What I was asking about is why not use all bipolar capacitors since they all interact with the audio signal? Is there any reason to not use all bipolar? Just like the input caps on the phono board, originals were polar and I installed bipolar. So why not to all of the caps in the preamp that deal with the audio path. The largest cap in there is a 4.7uF.
I’m sorry, but what are you saying exactly? Kind of went over my head. Let’s say there were larger transients at power on and power off, how would a polar capacitor deal with that better than a nonpolar? You have a polar capacitor rated for 35 V and it sees a transient of 40 V which it can handle for so many seconds, wouldn’t it be the same for a 35 V rated?
Dan
I don't know all the possible reasons. But one reason is often the cost. Another is the very small capacities that are available as bipolar, which are rare or even unfeasible as polar. Since the vast majority of devices are not developed by ear, and certainly not back then, sound, tonal tuning, is not the reason;-)
with vintage amps, the film caps would be the least of my concern, those electrolytic caps will need the most attention, so using films in place of electrolytic caps will be a worthwhile upgrade...
Transient voltages across a coupling capacitor can be as large as the rail voltage.
In some circuits the transient voltages can be of reverse polarity compared to the steady state voltage,
which would damage a polar electrolytic capacitor.
a capacitor, any capacitor will have its voltage specs based on its insulation properties...as long as the insulation can handle the voltage without damage, then everything is fine, transients should not cause any capacitor to dissipate power, that would have to be catastrophic...
So in that case it would actually be better to use a nonpolar capacitor in those spots which is what I want to do. Since they used polar I’m guessing they the transients are bad enough to damage the caps since they all still work in a sense, but regardless, the UES I want to place there are a bit higher voltage.
I’m getting a little confused here, are you saying it’s a bad idea to put the UES nonpolars in on the preamp/tone board?
Dan
I've used the UES bipolars for coupling with good results. There's no reason you can't use them instead of a polar type.
You have to consider the normal circuit operation, transients from turn on/off, and possible failure modes.
If a transistor shorts, etc, you don't want the coupling electrolytics to be damaged from excessive or reversed DC voltage.
You have to consider the normal circuit operation, transients from turn on/off, and possible failure modes.
If a transistor shorts, etc, you don't want the coupling electrolytics to be damaged from excessive or reversed DC voltage.
Then no lytics in signal path - throughout the device (except some in feedback chains and tone control - depending on the circuit solution).
If you keep whatever lytics in signal path then it is just not worth any effort.
The circuit does not have to be perfect in order to be able to hear improvements at any one point.
Masking does happen, but that does not mean any and all efforts are futile.
Masking does happen, but that does not mean any and all efforts are futile.
We all have our own preferences - the context is 5000 LPs which is not just trivial listening... 🙂
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What, for example, a parts replacement, such as capacitors, does not achieve, different materials can achieve as the base of the device;-)
Or even just tightening or loosening the housing screws;-)
A captain knows every screw on his amplifier... ehm: ship;-)
Or even just tightening or loosening the housing screws;-)
A captain knows every screw on his amplifier... ehm: ship;-)
It's possible that enlarging the coupling caps might lower the phono stage's low frequency cutoff to below what is needed, inviting excessive woofer flap caused by warped disks. It depends upon the impedance the stage is working into. I'd be careful about enlarging the caps; they might cause trouble with no real sonic improvement.
Like I wrote, we all have our preferences.
Once and old cap from signal path is soldered out I personally see no sense in soldering in another lytic (unless the target is to preserve original look as much as possible) - polar or bipolar, does not make any difference.
I've found many crummy film capacitors that I would never use, and the UES are excellent alternatives.
for 10uF and up capacitors.
for 10uF and up capacitors.
Connect some wires to where the caps are and try out different caps to see what you think sounds best. Using crocodile clips. Seen it done on point to point tube guitar amps before to get the correct value.
Experiment with it ,see what results you get.
Look at different amp schematics and compare what they use. I’m looking at power amps at the moment and can’t understand why the input stage is different across the different brands.
I’m looking at the Yamaha P series. They use resistors ,coils , opamps ,diodes and caps on the input stage. Crazy.
Experiment with it ,see what results you get.
Look at different amp schematics and compare what they use. I’m looking at power amps at the moment and can’t understand why the input stage is different across the different brands.
I’m looking at the Yamaha P series. They use resistors ,coils , opamps ,diodes and caps on the input stage. Crazy.
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