Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: dmannnnn on June 14, 2010, 01:59:01 PM

Title: I built a crossfeed circuit last night.
Post by: dmannnnn on June 14, 2010, 01:59:01 PM
I had to scrounge around the parts box, but I found everything I needed.  First I tried the circuit shown in figure 1 here:
http://gilmore2.chem.northwestern.edu/projects/meier_prj.htm (http://gilmore2.chem.northwestern.edu/projects/meier_prj.htm)

The results were interesting to say the least.  It did drop the overall output by maybe 8db, so it is hard to get a 'flick of the switch' comparison (I wired it into the output with a 4pole 2throw switch).  The circuit definitely attenuates the bass quite a bit, while at the same time excentuating the treble.  It's not as bad as it sounds.  It actually is quite non-fatiguing to listen to.  I miss the bass at first, but after a few minutes you get used to it and the depth of detail seems to increase greatly.

I then decided to try the enhanced bass version shown here:
http://gilmore2.chem.northwestern.edu/projects/meier2_prj.htm (http://gilmore2.chem.northwestern.edu/projects/meier2_prj.htm)
I used the values for 'medium' crossfeed level.  The bass improvement was not huge but surely a little better.  I'm going to see if I have parts to try the 'high' crossfeed level.

One strange thing I noticed,  with the enhanced bass version I can hear a difference in the response when grounding the center cap, but only when one side of my phones are connected.  If I have both  channels connected I can hear no difference when grounding the circuit.  I wonder if this has something to do with the resistors on the output jack.