Metropoulos Forum

I know there has been much discussed on the orientation of Sozo caps and the line should be closest to the tubes, but what about mustards? if the chassis is upside down and the tone pots facing you should the writing be facing towards or away from the PT? I have found examples of them just about every way... does it matter? is there a "right" way? here the writing is facing the PT...

http://www.amparchives.com/album/Marsha ... F0115.html


Thanks,
Mike

I believe so...I know there is a "more positive" side to the cap and it is recommended that it face a certain direction in the circuit. I'll look up the article and post the recommendation. At the moment...I can't remember exactly.

Maybe someone else can chime in...

Yeah, there's been a lot of talk about SoZo's, but the issue applys to any capacitor where one side of the cap surrounds the other. Physically, one lead is attached to the outer most conductor. Attaching that lead to ground constitutes a shield. Supposedly you are reducing some component of the overall noise in the circuit by making these individual caps a little quieter by mounting them as such. If the Mustards have no obvious markings indicating which lead is which, then you would have to scrape down to the first inkling of metal and check continuity to determine which lead is connected to the outside foil (sounds like overkill to me). Can anyone attest to the effectiveness of this, and whether the proper cap orientation its even noticeable compared to all of the other noise?

Sam

Two words ; scope method ....in aiken amps website there is an article which show how to do it ....

thanks for the info, but what about those who do not have oscilloscopes??

Cerrrem explained that long time agao at the PP, will try to find it....

Yes can anyone confirm this?

basisfunction wrote:http://www.aikenamps.com/OutsideFoil.htm

I did the scope thing like aikenamps explains, and I did find the foil end side on some of my mustard caps, damn now I'll have to check all of them in my fizzy amp, maybe this will help...

I have no idea how to do this whitout a scope, even with the scope it is a little difficult but you find them....

Foil end for the coupling cap should be towards the plate resistor of preceeding stage...
It makes a small difference for noise/interference shielding...

So for the two coupling caps at the 12AX7 tubes, put the foil side facing the tube sockets connecting to the plate resistors...
For the 2 caps in the TONE stack, put the foil side toward the potentiometers... For the input cap for the PI, place the foil side towards the pots also...
The two PI coupling caps have the foil side facing the tube sockets connected to the plate resistors...


What if the capacitor doesn't have a banded end?
This marking of the outside foil was very common in the "good ol' days" of electronics, but, sadly, most capacitor manufacturers nowadays do not bother to mark the outside foil, so we're left to fend for ourselves. If the capacitor has no banded end, the outside foil connection could be on either end, so there is no easy visual method to determine the best orientation of the capacitor. However, if you have access to an oscilloscope, you can do a simple test to determine which is the outside foil terminal. Set the scope up to the most sensitive vertical scale (20mV or less, preferably) and connect the scope probe across the capacitor (ground to one side of the cap, probe tip to the other). Grab the capacitor tightly with your fingers, and note the amplitude of the induced 60Hz AC signal (or 50Hz if you are on the other side of the pond). While still holding the capacitor tightly, reverse the scope leads and you should see a dramatic difference in the amplitude of the induced AC signal. The orientation with the lowest induced signal is the one you want, and the ground lead of the scope is connected to the outside foil in that position. Mark it, and connect that side of the cap to the lowest impedance point in the circuit, typically the driving source plate when used as a coupling cap, or the grounded end if used in a shunt position. If you cannot see a large enough induced AC signal by holding the capacitor between your fingers, place the capacitor on top of an AC line cord (that is plugged into the mains wall socket, of course!) instead of holding it between your fingers and you will see a larger signal on the scope. If you are new at this, start with a 0.022uF cap or thereabouts, as it is easiest to see the difference between the two orientations. The induced signal is smaller at 60Hz with larger value capacitors, and is more difficult to see on the scope.
In the case of some types of capacitors, such as ceramic disks, multi-layer ceramics, or silver micas, there is no "outside foil", because the capacitor is made of a single-layer, or stacked layers of dielectric material and conductor. The orientation of these capacitors makes no difference. Also, some higher-voltage film caps (typically the 1000VDC/450VAC and higher values, such as the Orange Drop 716P high-voltage units) use a "series-wound" technique that has two separate sections, side by side, with a common "floating" connection layer, usually at the bottom of the layer stack. These caps will have no inherent shielding either.

Proper orientation of the capacitors will make the amplifier much less susceptible to outside noise, including hum, interference from fluorescent lighting, and tendency towards oscillations or frequency-response peaks and dips due to unwanted feedback from nearby signals within the amplifier, which can affect the tone of the amplifier (and is the reason why some people claim the amp sounds different if the caps are oriented in the opposite way - if there is no accidental coupling, there will be no tonal difference, but there will still be a noise benefit gained from orienting the caps the correct way).

they're non-polarized......

it doesn't matter

I've cut a mustard open and there is no difference. Both ends are the same. There is no outer/inner foil.

PLEASE tell me it wasn't a .68 or a .022 !!

S.Marshall wrote:I've cut a mustard open and there is no difference. Both ends are the same. There is no outer/inner foil.

Well the scope says otherwise...... I guess it's lying

lifer wrote:PLEASE tell me it wasn't a .68 or a .022 !!

I might do some off the wall shit but I wouldn't do that.

I grabbed a few .0047's just to have on hand awhile back and the guy sent me a whole bag.


-Steve

5150loveeddie wrote:
Well the scope says otherwise...... I guess it's lying

I'm not saying your scope is lying I'm saying that it's not an inner/outer design like most caps that are marked at one end. There are two layers of foil and film. Each lead has it's own but the way it's rolled there is no inner/outer.

And for the record..I don't know your scope well enough to call it a liar!!