Bazz Me Fuss You has no octave effect

Forum dedicated to helping people debug and troubleshoot non-functional pedals or builds. Please use an clear and informative title, indicating circuit and basic problem. Don't forget to mark the issue as fixed if this is the case.
Post Reply
User avatar
mr.mdh001
Information
Posts: 12
Joined: 10 Dec 2023, 21:31
Has thanked: 2 times
Been thanked: 1 time

Post by mr.mdh001 »

I came across the layout from viewtopic.php?t=32194 and thought I would try it out after reading the entire post. I successfully got the fuzz effect going, but I get no octave effect at all.

Here are the measurements I have taken so far:
Q1 - MPSA13
C: 3.36v
B: 1.15v
E: 0

Q2 - 2N5088
C: 8mv
B: 0.44v
E: 7.99v

Q3 - 2N3906
C: 8v
B: 7.43v
E: 0

These are water clear blue LEDs
D1: 3.36v (this is the only one that lights up when I play thru the circuit)
D2: 7.99 (I forget if this is v or mv)
D3: 0.44v

I put a 1N4148 as D4.

Here is my work on the board:
populated board.jpg
underside.jpg

I got the wiring correct:
Red = +9v
Green = Vol 3
Pink = Octave 2
White = Input
Green = Octave 3
Black = Ground to Vol 1

Volume is B100K
Octave is B1M (did try a B1K, but that made no difference)

I don't know much about reading schematics, but I am good at following instructions. I just don't know if I went wrong somewhere, or not. Please advise.

User avatar
lykwydchykyn
Breadboard Brother
Information
Posts: 74
Joined: 25 May 2021, 21:16
Has thanked: 19 times
Been thanked: 79 times

Post by lykwydchykyn »

As with any octave fuzz, you'll get the cleanest octave sound by rolling back the tone knob, using the neck pickup, and playing around the 12th fret. If you're doing that and don't hear an upper octave coming out, then something is wrong.

Your build looks good from what I can see, so not sure. I've built a fair few of these, though I altered the placement of the octave pot a bit.

All I can think is that the 5088 has a higher Hfe in general than a 2n3906. You might get a better effect with a 2n3904 instead of the 5088? I haven't tried unbalancing the pair, so I don't know for sure.

User avatar
Dr Tony Balls
Diode Debunker
Information
Posts: 844
Joined: 07 May 2009, 14:29
my favorite amplifier: Sunn Model T
Location: Brooklyn, NY
Has thanked: 4 times
Been thanked: 172 times

Post by Dr Tony Balls »

Have you tried asking JHS? Pretty sure he's the inventor of this circuit.

User avatar
mr.mdh001
Information
Posts: 12
Joined: 10 Dec 2023, 21:31
Has thanked: 2 times
Been thanked: 1 time

Post by mr.mdh001 »

Thank you!!!! The 2N3904 made the octave come to life. The octave works wonderfully on all strings and on all pickup settings. This has been solved, dude!

User avatar
mr.mdh001
Information
Posts: 12
Joined: 10 Dec 2023, 21:31
Has thanked: 2 times
Been thanked: 1 time

Post by mr.mdh001 »

I'm really enjoying the circuit, but I can't tell if the Octave knob has any affect on the octave sound at all. I am using a B1M, and have tried a B500k, but I can't really tell if there is any affect to the octave sound; it always sounds at full octave. It's a wonderful octave sound, don't get me wrong, but I was just wondering if anyone else has built this and has been able to hear a difference with using the Octave pot. Also, what would removing the Octave pot from the circuit entirely produce (I'm not up to finding that out on my own yet)?

User avatar
lykwydchykyn
Breadboard Brother
Information
Posts: 74
Joined: 25 May 2021, 21:16
Has thanked: 19 times
Been thanked: 79 times

Post by lykwydchykyn »

If you remove the octave pot and leave it unconnected, you'll have no octave. If you connect directly, you'll have full octave. You could do a switch here and see if that's doing it for you.

Here's the idea: the NPN/PNP pair cancel out the fundamental, thereby generating the upper octave. By "unbalancing" the transistors in some way, you reduce the octave generation (which is why you weren't getting octave with a high-hFe transistor). The idea of the octave pot was to do this unbalancing by reducing the signal going to the base of the PNP.

