Thanks.In my opinion there is a bit to much noise in your recording when you are using the amp (I made the same experience several times).
TG is solving this issue with it's crazy good filtering algorythm. But in your first video one can see as well the noise in the graph.
Biburo is not able to detect if it's a signal or if it's noise and has to surrender.
Here some points how I get rid of the noise, depending where it's based:
1. power supply: I first tryed a 5V wall power supply which produced a lot of 50Hz noise. So I switched over to a 9V battery (very effective)
2. grounded shield: as shown in the first picture of the thread, about 15 centimetre length taken from an old coax-cable around the pickup-cable and as an extension the red cable which I can easily grab or even more comfortable just step on with my foot :-d (very effective and you see the difference immediately grabbing it or let it hang loose)
3. amplification (computer): give it a try to play with the amplification of the internal soundcard. For me +12dB and about 30% volume for soundrecording is comfortable (if the battery is getting weak I switch to higher amplification), drawback: higher values will amp as well the noise (basic)
4. amplification (external amp): same as before, mine has two potentiometers (Conrad 197688 one for amplification the other for load voltage) trimming those two potentiometers is very important for a good signal to noise ratio (basic)
for both amplification methods I use biburo to adjust to a combination of good soundsignal and low noise level. Noise then is just a few millimetres (about 1/3 of the signalgraph see picture in post #19 or even less when testing loud vintage watches)
If you give it a try and at least modify 3 and 4 your biburo should work fine as well and you will be able to compare ratio, amplitude and repere/beat error of different timing programms.
I'm running it from 9V battery.
All cables are shielded, and the circuit is in a metal box, also connected to the shield.
I'm not using any extra gain on computer side, I can only lower it from 0dB. (it doesn't help)
Mine has 1 potentiometer, I've tried fine tuning with it, but didn't really help ( Building a Microphone Amplifier - Watch Timing System I've made this amp)
(I'm not a pro in, so I don't know how to tweak it, I could just make the soldering, and PCB...)
However it is sure, that TG has a really good noise filtering algorithm.