I finished my BeePre2 a few weeks ago and noticed a hum/noise right away that gets louder with the volume.
During a built I triple check ever step. I use a Pace soldering station set between 650F and 800F depending, I clean all connections and leads and I use Cardas leaded solder. All the voltages and resistances during my build passed.
I use a SS power amp with a lot of power. The hum/noise is noticeable in between songs or in quiet passages when watching movies.
I have a hard time figuring out what kind of hum/noise it is, it definitely has a buzzing component.
I recorded it and also recorded the residual noise with my extended Foreplay 3 as a comparison (no problems there). But I noticed I can not upload audio files here.
The same happens with my Crack. If I have my BeePre up half way and the Crack half way up music is at good listening level through HD650ies. At that volume I also hear the noise in quite passages and in between songs.
It does not matter if the input is shorted or if a muted source is connected.
Here is what I did so far:
I visually inspected every solder joint again, passed.
I measured all the ground connection continuity, passed.
I listened with Crack and headphones with no source, so I just could hear the noise and pocked every connection with a chop stick. No change in the sound, no crackling.
I would appreciate some guidance on how to troubleshoot this further. I can re-flow all the connections if deemed necessary. I was thinking about doing the BeePre 2 Modification for Highly Sensitive Systems? I am very curious if this is a solder connection problem or if it might be something else. Thanks for any input.
I attached a photo of my oscilloscope reading, left and right channel, source is shorted. Not sure if this is helpful.
Stefan Hampel
Soundsmith Carmen, modded Technics SL-1200mkII, Thorens TD 125 mk2 with SME V, Eros, Extended Foreplay III, BeePre2, Crack, Pioneer Spec 4, Sonus Faber Electa