Product design and the feel of knobs

[rattlesnake]

I am impressed with the silky feel of the knobs on the Douk A5, which Amir reviewed recently. Even though it's not a high-end amp, the knobs feel high-end to me. I have a question about how volume knobs behave. I find that some volume pots are tapered so that the music gets a lot louder with a very small change near the lower settings - like the difference between 7 o''clock and 9 o'clock is big, and then as you turn it up, the amp starts clipping just past about 2 o'clock. It's kind of like a car with a gas pedal that gives you a big "push" when you barely tap it and it makes the car feel more powerful than it is. But on the Douk A5, there is a relatively smaller (compared to most other amps I've had) increase in volume when turning the knob from 7 o'clock to 9 o'clock and the amp doesn't seem to start clipping until pass 3 o'clock - by that time it's getting pretty loud, it's rated at about 110 wpc into 6 ohms with the power supply I got, and my speakers are 90 db efficient. The difference in taper is not due to the input signal strength, as I am comparing with the same line-level device going into the amp input. When I first hooked up the Douk I wondered if something was wrong with it because I thought it would be much louder with the knob at noon, until I realized that the vol pot taper is just different from what I am used to.

I wonder if amp manufacturers often do a volume pot taper that gives you more oomph at the very beginning like the gas pedal example, because it makes the amp feel more powerful even though it isn't. Has anyone else noticed this?

 

[Chrispy]

Is it just weight? Some actual technical difference from what you're accustomed to? I could care less for knob feel myself, don't even particularly want knobs. Depends somewhat if the knob is dB based or not I suppose...

 

[Keith_W]

It may have something to do with the gain structure of the amplifier. For e.g. if an amp has 27dB of gain, the volume control would feel "faster" than an amp that has 21dB of gain.

As for knobs - don't care for them myself. I guess that tells you who on ASR is a couch potato (prefers remote) and who gets up to adjust volume

 

[DVDdoug]

Audio taper pots sound linear. Regular linear pots are perceived to have most of the change on the lower half of the rotation with little perceived change over the "loud half".

And it also depends on the gain. i.e. If your signal & gain are strong enough to clip at the mid-setting, or if the mid-setting is as loud as you want to go, then you're only using half of the knob's range.

Optical encoders that go more than 360 degrees can make smaller, more precise, adjustments.

 

[rattlesnake]

It may have something to do with the gain structure of the amplifier. For e.g. if an amp has 27dB of gain, the volume control would feel "faster" than an amp that has 21dB of gain.

As for knobs - don't care for them myself. I guess that tells you who on ASR is a couch potato (prefers remote) and who gets up to adjust volume

It may have something to do with the gain structure of the amplifier. For e.g. if an amp has 27dB of gain, the volume control would feel "faster" than an amp that has 21dB of gain.

As for knobs - don't care for them myself. I guess that tells you who on ASR is a couch potato (prefers remote) and who gets up to adjust volume

If the amp with the volume knob that feels “faster” is rated at lower power, and if the amp with the knob that feels slower has more power and gets louder, does that rule out this possibility? I ask because I don’t know much about how gain structure works in a hi-fi amp. I know that in guitar amps I can adjust the gain of the preamp and power amps separately and the two interact (and the timbre and tonal balance changes also).

 

[LTig]

I have a question about how volume knobs behave. I find that some volume pots are tapered so that the music gets a lot louder with a very small change near the lower settings - like the difference between 7 o''clock and 9 o'clock is big, and then as you turn it up, the amp starts clipping just past about 2 o'clock.

This is wrong, and happens if an analog volume pot accidentically has linear characteristic.

 

[Frank Dernie]

As for knobs - don't care for them myself. I guess that tells you who on ASR is a couch potato (prefers remote) and who gets up to adjust volume

I detest up/down buttons and like to use a remote.
It rules out a lot of hardware because so few have a rotary volume control on the remote but it is a must have (and do have, fortunately) for me.

 

[Frank Dernie]

Back when I worked for Garrard we had in an OEM cassette deck to evaluate which Garrard were considering badging and selling alongside the record decks.
The record level control was a beautiful looking and feeling rotary which made the item feel top quality but when we stripped it whilst the knob itself was beautifully made but the feel was entirely due to a pressed steel disc on the same shaft coated in thick damping fluid and spring loaded against the chassis. The feel was entirely cosmetic, the knob actually even had a screwdriver end turning a preset pot!
Nothing about it was actually high quality apart from the bit you saw and felt.

 

[Keith_W]

If the amp with the volume knob that feels “faster” is rated at lower power, and if the amp with the knob that feels slower has more power and gets louder, does that rule out this possibility? I ask because I don’t know much about how gain structure works in a hi-fi amp. I know that in guitar amps I can adjust the gain of the preamp and power amps separately and the two interact (and the timbre and tonal balance changes also).

Amplifier gain is different to rated output. If your power amp has a gain of 21dB, it will amplify the low level signal from your preamp by 21dB. Whether it can supply this much current to drive the loudspeaker is another story.

So it is possible to have a 1000W amplifier with 21dB of gain, and a 50W amplifier with 27dB of gain. The 50W amp will "feel" more powerful than the 1000W amp because it goes louder at the same preamp setting, but it will clip earlier.