With paint I think you'd have a lot of problems with pixelation, unless you somehow manage to increase the print resolution it's something like 75dpi which is nowhere near enough for quality PCBs. Although I might be wrong there... 
Point to point is really only good for tube amps as the tubes sit in sockets with nice easy to solder terminals that can accommodate quite a few connections each, as well as the fact that tube amps are usually simplistic designs that don't usually require more than 30 different connection points. It can be good for the output stages of power amps where the components are screwed down to heat sinks and are static, but is difficult for any small active solid state devices. I've had excellent results with veroboard combined with point to point for hybrid amps, lots of people put veroboard down as a cost cut construction method but for one offs where board space isn't too much of an issue IMO theres nothing better.
Point to point is really only good for tube amps as the tubes sit in sockets with nice easy to solder terminals that can accommodate quite a few connections each, as well as the fact that tube amps are usually simplistic designs that don't usually require more than 30 different connection points. It can be good for the output stages of power amps where the components are screwed down to heat sinks and are static, but is difficult for any small active solid state devices. I've had excellent results with veroboard combined with point to point for hybrid amps, lots of people put veroboard down as a cost cut construction method but for one offs where board space isn't too much of an issue IMO theres nothing better.
KiCad is supposed to be a good piece of layout software as well: KiCAD - Wikipedia, the free encyclopedia
~Tom
~Tom
I use PC boards for almost everything, even prototypes. There are several ways to make the board, some are real cheap, but not terribly easy, and some are easy, but not cheap.
For layout software I have been using Eagle ever since the DOS version 2.6 (20+ years). They have offered an upgrade for long time users that has been around $100 every two years or so. Cadsoft (the Eagle company) was recently purchased by Newark / Farnell. THey offered a free upgrade to version 5.11 that allowed the use of Newark / Farnell part numbers in the library. Cadsoft now wants over $600 for me to upgrade to the latest version. Not going to happen!
Allied / RS purchased a PC board package which is now called Design Spark. They offer it completely FREE even for commercial use. It is said to be capable of importing Eagle designs and libraries. I installed it, but have not had the time to work with it.
I print the artwork onto a transparency and use that to expose a pre sensitized board. A double sided 6 X 9 inch board is about $10. Expose with a flourescent desk lamp. Develop in sodium hydroxide (lye). Strip with acetone or lacquer thinner. You will need to make some test paterns to determine the exposure time and developer strength. They are inter related.
I used to use the toner transfer method which worked great until I got a new laser printer, now it doesn't work at all. The iron won't melt the toner....even if I superheat it on the kitchen stove.
For simple boards where you only want one, just skip all that. Use a waterproof marker (a Sharpie works) to draw the image directly on an unsensitized copper clad board, drop it in the Ferric Chloride, done! Ferric Chloride works better the hotter it is, but watch the heat with a marker drawn board. The ink will turn loose. Sometimes it helps to let the board dry overnight and go over it again.....lightly.
Another low cost method is to cover the board with masking tape. Use the back of a spoon to go over the tape pressing it firmly onto the board. Overlap seams about 1/8 inch. Go completely around the edges and on to the other side of the board. Then draw the circuit onto the tape, then cut with an Xacto knife and peel.
Ferric Chloride is still stocked by many Radio Shack stores, but you will get a blank stare from the sales person when you ask for it. Their stock # is 276-1535. You can check stock on the web. They have more than doubled the price since I last bought any.
I have had limited success with a 50 - 50 mixture of pool acid (muratic or hydrochloric, NOT sulfuric) and hydrogen peroxide. The peroxide you get at Walmart is only 3%, which isn't quite strong enough. Some beauty supply stores have "blonde in a bottle" formulas that contain up to 10% peroxide but the other ingredients make a sticky mess out of the board.
For layout software I have been using Eagle ever since the DOS version 2.6 (20+ years). They have offered an upgrade for long time users that has been around $100 every two years or so. Cadsoft (the Eagle company) was recently purchased by Newark / Farnell. THey offered a free upgrade to version 5.11 that allowed the use of Newark / Farnell part numbers in the library. Cadsoft now wants over $600 for me to upgrade to the latest version. Not going to happen!
