Mistakes you Learnt from! (might be helpful for beginners)

Today I was thinking about mistakes I made in the past building amplifiers, things that today i would do differently.

I thought if we keep this thread nice, simple and to the point it will be helpful for those creating their first amps and help them hopefully not blow the thing up! :D

Im not one for making guidelines as Im still a newbie myself but ill let you lot do that lol


1: Long wires from Mosfets to PCB in my case didn't help, my ZenV4 amplifier build Was close to oscillation. Im not sure but i think the Gate resistors need to be close to the Mosfet too ?

2: Audio Input Wires want to be kept away from Power supply wires to avoid interference.

3: when drilling Heatsinks if using a hand held Drill make sure you use a Tap first as one of the holes i drilled i slipped a bit. and for drilling the right positions for the Mosfets in some situations you get one chance to drill it right.


Ok, ill post some more of my experience soon :)
 

jhsjhs99

Member
2013-02-14 4:37 pm
Multi-meter probes with exposed metal.

Insulate the probe tips so that only the last 1mm is exposed to accidentally touching other components.

This is really clever; I will do this, thanks. A fuse gave its life due to this issue.

Does anyone have tips around neatly preparing cases for these projects? I have had problems making clean holes without bending the metal around them.
 

tool49

Member
2003-04-29 7:33 am
Montreal
If drilling before tapping, I like to have extra sharp bit, so a sharpener does a really good job and reduces the pressure required to actually punch metal through Drill Doctor

Also sometimes when making panel holes that are quite large and the panel quite thin, the regular twist bits will make oval holes, for this I like to use steppers which give you perfectly rounded holes with no vibrations: Irwin Unibit
 
Before switching on for the first time, check for open circuit between heat sink and middle (source) pin on output transistors to ensure that thermal pads are in fact electrically insulating.

Thanks, yes this is one of them Iv'e not forgotten, mostly that im scared of blowing a Mosfet when it can fry them all like dominoes and cost you a bit.

Will read what you all put when I have time, Cheers i needed to see some of this stuff myself!
 
1. Read the pin out on the datasheet (IE 7812 and 7912 voltage regs have different pin outs) my first project and first error!

2. make sure you connect the proper ground to the circuit in a dual mono amp (when I cased up my dual mono Mini A, DUH!)

3. be VERY CAREFUL with Caps, Goggles are your friend...be Careful if you did not buy them BRAND spanking new. Build yourself a isolation area to apply voltage to them slow.

4. Dont pull an "all-nighter" and then try to power up your build, walk away comeback after lunch and double check the basics first!

5. Get a Variac, Bulb Tester, Fuse board, and make a test rig.