freestompboxes.org

V_____ wrote:

mmolteratx wrote:

soggybag wrote:I think c3 goes to ground.

No, I traced that part, it doesn't go to ground. It should, but it also really shouldn't matter all that much since it blocks DC. Any steady reference should behave the same. I suspect it may have been easier to route it there on the board than to ground.

EDIT: V, I meant R10 should go directly to ground, and the only the positive end of the cap should connect to R10. Haven't actually traced that part yet, but if that's how it is in the actual pedal, it really doesn't make any sense.

You're right. I realized I made a boner a minute ago. That section seems to go like this.

[ Image ]

I breadboarded this up to C7. From C7 it doesn't sound like anything special. Splatty/gated with a hint of octave. The first stage sounded okay by itself. More overdrive than fuzz, with a little octave.

The TL-018-R change is good news, I think I have one if these in the parts bin.

tube-exorcist wrote:Transformer is TL018 - and not TL012:

Grubgoat wrote: Transformer is green in the middle, one side has a big "P" on it, other side nothing. On the metal sides, one has "TL018-R", and....and after great potential peril to the pedal, (seriously he's got this thing wound tight), 1019S I think.

http://www.thegearpage.net/board/showpo ... stcount=31

Mine has a TL012 in it. It's also blue and says Mouser on the top of it, so I guess that means they vary some.

Mine was also made 10 years ago, so maybe it changed over time or it just doesn't matter too much.

Can someone explain me what is the purpose of D4 at the collector of the second transistor? I can't really think of anything except for dropping the voltage by 0,7v

Cannibal wrote:Can someone explain me what is the purpose of D4 at the collector of the second transistor? I can't really think of anything except for dropping the voltage by 0,7v

Different saturation characteristic.
It does make a difference wether you take the signal at cathode or anode of the diode.
Signal voltage will be distorted different.
It does make a difference wether the transistor will be loaded (Fuzz Face Q1)
or not (Fuzz Face Q2).

There are a lot of possibilities with diodes beside clipping to ground and TS-NFB
but these are not as intuitive as dealing just with resistors.

electrip

I have to correct my above posting and try to be more specific.

The Moonrock schematic shows that the signal is taken direct at the collector of the transistor
so we have to see the diode as part of the collector resistor.
In this case the saturation characteristic is not altered.
When reaching cutoff Ic is going to zero and R_diode rises so R_collector rises.
The voltage divider (where we take our signal) consisting of R_transistor and R_collector will behave differently.
This is for the unloaded case when you are looking for the signal voltage.

If we take the signal above the diode one could see the diode as part of the transistor
then saturation characteristic is altered cause of starving collector-voltage at high Ic.
Not only the residual voltage of the (compound)-transistor is higher but also the slope at low collector voltages in the Ic/Vc-graph. (That's when the Peak DCApro becomes really usefull for plotting measurent data)

Ok, and then you can put a diode in series with basis or emmiter.....

So is this
Love or Confusion,

electrip

Here you go folks! Courtesy of Cozybuilder, who was kind enough to lend me his unit for examination.