Ok I will experiment with the earth wire, but does it have to have the inductor in? I have one ready think it was 1.75mh... was about 26 turns....
Just measured HFE, the output transistors survived the error... 100 on one 94 on other...
The board is a work of art dude...
negative points... very limited range of caps that will fit input cap space... and I think 12mm spaceing between elcos and 100nf caps will allow better selection of low esr caps etc... according to the checks I did...
Very easy to assemble.... I will just run it from the psu of the RAJ board until my components for the proper psu comes in.
Just measured HFE, the output transistors survived the error... 100 on one 94 on other...
The board is a work of art dude...
negative points... very limited range of caps that will fit input cap space... and I think 12mm spaceing between elcos and 100nf caps will allow better selection of low esr caps etc... according to the checks I did...
Very easy to assemble.... I will just run it from the psu of the RAJ board until my components for the proper psu comes in.
Hi Nordic,
The ZE wire is just a wire.
The inductor, if you choose to use one, goes between the output and the speaker post.
Stick the bypass caps under the board directly on the cap leads if you use oversize caps (or don't use bypass caps). Actually, putting the caps underneath is better than putting them on top.
regards
The ZE wire is just a wire.
The inductor, if you choose to use one, goes between the output and the speaker post.
Stick the bypass caps under the board directly on the cap leads if you use oversize caps (or don't use bypass caps). Actually, putting the caps underneath is better than putting them on top.
regards
Nordic said:
Hi Nordic,
Have a look at the gallery here, no heatsinks on drivers.
http://users.tpg.com.au/users/gerskine/dxamp/
I doubt you will need them, but if you did they would be 25 mm square, this is a metric amp afterall.
If you really want to have heatsinks, don't use the spades, just enlarge a hole and run wire direct. BTW: Heatsinks fit on my prototype with 3 mm to spare.
regards
Yes.... was included to Klaas because he had problems.
He had suspections that the drivers were creating his temperature troubles...he include VBE multiplier and heatsinks.
It is a good idea to include them...i am not using..but i have a very big heatsink...also VBE multiplier.
I have commented with Greg..but i did not asked him to include, and Greg normally moves thing there when i ask him to do.
He is extremelly kind, has a lot of care with those things...a nice partner.
regards,
Carlos
He had suspections that the drivers were creating his temperature troubles...he include VBE multiplier and heatsinks.
It is a good idea to include them...i am not using..but i have a very big heatsink...also VBE multiplier.
I have commented with Greg..but i did not asked him to include, and Greg normally moves thing there when i ask him to do.
He is extremelly kind, has a lot of care with those things...a nice partner.
regards,
Carlos
OK, scratched out 6 thinner heatsinks from junkpile... so I can heatsink all the transistors except input ones, which I will go buy now... first get it to work with 2n5401, then try bc640 again... with some legbending...
Thank you guys so much for all the patience... I am realy takeing in lots... and next time I do solidstate won't be so painfull...
PS. I made the VBE multiplier too, which I will use.
No, we will still test RAJ boards... left all components in place as pin spaceing was diffirent... just transplanting transistors.... so far we know the tip42 with 200hfe was broken and the 4r7 resistors were wrong....as soon as my dx plays I promise to investigate again, uncle Charlie.
Thank you guys so much for all the patience... I am realy takeing in lots... and next time I do solidstate won't be so painfull...
PS. I made the VBE multiplier too, which I will use.
No, we will still test RAJ boards... left all components in place as pin spaceing was diffirent... just transplanting transistors.... so far we know the tip42 with 200hfe was broken and the 4r7 resistors were wrong....as soon as my dx plays I promise to investigate again, uncle Charlie.
Attachments
Those heatsinks will be a good inclusion Nordic.
Mine is not using, and temperature there is 37 celsius as i publish the image measuring that temperature...not a problem.
But using heatsinks you will work with lower temperature..this will make your amplifier work till year 2300 than the 2200 life expectations.
Well...will not be working, as speakers will be substituted by sensors in your skin.... behind the ear.... power will be microwatts.
hehe...future will be very interesting....you will control emotions.... try to imagine not to laugh when your receive the informs your damn boss died!....in the future you will have a button to turn you sad... very convenient..adequated.. a nice
behavior....hehe
And yes...you are rigth Nordic...i have suggested the use of heatsinks...see the image i have posted monthes ago.
Carlos
Mine is not using, and temperature there is 37 celsius as i publish the image measuring that temperature...not a problem.
But using heatsinks you will work with lower temperature..this will make your amplifier work till year 2300 than the 2200 life expectations.
