a supply, having those colour into wires, could be inverted.....thousand times it was correct...hundreds supplies were made to other folks, including for HAM radio and other appliances.... always worked....of course i could not, even belief into the possibility, that there's a chance of something wrong there...... and because of my belief (our worst enemie...the belief) i have not checked the supply.
2 days lost...a lot of frustration..... Hugh was very sad..... many mails going and returning..... and hugh saying.
The drivers can sound..... remove output and pick the output power from the drivers to see if you listen something....ahahahah....and nothing (inverted power)
And Hugh surprised:
What!!!....of set?
Than i decided to re-arrange the wires...too much twisted, because of boards routation.... and i found.
Inverted worked fine...with wrong colours..because wrong connection into the rectifier bridge.
That nice sound, from Aksa....that violine came alive and made me forget how stupid i was (I am already stupid...very old, very human... a creature from planet earth)
Errors are obvious, very easy to find...so easy that you do not give importance to them...reason why they remain safe into the board .... sometimes the board we make have enormous mistake..and we have checked many times.
The more you think about yourself as clever, the biggest time will be spent to find errors.... more humble people will find them fast.
This is an interesting thing, to reflect about.... idiots can be better than clever folks!.... so...if you need to employ someone to debug, for instance, boards....better if they are not very intelligent..also better if they are not self confident...those ones, will loose time because their stupid pride.
regards,
Carlos
Wires travelling out..... i had not my traditional red for positive, blue for negative and black for ground....i had not those wires....and because of that, other colours were used....not exactly other colours...but other type of red (violet) were used.
But you see that violet and red is easy to select, easy to find.
Also the blue was different...was a ligth blue....not a problem too.
the black one was changed for dark brown...well...dark brow and black not hard to select too.
And then i started to construct an amplifier... was in 2004, my first beloved Aksa.... a very old model and anything worked.
And Hugh said:
Impossible to have 4 volts from base to emitter into the VAS Carlos...check your circuit.
And theres the voltage...also the off set was big....but how those folks(transistors) could hold that voltage without burn?...and were's the heat?..... even today i cannot believe i could be so stupid.
The problem was my belief that my supply was fine....i have not measured the supply into the board.....of course i have measured the supply separated from the board when constructed.....but i could not perceive something strange, off course the digital voltmeter show me the negative sign when positive should appear in that moment, but...as i use to understand (my error) voltage without polarities... i could go on with the mistake....the wires were wrong inside the case...positive was negative...inverted!
Hugh circuits has protections....invertion do not burn Aksa modules (clever...more clever), because of that, strange voltages appeared into VBE junctions, as not direclty biased, bigger voltages were there, and not conducting....no junction diode zener effect...no 600 milivolts (650 milivolts others accept as standard) there.... and i was removing transistors alike an idiot...not alike an idiot...i was an idiot!
This is the problem...very obvious...very simple..so simple that you will never realise (I did not) that a supply, having those colour into wires, could be inverted.....thousand times it was correct...hundreds supplies were made to other folks, including for HAM radio and other appliances.... always worked....of course i could not, even belief into the possibility, that there's a chance of something wrong there...... and because of my belief (our worst enemie...the belief) i have not checked the supply.
2 days lost...a lot of frustration..... Hugh was very sad..... many mails going and returning..... and hugh saying.
The drivers can sound..... remove output and pick the output power from the drivers to see if you listen something....ahahahah....and nothing (inverted power)
And Hugh surprised:
What!!!....of set?
Than i decided to re-arrange the wires...too much twisted, because of boards routation.... and i found.
Inverted worked fine...with wrong colours..because wrong connection into the rectifier bridge.
That nice sound, from Aksa....that violine came alive and made me forget how stupid i was (I am already stupid...very old, very human... a creature from planet earth)
Errors are obvious, very easy to find...so easy that you do not give importance to them...reason why they remain safe into the board .... sometimes the board we make have enormous mistake..and we have checked many times.
The more you think about yourself as clever, the biggest time will be spent to find errors.... more humble people will find them fast.
This is an interesting thing, to reflect about.... idiots can be better than clever folks!.... so...if you need to employ someone to debug, for instance, boards....better if they are not very intelligent..also better if they are not self confident...those ones, will loose time because their stupid pride.
regards,
Carlos
Debug an amplifier is easy...hard is to answer those tree question watching the image
With one are twins here?
There's someone very tired...could you detect the one?
How many girls exist in this image?
Well.... before give up... enjoy.
Answers directly to my mail.
