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Topics - garfo

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General Questions / Colorsound Wah wah 1979 help
« on: March 20, 2019, 11:35:40 AM »
Hi guys.
Got this wah wah pedal dated from 1979 that it's not working.
It uses two bc184C transistors, for reference, even though I have noticed that on similar circuits (fuzz wah pedal) found on the web, the second transistor is a bc167B.
The pedal has bypass working, when the effect is engaged there is some signal going through but at a very low volume and the pot is doing something but barely and very focused on the lower frequencies.
I have tested the switch and it's fine; wired an external pot to see if the pot was the problem, it is not. Checked if there was voltage going to the circuit from both battery and power supply. Replaced the caps and transistors to no effect.
Also inverted the second gain transistor to match the pinout of a bc167 but the result was exactly the same.

I am wondering if this could be an inductor problem? I don't have a lot of experience with Wah wahs, so, I don't know how to evaluate the inductor.

Hopefully someone could help with this one.

General Questions / Help identifying a component
« on: November 29, 2018, 04:23:13 PM »
Hi guys. I have this circuit where the clipping section should have a pair of germanium diodes but instead it has a Red led and a yellow "diode"? I'm trying to identify what this diode is but with no luck.

General Questions / Sea Urchin Pt2399 winning noise problem
« on: September 30, 2018, 04:03:59 AM »
I have built a couple of Deep Blue Delays and with the last one I have a weird working one. Everything works fine except that there is a winning (almost theremin like) hi-pitched noise always present on the Delay side. It becomes even more obvious once I start Rotating the Delay Pot as the noise moves with it.
The only significant changes I have made to the circuit was changing the input Gain and impedance from r2-180k / r3-390k configuration to 470k/ 470k respectively and used Tantalum capacitors for all 1uf caps on the Audio path.
I anyone could give me an hint on what to look for it would be appreciated.

Voltage on Pt2399

1- 4.93v   
2- 2.45v     
4- 0v       
5- oscillates beetween 2.87 and 2.91v
6- 2.45v   
7- 1.92v     
8- 1.98
9- 1.5v     
12- 1.42v

General Questions / Most Pt2399 delay designs boost signal?
« on: September 09, 2018, 03:15:41 AM »
Hi guys, I have been away from the forum and I'm sure this debate has been covered before.
Anyway, after twicking with a Delay that I have built before, a Sea Urchin, I have noticed that with some pedals the Delay acts as a boost but with others it remains at unity gain. I was explained that this was due to the amplification being made on the inverted side of the opamp. I have also noticed that the pedals that make the Delay pedal boost are the ones that have a pot (Master Volume) on the output stage.
My question is:
If I want to leave the design as it is, would adding a simple jfet buffer at the input of the circuit control this boosting problem?

General Questions / Guyatone Rolli Phaser
« on: April 11, 2018, 06:24:47 PM »
I haven't been to the forum for a while now.
Not sure if this is the best place to post, but I'll give it a try.

I need your help, bought this Guyatone Phaser second hand and it doesn't have the knobs. I would like to get these exact knobs but I have never seen anything like it. If anyone knows anything about these and where to get them it would be amazing.

General Questions / memory boy chorus oscillation problem
« on: November 17, 2017, 08:23:02 AM »
I've got a second hand Memory boy that works fine except when the Depth pot bleeds in some of the modulation. Specially on Echo mode, because I've done the Madbeanpedals Zero Point SDX, I know that the chorus effect should be more subtle. The Rate of the Chorus on the Memory boy is very slow and incredibly wobbly. Any idea where I should be looking at? Tried messing with the little trims but no result came out of it so I settled them back to the original positions.
It's such a shame cause it sounds pretty good.
Anyone has any idea which IC controls the modulation? I believe it might have gone bunkers.

Open Discussion / EHX Memory boy. Is it me or is it a very crazy delay?
« on: November 17, 2017, 06:05:27 AM »
I got this EHX Memory Boy. The guy who sold me thought there was some problem with it, me, on the other hand can't tell cause I have never had one.
Truth is, with the Depth Knob turned all the way down, the delay sounds pretty good to me. Once who introduce the Depth, specially on Chorus Mode it goes really crazy, and it's not subtle, it's a lot.
Is it supposed to be like this?

General Questions / Boss OC-2 octave Down 1 not working
« on: November 07, 2017, 07:40:08 AM »
I got a Boss OC-2 that was in a very bad shape full of rust and solders gone pretty bad.
Anyway, I plugged in the pedal before anything else and it works. Octave two and direct signal work, is just octave one that is not working.
I've gone through the pots and the bad solders and nothing changed. Gone through the IC's resoldering and nothing. There is still no First Octave Down on this damn circuit.
Anyone with any in-depth to where I should be looking at to find the problem?

