How to have BOSS like volume control

[Le québécois]

Hi, is there a way to have effect independent output volume like what we can see with BOSS pedal. In other words, when you boost the distortion of a metal zone for example, you don't end up with super high output volume or vis-vers-ça?
I ask this because I have build the Dynacomp from tonepad (stock version with the attack mod) and I really like it but when i turn the sustain lower then 12 o'clock, I have to increase the output volume to return to unity gain with my dry sound. Worst, when sustain is lower than 9 o'clock, even with max output volume the volume drop is to high to be usefull in a jam (at least without a booster). The other extreme is also true : when I max the sustain I have to turn the volume down.

Of what I understand, (very little) I need to increase the voltage at the output pot if I want to increase the volume and the only way I know is by using a op amp boost or something similar but apparently this will introduce noise.

sorry for my English. (cool I just met the spell checker! very helpful indeed)

Charles

[Thomeeque]

 Hi!

Few notes:

1. Achieving unity "loudness" over whole sensitivity range in compressor pedal is on principle much more complicated than in case of distortion pedal (plus you may need to tweak volume pot when going from very low to very high gain on distortion as well). MXR simply decided to use simplest and probably most precise method - user control. And most users don't mind Thanks to this it is a nice simple pedal with minimum of issues (reliability, noise..) and simple build for us Btw. do Boss CS-x pedals perform better from this point of view?

2. You may try to use dual pot for the sensitivity control and try to gear second half of pot for volume swing compensation somehow.. personally I would not bother, but on the other hand if you will succeed lot of people here may love one-pot compressor build.

3. There may be something wrong with your build - my Dynacomp clone provides significant volume boost even at the lowest sensitivity setting when the volume pot is at max.

Good luck, T.

[auden100]

I had the same problem with my Ross comp (VERY similar circuit). I ended up having to mod it with a mosfet booster at the end. While I was at it, I also added a dry blend. Ended up being so much circuitry I've had to increase the enclosure size and re-work a lot of things, but it appears to have essentially taken care of the problem. In this case, it's not the exact solution you're looking for (there would still be volume change with compression change, but it provides enough boost to accommodate the full range compression. One drawback is the addition of a tiny bit distortion now, but I can live with that.

[Le québécois]

Thanks for your answer.

2. You may try to use dual pot for the sensitivity control and try to gear second half of pot for volume swing compensation somehow.. personally I would not bother, but on the other hand if you will succeed lot of people here may love one-pot compressor build.

3. There may be something wrong with your build - my Dynacomp clone provides significant volume boost even at the lowest sensitivity setting when the volume pot is at max.

The dual pot is a good idea although I'm afraid that the mats around it are to tricky for me. I don't ear (when I play with volume and sustain pot) that compensation is inversely proportional in a linear fashion therefore I would require different taper. In any case, I may forget the math and just test it for fun (i have dual pot in hand).

If my built is wrong? Well, it sound great when I don't care about the volume issue! 
I have read in other post that 2N3904 have lower gain (100-300) compare to the dynacomp ''official'' transistor (100-600 if my memory is good). Since your dynacomp work well, do you remember if you used 2N3904 or others higher gain transistors?  This would be my next try, changing to higher gain transistor like 2N5088. Playing with transistor gain was one solution propose by Mark Hammer elsewhere in a post that I can't find back.

My dynacomp problem is only an example but my initial question still remain to be elucidate. Many boss pedal that I have used always have a volume knob that allow high flexibility in order to control the output volume of the pedal. We normally put the volume at 12 o'clock and then the volume is lowered when we turn counter clockwise and increase on the clockwise turn. How they manage to do that? Is it obligatory to have volume gain circuit somewhere or a special trick that one of you may know can be use to achieve this goal?

thanks for your help.
This is a great forum!

Charles     

[Thomeeque]

If my built is wrong? Well, it sound great when I don't care about the volume issue!  
I have read in other post that 2N3904 have lower gain (100-300) compare to the dynacomp ''official'' transistor (100-600 if my memory is good). Since your dynacomp work well, do you remember if you used 2N3904 or others higher gain transistors?  This would be my next try, changing to higher gain transistor like 2N5088. Playing with transistor gain was one solution propose by Mark Hammer elsewhere in a post that I can't find back.

Oh yes, that's it probably Now I remeber that when I have cloned DynaComp for the first time I have used some common transistors and I liked the result as well but only until I have compared it side by side with the original store-bought MXR DynaComp borrowed from my friend - it was like sensitivity of mine ended somewhere in the middle of the original's range. So I did open friend's unit (I can say it loud, he does not go here ) and findout exact type of transistors used in there. It was MPSA18. I have bought these, replaced all old ones with them and since then it is perfect. Not so long ago I did build another clone, I have used MPSA18's from the start and it's perfect again.

My dynacomp problem is only an example but my initial question still remain to be elucidate. Many boss pedal that I have used always have a volume knob that allow high flexibility in order to control the output volume of the pedal. We normally put the volume at 12 o'clock and then the volume is lowered when we turn counter clockwise and increase on the clockwise turn. How they manage to do that? Is it obligatory to have volume gain circuit somewhere or a special trick that one of you may know can be use to achieve this goal?

Well, as I said, it depends on the type of the pedal a lot. What type of Boss pedals are you talking about? For e.g. overdrives, distortions or delays it's simple (you basically do nothing and it works this way ) and MXR overdrives, distortions or delays will probably allow the same. Do you have same experience with Boss compressor (e.g. CS-3)?

T.

[Le québécois]

Well, as I said, it depends on the type of the pedal a lot. What type of Boss pedals are you talking about? For e.g. overdrives, distortions or delays it's simple (you basically do nothing and it works this way ) and MXR overdrives, distortions or delays will probably allow the same. Do you have same experience with Boss compressor (e.g. CS-3)?

T.

Ok, I think I get it Your right, I only test distortion pedal yet. I did ask a friend who own a flanger and CS-3 and he will come back on that.
Beside, I really like your first build pictorama. If that was your first build than your new one are probably amazing! I notice that you have pink ''stuff'' for your PCB layout. I did the etching and everything with blue P'N'peel paper. What is that pink think (same thing than blue paper?). Is it a better approach? My girlfriend did'nt like that I use her iron for layout transfer!

thank again for your answers
Charles