i want to cut high freq- how?

[wavenator]

i have too much high freq(treble) with my booster
what can i add from outside to cut the high freq
i want to down it until i wont sound it too much
what should i do

[frokost]

The FAQ links to the simple mods page: http://www.diystompboxes.com/wiki/index.php?title=Simplemods#Simple.2C_Easy_Mods.2FTips_.26_Techniques

Scroll down to "Add a lowpass filter".

[wavenator]

i've tried it and it doesn't help me

[dschwartz]

i've tried it and it doesn't help me

then you tried wrong.
low pass filters can´t "not work"..maybe you calculated it wrong or implemented it wrong..
try a 10k resistor inseries with the output and a 3.3nF cap from output to ground, that will cut 4800hz and higher..if not enough, make the cap bigger, like 4.7nF, or until you like it.

by the way..change the cap that makes that booster a "treble" booster for a bigger one..probably a 4.7nF or lower in series with the signal path somewhere..

[wavenator]

the marsha valve
how can i boost the bass there
and lower the high freq

[John Lyons]

It would help to know what boost you have built.
Otherwise we can guess all day long.

EDIT: you just posted as I was typing...

Which amp are you using?

john

[petemoore]

how can i boost the bass there
and lower the high freq
  Frequency selective resistances [capacitors].
  Caps block DC and soon after that [ie at very low frequencies of AC], have high resistance [ie don't wanna let low frequencies through so easy as the high ones...see data sheets and 'curve charts' for the necessary graphics which visually depict this behaviour.
  So you have a high pass filter with these caps, ie highs can pass with much lower resistance than lows.
  ..put that^ in a signal path [in series...see 'interstage capacitors'] and you get to choose the value which cuts off the low frequencies adequately to suit your frequency selection needs.
  But
  put same cap From signalpath To ground...the opposite 'effect' [cap function hasn't changed, just it's application]...it passes highs, but now it is allowing the high frequency content from SP to be shunted To Ground ['lost forever'] instead.
  Either way you use them in frequency selection [although it's a curve, not a cut-off point] they do what they do, what comes out 'the other side' will have the caps 'mark' on it if the frequencies are 'relevant...if you send only HF's through a large cap it may look 'transparent'...the DC and LF AC will tend towards being attenuated...depending on the frequency input and the value of the cap.
  An easy personal demonstration can be had...take adinky cap [say .0047uf] and splice it in the signal path, notice how only HF's are passed. Take same [or larger value for dramatic effect, say .1uf] and put it from SP to Gnd., notice how most the high frequency content took the easy path to ground, and are no longer part of the signal content.