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Messages - thomasha

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1
Build Reports / Re: Build log Harbinger 2 build, pic heavy
« on: April 18, 2022, 02:26:12 AM »
Omg, just came by to praise the wiring.
The plexi lid is a must with such an organized interior

2
Build Reports / Re: MadBean Wavelord (extra-wide)
« on: March 26, 2022, 06:13:13 AM »
Nice, I also like my builds in layers.
The 3D printed part is a nice touch
Using the lid also helps to get a better view, have to try that one at least once.

3
Do you think it changes with the speed knob, and could be associated with the LFO?
Or is it more like delay feedback oscillation?

The first case would be leaking LFO. But that would be weird, since it should be there when you remove the BBD.

The second case would be a short somewhere in the wet line to the input or a specific position of the input.
What is weird, is that it should be really fast. Maybe the LFO changes that.

My next suggestion would be AC grounding some places through a cap (anything between 100n to 100 uF, one leg to the signal path, the other to ground). Start from the mixer stage and go towards the BBD. It will short the wet signal and at some point there should be no noise left.

If you are lucky, it is in the region where the signal is shorted to the input. Otherwise, you just cut to much of the signal.

4
Ok, that changes things a bit.

Distortion can be a result of wrong bias somewhere. Probably at the input of the BBD.

My suggestion would be analysing parts of the circuit:
First, remove the mix resistors (If the MN3207 is socketed removing it will break the signal chain there, and no desoldering is necessary).

Let's hear how it sounds without chorus at all (just the clean sound). If there is something wrong with an OpAmp it should be noticiable.

Second, there should be no distortion (when using the audio probe) until you get to the input of the BBD. Chorus do not have feedback, so there should be nothing returning to the begining of the signal chain.

Third would be to remove everything associated with the BBD (clock, BBD, LFO(TL062)) and see if the clean signal works now.

That should give an idea where the Problem is.

5
Well, that might be a cold solder joint at some ground in the circuit. Every time I have buzz it's either a bad cable or wiring problem.
Your wiring looks exactly like the one in the PDF, but It could present some lose or cold joints.

How are you using the audio probe? Are grounds connected? There should be no noise at R1.
Noise at R1 means noise at the input jack. Any weird noise caused by the circuit should not be present at the input, unless there is a problem with grounding.

Does it work when bypassed? Or is the noise bleeding through even when bypassed?
Can you check continuity between some ground points and some components? For example, one side of R1 should be grounded.

6
Which build doc are you using? I have the 2019 one, and voltages seem correct for the MN3007.
Voltages on IC2 depend on the type of BBD that you used, though.
Unfortunately, the image is too dark to identify your IC2. Voltages suggest a **3207. Are you using the correct clock (3102)?

Have you tried checking the signal path with an audio probe?



7
Build Reports / Re: Apparently, I'm obsessed with Brassmasters
« on: March 03, 2022, 03:52:16 PM »
That looks gorgeous!

8
Build Reports / Re: Apparently, I'm obsessed with Brassmasters
« on: February 24, 2022, 11:04:07 AM »
That looks nice, is that the primer or some sort of hammer paint?

9
General Questions / Re: Modulation Section Schematic Help
« on: February 17, 2022, 04:06:51 PM »
What about jumping r38?
Depth only goes to 90% with it in place.

The second OpAmp max. gain (above the 100n bypass) should be
-R_feedback/R_input=(220k+1M||470k)/220k=-2.45.
If you remove the 470k resistor it goes up to 5.45.

10
Nice set!

those smd parts give me nightmares, good to know they have this kind of service.

11
Build Reports / Re: PedalPCB.com Dark RIft Delay
« on: February 16, 2022, 03:26:30 PM »
Nice,
really liked the shape knob.
Now I have to check what it does.

12
Tech Help - Projects Page / Re: Current Lover Matrix Setting does not Work
« on: February 05, 2022, 03:47:48 AM »
Hi,
to understand how it works:
- VCO receives a fixed voltage and outputs a fixed frequency
- As a result the BBD outputs a fixed delay (no flanging)
- The metallic sound has to do with the very fast delay and how it combines with the original signal (basically the flanging is stuck at a position)

So, first thing you can check, if you have an audio probe, is whether there is signal at the output of the BBD. If there is no signal, there is something wrong.

You can then check if the clock pins of the BBD have any clock signal. If there is no voltage at those pins or it is too low there is something wrong with the VCO.

By checking the input of the VCO (pin 3) you can verify which voltage it receives in matrix mode. If this voltage is below a certain value the effect will not work. I played with the VCO in mine by connecting the input directly to a pot connected between ground and 9V and I could adjust the voltage at the input and get different clock frequencies. The matrix mode can sound different depending on the voltage setting.

In the original this is provided by the OpAmp, so if the voltage at the VCO is wrong it might be something with the OpAmp, which inputs are controlled by the matrix switch. So, that is why I suggest looking at the switch first. If the OpAmp is biased wrong there will be a wrong voltage at the VCO, resulting in a wrong clock frequency, and no apparent effect.

13
Tech Help - Projects Page / Re: Current Lover Matrix Setting does not Work
« on: February 04, 2022, 01:10:00 PM »
Check the voltage at the VCO chip. More specifically Pin 3 of the 4013N.
Also, check the wiring at the switch.
In matrix mode it should ground one of the sides of r30 (15k) and present a constant voltage at pin 10 of the LM324.

Ideally, take pictures of the build and read all IC pin voltages with a multimeter.
That will definitely help us. 

14
Global Annoucements / Re: Instagram
« on: January 29, 2022, 04:43:22 AM »
I also use instagram, not as much as in the beginning.
By only posting photos of pedals and guitars I could filter out some content.

Since the advertising every three posts started I tried to train my instagram to only show me guitar related stuff, but every now and then there is some weird shit, like local stuff I am not interested in. Good times when there was no ads on the internet...

When I started I used it a lot to check what was everyone doing and using it as a way of help me having new ideas concerning builds, design and graphics. And surely lots of beautiful guitars to feed the GAS.

Now posting in the "new" rhythm that instagram imposes to make you been seen by more than a couple hundred people is not for this hobby IMHO. I cannot build and finish something new every 5 hours, and I don't like to flood the timeline of other people with a different angle of the same pedal. At my work they call it salami slicing, when you try to make out more content from the same piece.

On instagram I like to play a game called: guess the pedal.
I look at the guts and chips and try to identify which pedal it is. Last of Brian's post had the board with the visible spot for two BBD chips, so I checked for other clues like number of stages and position of the pots. Surely 90% of the posts are fuzz faces, but every now and then there is something unique and interesting, which catches my attention.

15
General Questions / Re: Total Recall - Odd voltages on 4558 ICs
« on: January 28, 2022, 11:32:37 AM »
Yes, that sounds the case. You can play with the cap and bypass other parts of the circuit to pin 3.
Stick one pin in the socket and solder a wire to the other and voila, you can now connect it anywhere where there is signal, even the input jack. The Cap will protect anything that comes after pin 3.

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