Taking IC4 out stopped Octave Down 2 from working which I assume they are sharing the same opamp.
I'm very lost and since I don't have a sound probe I can't really follow the path and find the faulty component.

Hope someone could help.
I took out BA634 and the pedal still works exactly in the same manner.
Could it be that this is the faulty IC since Direct output and Octave 2 still work and Octave 1 doesn't!?

I took the readings for all the IC's:

IC1: TL022
1- 9.56
2- 9.56
3- 9.19
4- 9.63
5- 9.20
6- 9.20
7- 9.20
8- 9.63

IC-2 TL022
1- 9.04
2- 9.19
3- 9.20
4- 9.63
5- 9.21
6- 9.19
7- 8.91
8- 9.63

IC3 TL022
1- 9.04
2- 9.21
3- 9.20
4- 9.63
5- 9.21
6- 9.20
7- 8.92
8- 9.63

IC4 TL022
1- 9.56
2- 9.56
3- 9.21
4- 9.63
5- 9.20
6- 9.18
7- 9.18
8- 9.63

IC5 TL022
1- 9.53
2- 9.56
3- 9.63
4- 9.62
5- 9.62
6- 9.56
7- 9.53
8- 9.63

IC6 BA634
1- 9.16
2- 9.17
3- 9.62
4- 9.63
5- 9.63

IC7 MN4013B
1- 9.11
2- 9.15
3- 9.11
4- 9.62
5- 9.15
6- 9.62
7- 9.62
8- 9.05
9- 9.62
10- 9.05
11- 9.62
12- 9.11
13- 9.12
14- 9.62

General Questions / 18V through protection diode
« on: October 25, 2017, 08:46:07 AM »
I am considering buying a EVH MXR Phase 90. The owner has run 18 volts through the pedal and it stopped working. Before I buy the pedal, I wanted to know if the protection diode that, as far as I know, is there to protect against wrong polarity, would let the 18 volts go through and burn the other components making the fix harder!?
Or is the protection diode also voltage sensitive?

General Questions / Mudbunny little simple mod help
« on: October 21, 2017, 03:27:36 AM »
Hey guys. After I have built a mixed version of the mudbunny box, I wanted to know how could I filter some of the higher frequencies off the effect?
I wad thinking of just adding a capacitor to ground after or before the volume pot.
I play bass with it and run the tone at 1 o'clock to get a bit more of the trebly sound. The problem is the hiss part of it, somewhere around 10k that needs to go specially when I'm playing through a DI box.
Guys, any idea of where to put it and what an approximate cap value I could use?

Open Discussion / Fuzz that is active friendly???
« on: February 06, 2017, 01:27:09 PM »
Ei guys, I'm getting quite frustrated here.
I've built two pedals already, a Big Muff and a Tonebender MKiii, and I love the sound of both on my bass.

My bass is Active ( ACguitars Filter preamp) and has a lot of output. Both pedals fart if they see the full signal of my bass, and need to roll back the volume to get effected and clean signal at similar volumes.

I have both now sitting and feel really frustrated, specially cause I love the Tone of the tonebender...  :'(

Any fuzz pedals out there that won't suffer from this???

General Questions / Two circuits same box in parallel
« on: November 04, 2016, 01:51:07 PM »
I'm in the need of reducing the size of m pedal-board, and therefore I'll be changing some things. One of them will be stacking some circuits in the same enclosure as I use them simultaneously anyway.

I have a Boss CE-2 clone and a Sea Urchin Delay that I was thinking of running them in Parallel instead of series. I remember once I encountered a problem when wiring two circuits in parallel ( Two identical State Variable Filters) and I fixed it placing a small resistor of the same value on the output of each one.

What are the odds this would happen again?

General Questions / Nautilus Low pass only
« on: November 03, 2016, 04:34:28 AM »
Guys, I've been using the Neutron for quite some time and I'm moving the pedal to a smaller enclosure. As I want to save space and only use the Low Pass section. How do I wire it without the switch?

I was checking the project and there's S1, S2 and S3. I understand I should bypass one of these to SA. But witch one is witch?


General Questions / Big Muff too much source volume not matched
« on: October 17, 2016, 09:17:27 AM »
So, I've go this Colorsound Jumbo tonebender that has a huge volume drop if I plug my active bass into it. My bass has a decent amount of output (hot) signal witch makes the Jumbo stuck in terms of volume.
I have added an impedance input control pot already but that is not helping. I am also adding the last gain stage to see if it is possible to recover some of the volume. I'm under the impression this will not work though.
Any one knows how to emend this?

Thanks guys

Requests / Microtubes b3k type of distortion for bass
« on: May 21, 2015, 06:54:16 AM »
This pedal sounds amazing, but it is expensive as hell. Darkglass has now the newer version which is the Microtubes b7k, so maybe doing a version of the previous model would be a good deal for us bassists.

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