Every part has inductance, it's the law of nature but I know what you mean, those metal film resistors are pretty good for this purpose and has been used by Mr. Härfågel*), picture here and here.jacco vermeulen said:
*) http://www.google.com/url?sa=U&star...ofbritain.co.uk/bird-guide/hoopoe.htm&e=10141
http://www.websters-online-dictionary.org/definition/Hoopoe
Not my invention, a number of diy-designs in the low 80s used the trick
If you open a dummyload for 50 ohm 500Mhz you will find a lot of parallel resistors.....
something else:
Hi jacco, i am leaving to italy for 3 weeks tomorrow, can you please look after my 4 boards or will you maybe share our order?
Thanks and i will try to check DIY forum.
Loek
If you open a dummyload for 50 ohm 500Mhz you will find a lot of parallel resistors.....
something else:
Hi jacco, i am leaving to italy for 3 weeks tomorrow, can you please look after my 4 boards or will you maybe share our order?
Thanks and i will try to check DIY forum.
Loek
Loek,
either is fine by me.
I noticed you work at TWI, i needed plenty of lectures and practice there in the past.
(with fond memories of Mr Edelaar and his math lectures)
So bringing or picking up boards should be easy
Wim and I are already sharing on Al-Pinkostino KSA50 wiki.
Enjoy the holiday.
either is fine by me.
I noticed you work at TWI, i needed plenty of lectures and practice there in the past.
(with fond memories of Mr Edelaar and his math lectures)
So bringing or picking up boards should be easy
Wim and I are already sharing on Al-Pinkostino KSA50 wiki.
Enjoy the holiday.
peranders said:
Sorry Per-Anders,
you are right, i should be more prudent with statements and specific words.
The boards you posted look great, U-Poo-Doo does make lovely designs, he was so kind to hand me the circuit.
Apart from the spare required imo parallelling offers advantages, and can even look nice.
I already know Pavel is a strange exotic bird
, even longer than he suspects.
See if you like this:
http://www.delta-audio.com/temp_jens/Leach_ver_6.8.11_PCB.pdf
Added the non inductive resistors in parallel with the others
\Jens
http://www.delta-audio.com/temp_jens/Leach_ver_6.8.11_PCB.pdf
Added the non inductive resistors in parallel with the others
\Jens
Jens, I've checked your layout. Why don't you use a fat traces as possible at each output transistor? I would try to have at least 150 mil but you seems to have chosen max 100 mil. I know that you hardly won't burn any traces but still.
Where is your feedback exactly? It should be located at the output inductor. This will exclude all pcb "defects". The feedback should be applied as near the output as possible for minimum distortion.
If you want to improve the step response you should also cut a whole in the groundplane under the emittors/current generators of the input transistors. The goal is to reduce stray caps if the current genrators. This is equally important as snubberize, meaning you can easily see this with an oscilloscope but how important is it in real life?
http://www.national.com/an/AN/AN-A.pdf
Check especially page 11.
Where is your feedback exactly? It should be located at the output inductor. This will exclude all pcb "defects". The feedback should be applied as near the output as possible for minimum distortion.
If you want to improve the step response you should also cut a whole in the groundplane under the emittors/current generators of the input transistors. The goal is to reduce stray caps if the current genrators. This is equally important as snubberize, meaning you can easily see this with an oscilloscope but how important is it in real life?
http://www.national.com/an/AN/AN-A.pdf
Check especially page 11.
Manual - power dissipation method
Hi Jens,
are you still looking for a power dissipation prediction calculation that allows inductive loading?
then go to http://www.diyaudio.com/forums/attachment.php?s=&postid=644221&stamp=1116358062
it is located in thread "Started to design solid state amp + calculations"
To all our experts,
The spreadsheet writer is looking for confirmation of the correctness of formulae and calculation method. Please have a look & feedback to the writer.
Jens,
the pads under the fuses do not fit my odd sized fuse holders. Save me some money & make the pads bigger. Can you enlarge to lie under the full area of the metallic fuse ends. i.e. each pad is both wider and longer and end up closer together. I will drill the new holes myself.
Hi Jens,
are you still looking for a power dissipation prediction calculation that allows inductive loading?
then go to http://www.diyaudio.com/forums/attachment.php?s=&postid=644221&stamp=1116358062
it is located in thread "Started to design solid state amp + calculations"
To all our experts,
The spreadsheet writer is looking for confirmation of the correctness of formulae and calculation method. Please have a look & feedback to the writer.
Jens,
the pads under the fuses do not fit my odd sized fuse holders. Save me some money & make the pads bigger. Can you enlarge to lie under the full area of the metallic fuse ends. i.e. each pad is both wider and longer and end up closer together. I will drill the new holes myself.
Re: Manual - power dissipation method
They fit mine very well, so I think I will keep them the way they are. 😉
\Jens
AndrewT said:
They fit mine very well, so I think I will keep them the way they are. 😉
\Jens
I like it very much.
Thanks for all the trouble, Jens, it is very kind of you to do all the extra labour.
Thanks for all the trouble, Jens, it is very kind of you to do all the extra labour.
Per,
Do you think this is better?
http://www.delta-audio.com/temp_jens/Leach_ver_7.0.10_PCB.pdf
\Jens
Do you think this is better?
http://www.delta-audio.com/temp_jens/Leach_ver_7.0.10_PCB.pdf
\Jens
I'm sorry but I have a hard time to see the difference. Could you please make on picture with print+comp side, print+solder side, schematic which corresponds exactly with the layout.JensRasmussen said:
Could you also make a picture over the groundplanes if this is possible?
I have some recommendations concering your pads also.
Can you fix those files and I will have a check on this tomorrow.
Hi ,
nice to see your PCB's, JENS
I very much liked the way you design your PCB's. I really love the layout and artwork involved, and still maintaining the high level of persistence.
regards,
Kanwar
nice to see your PCB's, JENS
I very much liked the way you design your PCB's. I really love the layout and artwork involved, and still maintaining the high level of persistence.
regards,
Kanwar
New files are here with and without gnd plane (1.8Mb):
http://www.delta-audio.com/temp_jens/Leach_ver_6.7.10.zip
\Jens
http://www.delta-audio.com/temp_jens/Leach_ver_6.7.10.zip
\Jens
Jens, nice PCB, but notice of P-A is correct : output line is not so wide ( cca 5 mm I think ). By high current, you get difference from beggining and end of this line. You take feedback from beggining, but better will be to take it from end of this line ( before choke ).
How much ? I don't know, but I think that distortion fall down. If two times or ten times, it's the question, I haven't personal experience. Quite sure rise in this case DF 😎 .
I changed it.... will put more vias in to connect the gnd plane between the two sides of the FB and the two sides of the PCB
\Jens
\Jens
Upupa Epops said:
Seems to me that if the ground connections for the 100nF capacitors were only taken on the bottom side, the output trace can be made as wide as 2 cm ?
Hi Jens,
Very, very professional pcb. Hats off!!
Have you had a good listen? How does it sound?
May I ask what package are you using? Is is inexpensive and easy to learn? I'd like to get away from my present US software as I need ground plane creation which works and doesn't get carried away with database/project files of more than a megabyte.....
Cheers,
Hugh
Very, very professional pcb. Hats off!!
Have you had a good listen? How does it sound?
May I ask what package are you using? Is is inexpensive and easy to learn? I'd like to get away from my present US software as I need ground plane creation which works and doesn't get carried away with database/project files of more than a megabyte.....
Cheers,
Hugh
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