To bleed or not to bleed...

ArnaudS1979

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The treble!

When I first played my SE Custom 24 through the Vox Amplug AC30, I was quite happy rolling off the volume without feeling I was losing out too much on the treble.

When the Tweaker was fixed and started to use it again, it seemed to me that some of treble was actually going away in the process. I think I read somewhere on the forum that, while the Core models all have a treble bleed, the SE didn't. When I opened up the control cavity the first time round I didn't see one. So I ordered a capacitor and when I opened up the control cavity again yesterday, I saw that there was a capacitor fitted, a very small one, hidden behind the wiring.

I played the guitar again with the Tweaker last night, and I guess it doesn't loose that much treble, but it does feel different enough when the volume is rolled off that it is annoying me.

The capacitor I got is about twice the size of the one factory fitted, although I believe they are similar rating. Could it make a difference on the treble bleeding effect if I swapped? Or should I look into a different rating (lower or higher) or even consider adding a resistor?

Thanks for the help.
 
Doesn't adding a resister reduce the effect of the treble bleed? The capacitor value affects the frequency of the circuit (smaller value higher frequency I believe) and the resister sets how much of the effect you have, with no resister full effect, and progressively getting less affect as you add resistance.

If the capacitor you got was of the same value, even if it physically was twice the size, it should have no difference on effect of the treble bleed. Of course in reality the capacitors have a tolerance so we'll likely be out at least slightly different values and thus could potentially sound a little different.

There is no right value of capacitor (or resister) I'm afraid, as it comes down to tuning the circuit to your particular circumstance - how much cable run, pedals etc you have

Myself, I'm not a fan of the treble bleed and de-soldered one of the legs of the capacitor from my PRS. This had the added bonus of smoothing out the taper of the volume pot so that it worked in a much more linear and progressive manner.
 
Very interesting, thank you for chiming in Tone-y. So if I wanted more treble left in the mix I should go for an even smaller cap?

Not really understanding how these things work, back in the days I fitted a treble bleed on my LP with both a cap and a resistor - based on discussions I had on a forum. It worked fine on this guitar, so it might be worth experimenting until I get a result I am happy with.
 
Hi Arnauds. Yeah I think that's how it works. I'm sure someone will chime in if I'm wrong.

Certainly worth experimenting, what's the worst that can happen?
 
In theory: nothing. In practice: it can be months between outings of the welding iron :D. I'll start with a bit more homework.
 
Stewmac has a circuit that you could try, a small resistor and capacitor in parallel. I've tried it on one of my guitars and it works well. Although, I think you'll find as mentioned above, there are a lot of factors in a signal chain that play into how effective a treble bleed can be.
 
The higher the capacitor value, the more treble comes through as you roll down the volume. The resistor impacts the taper of the roll-off, though I'm not sure how.

I like the 180 pf value used by PRS, but caps are cheap so buy several up to maybe 1 nf. You can connect them via jumpers and alligator clips to see which you like best and then solder in the winner. Too low a value and you won't get enough treble.

Too high a value and it will turn into an ice pick as you turn the volume down. The sweet spot can vary depending on the pickups.

You're not going to get any advantage going with a higher voltage.
 
I have a few 130k resistor kicking about but I ran out of 0.001 uf orange drop. I know they don't cost the earth but I haves election of others I could trial. I was actually wondering, I probably don't need much more than the stock 180pf. Since I have a few more 180pf quicking about, could I put 2 or 3 in parallel (not in series apparently) to get a 360pf or 540pf? Worth a try?

I like the idea of the alligator clip.
 
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I have a few 130k resistor kicking about but I ran out of 0.001 uf orange drop. I know they don't cost the earth but I haves election of others I could trial. I was actually wondering, I probably don't need much more than the stock 180pf. Since I have a few more 180pf quicking about, could I put 2 or 3 in parallel (not in series apparently) to get a 360pf or 540pf? Worth a try?

I like the idea of the alligator clip.

Yeah definitely. Add a second 180 pf in parallel and see what you think.
 
Right! Finally got round to dust off the soldering iron. I have prepared 2 trial kits using alligator clips:
- 3x 180pf capacitor in parallel.
- 180pf + 130k in parallel.

Now, I ran in a bit of problem. I have a temperature controlled 48W soldering station and heating up the connection on the pot at 420°C / 790°F, I couldn't melt the stock solder to realise the treble bleed already in place. Any thoughts as to why that could be? I am a bit rusty at this and could easily be missing a simple step in the process.

Cheers.
 
It is very hard to get solder to stick to pots. I scuff them with a knife, use flux, etc. Could be they used a heavier solder and roughed it up good to make sure it stays put.
 
Does your soldering iron have a small pointy tip? Sometimes if the area is too small you can't get enough heat into the joint. I suspect that they've also used lead free solder; I don't know if this has a higher melting point than the old traditional stuff
 
Did you tin the tip of the iron? Need a little solder on it to conduct the heat. 48W should melt solder on the lug real quick.
 
Once I let it bleed I squirmed around for the first week or so but now I have to have them on all my guitars. But it suits my style of playing, type of gain (overdrive) that I use. I ordered a PRS volume pot after mine started going, and when the prices dropped to a reasonable amount.
 
I've always used my fatter iron top when trying to solder to pots. They definitely need more heat.
 
Did you tin the tip of the iron? Need a little solder on it to conduct the heat. 48W should melt solder on the lug real quick.

I have done that, but maybe I haven't put enough on. I am just slightly nervous with the pots as it looks like I have screwed up the ones I have in the Epi LP. I think I'll give it another try with the maximum temperature and if it still doesn't move I'll get someone who knows what he is doing on the case. I don't really want to fry my SE C24!
 
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