How Do I Wire A Potentiomer?

[lazaroff]

First time building my own equipment, an ESP P06 Phono Preamp.
Never wired a dual gang potentiometer before. Can anyone explain to me how?

I'm using a cheap 100k stereo taper pot from Parts Express.

[AndrewT]

has it got two rows of three pins, 6 in total?

[cyrusnut]

Originally Posted by AndrewT

has it got two rows of three pins, 6 in total?

could you fix the potentiometer in my cyrus11, it got broken in the post. Its still attached but only just. I can send you pics if your interested. Im trying to locate a used one, but very hard to find. cheers from cyrusnut, another mad scotsman

[lazaroff]

yes it does

[AndrewT]

Hi,
each row of three are from a single channel.
The middle pin is connected to the wiper.
The two outer pins are connected to the track ends.

With the control shaft pointing towards you and the pins pointing to the floor, the left pin is the signal ground, the right pin is the input signal hot, the middle pin is the attenuated signal hot (output).

Repeat for the other row of three.

For a final check:
turn the control shaft to near exact half geometric rotation, ~135degrees clockwise from off.
Measure the resistance from wiper to left pin, from wiper to right pin.
The two resistances will not be the same, not even close. That confirms you have not got a linear track. The left ohms << the right ohms. An audio taper should be ~12dB down from maximum at half rotation. That requires the left ohms ~30&#37;of the right ohms.

The output impedance of the 100k attenuator rises to 25k @ -6dB. This requires VERY low capacitance before the buffer stage. An absolute maximum of 60pF and preferably <33pF
The DC blocking capacitor fitted between the source and the 100k pot can be much lower than usually adopted, try 1u5F or 2u2F

[lazaroff]

Okay, I definately had it hooked up wrong.

1u5f? Is that 1500uf? I am unfamiliar with this notation, can you type it a different way?

Space is an issue, when I finally put it together in the case would it be better for me to use a pot with a different resistance value, so that I don't have to stick any capacitors in there?

[mjf]

1u5f?

hello.
......1,5uf or 2,2uf.

[lazaroff]

Okay guys.

Dumb it down to intuition-lacking American teenager levels.

As far as I know, commas only separate sentences and numbers over 999.

Feel free to use the "headbash" emoticon.

[Iain McNeill]

Allow me to translate from English to American

In US we use a decimal point, period. (yes, a pun)

In EU, it was considered that periods can get lost in fax/scan etc so to make things more robust Europe used a comma hence 1,5uF is one-and-a-half uF. But even a comma can get lost after 3 photocopies so then they started using the multiplier as the decimal point hence 1u5F is also 1.5uF and 1,5uF. 22m1H is 22.1milliHenries.

Actually makes sense, although I always get shouted at when I do it here.

[lazaroff]

Makes much more sense.

Hooked up the preamp through the computer for now, sounds amazing, I'll add the pot when I eventually work out the bugs.

Thanks guys!