Tonefiend Forum

hello. I have an update.

I got the LED to work. then I blew it up somehow

I cleaned up the connections, checked the schematic a ton. it works but it really fizzes out on the decay and when the tone is all the way up on the treble it barely comes through with any signal at all.

even full gain cranked it's not much above unity even at low volumes

this thing is driving me nuts

wahhhhhhhhhhhhhh!

bring out the wa-mbulance!!!!!!!!!

paging Dr. Gore

To be clear, I'm talking about this circuit:

https://www.seymourduncan.com/tonefiend/wp-content/uploads/DIY%20Club%20Project%204%20v01.pdf

I am going to go out on a limb here (because I have not built this circuit, what follows is only theoretical) and strongly suggest that you increase the value of R3. As I calculated the DC operating point of that circuit, with R3 = 3.9K the transistor is in saturation. This means you don't get anything out at low signal levels. The DC operating point will set the balance of the clipping and thereby the even/odd harmonic balance. Try increasing it to 10k? Or put a 10k pot in series (with the wiper connected to one end) with the 3.9k - at one end you'll have what you have today, and once Q1 comes out of saturation at DC hopefully the gating behavior will stop and you can dial in what kind of harmonic tone you want. Maybe you'll even want to leave the pot in there.

The AC gain of the circuit is dependent on C3 being a low impedance at signal frequencies. Xc = 1/(6.283 * f * C), or for 22uF and 440 Hz, 16.4 ohms. The gain is then POT1/Xc, or about 10,000/16.4 = 608 assuming there is a high impedance load connected to the output. (Lower gain with lower impedance load). C3 is a polarized capacitor - make sure it's in the right way (+ should be connected to the battery's +).

(Cough) sorry, not trying to make things worse...

Try a larger value for R3. I'd try 4.7k, 7.5k, 10k, 15k. I think they will all sound different. Choose the one which most rocks your world.

I'm back! and I made a crappy video!

It's me trying to put the fiendmaster through it's paces so someone can tell me if it sounds reasonable or like barf. or.......reasonable barf!

Please excuse the poor cinematography, sound quality and lack of plot.

first is clean

then you look right into the blinding LED and I have both dials at noon (hardly any volume, lower than unity)

then I flip the blend over to the fatty boombatty deep end and it the volume spikes to barely above unity and sounds more like it should but still miles from my impression of Joe's video.

the other side of the blend didn't get recorded but it is tinny at best w/ low volume.

My assumption, is that at the very least my connections between the 2 ends of the tone caps is not so good.

However, maybe not? They both work, it's just the overall sound just seems weaker than expected so I'd think it has something to do with my connections either in or out? Or perhaps my germ?

Any ideas? I want this to be awesome. Thanks!