Tone Pot / Cap Confirmation

[adamg67]

I’m getting a bit more confident with passive wiring, but I still just need a bit of BC backup to make sure I’m looking at this right before I get the soldering Iron out. 

I’ve got a Maruszczyk Hellwood which is basically, electronically, a passive VVT Jazz. It has Haussel pickups which are usually described as a bit vintagey which makes sense to me and is why I like them, they make me feel like I can go DI with nothing else and it will sound good. It’s a good old BC purchase, lovely bass but the seller did tell me that the electronics had all been swapped out (the origanal electronics were included as well).

Originally it had 500k volume x 2 and tone pots, and these have all been swapped for 250k CTS pots. It has a neat little cap holder and those little square swappable capacitors, so tone wise I’ve got a 250k pot and can swap between 0.01, 0.022 and 0.047 caps, and can also leave the capacitor out to see what what the pickup is like “raw”, which is handy.

I’ve tried a few things and found this:

• The setup it came with, 250k pot and 0.047 cap, loses too much high and high mid for me. Too bassy for what I’m after this bass for.
• With the 0.022 cap, it’s still not there, same effect of too bassy  just not to the same degree.
• With the 0.01 cap it’s a lot more like it, nice tone with more mids but just a bit too honky.
• With no cap, so no tone circuit, it’s nice, more like what I’m after, but when I flick between that and the 0.01 cap I like both and almost want something in between.

So based on that, and the fact that I’ve got a stash of bits including some DiMarzio push/pull pots, I’m thinking of switching the tone circuit for a 500k pot plus the nice swappable cap thing, with the push/pull wired up for direct out, ie tone circuit bypass. So, I know the direct switch will give me the same tone I’m getting now with an open circuit, and I want that as an option. I’m hoping the 500k pot will then give a different tone again, along the same lines as the 250k pot + 0.01 but with more mid highs and highs, and a less honky frequency bump. I’ll have the different caps to play with to get that.

Am I thinking along the right lines, with the 500k pot meaning I lose less highs than I am with the 250k one? And the tone with the cap still in there will give less of a high cut, but still with a bit of a “tone cap bump”.

[paul_5]

500k pots will brighten your tone, so if you're after a slightly dull sound out of your bass then that's not the way to go.

0.01µf is 10nf (nanofarrads), if you want something in between this value and no cap then pop a 0.0047µf (4.7nf, sometimes written as 4n7), as that's the value that's closest to the halfway point. 

The code for this value of capacitor is 472, though some brands of capacitor have the value printed on.

[adamg67]

8 hours ago, paul_5 said:

500k pots will brighten your tone, so if you're after a slightly dull sound out of your bass then that's not the way to go.

I am wanting to brighten it up a bit, I have a feeling the previous owner swapped things over to make it duller and I'm just reversing the mods they made.

[paul_5]

You can take the guesswork out of this by using the mathematical formula for calculating the corner frequency (point of roll-off) for a passive low pass filter -which is exactly how the tone control on passive basses work:

     1/2(piRC), where R is the resistor value, C is the capacitor value, and Pi is delicious.

Failing that there are a couple on online calculators, I tend to use this one...

http://sim.okawa-denshi.jp/en/CRlowkeisan.htm

[2020Jazz]

27 minutes ago, paul_5 said:

You can take the guesswork out of this by using the mathematical formula for calculating the corner frequency (point of roll-off) for a passive low pass filter -which is exactly how the tone control on passive basses work:

     1/2(piRC), where R is the resistor value, C is the capacitor value, and Pi is delicious.

Failing that there are a couple on online calculators, I tend to use this one...

http://sim.okawa-denshi.jp/en/CRlowkeisan.htm

Pi is infinitely delicious.

[adamg67]

3 hours ago, paul_5 said:

You can take the guesswork out of this by using the mathematical formula for calculating the corner frequency (point of roll-off) for a passive low pass filter -which is exactly how the tone control on passive basses work:

     1/2(piRC), where R is the resistor value, C is the capacitor value, and Pi is delicious.

Failing that there are a couple on online calculators, I tend to use this one...

http://sim.okawa-denshi.jp/en/CRlowkeisan.htm

That would work if I knew what frequency I wanted  Handy, I will keep a link to that.

Just popped the 500k push/pull in there and that works nicely, with the tone up full it's a little bit richer than with no tone circuit, with the tone rolled off it goes nice and middy. That's the bridge pickup, the neck pickup is nice and bassy so between them it's a good range.

Cheers for the advice