thank you all for your responses so far. Very helpfull.
@passinwind and all other homebrewers, see below a description my well proven protoype PCB development method:
I use MicroCap software for schematic design, simulation and analysis. Once the schematic design is ready, I design my prototype pcb.
I use Sprint Layout 5.0 pcb design software for simple pcb's. This software is very intuitive, however it does not provide schematic support, rubber banding etc. It has a nice components library and editor (so that you can draw your own components and footprints).
For prototyping I use the 'toner method' to transfer my layouts to the pcb. (This method does not works without a decent laser printer) Once the prototype design in Sprint Layout is ready I print the mirrored design on standard glossy foto paper.
Then comes the tricky part: I have to wait until my wife is out of the house. At an unguarded moment I get hold her electric iron and I iron the layout on a clean and lightly sanded piece of circuit board. Put the printed side of your layout on the copper surface, heat up the iron at max. heat and push firmly, with the iron at max temperature (no steam). After a minute or two, the toner melts and the paper sticks to the pcb. The photo paper may discolor lightly.
Let the pcb cool down a while and put it in a small tank/bowl with water. After cooling down, put the iron back where it originally came from, without letting your wife know you used it for other purposes
After 30 mins or so in the water, the paper is saturated and it loosens from the pcb. Peel it off carefully. Use an old toothbrus to brush all remaining paper off. The toner remains on the pcb (when you have done things right). If you spot any damaged traces, you can try and repair with waterproof ink (in EU: use an edding 8400 pen). If traces have damaged too much, the toner transfer was done at wrong temperature. You just clean your pcb and start with a new transfer. Not too many costs, except lost time. . .
Send your wife away (again... she better not knows...
Put on old clothing, rubber handgloves and protective glasses.
Check pcb for a 2nd/final time. Heat up a water pan in your kitchen and make sure your kitchen is (well) ventilated.
Put a jar with etchant in the water pan and heat it up until the water just boils. Then turn of the heat. Drill a small hole in your pcb, put a piece of isolated wire through and put your pcb in the jar. Let the etchant dissolve all uncovered copper. Normally this is ready in 10-30mins, so check the etch process with regular intervals (every 2 mins) by taking the pcb out of the etchant and expose it to the air. Do not inhalate over the etchant (too much
After etch process has finished, clean with plenty of water.
Use a 'metal sponge' to rub away the toner or use some fine sandpaper. Clean again. Drill pcb. Clean again. Prototype PCB ready.
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If you're not in to all this chemist work, you may as well order your pcb at a professional pcb manufacturer. Export the gerber files from your sprint layout design and send them to the manufacturer.
(This will probably take some more time and costs to realise a prototype pcb. . .)
Hope this helps.
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Below I have a picture of my preamp enclosure. (bought on Ebay). I will post pictures of the built process within next weeks.
BRs
Willem
Netherlands
That said, I'm all for using output transformers when budget and space constraints allow, even with solid state preamps.
