Author Topic: MAGNUS MODULUS - PROJECT - Another PT2399 Echo Modulator/Chorus/Tremolo/Boost  (Read 79046 times)

ForcedFire

I think I'm in love with this.  :icon_redface:

Did you build it?

frequencycentral

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I think I'm in love with this.  :icon_redface:

Did you build it?

Not yet. I'm in love with your sounclip though, I've listened to it a bunch of times. I've had a few PT2399's for a while, just never decided 'which one' to build. This is it. I'll be ordering a board from John.
http://www.frequencycentral.co.uk/

Questo č il fiore del partigiano morto per la libertā!

frequencycentral

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I think I'm in love with this.  :icon_redface:

Did you build it?

Just ordered my PCB from John, so I'll be building this in January.  :icon_biggrin:
http://www.frequencycentral.co.uk/

Questo č il fiore del partigiano morto per la libertā!

niopren

 I build this effect, I am very happy.
worked on the first attempt

I have some doubts and problems that do.

1. I have a problem of "popping" when the tremolo active, occurs in the version of you?.
2. I doubt the end of the bypass wiring. I saw in the photos is the first 3PDT is the true bypass and  the second 3PDT was the "tails", is that correct?
3. the switch from "tails" to turn off functions as a bypass, but "always" the effect is slightly heard in the background, itīs normal?

to see if I clarify this before the board put in the box

greetings

waltk

ForcedFire,

OK, so I've etched a PCB, built the board, and am currently testing it.  First, let me say thanks for designing this and sharing it with us.  My build worked on the first try, and I'm getting some awesome sounds out of it.  I'm just a little confused about the function of some of the pots/switches.  If you have time, could you provide a short tutorial (or maybe just some hints) about how the delay, tremolo, and modulator interact - and which of the pots affect the others.  I think I have most of it figured out, but could still use a better understanding of how it all works together (the "space" pot in particular doesn't seem to do much).

ForcedFire

I build this effect, I am very happy.
worked on the first attempt

I have some doubts and problems that do.

1. I have a problem of "popping" when the tremolo active, occurs in the version of you?.
2. I doubt the end of the bypass wiring. I saw in the photos is the first 3PDT is the true bypass and  the second 3PDT was the "tails", is that correct?
3. the switch from "tails" to turn off functions as a bypass, but "always" the effect is slightly heard in the background, itīs normal?

to see if I clarify this before the board put in the box

greetings


I have the tremolo on a toggle switch and do not get any pops.

You are right about my build with the true bypass and tails switch. I have noticed the same thing about hearing the effect in the background. I think this is due to some feedback from the delay configuration. I just took half of the BYOC Ping Pong delay and used that and didn't put the tails switch in until the very end. When I was working on the breadboard I was just using the delay level knob to turn off the delays instead of a switch so I never noticed this. To remedy this, you need to use another pole of the 3PDT (delay tails switch) to cut the path at either R21 or C24. To do this, remove either of those two components (the resistor is cheaper to replace usually) and put a pole of the 3PDT switch in series with the resistor or capacitor you took out and wire that to the pads where the component you removed was. This will ensure nothing feeds back to the input of the delay. If anyone doesn't need the delay tails, just put a jumper across the pads for the delay tails switch. Use the delay level knob to turn off the delay in this case.

In my build I get a pop from my delay tails footswitch when I turn it on, I think this is because there is zero resistance between the source of the pop created in the switch and the input to the first op-amp filter so there is infinite gain that leads to the audible pop. I might try shorting R14 and putting it between the switch and the pad at R7. I am on vacation until January 15th so I do not have time to try this out. I was super busy before the holidays and just managed to squeeze out this project between the work I was doing for school. Hopefully we can work out these little issues. I'm glad you're happy with the overall effect though!  :icon_lol:

ForcedFire

ForcedFire,

OK, so I've etched a PCB, built the board, and am currently testing it.  First, let me say thanks for designing this and sharing it with us.  My build worked on the first try, and I'm getting some awesome sounds out of it.  I'm just a little confused about the function of some of the pots/switches.  If you have time, could you provide a short tutorial (or maybe just some hints) about how the delay, tremolo, and modulator interact - and which of the pots affect the others.  I think I have most of it figured out, but could still use a better understanding of how it all works together (the "space" pot in particular doesn't seem to do much).


