New old schem? - Hofner Buzz Tone

[smnm]

from the DAM forum...

not a startling design - looks like an NPN Maestro Fuzztone - but an easy build with easy to find transistors. Worth a go.

[the_random_hero]

Is it just me, or would that end up being extremely bassy? The input and output caps are large, with no sort of LPF to remove some of the bass content.

[MartyMart]

IIRC I built one a year or two ago, it was VERY bassy and farty !
I reduced all those 50u and 25u caps down to 100n's or so, also the bias needed a good "fiddle"
with to get right, think I had three 20k trimmers on all the collectors across the 9v rail wired as
variable resistors.
Got it sounding OK but not breathtaking !
Lower hfe trannies may help, like 2369's (?)
MM

[smnm]

IIRC I built one a year or two ago, it was VERY bassy and farty !
I reduced all those 50u and 25u caps down to 100n's or so, also the bias needed a good "fiddle"
with to get right, think I had three 20k trimmers on all the collectors across the 9v rail wired as
variable resistors.
Got it sounding OK but not breathtaking !
Lower hfe trannies may help, like 2369's (?)
MM

doh - I thought this was going to be an easy one!
Leon on DAM (leonhendrix here) traced the circuit from one he recently bought - I've asked him how it sounds over there.

[tcobretti]

Thanks! I hadn't seen that one.

[ambulancevoice]

50UF I/O CAPS!!!!!!!!!!!!!!!!! what the hell were these guys on?

[aron]

Someone will think it's the golden tone. You know it.

[leonhendrix]

The thing is this pedal is not as bassy as the schem makes out.

I know the output cap is 50uf which is huge compared to the fuzz face with a 0.1uf output cap (which is quite bassy with that value cap.) So i'm guessing the output cap is not the only thing deciding the amount of bass it produces.

It's a good old silicon fuzz, not harsh and buzzy and way too loud.

[foxfire]

i slapped one together this morning. it's probably about what you think it is... mine was at least. it sounds ok through my little peavey. as always i'll need to here it through one of my big boys to say for sure. anyway, i guess i'd say it's a fuzz like the "Red Fuzz" is a fuzz. i did swap some things though,
1. both 50uf's became 47uf's
2. both 25uf's became 33uf's
3. i ditched the depth pot for a 100k resistor
4. i'm using 2n2222a's for Q1-Q3

in conclusion, my "underwhelmed" feelings about the pedal may be premature as i haven't heard it coming out of a righteous 70's tube monster yet and, it's gonna take one hell of a pedal to compete with the colorsound overdriver i built last week. anyway here is my perf layout for anyone who might want it. in an effort to "keep it interesting" i went for a really tight layout.   

[foxfire]

i'm guessing that i could just let this one go and no one would've minded. oh and i just realized that i spelled Hofner wrong. anyway i kept on playing around with it and, have a whole new opinion about it. first i started testing some tranny's i got in a bulk lot on ebay.
so what i ended up with is,
Q1= 2sc313 with a Hfe of 60 
Q2= Sony 2sd65 with a Hfe of 70-80 it's a GE
Q3= Sanyo 2sc933e with a Hfe of 122.
(my Hfe testing consisted of putting the transistors in to my DMM and typing the number i read in the display.)

i also put a 0.01uf and a 0.1uf cap on a 2pdt from lug 2 to lug3 to ground out some of the "torn speaker buzz." that helped a lot but, i think i'll use an on-off-on switch so i can keep  "stock" as an option. i felt like i ought to post my tinkering since i'm starting to like it more. i'd hate to leave it on a sour note.

[leonhendrix]

That's great work Rylan. 

...anyway here's pictures of the original 




Arggh sorry the pics are big photobucket is being an ass 

[drewl]

I could look it up, but you guys probably know.....about what hfe are the BC108 original transistors?
obviously lower gain ones will sound better like most of the old pedals.
Using 2222's probably won't yield any magic.

[foxfire]

i tried 2n5089's, 2n2222a's, bc547's, 2n5133's, and a whole bunch more. i didn't notice any real difference in sound until i started messing with the bunch of older Japanese tranny's. based on what i ended up with i think your right about it wanting lower Hfe values. but then again you may like it with 2n2222a's or the like? i took a lot of the buzz out of my build. just use sockets.

[ebulakowski]

Thank you DIYStomp, guitar nuts, the internet and nerds everywhere. I have been tying to fix an non-functioning Hofner 500/8 BZ bass. As it turns out circuit in the bass is the buzz tone with the addition of a bass boost and rotary selector switch. Thanks to you all there is now a nice schematic for me to trouble shoot off of. As for being 'bassy' I hope so.  But only because it is mounted in a bass. I'll let you know the end result. Thanks to everyone

[Morocotopo]

The thing looks like you could use it as a very effective weapon against aggressive audiences.

The idea of miniaturization hadn´t reached Europe by the time they built this, apparently.

[tcobretti]

Thank you DIYStomp, guitar nuts, the internet and nerds everywhere. I have been tying to fix an non-functioning Hofner 500/8 BZ bass. As it turns out circuit in the bass is the buzz tone with the addition of a bass boost and rotary selector switch. Thanks to you all there is now a nice schematic for me to trouble shoot off of. As for being 'bassy' I hope so.  But only because it is mounted in a bass. I'll let you know the end result. Thanks to everyone

It would be very cool if you posted the schem for the bass fuzz!

[gigimarga]

Any chance for some soundclips?
I am very curious about it...

[ebulakowski]

More Pics @
http://s131.photobucket.com/albums/p303/ebulakowski/Hofner%20500_8%20BZ/

The board looks almost identical to the buzz tone. I'm having a bit of trouble saying for sure because of the additional bass boost and mess of wires. I should say that to this point I have only done basic guitar wiring. I am mostly do violin restoration, but the acquisition of a older deluxe reverb and some other toys I am tying to get more into pedal, circuits, etc.

I bought the bass off of ebay know that the boost and fuzz were not functioning, and the controls had some issues. I figures at worst I would gut it and start fresh. Now I REALLY want to get it up and running as original. The challenge is the mess of wires for me. and lots of cap->ground. I'll see what else I can figure out about it.

From left to right controls are as follows. 3 way rotary(bosst. fuzz, both). boost pot, fuzz pot, tone, volume. Someone else has toyed with it for sure. Turns out the battery was just looped to itself via the stereo control jack. No wonder it didn't work. That and a few broken leads.


All caps on it are 25uF. admittedly I don't know enough to know how that effects the circuit.

The Bass
It's a Hofner 500/8 BZ. They made one with standard controls that looks much nicer, but oh well. Ibelieve it's 68'-72' somewhere in there from the looks of the pickup. 32" scale. I wanted a club bass sound and feel with a larger neck/body. Looks like I got it.

Once this guy is up and running I will post a video or some sound clips. In the mean time i'll keep checking back with this thread.