Mamat wanted to see a vero layout for the “Seventheaven” Bogner Ecstacy preamp emulator, and here it is. It’s not verified as of now, but looks right. I found a discussion thread talking about this effect and incorporated some of the “fixes” discussed there. I pulled the pot tapers from another schematic I was able to find on the web, so they may or may not be correct (but that shouldn’t matter too much).
Harald. I finally got it working last night with surface mount j201s. Not as much distortion as in others videos so I will look at the mods. Also the tone stack is…well…crap. Lol so I will look into that. Thanks for all your help. I will update as things progress. Maybe this will generate some more users to build this. Oh my bias points were all over the place
Looks cool, Fred 🙂
Hi,
Built one:
http://imageshack.us/a/img20/1742/nbvt.jpg
Thanks for the layout! 🙂
Got this sucker going last night.
Here’s a demo of it.
http://www.youtube.com/watch?v=lbQDwg0u6wE
Thanks for the great work Harald!
That’s correct, Tim. The 4 trimpots control the drain voltage of the corresponding transistors. Q5 is a source follower and is always connected straight to +9v.
Adjust VR1 to give Q1 a drain voltage of about +5V, VR2 to adjust Q2 drain voltage to the same voltage, etc. Next problem would be the squealing which is indeed related to wires, shielding etc.
I found one tiny solder bridge. I now have sound, but there is squealing present sometimes (just wire routing and shielding,I guess) but I still have the issue where I can’t get q5 to bias below 9V. Vr4 seems to do barely anything, but when I put the meter on the pins I can see it sweeping thru it’s range..
So i just double checked everything.
the problem is with Q5
I can’t seem to get it to drop below 9V
VR 3 and VR 4 don’t seem to do much, but both VR3 and VR4 affect Q4
Sounds to me like the trimpot is bypassed (solder bridge or broken trimpot maybe) and Q3 drain is in effect connected straight to +9v (which isn’t going to work so well).
Harald, about 9v. Full rotation of the trim pot barely changes the value.
The first thing I checked was for solder bridges, but I will check again.
Tim, could it be that either the trimpot is bad or that there’s a solder bridge or misplacement of the jumper from Q3 to the trimpot? What voltage are you reading on Q3 drain?
I just finished putting this together and I’ve run into issues. No Sound. 🙁
I’ve adjusted trimpots 1, 2, and 4 to 4.5-5V, but when i adjust trimpot 3, i see no change in the voltage on the drain on Q3 (i think) and Q4.
Any suggestions on where to start?
I hope that this is something stupid simple to fix but that it’s just that it’s late and i’m tired and i can’t see it…
Thanks
I built this and it sounds great. I put it head to head against the Bogner Red pedal and found the EQ on this to be much more accurate to the amp, and far more usable. This pedal is also less harsh than the Bogner version, and has the low gain range as well as high. One question… in my build when wired according to this schematic the mid pot worked backwards. I switched the mid outside wires (corrected to Mid1 > Volume 1 > Ground and Bass1 > Mid3) and the mid knob worked correctly. Anyone else notice this?
http://www.youtube.com/watch?v=Cto-9MEJhI0
Here is a demo. Gain swich chainges R17 to 1M for more gain 😉
No, the 680nF is correct. It’s a bypass cap that gives a frequency specific gain increase. Larger cap equals more bass frequencies given a full boost (i.e. you can also decrease it to lift the boost frequency threshold higher).
Is that 680nf supposed to be 680pf?
This is awesome. I am hoping to build it soon. Does anyone know where I can get the schematic for this, because I am not sure where the bass pot connects and would like to see the schematic to make it easier to build.
Thanks,
Jason
Excellent. Thanks for letting us know 🙂
This thing beast!! but to much hiss. so im doing little mod: R10=2.7K, R14=4.7K. now sounds WOW… better then dr.b i think.
Thxs Harald
Hi,
once again Harald thank you for your fantastic job on the seventheaven layout and for sharing it!
That thing sounds f**king fantastic! When I finally found the best drain voltages on each trimpot I simply couldn’t stop playing this little fella. I’m delighted to build your Mesa Mark IV emulator as well, but I gotta stop … too many pedals for just two feet.
One last question concerning the goosonique version: that one has switches for feedback and channels 2 and 3. I suppose the feedback switch equals your structure switch, but what might channels 2 and 3 be? Some resistor switching for Hi and low gain?
Cheers
Chris
I just might try it, but I already have a whole bunch of project waiting so it’ll be a while. Happy to hear it’s working 🙂
i build it, the layout is working sounds great very amplike i might say. need to hv a good set of j201 very impt.
The treble pot as u increase it takes away the bass and increse the highs, i do not know whether the original works
like this or not.
Give it a try harald its worth it.
Your layout is very good as always! Keep it up man!
A friend of mine tried out the layout and he told me that it works. But he couldn’t do a proper A/B because he doesn’t have the original pedal. He only compared it to the videos over on youtube and he said that it’s close enough. The only downside is that for the treble, it’s behaving weirdly for him. If I’m not wrong, he told me that as he turn up the treble, the output sound became “empty”(?)..something like that? Hehe I’ve really gotta go ask him again. hmm.. Anyway! Thanks again, Harald, for your help in making up the vero. I really appreciate it. I look forward to more vero layouts coming from you. Have a good day! Take care!
You can bias it by ear too. An audio probe on the Drain of each jfet will allow you to tune each separately. Alternatively you can use a multimeter and adjust the Drain voltage on each jfet to approx. 4.5-5v which should get you in the right area, and then fine-tune by ear from there. I think… 🙂
thats a lot of Jfets. does this have to be biased with a scope?
Happy to help. Hope your build turns out nice! I’m pondering whether I should give it a try myself.
Wow! Thanks, Harald! That was fast! He he. I’ll try it and see if it works. Will report back soon.