Prize will be a smile.
"Dx amplifier, you do not need to be a gênius, answering this test, to have one"
Carlos
With one are twins here?
There's someone very tired...could you detect the one?
How many girls exist in this image?
Well.... before give up... enjoy.
Answers directly to my mail.
Prize will be a smile.
"Dx amplifier, you do not need to be a gênius, answering this test, to have one"
Carlos
Attachments
The more you think about yourself as clever, the biggest time will be spent to find errors.... more humble people will find them fast.
This is an interesting thing, to reflect about.... idiots can be better than clever folks!.... so...if you need to employ someone to debug, for instance, boards....better if they are not very intelligent..also better if they are not self confident...those ones, will loose time because their stupid pride.
How true is that!!!!
No women in that photo....at least not in my eyes that is!
Regards,
Peter
Oops, the boss is coming...of to work....
This is an interesting thing, to reflect about.... idiots can be better than clever folks!.... so...if you need to employ someone to debug, for instance, boards....better if they are not very intelligent..also better if they are not self confident...those ones, will loose time because their stupid pride.
How true is that!!!!
No women in that photo....at least not in my eyes that is!
Regards,
Peter
Oops, the boss is coming...of to work....
Dx is friendly...good to play for our friends.
The problem is that friends use to be friendly, and they produce some friendship meeting addicted to appreciate everything we show them.
Even a Gramophone...that one has a nail..ahahahahaha
But Dx is fine...for sure sounds nice.
regards,
Carlos
......................................................................................................
Lovely that Fítero!
The boss i coming...i must go!
ahahahah..perfect.... very nice... very human that.
regards,
Carlos
The problem is that friends use to be friendly, and they produce some friendship meeting addicted to appreciate everything we show them.
Even a Gramophone...that one has a nail..ahahahahaha
But Dx is fine...for sure sounds nice.
regards,
Carlos
......................................................................................................
Lovely that Fítero!
The boss i coming...i must go!
ahahahah..perfect.... very nice... very human that.
regards,
Carlos
My boss has gone as well so I've escaped home 
I'll do a run around the Vbe's.
Some info: I removed the bc546's and put a 2k and 820r in their place, just like the Dx. I can change the Op voltage, the reading on the meter behaves just like the Dx. I like this
Latching problem, monostable as Carlos describes the behavior, is still there but the voltage across the +ve safety resistor is now 4.5 volts, before it was 9 volts.
Would it be a bad thing if I removed the Vbias circuit ?
I'll do a run around the Vbe's.
Some info: I removed the bc546's and put a 2k and 820r in their place, just like the Dx. I can change the Op voltage, the reading on the meter behaves just like the Dx. I like this
Latching problem, monostable as Carlos describes the behavior, is still there but the voltage across the +ve safety resistor is now 4.5 volts, before it was 9 volts.
Would it be a bad thing if I removed the Vbias circuit ?
Diodes used into the rail regulators are inverted...they are not bypassing
If was this your intention.....to produce a jumper over the regulators to check the circuit without those suspections.
To do this, invert the positive rail diode...arrow pointing left
Of course, into the negative rail, arrow pointing rigth.
I will check, gladly, other informations..this one exploded in my view in advance.
If you wanna check the VBE multiplier...disconnect it and replace with a 500 ohms trimpot...and adjust it to...will check now..... adjust to 420 ohms to 70 miliamps into the positive rail...and around 60 miliamps to negative rail.....made that..reduce to 40 miliamps positive rail...you will see adjusting why i am asking you to do that 420 ohms in advance.
regards,
Carlos
If was this your intention.....to produce a jumper over the regulators to check the circuit without those suspections.
To do this, invert the positive rail diode...arrow pointing left
Of course, into the negative rail, arrow pointing rigth.
I will check, gladly, other informations..this one exploded in my view in advance.
