freestompboxes.org

Somebody borrowed one to me and I drew the schematic.



If somebody could please explain the function of the network of R5, R6, R7, C6 and C7?
I couldn't identify the diodes yet, but I guess these are silicium.

Also the Rustride has got two inputs (active/passive) and two outputs. I'll draw the concerning circuits later.
The input for the power supply has got some special parts, too. It's a zener diode and some resistors.

The schematic is very similar to the RustDriver; maybe someone could explain how the differences make this pedal suitable for bass guitar.

Isn't it possible to exchange R4 with a 500k-pot to make the drive adjustable?

Thanks for posting!!

You should be able to replace R4 with a pot, but put a 3K-ish resistor in series with the pot.

If it's bass specific then the main differences would be the sizes of the capacitors, and maybe some values for high/low pass filters IIRC.

Here are some gutshots. I'm especially interested if some could identify these small diodes marked with a yellow ring.

BTW:

The "Direct Out" is simply a connection from input to output, which is always activated and without any buffer.


The "Active In" is mainly a voltage divider consisting of two resistors: One 1M and the other one 330M; this is what the colour-code shows, but I can't believe that, so I will measure it later.

The offboard-switching can be made in the standard way. In this case the series resistance (1,2k) of the LED is mounted onboard and has got a voltage protection using a diode (I don't know if it is a Zener; can only read a "B" and a "5" written on it.)

Also there's a protection diode from V+ to Ground (the black one).

scaai wrote:Here are some gutshots. I'm especially interested if some could identify these small diodes marked with a yellow ring.

I think they are 1N4148.

1SS119 probably as they are very common in japan. sub is the 1N4148.

Just degooped the opamp - it's TL072CN!

The resistor at the "Active In" is a 330 and not a 330M - I'm a bit colour-blind.

Updated:

here is the schematic that i've been working on for my rust ride. there are a few differences in my schematic and the one above but it is accurate for my pedal. i will add the input wiring for the active/passive jacks when i get time to open it back up. i will also post the serial number for my pedal for reference and try to add some pics as well.

jbrew73 wrote:here is the schematic that i've been working on for my rust ride. there are a few differences in my schematic and the one above but it is accurate for my pedal. i will add the input wiring for the active/passive jacks when i get time to open it back up. i will also post the serial number for my pedal for reference and try to add some pics as well.

Hi jbrew73, thanks for your schematic. I think there are no differences except the network of resistors and caps at pin 3 of the IC. Your drawing makes a lot more sense to me! Maybe I lost sight of one pcb-route.

Can you please tell me which software you use for your schems? Looks very nice.

BTW:
Does it really have an effect to the sound, that HAO uses carbon resistors and "cheap" tinfoil caps?

Playing through the HAO Rust Ride gives me some loss of low frequencies.
So I connected the "Effect Out" and the "Direct Out" each to one input of my
mixing console and got them back.

I thought I could do this mixing inside the box and added some parts to the
original circuit. I just took some "modules" not really knowing if this could be
right.

So, please have a look at this schematic and correct me if necessary:

Updated the modded schematic - don't know if it's better now. Need your help, please...

I would use a 50K volume pot and get rid of the 47K( R9)

C9 and C8 are for a low pass filter than works with R8 and the volume pot and R9

More bass needed? increase C1 and/or C3 and/or C5.
It looks like C3 cap might be the one to change first. about a 1.6KHz high pass with the 1K. Try a .22uf and maybe a .33uf adjust the value to taste

i just used a similar schematic that i found online and edited it with "paint".

for the low end problem

C2 acts with the 39k input resistor and forms a high pass filter. you could change C2 from .056 (72hz) to .100 (40hz) or .22 (18hz).

i will probably change the 39k to 100k to lower the gain a bit on mine. this will also change the high pass filter to about a 28hz roll off using the stock .056n cap.

i may also play with the caps on the voicing switch. normal and bright are ok but dark is too muddy.

jbrew. The calculations done in your post are for a 0 ohm voltage source feeding the input of the circuit, a guitar is not a 0 ohms. Inverting opamp circuits like the input of this can have some interaction with the source feeding it. If you look at books it is often drawn with and input resistor R1 and a feedback resistor R2 and the equation the gain = R2/R1 inverting, In this case R1 is the 39K and the source Z of the guitar.

to be honest gus i dont really know the 100% correct way of doing the calculations. i have read that you need to add the source z and input resistor in parallel and read that the source z has no bearing on the equation at all. the internet is a great resource but there is a lot off conflicting info floating around.

do you know of any good sites that i could read more on the subject?

Just finished building my Rustride clone and I thought I'd share it with you. Send me a PM with your email address if you want my eagle files and let me know of any corrections / errors if you spot them!

The PCB is 300dpi. Please note that I dropped the protection diode and implemented a 500k gain pot and 3.3k resistor for R4 in the layout. I guessed from the description by scaai of the active input set-up that the 1M resistor is the pulldown resistor and the 330 Ohm just sits in between the active input and the normal input of the circuit. As I set my pedal up with a 3PDT (for true bypass) I didn't do anything with the active input on the board (IN2) as I came to realise that it can't be switched and would have to be implemented before the switch. For my build I also increased the coupling caps from 56n, 100n and 100n to 100n, 220n and 220n (to let through more bass).

Thanks to scaai and jbrew73 for the schematics!!!

great work