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PCB design

July 20th, 2020, 10:13 pm

I need to get PCBS made for the 5-way line level crossovers. Anyone have experience with Designing PCBs?
What is involved? Resources?

Re: PCB design

July 20th, 2020, 10:52 pm

Cogito wrote:I need to get PCBS made for the 5-way line level crossovers. Anyone have experience with Designing PCBs?
What is involved? Resources?

You might be happier to draw up a schematic and then build a hard-wired version on perforated board rather than PCB.

It will provide you with greater flexibility in terms of updates as you do trial auditions and it will sound better especially if you wire it up with silver/Teflon or silver/polyethylene hook-up wire.

PCB manufacturing is a royal pain-in-the-ass photo-etching process using blank PCBs, the photo resist chemicals, the photo ready pattern, the etching chemicals, drilling the holes, etc.

In the time it takes to just get to a board ready for loading parts you could have been done with your prototype and already listening to music.

Re: PCB design

July 20th, 2020, 11:00 pm

If you want to go ahead this may be of interest. As suggested I would use point to point wiring.

https://www.instructables.com/id/Creati ... KJET-Prin/

Re: PCB design

July 21st, 2020, 5:10 am

Jlcpcb provides free software for layout and produces good quality boards very cheaply
I know of a small audio company that uses them for prototyping and production
https://www.jlcpcb.com

Re: PCB design

July 21st, 2020, 8:08 am

I agree that if it is a one off situation you are probably better off using Vector board with pins than going straight to a PCB design. When I make more than one off I use Express PCB because they provide the software and have reasonable prices for small runs. Here is a link to Vector and a photo of one of the boards that Express did for me:

https://www.vectorelect.com/vectorbord-patterns.html

https://www.expresspcb.com/
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Re: PCB design

July 21st, 2020, 7:42 pm

SoundMods wrote:
Cogito wrote:I need to get PCBS made for the 5-way line level crossovers. Anyone have experience with Designing PCBs?
What is involved? Resources?

You might be happier to draw up a schematic and then build a hard-wired version on perforated board rather than PCB.

It will provide you with greater flexibility in terms of updates as you do trial auditions and it will sound better especially if you wire it up with silver/Teflon or silver/polyethylene hook-up wire.

PCB manufacturing is a royal pain-in-the-ass photo-etching process using blank PCBs, the photo resist chemicals, the photo ready pattern, the etching chemicals, drilling the holes, etc.

In the time it takes to just get to a board ready for loading parts you could have been done with your prototype and already listening to music.


Few months ago I breadboarded a 3-way crossover using cheap caps and resistors from Amazon. Surprisingly, it sounded very good.



C5A9B4D1-68E2-4DE5-AACC-7D2D03110F8F.jpeg
C5A9B4D1-68E2-4DE5-AACC-7D2D03110F8F.jpeg (25.62 KiB) Viewed 2442 times


BTW, what resistors and caps do you recommend?
Last edited by Cogito on July 21st, 2020, 7:59 pm, edited 1 time in total.

Re: PCB design

July 21st, 2020, 7:44 pm

Pelliott321 wrote:Jlcpcb provides free software for layout and produces good quality boards very cheaply
I know of a small audio company that uses them for prototyping and production
https://www.jlcpcb.com


Thanks Paul. They are very affordable, I will give them a shot.

Re: PCB design

July 21st, 2020, 7:58 pm

It would be very interesting seeing how some of the very experienced crossover designers in the group go about constructing such a complicated beast as a five-way crossover, particularly the physical layout. Could you post the schematic as well as the part numbers of the components? I suspect many of us could learn a lot.

Some of the components could be quite large and heavy. A PCB may not be robust enough whereas point to point would be stronger.

On a separate note, we leave for Australia on Saturday. The house is sold, the boxes are shipped and we are looking forward to two weeks in quarantine with nothing much to do. An exercise like this crossover would help fill in the time.

ray

Re: PCB design

July 21st, 2020, 8:21 pm

tomp wrote:I agree that if it is a one off situation you are probably better off using Vector board with pins than going straight to a PCB design. When I make more than one off I use Express PCB because they provide the software and have reasonable prices for small runs. Here is a link to Vector and a photo of one of the boards that Express did for me:

https://www.vectorelect.com/vectorbord-patterns.html

https://www.expresspcb.com/


Tom,

I will go with the PCB method. What do I need to take into consideration for the PCB?
Any recommendations on potentiometers ? I need them on each channel for level matching.

Re: PCB design

July 21st, 2020, 8:23 pm

ratbagp wrote:It would be very interesting seeing how some of the very experienced crossover designers in the group go about constructing such a complicated beast as a five-way crossover, particularly the physical layout. Could you post the schematic as well as the part numbers of the components? I suspect many of us could learn a lot.

Some of the components could be quite large and heavy. A PCB may not be robust enough whereas point to point would be stronger.

On a separate note, we leave for Australia on Saturday. The house is sold, the boxes are shipped and we are looking forward to two weeks in quarantine with nothing much to do. An exercise like this crossover would help fill in the time.

ray


I am using this site for the crossover design. Parts are not big because line level voltages are low.

http://www.t-linespeakers.org/tech/filt ... eHLxo.html
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