Orange Drop "polarity" ?

[butwhatif]

[quote="lymo"]I read all the cap discussion here, and feel thankful for the forum. In a recent '97 circuit dumble build I did (with reverb added) instead of a tone stack for the OD channel, I put in a 6 position switch that changed the coupling cap to the output. I put in mallory 150s, Orange drops, and ceramics. Every position has a little different sound. I was surprised how much I liked the cheap ceramics. Everything I read seems to point a guy to use Mallorys or Orange Drops, but well, I like meatball sandwiches too, so maybe I'm just low brow. The guy who bought the amp keeps sending me emails saying he likes it, so I'm not alone...

I just picked up a '72 Montgomery Ward Airline G1M-9131a amp for $50 from a friend, and was in disbelief at how good it sounds. Never having played thru one in all the years, it was impressive, and has found a place in my pile. And guess what, every cap except for power supply and a couple cathode bypass are ceramic. The way the tonestacks are designed is also an eye opener.

[ottomatic]

If you take a look at the board in a Black Face Fender you will see the cap alignment setup.
The old blue Mallory's have the bar on them and Leo aliened them correctly in and out.
Leo built thousands of amps and It is amazing how good they still sound. Every cap and wire is in a specific place for a specific reason, because that is where the tone is.
If you happen to get a old fender amp and if it sounds good leave it alone. If it needs a little help check the heater wire and balance the last two caps before the power tubes. Sometimes the wire sequence changes and the caps are usually always out of whack. You can do this sometimes by switching the order. In general the right side is the output if unmarked and untested. Left is to ground or input.
I always try to get the caps faced correctly. All my builds are neat, clean and quiet.
The quiet part is important to me. I feel that quietness increases head room.
Who likes to hear buzzing between every note?
I have someone's sloppy, noisy, expensive amp that is just sitting.
I am working on a overdrive 100. Twin, 2 x Express, Liverpool and Hendrix 100 kt66.
Some are ground up and some are off the shelf stuff/kits builds that I modify by putting top shelf iron in and tweaking the components.
It has to be quiet, reliable and sound great before I will let it go.

[jnick1947]

The engineers at SBE - who took over the "Orange Drops" told me that they are randomly oriented. The idea is to have the outer foil connect to the low impedance side of the circuit, thus - contrary to Gerald Weber's recommendation - the outer foil would go to the plate of say a 12AX7 (~62K//100K) instead of the cold side with the 1M grid resistor. Can this make a difference? Yes, a friend of mine was troubleshooting an MV amp he had built and was wondering why, with the MV totally disconnected, the amp was still putting out a signal! The coupling cap to the MV was radiating signal to the coupling cap at the input of the Schmitt PI (which is bootstrapped
and high impedance).

[Johnhenry]

Here's a pic of my homemade cap tester, I used half of an old guitar cord,
a plastic box, 1 switch for shorting the tip to the sleeve, ( keeps the amp quite while switching cap's } a on/off/on switch for ( quickly changing the polarity ) and 2 short leads with alligator clip's.
any small amp will work, adjust a small amount of volume up on said amp, lightly pinch the cap between your finger's, the loud hum will be the outer foil side, and i get very little hum if any from the inner foil side, i did put a small piece of heatshrink over each switch lever to keep from induceing hum through the switch.
This will help those that do not have a scope find the outer foil.
[IMG768]http://i199.photobucket.com/albums/aa33 ... ure006.jpg[/img]
Johnhenry

[Firestorm]

johnhenry--
That is so cool! I love homemade tools and test rigs.

[Johnhenry]

thank's Firestorm, It's sorta on the HillWilliam side, LOL ! but it work's for me and it's cheap, for those that can't invest in a scope, this will fit the pocket book a little better.
I hope my small contribution help's those that are seeking more knowledge !
Johnhenry

[summitcity]

johnhenry--

You Rock dude. I have a scope but this would be less trouble and a fun project.
Jon

[Johnhenry]

Thanks Jon, i found this idea in an old Electronic's book yr's ago, it told how to use your amp and a guitar cord to find the foil side, it's not my idea, i did build it in a box with switch's to make it fast and easy to use,
it may not be something that everybody will use or even want, it's like the old light bulb limit'er, i still have one and still use it, even though i have several Variac's, it's just somethin i thought a few people would enjoy and use, and it's simple to build, just use a plastic box to mount it all in or you might get some induction from touching the box while testing your cap's.
Johnhenry

[weld]

Karl, That's what I saw on my scope and when useing the Amp test i see that when the tip of the cord is connected to the outer shield i got the loud hum, I tested about 20 or so cap's and i noticed that on all the Sprague's i tested, if you can read the writing on the cap the outer foil lead was on the right end of the cap

I took 2 0.22uF OD715 caps with me to school and tested both. I got a different result. On one cap the outer side was on the left and on the other the outer side was on the right of the writing.

SBE say that....

http://www.sbelectronics.com/images/PDF ... cation.pdf

First of all, our manufacturing process for 225P, 418P, 715P, 716P and other capacitors cannot, and never could
[even when Sprague manufactured these capacitors], differentiate which lead is connected to the outside foil.

[Johnhenry]

Gee ! And just think about it, they make a big paycheck for being that
( SMART )
Johnhenry