I hate discussion....reason why i accepted the inclusion of this terrible
transistor to avoid discussions about.
You decide...the amplifier is yours...but please, do not start a discussion about.
With the transistor you have safety and worse sonics
Without the transistors you do not have too big safety but better sonics.
Please, decide by yourself.... long threads, enormous discussions we had about...it is more than enougth to me...amplifier is ready to go.
Carlos
transistor to avoid discussions about.
You decide...the amplifier is yours...but please, do not start a discussion about.
With the transistor you have safety and worse sonics
Without the transistors you do not have too big safety but better sonics.
Please, decide by yourself.... long threads, enormous discussions we had about...it is more than enougth to me...amplifier is ready to go.
Carlos
I've received my boards, thank you Nico and Carlos.
Is there an up to date BOM / parts list showing the min. power ratings of the resistors?
It will be some time before I build and I don't want to lose track of the information...
Thanks!
Stuey
Is there an up to date BOM / parts list showing the min. power ratings of the resistors?
It will be some time before I build and I don't want to lose track of the information...
Thanks!
Stuey
Excelent Stuey, i am glad you have received
10K resistance, the one marked 2 watts....good idea to increase to 3 watts, or to replace by two 22K units, 2watts each one, installed in parallel.
Nico found it very hot.....hummmm... maybe he has too much sensitive fingers.
There's 1.7 watts there..... well.... bigger will work cool.
Of course, one single unit is prefered not to make mess...but do whatever you want...the sound will remain very good.
Resistance is R16
heheheheh.
Carlos
10K resistance, the one marked 2 watts....good idea to increase to 3 watts, or to replace by two 22K units, 2watts each one, installed in parallel.
Nico found it very hot.....hummmm... maybe he has too much sensitive fingers.
There's 1.7 watts there..... well.... bigger will work cool.
Of course, one single unit is prefered not to make mess...but do whatever you want...the sound will remain very good.
Resistance is R16
heheheheh.
Carlos
Attachments
Well...hahahaha.... ready...here is the chart
When listening to the sound you should be watching the chart.
Sound may be better if biased into half way the chart.
Kidding.
My God Nico, and i was thinking that crazy folks are found only in Brazil....
ahahahahaha.
Carlos
When listening to the sound you should be watching the chart.
Sound may be better if biased into half way the chart.
Kidding.
My God Nico, and i was thinking that crazy folks are found only in Brazil....
ahahahahaha.
Carlos
lol firstyou say my finger is sensitive, then when I back up the temperature with a graph from a resistor datasheet...
😕
😕
Ahahah.... relax man...too much worries will make you older than i am
I am kidding, having fun.... this is not important.... i feel as funny someone worrying with such a small detail.
The resistance is not into the audio chain, it is very auxiliary...so...hot, not hot, noisy, well calculated or not..will not disturb our main focus.... sound quality.
Fine!...you finger is good... resistant is hot...so folks, use bigger ones.
regards,
Carlos
I am kidding, having fun.... this is not important.... i feel as funny someone worrying with such a small detail.
The resistance is not into the audio chain, it is very auxiliary...so...hot, not hot, noisy, well calculated or not..will not disturb our main focus.... sound quality.
Fine!...you finger is good... resistant is hot...so folks, use bigger ones.
regards,
Carlos
I am not concerned by the audiability of the heat... only long term reliability of the amp... the temperature under my finger told me the 2W resistor was not going to have a long happy life... The datasheet just confirmed it.
So there you have it, use 3 to 5W and don't burn your houses down. 😀
So there you have it, use 3 to 5W and don't burn your houses down. 😀
Well.... TAJ asked me what to change... and this happened
Because weeks ago i have asked him to change this resistance watt indication into the schematic.
I do not remember anymore, i think this one was the one you have suggested to increase to 3 or more watts.
Are there anything more to change into the schematic Nico?.... only this resistance watt indication?
Please inform that an them i will ask TAJ to make the needed changes....well....he have offered, but i really could not remember exactly those details you have informed about resistances.
Are there more needed modifications to go to updated schematic?
regards,
Carlos
Because weeks ago i have asked him to change this resistance watt indication into the schematic.
I do not remember anymore, i think this one was the one you have suggested to increase to 3 or more watts.
Are there anything more to change into the schematic Nico?.... only this resistance watt indication?
Please inform that an them i will ask TAJ to make the needed changes....well....he have offered, but i really could not remember exactly those details you have informed about resistances.
Are there more needed modifications to go to updated schematic?
regards,
Carlos
No it was this resistor and the one connecting the 12V zener to the +55V rail...
I have spend some more time on this...
lets say someone uses 5% tolerance zeners, the max rail to rail voltage would be 115.5V. Subtract the 4.7V zener and you are left with 110.8V, which then goes over the 10K resistor leaving us with dissipating 1.108W... Wich is quite alot for something with a small surface area like a resistor... (I hate those burns you sometimes see on PCBs under power resistors)
This is the datasheet for those white rectangular ceramic resistors.
