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How to control volume on DIY transistor/mosfet Amplifier?
Do I need preamp or can I control volume only with resistor?
thanks
How to control volume on DIY transistor/mosfet Amplifier?
Do I need preamp or can I control volume only with resistor?
thanks
Last edited:
Simplest way to control volume is to put a potentiometer between your signal source and power amp.
I think you should give us more details about your problem.
I think you should give us more details about your problem.
I dont think potentiometer will work on rca to amplifier I think it will make it self oscillate
I dont like my amplifier volume always on the highest
what is the easiest way to control volume on diy high power amp because I didnt see any of diy amps with volume control built in on pcb
thanks
Why would it make it self oscillate? That's the normal way to implement a volume control, used in most commercial applications. You might have to carefully select the value of the potentiometer however.
You can build something like this, and it'll work just fine.
Or just integrate a potentiometer into your amp, like this:
Compromised URL removed by Moderation
You can build something like this, and it'll work just fine.
Or just integrate a potentiometer into your amp, like this:
Compromised URL removed by Moderation
Last edited by a moderator:
As above.
Try a 10K or 22K LogA pot. If you can only get 47K or even 100K they should all work, the best value will depend on your source and load impedances but it must be an Audio Taper Log Pot. A linear pot will work but the volume control will seem very weird (OK if you only want to set it and forget it).
Try a 10K or 22K LogA pot. If you can only get 47K or even 100K they should all work, the best value will depend on your source and load impedances but it must be an Audio Taper Log Pot. A linear pot will work but the volume control will seem very weird (OK if you only want to set it and forget it).
Hi,
Linear dual pots actually track better but need a bit of
trickery to get a decent volume characteristic, like fig 1
here : http://sound.westhost.com/project01.html
rgds, sreten.
Linear dual pots actually track better but need a bit of
trickery to get a decent volume characteristic, like fig 1
here : http://sound.westhost.com/project01.html
rgds, sreten.
The optimum potentiometer value depends on the input impedance of the amplifier, the output impedance of the source driving the amp, and noise considerations.
The potentiometer should have a lower value than the input impedance of the amp but not so low that the signal source has difficulty driving it. I used to use a dual 10k pot between my CD player and an old Hafler DH-200 power amp, with no preamp. That amp had an input impedance of about 20k.
If you intend to incorporate the volume control into the amp you may have more flexibility. The input impedance is often set by a resistor between the input and ground, which could be removed and replaced with the pot, or replaced with a different value.
The potentiometer should have a lower value than the input impedance of the amp but not so low that the signal source has difficulty driving it. I used to use a dual 10k pot between my CD player and an old Hafler DH-200 power amp, with no preamp. That amp had an input impedance of about 20k.
If you intend to incorporate the volume control into the amp you may have more flexibility. The input impedance is often set by a resistor between the input and ground, which could be removed and replaced with the pot, or replaced with a different value.
The amplifier gain should always be the same. The size of the input signal determines the volume. This is most easily done with a potentiometer acting as a variable voltage divider. If you change the gain in order to change the volume, then bad things happen such as a shift in phase margin and instabilities that in most amps will lead to a smoke release.
pga2311 | eBay
look for the bare kits - 29$ to 50$.
for 30$ , you have it all.
PS - you can always swap out the dubious china caps with mouser/digikey- panasonic/nichicon.
OS
look for the bare kits - 29$ to 50$.
for 30$ , you have it all.
PS - you can always swap out the dubious china caps with mouser/digikey- panasonic/nichicon.
OS
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Guys, a friend of mine wants to be able to adjust the volume on his monoblocks. He owns a Vincent preamp without balance and wants to set volume levels on his Hypex nCore mono blocks.
What would be the best option?
Thanks!
What would be the best option?
Thanks!
Not if you use the right value. A volume pot needs to be significantly higher in value than the output impedance of the source, and significantly lower in value than the input impedance of the load. For solid-state audio that often means 10k is fine. A log law pot will give good results.
Why have you specified a 3.4MHz filter for the input?
Why have you not set limits to gain and attenuation around the 5k lin pot?
I'd consider ~160 khz the relevant frequency because there's where input impedance (22k) starts being degraded by the parallel capacitor (47 pF).
And I guess the intention was adding an RF filter, yet well above audio band.
As of the gain stage, maximum gain *is* defined and ~2X or 6dB max .
Minimum gain is 0X .
Not dissing Mr Apex design, whom I hold in the highest respect, just as a side note, personally I would have used a plain unbuffered 22k (or 50k or 100k) *Log/Audio* volume pot at the input, and then buffered its output so it can drive "almost" anything, including a long cable, and just the unbuffered pot if mounted straight at each monoblock, driving a few inches cable.
But of course there's many ways to skin a cat.
And I guess the intention was adding an RF filter, yet well above audio band.
As of the gain stage, maximum gain *is* defined and ~2X or 6dB max .
Minimum gain is 0X .
Not dissing Mr Apex design, whom I hold in the highest respect, just as a side note, personally I would have used a plain unbuffered 22k (or 50k or 100k) *Log/Audio* volume pot at the input, and then buffered its output so it can drive "almost" anything, including a long cable, and just the unbuffered pot if mounted straight at each monoblock, driving a few inches cable.
But of course there's many ways to skin a cat.
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