If you wanna check the VBE multiplier...disconnect it and replace with a 500 ohms trimpot...and adjust it to...will check now..... adjust to 420 ohms to 70 miliamps into the positive rail...and around 60 miliamps to negative rail.....made that..reduce to 40 miliamps positive rail...you will see adjusting why i am asking you to do that 420 ohms in advance.
regards,
Carlos
Rail voltage after vreg
Amp Ok : 33.19, -32.74
Lockup : 32.15, -32.16
Other measurements, first is amp ok, second is amp fail:
A) 16.4mv, 2.5mv
B) 6.67v, 6.44v
1) 637mv, 337mv
2) 640mv, 215mv
3) 20.5mv, -200mv : Hold meter probe here for a second and the latch up clears
4) NA, 31.6v : I cannot get an Ok reading here, with the probe connected the amp always latches
5) 437mv, 250mv
6) -425mv, -1.14v
7) 1.02v, 0.71v
8) -1.00v, -1.30v
9) NA, -31.4v : I cannot get an Ok reading here, with the probe connected the amp always latches
Amp Ok : 33.19, -32.74
Lockup : 32.15, -32.16
Other measurements, first is amp ok, second is amp fail:
A) 16.4mv, 2.5mv
B) 6.67v, 6.44v
1) 637mv, 337mv
2) 640mv, 215mv
3) 20.5mv, -200mv : Hold meter probe here for a second and the latch up clears
4) NA, 31.6v : I cannot get an Ok reading here, with the probe connected the amp always latches
5) 437mv, 250mv
6) -425mv, -1.14v
7) 1.02v, 0.71v
8) -1.00v, -1.30v
9) NA, -31.4v : I cannot get an Ok reading here, with the probe connected the amp always latches
Diodes used into the rail regulators are inverted...they are not bypassing
Yay Carlos
The diodes are to protect the transistors in case of reverse bias, added by Nordic and myself. Will they cause a problem ?
Hi Nordic,
Hope you and your friend had a party
Schematics:
To be clear, Q8 and Q9 have been removed and replaced with 2k and 820r, emitter to collector. The Dx uses 1k but I had a 2k in my hand.
Correction for 4) I missed the - sign and just got an ok reading.
4) -31.9v, -31.5
Yay Carlos
The diodes are to protect the transistors in case of reverse bias, added by Nordic and myself. Will they cause a problem ?
Hi Nordic,
Hope you and your friend had a party
Schematics:
To be clear, Q8 and Q9 have been removed and replaced with 2k and 820r, emitter to collector. The Dx uses 1k but I had a 2k in my hand.
Correction for 4) I missed the - sign and just got an ok reading.
4) -31.9v, -31.5
If for reversing bias no problems...i was thinking you were trying to bypass, to
place a jumper, to eliminate, exclude, the regulator during your tests...if you want to used it... it will not produce harm...keep them.
The amplifier seems underbiased into the output..too much VBE into drivers and low VBE into the output.
I will take another look as i am moving some heavy parts now...i have to breath some air and will return.
regards,
Carlos
place a jumper, to eliminate, exclude, the regulator during your tests...if you want to used it... it will not produce harm...keep them.
The amplifier seems underbiased into the output..too much VBE into drivers and low VBE into the output.
I will take another look as i am moving some heavy parts now...i have to breath some air and will return.
regards,
Carlos
Use the same resistances as colector loads.... better to do that now
Latter you can tweak a little for matching purposes...for a while place two resistances of 2K...
I am needing VBE voltages from the 2 VAS transistors.
Also how is your off set and also your rail resistance values..as you are not informing current to me...said 4.5 volts...but the resistance..what is the unit you are using..we can use from 5 ohms to 100 ohms there...what was your option?
Also inform if you can measure alternated voltage into the output.
Your voltages are not too much strange...but the output seems off...needing more bias.
regards,
Carlos
Latter you can tweak a little for matching purposes...for a while place two resistances of 2K...
I am needing VBE voltages from the 2 VAS transistors.
Also how is your off set and also your rail resistance values..as you are not informing current to me...said 4.5 volts...but the resistance..what is the unit you are using..we can use from 5 ohms to 100 ohms there...what was your option?
Also inform if you can measure alternated voltage into the output.
Your voltages are not too much strange...but the output seems off...needing more bias.
regards,
Carlos
Re: Dx is friendly...good to play for our friends.
There are friends and friends.. this one has been my friend since I was about 14 years old... pretty close to 20 years... so honesty is not a problem, last time he was here I gave him another headphone amp to go test... ( I gave him another one before then) I he plainly said, he could hardly hear a diffirence between the two, when I asked him about it...
Ecat... keep on takeing out parts.. you nearly have a vanilla DX
destroyer X said:
There are friends and friends.. this one has been my friend since I was about 14 years old... pretty close to 20 years... so honesty is not a problem, last time he was here I gave him another headphone amp to go test... ( I gave him another one before then) I he plainly said, he could hardly hear a diffirence between the two, when I asked him about it...
Ecat... keep on takeing out parts.. you nearly have a vanilla DX
Dear Ecat, now your off set control will work fine, as you are using resistances as
differential colector loads.
