I tried again and when I connect the LED, the voltages double. I use a 100K RLED now and it should be fine I think (it glows). Before there was a 7K5 RLED but that was too bright.

I too have a problem I guess but I can't explain why: I use an isolated power jack. The power supply is a linear wall wart and a Tread. The case is metal (and powdercoated). There is a plastic sheet under the amp-board The amp worked until I rewired everything and changed the input jacks from...

I did a blurry snapshot. It goes on after a while and stays lit until I turn the amp off. It's as bright as before I broke the wire off.

A desoldering pump should do it.

I really like gas soldering irons (I have a Portasol). There is no cord and you can reglate the temperature.

Thanks! I guess there aren't touching wires. Quote: Perhaps there's some electrical field in the PIMETA. The LED lit up and there was no other light. Yes, I use a metal case but it's powder coated. Also I use RLED. I'll quit being lazy and redo the wiring then.

I completeley removed the + wire between the LED and the board. A minute ago I was listening to music and looking at the amp and suddenly the LED went on. What should I do now? I wanted to add a resistor for the light because it was too bright and the wire broke at the board's solderpad.

It seems like they're available here: link

Quote: Originally Posted by balou the PPM value is the variance in resistance they have with temperature, in parts per million (one tenthousandth of a percent per degree celsius), and in this application, it doesn't really matter how big it is. I'd say buy the cheaper ones for...

Thanks! According to the Dynalo Rev. C construction guide you should use a 511 Ohm resistor when omitting the pot. What should I use? I don't have room for a ground plane also all parts are close to ground. I read that the input of op amps don't like ground planes too.

I want to add a switch for bypassing the pot. Instead of the pot the signal goes through a resistor then (like in the Dynalo rev.C board). What value should the resistor have? (I guess the value of the pot?) Can I use 1% thick film resistors? They are rated +/-100PPM and cost 0.02€. The...

Is it worth buying an iron with adjustable heat output? Does this prevent the handle of the iron getting very hot after a while? What do you think about ceramic tips? I think a tip the shape of a screwdriver is very good.

I still have two questions: Are these transistors ok? NPN PNP I can't find 1.6V LEDs. Do I need to change resistors for using 1.85V I found (or even 2V-2.2V LEDs, which are more available)?

Thanks! What do you think of routing under a resistor? Also how thick should the routes be? I remember some tutorial for the diameter but I can't find it any more.

Thanks! I found SMD transistors. The TO-92 dissipates 625mW while the other does 1000mW on a 6cm2 mounting pad for the collector lead. Maybe I won't need a heatsink then? The SMD version has two collector leads. Should I connect both of them?