2 quick questions for mid/treble boost design

[iainpunk]

a friend wants a mid/treble booster designed by me, which he will build himself
i have mid/treble boosting design, how much boost should be expected to be available? 10dB? 20dB? somewhere in between?
also, should the frequency and gain pots be log or lin?

cheers, Iain

[antonis]

+15dB should be considered OK, I presume..

[Mark Hammer]

I concur with antonis.  Aim for more and one tends to invite hiss.  And I doubt your friend was asking for a hiss-booster.

[iainpunk]

thanks guys,
i guess i'll go for 17dB, since 17 is my favorite number.
LOG pot for both gain and frequency?

cheers, Iain

[Big Monk]

thanks guys,
i guess i'll go for 17dB, since 17 is my favorite number.
LOG pot for both gain and frequency?

cheers, Iain

What do you mean by frequency? A input cap blend? By gain, do you mean the traditional RM style boost pot?

If so, audio for both.

[ElectricDruid]

thanks guys,
i guess i'll go for 17dB, since 17 is my favorite number.
LOG pot for both gain and frequency?

cheers, Iain

Definitely log for frequency, since ideally you want a "octaves" character around the pot. The gain control depends a bit more how it's done, but probably log too. I suppose the ideal in that case is a "dB/degrees" relationship as you turn the knob - e.g. equal movements give equal increase in dB gain.

What tone control are you thinking of using?

[antonis]

What tone control are you thinking of using?

I should firstly get an answer and then suggest pot law..
(especially when dealing with nasty habits designers like iain..)

[iainpunk]

yeah, thanks for the complement, Antonis.
he wants it to be secret for now, since i am getting payed for the design, not the product. (he pays me enough to keep it quiet, until he has his finished his one that is)
your comments about pot taper made full sense, i already suspected log would be the best option, but i wanted confirmation.
thanks guys.

cheers, Iain

[PRR]

....... i am getting payed for the design, not the product. .....

So you out-source the design on strangers (us), but don't offer to split the pay? That's an old tradition, but not friendly.

[iainpunk]

....... i am getting payed for the design, not the product. .....

So you out-source the design on strangers (us), but don't offer to split the pay? That's an old tradition, but not friendly.

(hard to tell is sarcasm, but if not )
i'm literally getting 5 euro so i don't think its too controversial. and i'm not outsourcing the designs, i just wanted confirmation for the pot tapers, and an indication for a suitable gain range... not a full design

i talked to him, he doesn't mind me sharing the design on this forum, i'm not finished with the design yet, but ill post when i'm done designing it. or do y'all want the halfway-finished design now?

cheers, Iain

[iainpunk]

here is the elegant/nasty design i came up with.

falstad code:

Code Select Expand


$ 1 0.000005 89.03963197220334 50 5 43
c 176 208 176 288 0 4.700000000000001e-9 4.501052737571256 4.5
r 176 208 112 208 0 22000
r 176 176 112 176 0 100000
174 288 96 224 144 1 500000 0.5 Resistance
w 272 192 272 160 0
w 176 96 176 112 0
w 176 144 176 160 0
w 176 160 176 176 0
w 272 160 256 144 0
r 224 96 176 96 0 100000
g -80 288 -80 304 0 0
w -48 288 -80 288 0
c 320 192 368 192 0 0.000001 4.498141002093707 4.5
r 368 192 368 288 0 100000
r -128 160 -128 288 0 1000000
w -80 288 -128 288 0
w -48 288 96 288 0
w 96 288 112 288 0
w 288 96 288 144 0
w 288 144 272 160 0
w 304 288 320 288 0
w 320 288 352 288 0
w 352 288 368 288 0
w 144 288 112 288 0
w 304 288 256 288 0
w 256 288 208 288 0
w 208 288 176 288 0
c 256 144 176 144 0 2.1999999999999998e-11 -1.6761281948390243 0.001
w 320 192 272 192 0
170 -128 160 -160 160 1 20 20000 0.5 1
a 176 192 272 192 8 9 0 1000000 4.501024488608318 4.501052737571256 100000
w 176 288 144 288 0
w 176 112 176 144 0
R -80 96 -80 64 0 0 40 4.5 0 0 0.5
408 -80 96 -128 96 0 1 0 1
174 112 208 32 176 1 500000 0.5 Resistance
w 112 176 64 176 0
w 64 176 16 176 0
r -80 96 -80 160 0 1000000
c -80 160 -128 160 0 0.000001 4.4985407447840275 4.5
a -80 176 16 176 9 15 -15 1000000 4.9005852850645 4.90063562843206 100000
w 16 208 16 224 0
w 16 224 -80 224 0
w -80 224 -80 192 0
r -80 224 -80 256 0 680000
c -80 256 -80 288 0 1e-10 4.536781284433098 4.5
o 13 1024 0 94210 2.2245829417222955 0.0001 0 2 13 3


cheers, Iain