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i built a SHO...

Started by aziltz, February 18, 2009, 03:03:12 PM

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aziltz

And it crackles like its supposed to, but it doesn't go to zero volume, and the volume/noise seems to jump when i get close to the max value.  is something wrong?

edit: not a jump from the taper, but a drop out and pop into the highest gain.

zyxwyvu

Quote from: aziltz on February 18, 2009, 03:03:12 PM
And it crackles like its supposed to, but it doesn't go to zero volume, and the volume/noise seems to jump when i get close to the max value.  is something wrong?

That sounds normal. The gain control goes from unity to very high, and at high gains, it can get quite noisy. The jump at the end is more abrupt if you use a linear taper potentiometer. Assuming that is the case here, you can replace is with a reverse log to get a better feel.

earthtonesaudio

Quoteit crackles like its supposed to

:icon_rolleyes:

aziltz

#3
Quote from: zyxwyvu on February 18, 2009, 03:30:00 PM
Quote from: aziltz on February 18, 2009, 03:03:12 PM
And it crackles like its supposed to, but it doesn't go to zero volume, and the volume/noise seems to jump when i get close to the max value.  is something wrong?

That sounds normal. The gain control goes from unity to very high, and at high gains, it can get quite noisy. The jump at the end is more abrupt if you use a linear taper potentiometer. Assuming that is the case here, you can replace is with a reverse log to get a better feel.

to clarify, just before the pot turns to zero resistance (highest gain)  there is a dropout of signal and crackle, and then it fades back in.  is something wrong with the pot?


i want a smooth crackle! and no sound drop out.

earthtonesaudio

Well if you like the crackle this won't help you, but if you want the same sound minus the crackle...
http://solgrind.wordpress.com/2009/01/08/crackle-not-okay/

aziltz

could it be the point where the middle leg runs out of resistance and connects to the bottom leg?  why is it so abrubt?  are there ways around this?

reverbie

It's something with a transistor recalibrating (and subsequently turning off the sound momentarily) while you are changing the transistor's bias (which is what the gain knob is controlling)...it would be more pronounced if you turn the knob faster.

this is part of the design that is quite questionable if you ask me....imagine that type of issue in a home theater setup or any other high end audio field  :icon_confused:

that sounds normal for the SHO.
My tender heart bleeds for you, idiot.

aziltz

Quote from: reverbie on February 18, 2009, 05:25:48 PM
It's something with a transistor recalibrating (and subsequently turning off the sound momentarily) while you are changing the transistor's bias (which is what the gain knob is controlling)...it would be more pronounced if you turn the knob faster.

this is part of the design that is quite questionable if you ask me....imagine that type of issue in a home theater setup or any other high end audio field  :icon_confused:

that sounds normal for the SHO.

see that makes sense, but it doesn't seem like zvex's version does that.

reverbie

#8
The taper of his gain pot is probably different like mentioned before...the jump at the end of yours is altering a disproportionate amount of resistance as compared to the whole pot's range (and as compared to zvex type of pot), therefore throwing off that tranny as if you were "turning the pot really fast" right at the end of it's range. Try turning it very slowly and see if the dropout still occurs.

I read that article link by the way. That guy seems pretty on point with his design, so you might want to build his instead!
My tender heart bleeds for you, idiot.