Simple tone control?

I'd like to add a simple op amp-based tone control circuit to my preamp for
desktop speakers & sub that I'm modifying from stock.
This is the simplest I found:
(I have +/- supplies so I will be eliminating all coupling caps and changing
Vcc/2 to ground.)
What are the positives and negatives to this design?
Better circuit (yet simple)?
Thanks.
Reply to
DaveC
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If you just want to change the tone (lower), not adjustable, put a capacitor across the volume control. Start with a disc a little smaller than a dime and work up and down from there.
Reply to
gfretwell
I want adjustment of at least 2 bands. Not a 10-band equalizer, though... ;-)
Thanks.
Reply to
DaveC
This looks a lot like the kind of tone controls mass-market consumer-electronics equipment has been using for the past 60 years.
I don't know /exactly/ what your plans are, but the 1kHz corner frequency is about the worst possible if you're trying to correct errors in the speakers you're designing.
Unless you want a "tone control" that produces shrill treble and boomy bass, you need to move the treble corner up, and the bass down.
Furthermore, it would make sense to design the speakers first, and see what sort of correction they need. There are plenty of inexpensive drivers with relatively flat response (if you believe the spec sheets). Neither they nor most recordings will need much in the way of correction, so the best tone control would be one that supplies small amounts of boost and cut at the frequency extremes.
Unless you're looking for lots of boom and sizzle.
There are plenty of op-amps with a wider voltage range -- the 5534 and TL-074 come to mind, but these are rather old designs. I'm sure someone will be able to recommend something newer.
Reply to
William Sommerwerck
It would really help to explain what you mean by that. 6" drivers in wood cabs plus a 12" sub? Or 2.5" pc speakers plus a 4" sub? Very different animals.
As said, the odds are the freq response wont match what you want. A 5 band graphic equaliser would be better, and is pretty aesy to make.
If you wanted simplest, the circuit can be far simpler if you use the existing amp's nfb path to simply insert treble & bass boost controls.
Bass boost: Pot and C in parallel in the nfb path, Treble boost: Pot and C in series from nfb path to ground, after a resistor.
NT
Reply to
NT
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The video is pure marketing.
I don't have these speakers, but I do have the original SoundSticks I which are USB input devices (no analog input). I've converted them to analog input.
Looking for an op-amp-based filter circuit. Anybody have a favorite you can link to? Or put up an ASCII or Spice diagram?
Thanks.
Reply to
DaveC
nothing there
Reply to
NT
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Yes there is. Maybe you have to copy & paste the URL, but it is valid.
Reply to
DaveC
"DaveC"
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** The link leads to a home page and nothing else.
... Phil
Reply to
Phil Allison
Nothing here either.
I think the HK site redirects if it doesn't think you are in the US.
UK version here
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Recommended by the News Of the World:-)
Reply to
UnsteadyKen
You're links are broken/segmented.
Does work...
"Praised for its stunning design, the harman kardon® SoundSticks® II speakers and subwoofer system became a milestone in harman kardon history when it became part of the permanent collection at New York City?s Museum of Modern Art (MoMA). Improving on its famous sibling?s pop-culture appeal, the SoundSticks III system is all that and much more. As a three-piece, 2.1-channel multimedia sound system, SoundSticks III brings a new level of excitement to music, games and movies to your home ? with its exceptional sound clarity, enhanced color scheme and bare minimum of wiring. Beyond its eye-catching appeal, SoundSticks III continues to be incredibly capable ? with 40 watts of dazzling amplification, a down-firing powered subwoofer, eight full-range transducers and compatibility with all sorts of multimedia devices. As the sublime sequel to a prized performer, SoundSticks III is performance art at its finest."
Only $169
Jeff-1.0
Reply to
Jeffrey Angus
"Jeffrey Angus"
** Not from outside the USA it don't.
And the UK one is the same.
How boring of them.
... Phil
Reply to
Phil Allison
Well that sucks, what's the point of that?
Jeff-1.0
Reply to
Jeffrey Angus
Just need a proxy within the USA - always useful to have one available for every major country.
d
Reply to
Don Pearce
It looks bog-standard to me. Go ahead and use it and use your mind to go on to greater things! :-)
Cheers! Rich
Reply to
Rich Grise
_________________ Is *that* why many boomboxes and home stereos(cheap ones) have a tone knob labeled "Bass< >Treble"?
All I notices with those is that turning it to the left made the sound muffled and to the right made the sound more tinny/hissy. I didn't notice that the bass was being boosted when the knob turned left or that it was being reduced when turned right.
-CC
Reply to
ChrisCoaster
These pots on the circuit references aren't on a common shaft.
In other words, you can have muffled *and* tinny/hissy! ;-)
Dave
Reply to
DaveC
This is the classic Baxandall tone control. There is plenty of material if Googling for 'baxandall'.
Reply to
Tauno Voipio
Thanks! It really helps to know what it's called... ;-)
This page:
says: " This circuit must be driven from a low impedance, so connecting it after the volume control (for example) is a no-no. Ideally, the output of an opamp will be the source, thus ensuring the required low impedance. " The input to this circuit will be the output of a computer's sound card. I don't know if it's an opamp driving the output or not.
What do you suggest to insure driving by low impedance? Add a buffer opamp (gain of 1) at the input of this circuit?
Thanks.
Reply to
DaveC
The sound card output will be fine for driving this.
d
Reply to
Don Pearce

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