Here is an example of complete report of an audio power amplifier:
100 watts RMS
https://engineering.purdue.edu/people/nathaniel.e.pettis.1/index_html/amp/LinAmp_report.pdf
100 watts RMS
https://engineering.purdue.edu/people/nathaniel.e.pettis.1/index_html/amp/LinAmp_report.pdf
Oh I'm such a dumbass.... wired the bias servo the wrong way around...
Took it out... swaped the wires.... and now it works (bc639 and all) !!!!!!! nothing blew, nothing died... what a change from my normal luck!
I have to say the bias setting on the new amp is also much more stable by the looks of things...
Offset 0.4mV
Have to wait for F1 qualifying before I can hook up some music...
Took it out... swaped the wires.... and now it works (bc639 and all) !!!!!!! nothing blew, nothing died... what a change from my normal luck!
I have to say the bias setting on the new amp is also much more stable by the looks of things...
Offset 0.4mV
Have to wait for F1 qualifying before I can hook up some music...
Mmmmkay!!!! It is playing... !!!!!!!! all assembled in case again... and ready to please.
Strangely enough the offset control still has a little influence... enough to dial in 0mv...
It is even better in stereo...... absolutely incredible... if you are into accoustic music, this is the amp for you... just slipped in Norah Jones...I love the CD for the contrabass and many accoustic instruments...
But this amp is begging for some Dire Straits now.... I think I know where I put Communique CD
Strangely enough the offset control still has a little influence... enough to dial in 0mv...
It is even better in stereo...... absolutely incredible... if you are into accoustic music, this is the amp for you... just slipped in Norah Jones...I love the CD for the contrabass and many accoustic instruments...
But this amp is begging for some Dire Straits now.... I think I know where I put Communique CD
Hi Nordic,
we had a discussion on servo and offset and setting up.
We did agree that the offset should be zeroed before activating the servo.
Some of us (most did not bother to think about set up procedure) agreed that the zero offset should be set when the amp is cold. This allows the servo to monitor and minimise the drift in offset as the amp warms up.
But, DO NOT ask the servo to correct for excessive input offset from the source. It should be blocked with an input cap or the source should have it's own servo to minimise the offset at the source's output.
It would be useful to measure the output of the servo during amplifier operation taking particular note of how far/close the opamp output voltage approaches the supply rails over a range of temperatures and operating conditions.
Have you read Tom Gootee's thread on DC servo?
we had a discussion on servo and offset and setting up.
We did agree that the offset should be zeroed before activating the servo.
Some of us (most did not bother to think about set up procedure) agreed that the zero offset should be set when the amp is cold. This allows the servo to monitor and minimise the drift in offset as the amp warms up.
But, DO NOT ask the servo to correct for excessive input offset from the source. It should be blocked with an input cap or the source should have it's own servo to minimise the offset at the source's output.
It would be useful to measure the output of the servo during amplifier operation taking particular note of how far/close the opamp output voltage approaches the supply rails over a range of temperatures and operating conditions.
Have you read Tom Gootee's thread on DC servo?
Hello, and...the finish PCB
Hello, here I am again. I have the ci uPC1237 and have desire of realizing a protection circuit for speakers and adapt it to this amplifier (DX ST). Servira? Has someone algun circuit that facilitates me? Thank you very much
hola, aqui estoy nuevamente. Tengo el ci uPC1237 y tengo ganas de realizar un circuito de protección para parlantes y adaptarlo a este amplificador (DX ST). Servira? Alguien tiene algun circuito que me facilite? Muchas Gracias
Hello, here I am again. I have the ci uPC1237 and have desire of realizing a protection circuit for speakers and adapt it to this amplifier (DX ST). Servira? Has someone algun circuit that facilitates me? Thank you very much
hola, aqui estoy nuevamente. Tengo el ci uPC1237 y tengo ganas de realizar un circuito de protección para parlantes y adaptarlo a este amplificador (DX ST). Servira? Alguien tiene algun circuito que me facilite? Muchas Gracias
Nordic,
Yay,
. I've just got around to making a board for second channel
Andrew,
Sounds interesting, but the how's are beyond me. Do you have a link or two ?
Razorback
Is this the sort of thing you are looking for ?
See page 3...
http://www.ortodoxism.ro/datasheets/nec/UPC1237.pdf
or
http://www.diyaudio.com/forums/attachment.php?s=&postid=648867&stamp=1116958646
from
http://www.diyaudio.com/forums/showthread.php?threadid=57857
Yay,
. I've just got around to making a board for second channelAndrew,
Sounds interesting, but the how's are beyond me. Do you have a link or two ?
