Bypassing capacitors makes for better high frequency transmission. Here is an explanation:
http://www.tomshardware.com/forum/41067-6-bypassing-electrolytic-caps http://www.audioheritage.org/vbulletin/archive/index.php/t-3555.html The output capacitors in the original Squeezebox are fairly compact 120 uf electrolytics, which means they are tightly wound inside to get a lot of capacitance in a very small space. What do you have then you wind something into a coil? An Inductor. Inductors roll off high frequencies-which is why the woofer in your speakers probably has an inductor in series with it. Putting the small value capacitor across the electrolytic allows the smaller capacitor to pass the higher frequencies. Also, the smaller cap is normally made of a higher quality dielectric then the paper and alunimum foil of the electrolytic. As an example, the Radio Shack caps are made up of polypropolene film with a very thin foil sputtered onto it. It's easy to see the capacitors in the unit-they are the two that sit right behind the RCA output jacks. Indeed, for extra stregnth I actually soldered one lead of the bypass caps to the jacks where they came out of the circuit board. The leads to the two existing capacitors are right on top of the circuit board-so you don't have to remove the board, just the unit's top cover. The leads closest to the RCA jacks directly connect to the jacks and the ones further away would be where the other leads go. This modification requires precision soldering in tight spaces, so if you aren't good at soldering, have a friend that is do the mod for you. By the way, I have studied the audio chip in the original Squeezebox (Micronics MAS 35x9F) and found it's designed to be used in high end ($1000.00+) portable digital audio recorders. It also has an analog to digital converter on the chip-and a microphone preamplifier. The audio is pulled from an on chip high current amplifier that's designed to directly drive low impedance headphones. Try this unit with a pair of Grado headphones-you'll be blown away! It's headphone quality is FAR better then my Squeezebox 3's is. I use the Grado SR60s with quarter size holes cut in the center of the foam cushions. -- dpuopolo ------------------------------------------------------------------------ dpuopolo's Profile: http://forums.slimdevices.com/member.php?userid=21754 View this thread: http://forums.slimdevices.com/showthread.php?t=58554 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
