Yerasov 7000 question

djmiyta

djmiyta

Well-known member
I'm building this . Yerasov 7000 can anyone tell me how changing (subbing) the (3) 47pf caps with 39pf or 56 pf I have also but how drastic of a change would that likely make . I may just socket them and find out myself but I thought it'd be wise to ask and as I started typing thought of the sockets.
 

Attachments

  • Yerasov 7000V Modern High Gain Distortion.png
    Yerasov 7000V Modern High Gain Distortion.png
    239.8 KB · Views: 7
djmiyta said:
I may just socket them and find out myself but I thought it'd be wise to ask and as
Click to expand...
I think you should... to see for yourself. It's worth gaining experience.
I doubt you'll hear the difference between 39 and 47p... or 56p. Taking into account the tolerance spread, it may turn out that your 39p is 42p.

Green is 39p, blue 47p, red 56p. This is for a single cap, second opamp and pot @ max. With potentiometer @ min there's no difference, plots overlap.

1762631986709.png
 
Excellent that's what I like to hear. Ended up putting sockets in before I read your response. Thanks for taking a bit of your time to share. And I was not aware of what it was based off, interestingly the Metal Zone is a pedal I have 2 of. One is stock the other I did Wampler mods to, so that's a cool coincidence . I just liked what I can heard from youtube now I know why.. Thanks again
 
temol said:
I think you should... to see for yourself. It's worth gaining experience.
I doubt you'll hear the difference between 39 and 47p... or 56p. Taking into account the tolerance spread, it may turn out that your 39p is 42p.

Green is 39p, blue 47p, red 56p. This is for a single cap, second opamp and pot @ max. With potentiometer @ min there's no difference, plots overlap.

View attachment 105911
Click to expand...
Nice with a visual one can easily see there's barely any difference between them. That's really cool .Thanks for sharing that . Is this a screen shot of a / your O-scope or something similar?
So when I realized I didn't have enough of the right value (47pf) but did have enough with a value higher than and lower than. I shamefully asked AI "Can I sub in a 56pf for a 47pf ?" AI said "NO , you cannot ........" and then on with blah blah blah. Something wasn't jiving with me and what it was telling me was that 47 to 56 is a huge jump in value because of the low value they're at and of course "depends on the use and placement in the circuit the board might not even work. All what AI said is pretty much true except the "NO you cannot" part. That brings us to the reason I asked here where you people in the know ...would know, and I trust the info here over the robots. I thought it was a fairly simple question and really didn't think there would be a problem but AI cast doubt on my instincts and I had to find out for sure. Can you possibly tell me their function in the circuit ? Since changing the value slightly won't really impact the sound I'm now curious as to what their function in the circuit actually is.
 
In this particular circuit, they tame the high end a liiiiiiittle bit, not perceptibly as temol has shown. Also, they are probably there to tame possible high end oscillation around the opamp, which is good practice in high gain applications.
Bear in mind that, in feedback loops among others, resistors and capacitors values are inversely proportional, meaning that if you wanted to keep the same frequency response at the 3rd opamp, but changing R16 to 33k instead of 3.3k, you would have to fit a 4.7pf capacitor. If, on the other hand, you were to use 330ohm instead of 3.3k, you'd fit a 470pf cap, and so on. Keeping the current value (3.3k), if you increased the capacitor, I guess you would start hearing a difference at around 1nf or more, at least with these levels of saturation.
 
You must log in or register to reply here.
Back
Top