Potentiometers log vs linear

[Doug]

This sounds like a dumb question, but are the volume controls on audio amplifiers linear taper or log taper.

Doug

 

[jean-paul]

Volume controls are in 99.9 % of the cases logarythmic types because human ears are not too linear.

In the case of an inverted Gainclone you'll see that ( because of that particular topology ) a linear type is used. The way it is used in that schematic causes "log-like" behaviour.

 

[Doug]

Linear vs log

Thanks Jean-Paul;

Do I understand this right? A linear taper increases the volume in a linear fashion ie: 1/4 turn = 25% increase in volume, 1/2 turn = 50% increase in volume etc etc.

A log taper will increase the volume level a lot more during the first 50% of travel, then during the next 50% of travel the volume level becomes less and less ( more compressed ) or is the other way around. What am I missing??

Doug

 

[dhaen]

Log pot

The progression of signal level is very slow at the start. Rate of change increases with clockwise rotation.

 

[Doug]

Log pot

Thanks John;

Hey, I was close, just had it backwards

So, what do most amps have, log or linear? Build lots of speakers, but not amplifiers LOL

Doug

 

[jean-paul]

Volume controls are in 99.9 % of the cases logarythmic types because human ears are not too linear.

 

[Bricolo]

Volume controls are in 99.9 % of the cases logarythmic types because human ears are not too linear.

In the case of an inverted Gainclone you'll see that ( because of that particular topology ) a linear type is used. The way it is used in that schematic causes "log-like" behaviour.

shouldn't this apply to every amp that has negative feedback?

 

[Doug]

log vs linear

Thanks once again Jean-Paul

I am aware that the ear is a very non linear device ie: it dosent hear all frequencies equally well, especially at low volumes levels. The ears response flattens out as the overall volume level is increased. This is based on the equal loudness curves developed by Fletcher Munson. Attached is a link for those who are interrested.

http://hyperphysics.phy-astr.gsu.edu/hbase/sound/eqloud.html

Doug

 

[Doug]

Gainclone

In the case of an inverted Gainclone you'll see that ( because of that particular topology ) a linear type is used. The way it is used in that schematic causes "log-like" behaviour.

I'm not familiar with the " gainclone " design, although I've seen the name before, could you fill me in?

My son was in Toronto recently and has just discovered tube amps. He listens to headphones a lot and I have been thinking about getting him a kit amp for next Christmas for his first experience. It wont be the highest end amp, but wont be the lowest end either. Do any of you guys have any suggestions?

Doug

 

[jean-paul]

I'm not familiar with the " gainclone " design, although I've seen the name before, could you fill me in?

http://www.diyaudio.com/forums/sear...d=243979&sortby=lastpost&sortorder=descending

 

[fdegrove]

POTS IN FB.

Hi,

shouldn't this apply to every amp that has negative feedback?

Non, La France...

Normally the volpot is not included in the FB loop...

If you do, the settings of the pot inevitably influence the FB loop and vice versa...tricky stuff..

Cheers,

 

[Bricolo]

Re: POTS IN FB.

Hi,



Non, La France...

Normally the volpot is not included in the FB loop...

If you do, the settings of the pot inevitably influence the FB loop and vice versa...tricky stuff..

Cheers,

Fais gaffe ou j'ouvre un topic sur les blagues belges


I see what you mean, the gainclone is one of the tricky stuff you're talking about
and many other amps, in fact, every amp with nfb on it's 1st stage

 

[fdegrove]

LES PETITS BELGES...

Hi,

Salut la douce France...

I don't know much about this gainclown, normally the volpot is at the input of the circuit and not included in the overal FB loop.

En ce qui concerne les blagues, j'en ai pas peur...