Allied / RS purchased a PC board package which is now called Design Spark. They offer it completely FREE even for commercial use. It is said to be capable of importing Eagle designs and libraries. I installed it, but have not had the time to work with it.
I print the artwork onto a transparency and use that to expose a pre sensitized board. A double sided 6 X 9 inch board is about $10. Expose with a flourescent desk lamp. Develop in sodium hydroxide (lye). Strip with acetone or lacquer thinner. You will need to make some test paterns to determine the exposure time and developer strength. They are inter related.
I used to use the toner transfer method which worked great until I got a new laser printer, now it doesn't work at all. The iron won't melt the toner....even if I superheat it on the kitchen stove.
For simple boards where you only want one, just skip all that. Use a waterproof marker (a Sharpie works) to draw the image directly on an unsensitized copper clad board, drop it in the Ferric Chloride, done! Ferric Chloride works better the hotter it is, but watch the heat with a marker drawn board. The ink will turn loose. Sometimes it helps to let the board dry overnight and go over it again.....lightly.
Another low cost method is to cover the board with masking tape. Use the back of a spoon to go over the tape pressing it firmly onto the board. Overlap seams about 1/8 inch. Go completely around the edges and on to the other side of the board. Then draw the circuit onto the tape, then cut with an Xacto knife and peel.
Ferric Chloride is still stocked by many Radio Shack stores, but you will get a blank stare from the sales person when you ask for it. Their stock # is 276-1535. You can check stock on the web. They have more than doubled the price since I last bought any.
I have had limited success with a 50 - 50 mixture of pool acid (muratic or hydrochloric, NOT sulfuric) and hydrogen peroxide. The peroxide you get at Walmart is only 3%, which isn't quite strong enough. Some beauty supply stores have "blonde in a bottle" formulas that contain up to 10% peroxide but the other ingredients make a sticky mess out of the board.
Warning: Never pour water into acid.
Place the water first and pour the acid only after.
If one is talking tube sockets on fiberglass, I agree. If the sockets are chassis mounted, I respectfully do not believe it is manditory, as the design/layout makes the difference. Also, large companies design for turn around and not for lifetime quality.
Cheers.
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The quality of PC board material has come a long way in the past 30 years. The Phenolic junk used 50's and 60's was truly terrible. Some of the early fiberglass boards had adhesion issues. It was just too easy to rip the copper off.
Modern G10 and FR4 formulations can deal with the heat of a tube amp without issue. Just to be sure I have my own test case running with an SSE amp. The entire amp is built on a 10 inch by 12 inch chassis only 2 inches high, with zero ventilation. I envisioned EL34's at maybe 50 mA, but actually run KT88's at 100 mA each. Yes, the amp gets too hot to touch after being on for 1/2 hour. It often plays all day long. Its been working for 7 years without anny issues.
I have been experimenting with PC board amps in the 250 to 500 watt range. All PC board construction.
Modern G10 and FR4 formulations can deal with the heat of a tube amp without issue. Just to be sure I have my own test case running with an SSE amp. The entire amp is built on a 10 inch by 12 inch chassis only 2 inches high, with zero ventilation. I envisioned EL34's at maybe 50 mA, but actually run KT88's at 100 mA each. Yes, the amp gets too hot to touch after being on for 1/2 hour. It often plays all day long. Its been working for 7 years without anny issues.
I have been experimenting with PC board amps in the 250 to 500 watt range. All PC board construction.
Using the Datak board is easy and cheap. Only need a 100 watt light bulb to expose. See post #35 and #43. I use an 8X10 picture frame to hold the positive on the pre-sensitized PCB and expose under the 100 watt light bulb for about 10 - 12 minutes. Run the board thru the developer ($6.00) then the etching and the board is good to go. I have NOT had a fail. I did make a PCB to build an RIAA pre-amp using op-amps (8 pin), so small traces was not a problem. I hand draw a foil pattern on a sheet of paper. When I have verified the pattern is correct, I fire-up paint and go to work. When done, I print a copy and correct spacing. Now print a positive on a clear plastic sheet, stick in the 8X10 picture frame, expose, develope and etch. Done..