Well...will not be working, as speakers will be substituted by sensors in your skin.... behind the ear.... power will be microwatts.
hehe...future will be very interesting....you will control emotions.... try to imagine not to laugh when your receive the informs your damn boss died!....in the future you will have a button to turn you sad... very convenient..adequated.. a nice
behavior....hehe
And yes...you are rigth Nordic...i have suggested the use of heatsinks...see the image i have posted monthes ago.
Carlos
Attachments
The nice Dx amplifier, using the final boards, is beeing tested in Australia.
A couple of weeks will be used during those testings.
A laboratory tests will be performed...all needed instruments will be used into a research of distortions.
Listening A to B blind testing will be performed too.
regards,
Carlos
A couple of weeks will be used during those testings.
A laboratory tests will be performed...all needed instruments will be used into a research of distortions.
Listening A to B blind testing will be performed too.
regards,
Carlos
Attachments
Greg has many amplifiers in his home.
Also he knows how to compare, the blind testing method.
For sure he will compare, to check if really, using this board, the amplifier can perform so good as more expensive units...as the idea was to make something simple and cheap that could not be ashamed by other amplifiers.
Even to loose in something is reasonable, as we have to pay the price by the simplicity and the low diy home production cost.
Many famous amplifiers are there in Greg's home...and many of them in the same power ratio...some are Kits and others are industrial made units from the seventies and eigthties..
He may check the quality of audio reproduction not to be fooled, as designers and partners use to be a litlle biased....and A to B, beeing blind, is the tool we have to obtain more precision in the judgement made.
But do not wait the publicity alike "Dx amplifier smashed Thatone"...this is something we do not like....i dislike this behavior...a dirty action, and also Greg will never do that.
To cut designer heads is not our dream...just to publish real words....all we need is to check is:
"Dx amplifier, even beeing simple, and also cheap, can be compared to expensive and famous without be ashamed...can even lost...but never by a big difference"
This is the idea...to respect all others, as they are very good units, made by respectable folks and I did not made an amplifier to be candidate to forum bad guy, to be the Bandit.... the opposite, my real dream is to see all bad guys banished from this nice forum.
All them forming a strip, not a long one, as they are not too many...and having in their hands one way ticket to hell.
regards,
Carlos
Also he knows how to compare, the blind testing method.
For sure he will compare, to check if really, using this board, the amplifier can perform so good as more expensive units...as the idea was to make something simple and cheap that could not be ashamed by other amplifiers.
Even to loose in something is reasonable, as we have to pay the price by the simplicity and the low diy home production cost.
Many famous amplifiers are there in Greg's home...and many of them in the same power ratio...some are Kits and others are industrial made units from the seventies and eigthties..
He may check the quality of audio reproduction not to be fooled, as designers and partners use to be a litlle biased....and A to B, beeing blind, is the tool we have to obtain more precision in the judgement made.
But do not wait the publicity alike "Dx amplifier smashed Thatone"...this is something we do not like....i dislike this behavior...a dirty action, and also Greg will never do that.
To cut designer heads is not our dream...just to publish real words....all we need is to check is:
"Dx amplifier, even beeing simple, and also cheap, can be compared to expensive and famous without be ashamed...can even lost...but never by a big difference"
This is the idea...to respect all others, as they are very good units, made by respectable folks and I did not made an amplifier to be candidate to forum bad guy, to be the Bandit.... the opposite, my real dream is to see all bad guys banished from this nice forum.
All them forming a strip, not a long one, as they are not too many...and having in their hands one way ticket to hell.
regards,
Carlos
Not too much sensitive to those hfe differences.
But of course, the amplifier will work better ballanced if complementary ones (drivers and output) are matched in gain.
Of course differential is the most sensitive to gain unballances.
Voltage amplifier needs the highest possible gain...select them by gain to the voltage amplifier position.
PNP transistors use to have bigger gain related NPN.....i have some TIP42 with 142 of gain...and also some TIP41 with only 70.
Off course this is not good...but i have tested them, and sounded nice anyway...do not ask me how this could happens because i cannot tell you the reasons of that.
regards,
Carlos
But of course, the amplifier will work better ballanced if complementary ones (drivers and output) are matched in gain.
Of course differential is the most sensitive to gain unballances.
Voltage amplifier needs the highest possible gain...select them by gain to the voltage amplifier position.
PNP transistors use to have bigger gain related NPN.....i have some TIP42 with 142 of gain...and also some TIP41 with only 70.
Off course this is not good...but i have tested them, and sounded nice anyway...do not ask me how this could happens because i cannot tell you the reasons of that.
regards,
Carlos
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