master volume question

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Kagliostro
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Location: Italy

Re: master volume question

Post by Kagliostro »

I think the first thing to be try is a LINEAR pot with a resistor connected in parallel with one side and the wiper

this way you can obtain an AUDIO pot with good caracteristic, better than some audio pot you can find in the market
When we buy "audio taper" pots, we usually get something like Curve 3. For less expensive pots, manufacturers use a two or three-segment approximation to Curve 2. It's not perfect, but it usually works OK. Curve 4 is the typical resistance versus rotation curve for reverse log pots. In real life - that is, if you ever found one of these in real life - it is usually a two or three segment approximation, too.
this way is possible also to obtain a cheap AUDIO REVERSE pot, it is sufficient you connect the resistor to the wiper and to the other side of the pot

one other way is to use two cascaded pot in series, one 1MA and the other 100KL to have a fine regulation (we used that trick many years ago in radio receivers as to obtain a fine tuning), but I don't like to have 2 pots for a MV instead of one, if not strictly necessary

Kagliostro
iknowjohnny
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Re: master volume question

Post by iknowjohnny »

Well, i just stuck a linear pot in it and wow, now i'm really confused as to why anyone ever uses a audio in an amp like this. It works perfect now. I can dial it in easily. Thanks all.
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VacuumVoodoo
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Re: master volume question

Post by VacuumVoodoo »

curiosity killed Schrodingers cat..
Aleksander Niemand
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Structo
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Re: master volume question

Post by Structo »

I had to look that one up Alek :lol:
Tom

Don't let that smoke out!
brewdude
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Re: master volume question

Post by brewdude »

iknowjohnny wrote:Well, i just stuck a linear pot in it and wow, now i'm really confused as to why anyone ever uses a audio in an amp like this. It works perfect now. I can dial it in easily. Thanks all.
I was curious if there is a resistor across the PPIMV pot wiper to ground (grid leak resistor?) as I have seen in many examples. Wouldn't such a resistor cause the linear pot to act with a logarithmic taper? If so, wouldn't a logarithmic taper pot overcompensate for the taper?
ampdoc1
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Re: master volume question

Post by ampdoc1 »

Just wondering how you implemented your Pre PI master? In 2004 I decided to try the circuit shown on the attached schematic. I thought I had discovered something new, but later found out it had been discussed previously in one of the "amp" books.

Works well, and the audio taper pot reacted very smoothly/quietly.

a'doc
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Reeltarded
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Re: master volume question

Post by Reeltarded »

VacuumVoodoo wrote:curiosity killed Schrodingers cat..
You didn't have to look.
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