If you follow the original thread, DrewSpriggs discovered that a 1K pot at the PNP emitter works better, and I tend to agree. This is also what the Lizard Queen does, so we can give JHS full props for that one (though Drew did this change by mistake).

I've built the circuit the way you did maybe 3 times or so, and I feel like I had different experiences with the octave pot each time. I may have even tried tying the extra leg of the pot to ground with a cap once, just for kicks. It was different, but not terribly satisfying.

Definitely a circuit that could stand more experimentation.

User avatar
mr.mdh001
Information
Posts: 12
Joined: 10 Dec 2023, 21:31
Has thanked: 2 times
Been thanked: 1 time

Post by mr.mdh001 »

Thank you for that knowledge, it is helping me along my way to better understanding building these circuits. I did follow the OG thread and I even tried the B1K, but I heard no difference.

Now, for the switch; would that be just a SPST? Just something to engage/disengage the octave? That's sounds like that would be cool to try. I really like that idea, and that would make it a little more versatile for me, so I think I will try it.

Thank you again for explaining this to me, I really appreciate it. I have just started doing the perfboard/veroboard circuits (I prefer vero) after building 50+ PCB builds, and I wanted to up my gain and learn something new.

User avatar
lykwydchykyn
Breadboard Brother
Information
Posts: 74
Joined: 25 May 2021, 21:16
Has thanked: 19 times
Been thanked: 79 times

Post by lykwydchykyn »

Yes, just an SPST in place of the pot. Did you try the 1K in the position shown or just swap in where the 1M was? It goes in a different place.

I'm not clear why you aren't hearing a difference. Here is a demo of my last build of this, using a PCB. It uses the octave pot in the PNP emitter position, like the last schematic in the thread. I may have used a 10k with a 10k across it to make it a 5k with a slightly log curve. But you should hear difference with a 1k if you've correctly implemented the schematic.

User avatar
mr.mdh001
Information
Posts: 12
Joined: 10 Dec 2023, 21:31
Has thanked: 2 times
Been thanked: 1 time

Post by mr.mdh001 »

I just swapped the 1K in place of the 1M. I followed the layout in the thread for the wiring. The pink wire in my pic goes to the 1M to pin2, and the green to pin 3.

I'm not that good at following a schematic, but I just looked at it, and the layout, and I can't seem to see what the "different place" would be. Please clarify what the "different place" would be, since for some reason I am not seeing it.

Thank you again for taking the time to teach me this stuff, it is much appreciated, and it is helping me to decide more towards committing to trying breadboarding to learn more.

User avatar
lykwydchykyn
Breadboard Brother
Information
Posts: 74
Joined: 25 May 2021, 21:16
Has thanked: 19 times
Been thanked: 79 times

Post by lykwydchykyn »

I think it would take a bit too much mucking about with the layout to make the 1k work. It goes between the 22k resistor and the collector of Q3, but the 22k and the 100nF cap going to the output still need to connect to Q2. So you'd have to reshuffle a lot of components to make it work.

Ok, going over this layout again I see that I've made a mistake on it. Try swapping Q3 and Q2 and see if that changes anything. I'm going to fix the layout and replace the one above, but in the meantime that might work for you.

EDIT: Actually, I think you just need to flip Q3 and Q2 around, like so:
EDIT2: NM, that's wrong, diodes also need to move. I'll work on it some more and post a fixed layout.

User avatar
lykwydchykyn
Breadboard Brother
Information
Posts: 74
Joined: 25 May 2021, 21:16
Has thanked: 19 times
Been thanked: 79 times

Post by lykwydchykyn »

Try the first layout shown here: viewtopic.php?p=298803#p298803

All you should need to do is move D2 and D3, then flip Q3 and Q2 over.

User avatar
mr.mdh001
Information
Posts: 12
Joined: 10 Dec 2023, 21:31
Has thanked: 2 times
Been thanked: 1 time

Post by mr.mdh001 »

YES!!!! It works wonderfully! I did the first layout and find the B1M gives a lot of useable range to play with. Thank you, again!!! I do truly appreciate it.

Post Reply