Schaller - Fuzz (Germanium)

Schoppo · Post by **Schoppo** » 23 Feb 2019, 21:59

Hello Happy Fuzz Folks.
here some research update on the Schaller Fuzz:

After building one and testing the annoying sound of that didn´t remind me anything on that sound i remembered.
So something must be wrong. After switching on my head a little bit (sometimes it works

and some more research, this is what i found out:
1. there are two versions differ significant from the other one we now with the 1k 470R on Q2 Collector, but this doesn`t even bias Q2 in the neighbourhood of
a useful sound. there must be a whole Generation gone wrong, by swapping the "Intensität" Pot. Checked it by putting in some 100 Ohm and...
the sound was there: this "Fuck the whole Tonebenders, Fuzz Faces, and whatever you ever liked on a Fuzz" this thing Fucks them all ( mmmmhhh

a matter of taste, but you got to hear it-this sound i loved it till first time i heard

just wonderful.
but:
2. there is another but very rare Version, that has the same 8k/470R Voltage divider on Q2 as a fuzz face, but with the 15K on Q1 Collector (never seen one)

So Folks as result
"Intensität" Pot is 100R not 1K

Byby

Schoppo · Post by **Schoppo** » 23 Feb 2019, 22:02

oh and:
there are some versions that have 50K Volume Pot, but this just doesn`t make any difference (so 500k instead of 100k will)

BQmusic · Post by **BQmusic** » 17 Aug 2019, 09:10

Mine looks like this. AC151, 470R / 100R at the collector of Q2, 15k at the collector of Q1.
Lowering the 15k improves the sound dramatically so I added a bias trimpot parallel to that resistor.

Manfred · Post by **Manfred** » 17 Aug 2019, 16:54

BQmusic wrote:Mine looks like this. AC151, 470R / 100R at the collector of Q2, 15k at the collector of Q1.
Lowering the 15k improves the sound dramatically so I added a bias trimpot parallel to that resistor.

What is the value of the trimpot?

mictester · Post by **mictester** » 29 Dec 2019, 04:23

Use a 10k fixed resistor in series with a 25k preset trimmer wired as a variable resistor. Start with the trimmer shorted out, so the resistance is 10k. Increase the trimmer resistance slowly while playing through the thing. You'll soon find the "sweet spot"!

One build I did recently for a friend of this kind of circuit had a 22k fixed resistor and two switchable trimmers (each 25k) to select between two quite differently sounding "sweet spots".

Schoppo · Post by **Schoppo** » 15 Oct 2020, 06:08

Hello,
I'm sorry about taking n old thread out, but the germ schaller fuzz schematic is slightly wrong: the 100R on Q2 Collector has to be 1K.
Best regards,
Markus

Manfred · Post by **Manfred** » 15 Oct 2020, 20:22

The circuit boards of Schaller fuzz pedals are equipped with different resistors, depending on the types of transistors used.
Here at the shots of the AC192 version from 1960 the resistors are 4K7, 100R, 100k and 10k.
The third ring of the second resistor from the left could also be red and the value therefore 1k.
Does anyone have the original pedal and could check which resistor value is correct?

: Schaller1960_AC192FuzzPCB_Shot2.jpg (45.05 KiB) Viewed 3580 times

Schoppo · Post by **Schoppo** » 18 Oct 2020, 08:39

Hello Manfred,
just read your post. Have all three
Ge Versions at home, but i'm in hospital at this time. Expect, i will be out in about two weeks latest.
I'll write you back when i get out.
P.s : the Germans where very consistant on values, but not neccessarely on manufacturers.

Schoppo · Post by **Schoppo** » 18 Oct 2020, 08:43

Btw: Siemens and Phillips, the main available ones, were not the badest

Schoppo · Post by **Schoppo** » 18 Oct 2020, 10:02

Manfred, you're wrong with the Resistors:
The 4k7 you read, is truely 470R, it is yellow, Purple for 4 and 7,the third colour is the count of zeros, in this case - 1- (brown for one) and the third colour is for tolerence, its the E12 scheme.
The hundred R is 100k, its brown for - 1-, black for - 0-, and yellow for 4 times a zero...

Schoppo · Post by **Schoppo** » 18 Oct 2020, 10:04

Oh, i did a mistake too, go and get my medicine

But the schematic values are right.

Manfred · Post by **Manfred** » 18 Oct 2020, 15:13

Schoppo wrote: ↑18 Oct 2020, 10:02 Manfred, you're wrong with the Resistors:
The 4k7 you read, is truely 470R, it is yellow, Purple for 4 and 7,the third colour is the count of zeros, in this case - 1- (brown for one) and the third colour is for tolerence, its the E12 scheme.
The hundred R is 100k, its brown for - 1-, black for - 0-, and yellow for 4 times a zero...

You are right, I meant 470R but wrote 4k7 by mistake.
I meant the 100R or 1K resistor under the transistor leads, and the 100K resistor to the right of the first transistor.

Schoppo · Post by **Schoppo** » 18 Oct 2020, 15:47

Yes, it's a 100k and 1k.
I found some "research" Fotos on my Phone with the Ac192, if you want, i can put them in, but give me some time, will do it before i asleep

Schoppo · Post by **Schoppo** » 27 Oct 2020, 13:01

@Manfred
Hier Bilder aus meinem Eigenen, mit Ac192, da ich dich ohnehin vergessen hab und jetzt wieder zuhause bin.

Manfred · Post by **Manfred** » 27 Oct 2020, 16:54

@Schoppo
Danke, Super!

Manfred · Post by **Manfred** » 27 Oct 2020, 21:40

Hi Schoppo
As I can see from the photo the value of C1 is 5uF.
I took this value and the value of R1 with the value of 15 kOhm into the schematic.
Can you tell me the not visible values of the other electrolytes and the values and type of the potentiometers.

Schoppo · Post by **Schoppo** » 29 Oct 2020, 09:28

yes of course:
Output is 10uF and on Fuzzpot and Voltage Filtering is 22uF

Schoppo · Post by **Schoppo** » 29 Oct 2020, 09:50

Btw.The schematic above has some error: the "Intensität" (Love that label

) Cap goes from Emitter Q2 to wiper of pot.
I got two of mine re-biased, on a way, i didn`t have to change something on the pcb. Therefor You just have to desolder the wire whitch leads from pcb toFuzz pot, now i solder in a Trimmer from Ground of pot to that desoldered Wire-than, adjust sound by ear. Than i swap trimmer with fixed resistor next by read value.
Maybe i can make some sound recordings today ...

Schoppo · Post by **Schoppo** » 29 Oct 2020, 10:48

So, did n small doodling recording with my Neighbours Digi recorder, to get n impression of n rebiased Schaller Fuzz.

Guitar is a Cort Strat with Lace Sensors Gold, Amp is a Fender Concert II which i normally only use for loud Clean Sounds, but my Main Amp needs repair, but i think you got n idea of it.First part is Clean (real clean

on Neck Pickup. in part 2, With Fuzz on, ITried some rythm stuff first and some small soloing followed by n part changing the picking Attack (Fuzz allways full on, no Guitar pot turning)

Manfred · Post by **Manfred** » 29 Oct 2020, 11:13

Sounds good!

What value of the trim pot do you recommend for the bias setting?

Schaller - Fuzz (Germanium) [schematic]