Notice how at 1W there is not even much of a temperature drop before you use an 8W resistor...!!!!! I.e. at 1W dissipation the temperatures would be just under 60C for one rated as 4to5W and just under 50C when useing an 8W. And about 75C for a 2W unit. It is crazy!!!!!
I would never have though that the effect of 1W was that much.
I have spend some more time on this...
lets say someone uses 5% tolerance zeners, the max rail to rail voltage would be 115.5V. Subtract the 4.7V zener and you are left with 110.8V, which then goes over the 10K resistor leaving us with dissipating 1.108W... Wich is quite alot for something with a small surface area like a resistor... (I hate those burns you sometimes see on PCBs under power resistors)
This is the datasheet for those white rectangular ceramic resistors.
Notice how at 1W there is not even much of a temperature drop before you use an 8W resistor...!!!!! I.e. at 1W dissipation the temperatures would be just under 60C for one rated as 4to5W and just under 50C when useing an 8W. And about 75C for a 2W unit. It is crazy!!!!!
I would never have though that the effect of 1W was that much.
Change in P1 specified component?
Folks,
What I understood from discussions around post #1087 was that Q7 was incorrectly specified as a BC547C and should have been a BC546. However, since the function of Q7 is only to protect Q10 (2SC4793) on high music peaks, it could be left out for better (more dynamic) sound if one is willing to accept some risk of harm to the amplifier.
Did I understand correctly? Could someone please confirm? (To prevent misunderstandings, could we all use official component numbers instead of talking about "this resistor and that transistor".)
Since I'm all for good sound, are there other associated changes when Q7 is left out ?
Francois
Folks,
What I understood from discussions around post #1087 was that Q7 was incorrectly specified as a BC547C and should have been a BC546. However, since the function of Q7 is only to protect Q10 (2SC4793) on high music peaks, it could be left out for better (more dynamic) sound if one is willing to accept some risk of harm to the amplifier.
Did I understand correctly? Could someone please confirm? (To prevent misunderstandings, could we all use official component numbers instead of talking about "this resistor and that transistor".)
Since I'm all for good sound, are there other associated changes when Q7 is left out ?
Francois
Q7 can be keept as BC547, also can be replaced by BC546 if you wish
Sound is better without it.
Reliability is better with it.
Decision is up to you.
Want it more safe, use Q7
Want it with better sound, then remove Q7
The same way you prefer to talk about Q7, R2... i like to talk about the function.
Numbers seems to me bureaucracy, needed till you put parts into the board, them you will never listen those numbers when the music is playing... but the electronic function will be working.
regards,
Carlos
Sound is better without it.
Reliability is better with it.
Decision is up to you.
Want it more safe, use Q7
Want it with better sound, then remove Q7
The same way you prefer to talk about Q7, R2... i like to talk about the function.
Numbers seems to me bureaucracy, needed till you put parts into the board, them you will never listen those numbers when the music is playing... but the electronic function will be working.
regards,
Carlos
Thanks, Carlos, for the confirmation. I'm learning slowly.
Component numbers I understand, functions of components I understand only half the time.
Regards,
Francois
Component numbers I understand, functions of components I understand only half the time.
Regards,
Francois
R16 the 10k one should be no less than 3W, I am in fact going to change mine to 5 or 8W, putting the resistor under the board.
You guys have the disspation amounts and the tables to see the temperatures, now it is up to you to decide what level of temperature on a component you feel happy with.
Also R6 should maybe be a 2W... as it is dissipating about 500mW constantly.
You guys have the disspation amounts and the tables to see the temperatures, now it is up to you to decide what level of temperature on a component you feel happy with.
Also R6 should maybe be a 2W... as it is dissipating about 500mW constantly.
Nordic, My Precision 1 and protection boards arrived today - nice work. Still have some parts to order.
Guess where those boards you sent in error ended up?
There are two P/S boards (one piece), and one Stereo Speaker Protection board. No parts with these.
The only parts included were those for my Stereo Protection board.
Do you want me to send them to your address in SA (which is on the back of the package), or is there anyone in Australia you would like me to send them to? The postage is on me.
billabong.
Guess where those boards you sent in error ended up?
There are two P/S boards (one piece), and one Stereo Speaker Protection board. No parts with these.
The only parts included were those for my Stereo Protection board.
Do you want me to send them to your address in SA (which is on the back of the package), or is there anyone in Australia you would like me to send them to? The postage is on me.
billabong.
Lol no, I knew I sent the extra PCB's to you for all the waiting and worry, and I figured out the PSU went your way...
If you need a relay or chip for the extra protection board, just send me a message.
If you need a relay or chip for the extra protection board, just send me a message.
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