Works everytime for me.
Works everytime for me.
I agree, PCB is better, however Altium Designer costs in the order of $ 2 K.
I can live with that money four months !
ACCEL TangoPCB you can get it for free on the web.
It has no so many toys, but works pretty well.
TangoPCB is Altium Designer's grandfather.
Altium - Wikipedia, the free encyclopedia
Thanks for that info with TangoPCB. I use the university Altium license here. I sometimes do some jobs here and make some circuits and layouts for some chairs, but it is all SMD based. (Ever handsoldered a MSOP parts ?
) I can confirm that. hydrochloric acid and hydrogen peroxide works like a charm. No more muddy crap like the Iron(III) chloride and no more heating which is needed when persulfates are used.
Yes! However, not a problem for my 43 year old shaky hands & myopic eyes!
However, MLP-8 tax my abilities to frustration:
An externally hosted image should be here but it was not working when we last tested it.
Hot air gun + flux or fine-tip Metcal soldering iron usually suffice for me. Oh and a Mantis Vision aid too!
Everyone should embrace PCBs & SMT!!! *ahem*
Andy
Thanks for that info with TangoPCB. I use the university Altium license here. I sometimes do some jobs here and make some circuits and layouts for some chairs, but it is all SMD based. (Ever handsoldered a MSOP parts ?
TangoPCB works equally well with both normal and SMD.
Precision: 0.001 in.
You can make custom libraries, for valves, etc.
Despite being a DOS program, it runs perfect on Windows XP.
The creators of SMD hate DIYers.
The soldering station for SMD, is very expensive, then deal with a common soldering iron is a nightmare, imagine with a 100-pin chip.
In audio, just use sockets for valves.
Is your new laser printer a Brother? The toner on those printers is said to be incompatible with the toner transfer method. I use a laminator that was less than $20 for the transfer. It was modded with a higher temp thermostat.
Cheers,
Chris
Yes, it is a Brother, and yes the incompatibility showed up on the toner transfer web site a few days after the printer arrived. I got it on sale at Newegg for $79 with free shipping. As a laser printer it works good and operates wirelessly from any computer. For TTP it is useless, I can burn the paper before the toner melts.
I got the recommended GBC laminator, made the slow motion mod (swap the gears) and rigged it for a little extra heat. Still useless with the Brother.
I got the Brother to replace a 20+ year old HP Laser Jet 4L that still works great. You just can't get toner for it anymore. Oddly there were compatibility issues between the 4L's "microfine" toner and the TTP, but superheating the iron first on the kitchen stove fixed that. Applying the superheated iron directly to the TTP sometimes resulted in burns or tears. See below.
The HP is still alive and operating in the West Virginia house where it gets little use, but I am on the last toner cartridge. I got a cheap Canon for here and the Brother will go north. Then I should be able to do TTP boards when I am in a hurry.
I developed a method that worked with the HP. People who use it report good results with other printers.
Cover the kitchen countertop with a towel. Place an aluminum cookie sheet on the towel as a heat sink. Cover an area on the cookie sheet big enough for the board with a thick fuzzy COTTON washcloth (synthetics will melt). Place the TTP face up on the washcloth. Place a cleaned bare PC board face down on the washcloth. The two can be taped together using ordinary masking tape for registration of both sides in a double sided board. Apply the hot iron to the back side of the PC board. Move the iron around to insure an even heat. Too much time is usually not an issue here. I use about 5 minutes for a board that can be covered by the iron, up to 10 minutes on big boards. Toss the hot board in a pan of cold water.
I am using toner transfer paper and found this makes a huge difference. The paper comes off the board after about 30 seconds in cold water. The way it works reminds me of the decals I used to apply to model aircraft when i was a kid. With other paper my results were inconsistent with traces that needed to be repaired...
Cheers,
Chris
Cheers,
Chris
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