bypass capacitor?

[Guest crashie]

hi guys,

 

where should i put the bypass caps? the ground or the virtual ground? im quite newbie in electronics . care to share? thanks

[mouz 0]

Noob here, pardon me if i'm wrong... If you're thinking about changing sound signature, they'll go on the signal path, virtual ground. Check out the schematic at tangentsoft to get a better idea, C2 (amplifier section) should be the one you're talking about.

http://tangentsoft.net/audio/cmoy-tutorial...tangent-sch.pdf

 

After that, head on down to the sites below to get an idea of what kind of caps to use for the type of sounds you want. Hope this helps!

http://tangentsoft.net/audio/input-cap.html

http://tangentsoft.net/audio/cmoy-tutorial/tweaks.html#caps

http://ecp.cc/cap-notes.html

http://headwize.com/ubb/showpage.php?fnum=3&tid=2040

Edited September 20, 2008 by mouz

[angchuck 0]

'Bypass capacitor' usually refer to "bypassing" the larger bulk power caps by having smaller values nearer or at the power pins. Each supply side is shunted to ground and some designs also have one cap across the power pins.

 

Bypassing a signal cap, usually refers to placing a small/higher Q capacitor across the DC blocking input / output stage. This is usually not needed if the capacitor is already of decent quality. Electrolytics should be bypassed lest they are blackgates/Elna audio grade.

 

Wire leads of bypasses need to be short to avoid picking up HF or causing stray inductance/capacitance.

 

* less capacitors in the signal path is usually desirable.

 

In yr case, bypass to virtual gnd.

Edited September 22, 2008 by angchuck

[Guest crashie]

thanks people for the tips.

i will be posting my amplifier soon after solder some bypass caps.

[Tubeman 0]

'Bypass capacitor' usually refer to "bypassing" the larger bulk power caps by having smaller values nearer or at the power pins. Each supply side is shunted to ground and some designs also have one cap across the power pins.

 

Bypassing a signal cap, usually refers to placing a small/higher Q capacitor across the DC blocking input / output stage. This is usually not needed if the capacitor is already of decent quality. Electrolytics should be bypassed lest they are blackgates/Elna audio grade.

 

Wire leads of bypasses need to be short to avoid picking up HF or causing stray inductance/capacitance.

 

* less capacitors in the signal path is usually desirable.

 

In yr case, bypass to virtual gnd.

 

Agree with the above, but just to add that bypass caps are like adding spices to your fried rice. If the mixture is correct the taste will be heavenly. But if you get the mix wrong it may not taste so good. Trial and error is a good way but can be expensive and time consuming.

[Guest crashie]

yaya there is a taste indeed! the MKP capacitor taste better than the ceramic ones.

[Tubeman 0]

yaya there is a taste indeed! the MKP capacitor taste better than the ceramic ones.

 

The main caps, depending on what make you use (ie. brand), and the type (ie. silver in oil, copper in oil, teflon etc), will produce their own type of sound signature. What is also critical is the bypass caps matching. This is where it gets tricky. If you get it right, a not so high quality main cap with a slightly higher quality bypass cap can sound awfully decent. But, if incorrect, it can go the other way round and you may be better of without the bypass. The problems are mainly with phasing and distortions.

[angchuck 0]

I guess its no harm sharing some of my preferences.

 

Ceramics are good for snubbers.

 

A well known signal bypass cap is the mkp 1839, great for crossovers, esp tweeter networks.

 

For power supply bypassing , i like blackgate N series, and regular wima for my normal projects

 

for DC blocking, i like Clarity Cap SA, Obliggatos oil caps and Mundorf silver oil. no bypassing.

 

Only DC blocking requires a small burning in period as the signal power levels are much lower that the rest, thus if you tried something you didn't like afterwards, don't be afraid to take them out asap. Heat/ poor sound quality could be a sign of oscillation in the circuit.

 

YMMV.......