passive tone control?

[corbs]

there a few posts about this but i'm wondering what would be the best type to go in the effects loop of an amp...

the overdrive channel on my amp is always darker than the clean and unfortunately they share an eq.

as i only want to cut some of the low end / add mid treble i was thinking i wouldn't need a full eq and a simple tone control would do

any ideas?

[seanm]

Cutting the low end is not allowed  :twisted:

Just kidding, a simple high pass filter will work. But you cannot *add* with a passive control, you can only take away. So if you want to add mid and treble, you will need an active eq.

[corbs]

cool i may give a high pass a go (that low end is reeeely low man )

but in case, is there a simple active eq that could just boost the mid / high? i've done a bit of searching and people seem to think they are more trouble than they are worth.

[petemoore]

Aron explained it something like this once.
 Take away highs and lows and what do you have left...Mids !
 If you have a box that you'll be using on teh amp effects loop, try smaller value signal path cap[s, [like input and output caps, anything the SP goes through]. As a HPFilter, caps like this can be used to attenuate lows.
 Try adding caps to ground "from the signal path [LPFilters shunt the HF's to Ground].
 HP means 'High pass'
 LP Means "Low Pass'
 Any box used can pretty easily be modded to cut highs and lows, then, if they take away too much amplitude, you can reboost the signal volume.
 Sometimes it may be preferrable to drive the passives with a buffer...as soon as you put an active component in there it becomes an active filter.

[Mark Hammer]

Here's an idea.  Tell us what the amp is, and if we can find the schematic online, we can tell you what to mod on the overdrive channel to brighten it.

My guess is that there is no bass difference between channels but the manufacturer has elected to seriously roll off the highs for some reason (perhaps to avoid hiss).  The other thing to consider is that an amp itself can be designed to have decent bandwidth for its two channels but be married to a poor choice of speaker that fails to complement the response the amp delivers.

[corbs]

petemoore: sorry i'm not sure i understood... i'm thinking of building a specialised low pass + hi pass filter in one box - prolly with a rotary to select the cap and a pot (using this as a guide) where each can be turned off with a stomper. that can sit in the loop. but i'll be mainly cutting the lows (hopefully leaving the mids+highs!).

Mark Hammer: it's a tech21 tradmark 60, so i think getting a schematic will be a bit hard . i've been told that when cranked the second channel 'looses up a bit' and balances out better, so his is mainly for low practice volumes where i tend to only get bass from the dirty 'marshall' channel - esp compared to the clean 'fender' channel.