The factory volume question - too loud!

feilgrep

Hello! Sorry if this is already covered in other threads. I tried doing a forum search, and translate the german via google translate, but it didn't really work very well.. (transistors translate as "transexuals". Cute..:-)

I just built the factory kit, and the sounds are very cool. The problem is that the volume out of the pedal is way too loud! I have to keep the volume at minimum to match unity gain, and it's so I'm afraid what will happen to my guitar amp's speaker if I accidentally turned the pot to half-way and then engaged the pedal.

Is this normal with this kit, or did I do something wrong. My only deviance from the parts bill, is I'm using a bright blue LED I had lying around instead of the supplied. The volume pot is a 5k logarithmic.

Can this be fixed easily? A resistor somewhere?

Thanks!

PhaseShift

Hi! I haven't built the factory, but I just had a look at the schematics on http://diy.musikding.de/content/view/85/8/ and this says, the volume pot was linear and not logarithmic. I'm not sure, if this is really causing your problems, but at least it seems strange to me.

cato

Hello,

You need a lin pot: compare http://en.wikipedia.org/wiki/File:Logarithms.svg and http://en.wikipedia.org/wiki/File:Linear_functions2.PNG. With a logarithm pot, volume will raise to fast.

Gruß,

Franz.

feilgrep

Thanks, guys!

Seems the layout and the parts bill/schematics call for different pots.

But say I had a linear pot, and the curve was right, what could I do to make the whole thing (a lot) less loud when the pot is maxed? The total volume of this this is way too much for practical use. Could I change the pot value? Or place a resistor in between the volume pot and the pcb somewhere?

thanks again!
-eivind

PhaseShift

Zitat von feilgrep;293809

But say I had a linear pot, and the curve was right, what could I do to make the whole thing (a lot) less loud when the pot is maxed? The total volume of this this is way too much for practical use. Could I change the pot value? Or place a resistor in between the volume pot and the pcb somewhere?

From what I've seen on the schematic replacing R6, which is 5k1 Ohm in the original to a somewhat greater value (8k2? 10k?) should decrease the maximum volume. Maybe it could make sense to use a "smaller" pot, too, so e.g. 8k2 for R6 and a 2..2,5k potentiometer - but I'm not sure if this is really neccessary.

Greetings,
Oli

rrhoads33

You could decrease the value of R6 abit, but that would influence the way the pedal creates the distortion, so it won't sound the same. Oli's idea with the 6k8 resistor and the 2.5k pot is quite good, but i don't think you'll have a 2.5k linear pot at home...

Better: Place a resistor between C4 and R7 Instead of the direct connection between them. The ratio between the new resistor and R7 determines the max. output volume.
Example: New Resistor: 100k, R7: 220k - you'll get about 68% of output volume. (In theory, but because the human ear is not linear, you should try out different values for that. )

Another way would be this: Replace the P5 (vol. pot) with a 4k-6k resistor (from lug 1 to 3) and connect the points 7 and 8 from the shematic. Then you replace the R7 with a 100k-500k logarithmic pot and you'll have the same volume range as now, but the volume pot would have a more linear behavior to the ear.

Cheers

feilgrep

Thanks a bunch! Will definately try out the r7/c4 solution:)

feilgrep

Just thought I'd follow up on this one.

I tried all that you suggested, and I also tried several other changes. Changed the pot, changed different resistors, tried to implement a trim pot that sent most of the PCB-out to ground before hitting the 3pdt (only worked like an on/off switch, no sound or full sound). Nothing worked.

I've now given up, but I also found out that this possibly is an inherent problem with fuzzes like this. There are several complaints around the web about the Devi Ever US fuzz which is a pedal that sounds very similar to the Factory on high threshold gate levels. Maybe there's something about this kind of circuit that makes the output volume hard or unpredictable to measure for the guys designing the circuit?

I dunno, just nice to know that this may not be my own fault for a change:)

Thanks for your help!

yavadeg

Hi,

I built my factory and i would like to get the volume down.
I read the post by rrhoads33. I just don't fully understand it.
He said:

Zitat von rrhoads33;293811

Better: Place a resistor between C4 and R7 Instead of the direct connection between them.

Does this mean I either cut the lane on on the PCB and put the R over the C4 and R7 or
desolder C4 neg. side and R7 'OUT' side, put the R between them and also connect it the OUT wire?
This would put the new R in series with R7. So why not use a bigger value for R7 (like 300 k).

Or is meant that you put the R between C4 neg. and R7 'GROUND' side so the new R is parallel to R7 (which yields about 68k)
Isn't it easier to use a 68k R as R7?

I hope somebody can clarify this mod to me.

Thanks in advance.

yavadeg

SOLVED.

I put a 300 Ohm resistor over lug 1 and 3 of the volume pot.
Now i can control volume from a little quieter to a little louder than the bypassed signal.
This is a useful range for me.
Only on some settings with little fuzz the volume stays a little lower than bypassed. But that's not what i have the factory for ;D

eemmea

Hi,

I am new to the world of building pedals and this is my first post on this forum

I built a factory kit and mine is also extremely loud (unusable). I've tried as well putting a resistor on pins 1 and 3 of volume pot, but together with the volume it reduces a lot the gain.

So, as all the five pots interact with each others, I was thinking of adding a 6th pot, together with a circuit similar to the volume pedal (https://www.musikding.de/docs/musikding/volume/volume.pdf). Theoretically this would work as a master volume, not interacting with the other five, isn't it?

Sorry if this is a stupid question

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