You have to adjust your bias and off set in advance.... if not possible, try to debug and fix those controls.
When off set is wrong, strange voltages will appear, and will not give us clear informs related what is really wrong.... because the really wrong will be off set and bias in advance.
You know.... if you wanna to obtain a measurement of someone's fever, in advance, the one must present the measurement points hot to be measured.
Off set, or bias not adjusting, seems errors, connection errors or construction errors, missing connections, inverted parts and so on...this must be fixed in advance...and than the measurements will start to make sense.
Advancing your bias, you will have those output conducting and the current will be share into a better way...will be better splitted into drivers and output transistors, .... the VBE will not measure so different...also..when transistors are on and off...you have problems to measure and will measure wrong...as circuit is not stable..it is on and off, and then you can measure on...or measure the consequences of "off" state.
Bias is fine...when you can adjust both rails...trimpot must increase and decrease current, no matter if they increase a very high current or a very low current, but the action into the trimpot must result in the variation of current into the output.
The VBE multiplier transistor must show, at least, 2.2 volts measured from colector to emitter..if not... errors..connections, shorts, invertions, wire missed..and so on.
The off set control, when using resistances into the differential, will operate..each touch, and them an overflow into your digital meter and the off set will stabilize soon...into negative milivolts or positive milivolts.
Without those two controls working properly...i really feel myself very lost, voltages seems strange to me and i feel really lost.
HELP!...if someone can help to debug, when VBE multiplier not operating properly and off set not adjusted...please...present yourself to help us.
I will continue to carry my boxes....electronics inside.... amplifiers, parts, transformers, speakers...well...very precious..but heavy!
I have 12 cubic meters.... i will spend some days doing that...my car is small, so... i cubic meter each travel.
And also..life continues..not only moving i have to do here.
But i will try to help.....into my limits of knowledge of course.
regards,
Carlos
differential colector loads.
You have to adjust your bias and off set in advance.... if not possible, try to debug and fix those controls.
When off set is wrong, strange voltages will appear, and will not give us clear informs related what is really wrong.... because the really wrong will be off set and bias in advance.
You know.... if you wanna to obtain a measurement of someone's fever, in advance, the one must present the measurement points hot to be measured.
Off set, or bias not adjusting, seems errors, connection errors or construction errors, missing connections, inverted parts and so on...this must be fixed in advance...and than the measurements will start to make sense.
Advancing your bias, you will have those output conducting and the current will be share into a better way...will be better splitted into drivers and output transistors, .... the VBE will not measure so different...also..when transistors are on and off...you have problems to measure and will measure wrong...as circuit is not stable..it is on and off, and then you can measure on...or measure the consequences of "off" state.
Bias is fine...when you can adjust both rails...trimpot must increase and decrease current, no matter if they increase a very high current or a very low current, but the action into the trimpot must result in the variation of current into the output.
The VBE multiplier transistor must show, at least, 2.2 volts measured from colector to emitter..if not... errors..connections, shorts, invertions, wire missed..and so on.
The off set control, when using resistances into the differential, will operate..each touch, and them an overflow into your digital meter and the off set will stabilize soon...into negative milivolts or positive milivolts.
Without those two controls working properly...i really feel myself very lost, voltages seems strange to me and i feel really lost.
HELP!...if someone can help to debug, when VBE multiplier not operating properly and off set not adjusted...please...present yourself to help us.
I will continue to carry my boxes....electronics inside.... amplifiers, parts, transformers, speakers...well...very precious..but heavy!
I have 12 cubic meters.... i will spend some days doing that...my car is small, so... i cubic meter each travel.
And also..life continues..not only moving i have to do here.
But i will try to help.....into my limits of knowledge of course.
regards,
Carlos
Here comes Nordic once again with those therms
Vanilla is a vegetable.... has nice flavour, used to Icecream and other things.... people use to remove the flavor using alcohol..so..drinking Vanilla you may feel good...Hic!...hic!
What my beloved, wonderfull, pretty, lovely Dx has that connect it to Vanilla...is it delicious as Vanilla?
ahahhaha
Carlos
Vanilla is a vegetable.... has nice flavour, used to Icecream and other things.... people use to remove the flavor using alcohol..so..drinking Vanilla you may feel good...Hic!...hic!
What my beloved, wonderfull, pretty, lovely Dx has that connect it to Vanilla...is it delicious as Vanilla?
ahahhaha
Carlos
- Status
- Not open for further replies.