'Cap' modification

ken_j · Post by **ken_j** » Mon Oct 10, 2005 11:25 am

Aitch, you can just solder a wire to each end of the cap and bypass it. That way it is easy to go back.

Steve, you can find the schematic here. C3 is the cap we are discussing.

ozover50 · Post by **ozover50** » Mon Oct 10, 2005 11:42 am

Thanks, Ken - like this?

steve_hershberger · Post by **steve_hershberger** » Tue Oct 11, 2005 2:58 am

Thanks Ken. I did see that schematic yesterday after I posted the question. Which leads to some more questions...

That schematic is dated 1990, so in what year was this cap eliminated? "Later models" isn't specific, and I assume the cap was not included sometime after '90 because the cap in my '92 was supposedly installed by a previous owner.

Did the original guitars in the '60's have this cap as standard?

Lastly, and most important - if I remove this cap will I get better bass response over the whole guitar?

I usually play mine with both tone controls full up or close to it. But if I turn the tone knobs down more the overall tone gets dull and lifeless really fast. I'd just like to have more useful range on the tone controls if that makes sense.

rickcrazy · Post by **rickcrazy** » Tue Oct 11, 2005 3:41 am

I think the cap was eliminated in the early/mid '80s.
Yes, the cap was standard at least in the second half of the '60s. Someone correct me if I'm wrong.
Removing the cap will definitely improve the bass response on your guitar.

ken_j · Post by **ken_j** » Tue Oct 11, 2005 4:16 am

Yes Aitch.

Steve, "if I remove this cap will I get better bass response over the whole guitar?" Only the treble pickup. The cap is in series with the treble pickup. The bass pickup is paralleled beyond that point, if wired per the factory schematic.

ozover50 · Post by **ozover50** » Sat Oct 15, 2005 11:48 am

I bypassed the cap last night and boy, it does make a difference!! Much more like the sound I expected.

steve_hershberger · Post by **steve_hershberger** » Sat Oct 15, 2005 1:08 pm

So Howard, you just bypassed it with a wire and left the cap soldered in place? If that works, I'll probably do it to mine tomorrow.

Btw, what kind/value cap does yours have? And could you please describe the before/after sounds you're getting?

ozover50 · Post by **ozover50** » Sat Oct 15, 2005 1:29 pm

That's right, Steve. I can't find a value on the cap - it reads '472J', which may mean .0047pf. I'm no electronics expert, believe me!!

It sounded a little 'thin' before. It now has more depth and warmth and I think as a result, the 5th control has more effect. It sounds much closer to my 330 with vintage pups, but the 360V64 pups have been wound down to 7.4k. I don't know what the ones on the 330 are.

Sounds awesome with the JC-120 amp!!

steve_hershberger · Post by **steve_hershberger** » Sat Oct 15, 2005 1:41 pm

Thanks, my brother! You're right about the 472 meaning .0047 too (the "2" stand for zeroes after the decimal point).

"More depth and warmth" sounds exactly what I want too. And the extra effect the 5th control would be a most welcomed addition too.

My pickups were unwound to 'something' too (supposedly 7.8(?) but I've never taken it apart to check yet). Tomorrow I'll be taking it apart during a string change and will subject it to surgery and I'll report back on what kind/value of cap is in mine. Don't know if I'll disconnect the pickups to measure them or not though.

ozover50 · Post by **ozover50** » Sat Oct 15, 2005 1:50 pm

My pleasure, Steve. I gotta tell ya, I absolutely adore this guitar!! The neck is just sensational, the string spacing perfect (for me) and the sound is brilliant!!

It's unquestionably my #1 !!

ken_j · Post by **ken_j** » Sat Oct 15, 2005 6:03 pm

Aitch, I am happy to here that it worked out.

As far as measuring the resistance with out disconnecting the wiring you can get close by following this. Turn the tone controls to full (CW), select the bridge pickup to measure the neck pickup. Select the neck pickup to measure the bridge pickup. I believe this will get you fairly close because the volume pots are wired between the selector switch and the output jack. This will isolate the ohmeter from the volume pots. Even though they are 250K it would have a slight factor in the reading. Of course if both pickups were selected your numbers would be way low.

ozover50 · Post by **ozover50** » Sat Oct 15, 2005 10:37 pm

Thanks, Ken. It will be interesting to test the resistance of them all. Might give me a reference point.

I'm sure the collective resistance will be greater than mine!!

tony_carey · Post by **tony_carey** » Sun Oct 16, 2005 12:05 am

Ha,ha,ha Howard, the King of quips strikes again....

ken_j · Post by **ken_j** » Sun Oct 16, 2005 5:23 am

"I'm sure the collective resistance will be greater than mine!!"
Actually Howard it will be lower. The volume controls are in parallel with each other and the pickups. The resistance can be no higher than the lowest value. It only gets higher in series.

ozover50 · Post by **ozover50** » Sun Oct 16, 2005 11:33 am

But I don't have any volume controls and pickups, Ken - only my guitars!! Now you're confusing me with science! I do recall the effect on resistance when speakers are connected in either series or parallel, but that's my limit. Anything more than that and I'd have to call in the militia..........