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Rich_S
Silver Member
USA
219 Posts |
 Posted - 01/26/2010 : 20:18:45
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I recently acquired a battered-but-good-sounding old CS-2. I like it, but sometimes wish it was a tad brighter. Has anybody ever attempted to brighten a CS-2 with a cap across the level control? Any suggestions for the value of said cap?
Were it not a collector's piece, I'd be tempted to mount a mini-toggle as a "bright switch", but since it's a CS-2 with mojo, I'll probably just pick a cap value a stick with it. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/27/2010 : 14:01:29
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Hi Rich_S
PM me.
I've been experimenting - just a little.
Regards Dr. Bob  |
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Rich_S
Silver Member
USA
219 Posts |
Posted - 02/01/2010 : 16:00:09
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quote:
Originally posted by Dr. Bob
Hi Rich_S
PM me.
I've been experimenting - just a little.
Regards Dr. Bob
I sent you an e-mail the other day. Whatchu got? |
Edited by - Rich_S on 02/01/2010 16:00:38 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 02/02/2010 : 08:21:37
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quote:
Originally posted by Rich_S
quote:
Originally posted by Dr. Bob
Hi Rich_S
PM me.
I've been experimenting - just a little.
Regards Dr. Bob
I sent you an e-mail the other day. Whatchu got?
Hi Rich_S
Check your PM |
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Rich_S
Silver Member
USA
219 Posts |
Posted - 02/12/2010 : 16:34:20
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I finally got around to messing with my CS-2 last night.
First thing I did (on Dr. Bob's suggestion) was replace C22 with a same-value poly film cap. New poly > old electrolytic FTW. Since I had extra 1uF poly's around, I went ahead and replaced C13 as well. So, that got a nasty old electrolytic out of the signal path, and TWO of them out of the bypass path.
But I didn't hear much difference. So, I made up a toggle switch on pigtails and tried some bright caps across the level pot. First thing I discovered was the schematic on my CS-2 service notes is WRONG. It shows the high side of VR3 as terminal 7 and the "ground" side as 6 - but the pedal has them the other way around!
Once I figured out the right place to solder my bright cap (terminals 6 and 8), I started experimenting. I looked at a few amplifier designs with bright caps to figure out the approximate RC to go for. The Fender Super Reverb uses a 1M volume pot and 120pF cap. Keeping that approximate RC constant and adjusting for the CS-2's 50K volume pot, meant 0.002uF should put me in the ball park.
Then after a few late-night decimal-place-moving errors, I tried some caps that were WAY too big. They made the pedal brighter and boosted the gain a lot. Then I tried some that were way too small (470pF) they didn't do much of anything (as you'd expect). Finally, I abandoned my pedal-modding parts box and looked in my amp-building parts box. Bingo! 222K Orange Drops, so what if they're a bit over-qualified on voltage rating. I solder a 222K into my toggle switch setup, and it sounded pretty good through my Vox Amp Plug. Sadly, it was 1 AM and a test through the baby Marshall clone was out of the question...
Morning, and time to give it a good wringing-out. With the bright cap off, the CS-2 still sounds a bit dull to me, even with its new poly coupling caps. I run it with the squash control at 2-3 o'clock and the volume a smidge below half, for some 80's Brit-pop jangle ala Summers, Honeyman Scott, McIntosh, and Marr. With the 222K in there, it's bright. Sounds great on the bridge/middle notch setting on my Nashville Tele, playing Jamie West-Oram riffs like "One Thing Leads to Another" and "Better Be Good to Me". But on the bridge pickup, it's a little TOO bright. Hmmm... if I was going to use a .002 bright cap, I'd want a toggle switch to turn it off, and I'm reluctant to drill a vintage CS-2.
So, let's try a .001uF... replaced my 222K with a 102K (also a 100V Orange Drop, lol). THERE it is - a good compromise. Yes, it would be nice to have the option of the really bright .002uF or stock, but I prefer 3-knob simplicity to a more-fiddly pedal with a switch on it.
The great thing about a bright cap is, it goes away when you turn up the volume. If I want to use this pedal for sustain and lead boost, it would fatten up the sound as the "bright" function decreases at higher volume settings. For my purposes, with the volume below 50%, it adds just the right about of sparkle to my jangly chords.
So, the .001uF orange drop is soldered onto the pot-mounting board. Fortunately, there is plenty of room in that corner of the pedal. Pics later, when my daughter comes home from school and tells me what she did with my camera's one-of-a-kind USB cable. |
Edited by - Rich_S on 02/12/2010 16:39:39 |
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CS-2 Bright Cap?