Razorback
Is this the sort of thing you are looking for ?
See page 3...
http://www.ortodoxism.ro/datasheets/nec/UPC1237.pdf
or
http://www.diyaudio.com/forums/attachment.php?s=&postid=648867&stamp=1116958646
from
http://www.diyaudio.com/forums/showthread.php?threadid=57857
... and while there is room for two big holes in the top, it's not quite deep enough either.
To much time spent on the cases, the mono's should be easier. Or I could just buy some proper cases from somewhere like
http://www.modushop.biz/
To much time spent on the cases, the mono's should be easier. Or I could just buy some proper cases from somewhere like
http://www.modushop.biz/
Attachments
In the mean time of course there has been the DxHiResII. Second board just etched, seen here with one stepped attenuator board and the controller board.
I'm currently looking at how to do infrared receivers with PIC's. The Sony codes look quite simple. I like simple
http://winpicprog.co.uk/pic_tutorial5.htm
I'm currently looking at how to do infrared receivers with PIC's. The Sony codes look quite simple. I like simple
http://winpicprog.co.uk/pic_tutorial5.htm
Attachments
Thank you by the link to the tutorial
Nice work, all your work is pretty.... those cases are very interesting.
Those holes?... were they made to give room to rounded transformers, or to fan blowers?
In the case of fan blowers, will you use black or those plastic ones that have blue ligth inside?
Hehe...nice work you make...you are a naturall artist.
The case made me think into HII
regards,
Carlos
Nice work, all your work is pretty.... those cases are very interesting.
Those holes?... were they made to give room to rounded transformers, or to fan blowers?
In the case of fan blowers, will you use black or those plastic ones that have blue ligth inside?
Hehe...nice work you make...you are a naturall artist.
The case made me think into HII
regards,
Carlos
Attachments
WinPICProg is a very good introduction to PIC's. And good news on the infrared, the module I salvaged from a Toshiba TV works beautifully...
http://www.datasheet4u.com/share_search.php?sWord=LTM-8848A
... now I just need to write some software
The big holes in the top ? No. No fans, it's just easier for me to cut circles than it is to cut many slots or squares. These holes just let the warm air out. Because I had to heighten the case I have gaps around the sides to let the cool air in. Lucky for me that hot air rises
The little boxes on the back make room for phono and speaker connections. Each box held in place by M3 screws. The gromets are cut in half, one half for the little box, one for the inside of the case, super glue fixes them quite nicely.
Fans, blowers, flashing lights. I've tried them. I'm much happier with two big, 120mm, slow fans on a single radiator. Looks like they need dusting
<chuckle> See the bending on the graphics card caused by the weight of the water block ! Doesn't seem to hurt, but I'd not recommend moving the pc any distance without fixing some kind of support.
http://www.datasheet4u.com/share_search.php?sWord=LTM-8848A
... now I just need to write some software
The big holes in the top ? No. No fans, it's just easier for me to cut circles than it is to cut many slots or squares. These holes just let the warm air out. Because I had to heighten the case I have gaps around the sides to let the cool air in. Lucky for me that hot air rises
The little boxes on the back make room for phono and speaker connections. Each box held in place by M3 screws. The gromets are cut in half, one half for the little box, one for the inside of the case, super glue fixes them quite nicely.
Fans, blowers, flashing lights. I've tried them. I'm much happier with two big, 120mm, slow fans on a single radiator. Looks like they need dusting
<chuckle> See the bending on the graphics card caused by the weight of the water block ! Doesn't seem to hurt, but I'd not recommend moving the pc any distance without fixing some kind of support.
Attachments
Interesting...water cooling.
My microprocessor do not overheat.... Semprom 3 Megahertz.
I am using one extra fan directly over the microprocessor's fan, sucking air out from the cabinet.... creating low pressure.
To stablish the air circuit, 2 smaller fans are pumping air inside the cabinet to create high pressure.
Microprocessor is keept under 45 degrees celsius.....maybe too much cool.
regards,
Carlos
My microprocessor do not overheat.... Semprom 3 Megahertz.
I am using one extra fan directly over the microprocessor's fan, sucking air out from the cabinet.... creating low pressure.
To stablish the air circuit, 2 smaller fans are pumping air inside the cabinet to create high pressure.
Microprocessor is keept under 45 degrees celsius.....maybe too much cool.
regards,
Carlos
Attachments
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