cap foil direction

[martin manning]

"Reversed" is just the result of the layout. Generally the outer foil lead should be connected to the node with the lowest impedance to ground.

[ToneMerc]

Is there a simple explanation for why caps 3 & 4 are reversed?

Are you refering to the dumblelator or the main board? If you are refering to the "lator", the first two caps are closer to B+, while caps 3 and 4 are closer the ground side. I gues the same applies to the main board if read from left to right.

[Kregg]

The main board.

[hans-jörg]

Hi,
maybe a stupid question, but: with a ready board/amp - is it neccessary to solder the caps again out to proof the foil side?

Hans-Jörg

[glasman]

Is there a simple explanation for why caps 3 & 4 are reversed?

If 3 and 4 are in the drawing, they are the grid feeds for the PI.

You always want the foil side towards the low impedance side of the circuit. The Grids run in the 14Meg range the other side is much lower (300 to 5K for the .1uf side and 0 to 1M for the .02uf side).

Gary

[Bob-I]

Hi,
maybe a stupid question, but: with a ready board/amp - is it neccessary to solder the caps again out to proof the foil side?

Hans-Jörg

Not always. I've tested in circuit and in most cases you can still find the foil. I've had a few times I had to unsolder one leg.

[hans-jörg]

Thank you, this helps.

Hans-Jörg

[vibratoking]

If you are as determined as getting your parts right, the sky is the limit and you can figure out a lot of things beyond how to mark a cap.

May I ask specifically what you mean by this?

[erwin_ve]

If you are as determined as getting your parts right, the sky is the limit and you can figure out a lot of things beyond how to mark a cap.

May I ask specifically what you mean by this?

Sure: I see Joost is very determined to get his built right which I consider a very good thing. Adding basic electronics knowledge will give him or any (potential) builder insight why things the way they are.
Basic things like Ohms law, Electro magnetics(wiring!), RC / filters and a understanding of how a tube works, will be benificiant for a builder to understand why it sounds like crap or sounds stellar.

[gary sanders]

A big thx to Gabby for posting that youtube video. My amps sound far better after following that. I had 3-4 caps wrong, reversing made a noticeable difference.

I did too.Made mine so much better

[Kregg]

A big thx to Gabby for posting that youtube video. My amps sound far better after following that. I had 3-4 caps wrong, reversing made a noticeable difference.

I did too.Made mine so much better

Got any pics to back that up?

[hans-jörg]

Hi,
I tried this morning a fast version of the box. Two clips and the plugged in cable to the amp. Connected with Tip/Ground. The only thing is, you have to turn the cap to find out the side.
But with except 1 or 2 I could not find out the outern foil side. Especialy bigger caps, like 0,1uF.
The same noise on both sides. Evan touching the body/contacts.
What is wrong on my methode (two clipps on a plugged cabel)?
Do I have to crank the amp to 10 to hear some differnt?
Or are there caps with no outer foil? But evan with orange drops I failed with 90%.

Hans-Jörg

[Structo]

WHen I tried it about a year ago I couldn't hear much of a difference either on the 6PS caps.

[overtone]

Hans,
the dpdt switch is worth including because you have have a quicker reference and saves you changing the cap around.
Sometimes the difference is really subtle and you have to turn the amp up then. This is just based on one day of experience - I rigged one up yesterday after reading this thread.
On some of the Russian caps there was zero hum either way.
Some old Mullard mustards also had no hum at all and some showed a mild difference with the amp turned right up.
So all sorts of fun and games. I have not A-B tested the orientation in any amps yet in order to make my mind up on all this.
Best, tony

[Guitarman18]

This is one thing I haven't tried in my amps, so in the interests of refining them, I'm going to give it a go, however I'm a little confused by the Gabi video. When using the tester box, does he get the louder hum when the outer foil connects to jack tip or ground?

Any help with this probably 'dumbass' question would be greatly appreciated. Apologies for the de-rail.

Cheers,

Paul.