Xpress 500p Treble Tone Cap

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PlinytheWelder
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Location: North Jersey

Re: Xpress 500p Treble Tone Cap

Post by PlinytheWelder »

Noel Grassy wrote:Gary,
What are the part numbers for the WIMA caps you had success with?
In their MKP (polypropylene) series at 400v~630v ranges I can't seem to find any within the pF capacitances.
I only looked at the Mouser Bros..
:wink:


Noel Grassy.
I used the Wima FKP2 as seen here : http://www.mouser.com/catalog/641/usd/853.pdf
They're only 100Vdc (250V on the 470pF)but I don't think there is much voltage at the bright caps anyway. They're _really_ tiny and fit the switch nicely.

The polystyrene's from here: http://www.turretboards.com/ are really good and 630V, too.
Gary
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Noel Grassy
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Location: Vacuum Tube Valley-Cali

Re: Xpress 500p Treble Tone Cap

Post by Noel Grassy »

Gary,
Thanks man! I didn't take into account the more likely voltages this part of
the circuit sees. I appreciate the turretboards.com linky!

NG.
All excellent things are as difficult as they are rare__B Spinoza
Analog Assassin
Posts: 58
Joined: Mon May 14, 2007 11:15 pm

Re: Xpress 500p Treble Tone Cap

Post by Analog Assassin »

I used a polystyrene 250pf cap in my Super Reverb for a while.
Changed it out to ceramic after finding that ceramic sounded smoother with an overdrive pedal in front...

I'm about to put the polystyrene in my Ceriatone 1987 clone. I'm thinking that the poly is maybe too accurate when you have an OD pedal in front, but for an amp like a Marshall, where distortion is generated much later in the total amp circuit, that maybe this might work out well.
Analog Assassin
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Joined: Mon May 14, 2007 11:15 pm

Re: Xpress 500p Treble Tone Cap

Post by Analog Assassin »

I've tried a few different variations in my plexi clone and I think I've found what I like.
Tone stack treble: Haven't found a good ceramic, but silver mica is a bit warmer and smoother than styrene here. Not as clinical.
Tone stack mid and bass: CDE DME 1KV sounds REALLY GOOD here. Clear, uncluttered, I lost a lot of mud that I was getting from the sozos .022 here. Tightens up the bass end, just really good tone here.
V1B coupling cap (.002) I tried a xicon polypropylene here. I like it a lot for an aggressive, snarling marshall. It has less ESR so it actually seems to increase the gain to the next stage. It has a nice complex sound also.
Polystyrene sounds good in the 470pf/470k mixer bypass. Opens up the sound, lets the neck single on a strat sing.
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