Hey, here is a response to a similar question I answered on another forum, I'll just copy and paste:

Quote
The knobs in the pictures don't match up with the sounds in the video and the pot function and ordering doesn't follow a really strict order but it's something like this:

Right footswitch: true bypass / turns blue light on and off

Left footswitch: sends the guitar signal to the PT2399 for delay and modulation/chorus. When you turn it off, if you have the feedback set sort of long, the delays trail out (echo tails). Since the delay uses the Ping Pong delay setup, some of the output gets fed back in. I find with the delay turned off, so you hear sort of a faint reverb in the background. So if you want echo tails you can turn off the delay, then you're just playing through the buffer, once the tails fade you can turn off the buffer and have true bypass, then if you want delay again you can tap the delay switch and then turn on the bypass switch, of course if you don't want tails you can just use the one switch and turn on and off for true bypass or not. Then if you want just the tremolo or booster you keep the delay off, if the slight reverb bothers you, you can just turn down the delay level and nothing will come out of the delay chip. Then you use the true bypass switch to turn the booster or tremolo on or off. To omit the delay switch, you would put a jumper across the pads on the PCB and you can omit the two 1M resistors connected to them (R7 and R13). You'd just use the delay level pot for pure tremolo or boost. This is how I had it on the breadboard, I never tried the switch until it was all together, it works but I don't have much use for it really. The way I have it set, you need to really make sure the gain is set at unity for the tails to work out so that when they fade out and you switch from the buffer to true bypass that it sounds identical.

The modulation switch is a toggle on the top right. The delay switch has to be on for the modulation to do anything as it just modulates the delay section.

The tremolo switch is on the top left, the modulation depth has to be set pretty much at the max to get tremolo and the gain knob can be used to bring it up to unity or boosted volume (all tremolo usually causes volume drop).

You can have echo, modulation, and tremolo all at the same time.

For the controls, across the top:

Depth: controls the level of the Low Frequency Oscillator signal to the delay chip and tremolo transistor switch, as well as the intensity of the flashing white LED.

Delay Level: controls the volume of all signals coming out of the delay section, including modulated echo/chorus level.

Delay Feedback: controls the amout of repeats, with short echo it basically sounds like controlled feedback, crank it for self-oscillation. During self-oscillation, the two silicon diodes limit the output signal and start distorting. Originally I had used two red LED's so when it oscillated the two LED's would start to glow. Since this is followed by the booster stage it was way too loud and put out too much voltage. I used silicon diodes to protect peoples amps/other pedals. The diodes can account for a slight distortion but it's pretty insignificant, your signal shouldn't be very strong going in. I would not recommend taking out the diodes. Any distortion in the delay section can be attributed to the quality of the PT2399 (gets noisy at long delay times) and the delay filtering. I just used the filtering from the Ping Pong and I can make it distort with my bridge pickup on my Les Paul. I changed some of the capacitors to increase the filtering of the highs, increasing the filtering too much really darkens the repeats and doesn't sound good. You can play with the filter components to see if you can get it better, I think it sounds good with the values I used.

Gain: Controls the gain of the output amplifier. With all the effects off and just the buffers on you get a really nice clean/gritty boost with the NE5532 op-amp. I think it's a nice addition, also it allows unity volume with the tremolo.

Bottom row:

LFO Rate: controls the speed of the LFO, I used a 10kB pot, I think a C reverse log pot would be best but my goal was to build this out of parts I already had in my apartment (I'm a nerd), so I haven't tried it. The wiring diagrams and schematics show the rate pot with lugs 1 and 3 reversed. On my build you turn to the left for higher rate, I'll update the file so it goes faster with clockwise turns, not a big deal. The original had a 'fine' rate control. 8 pots looked better than 9 so I took it out. Add this in series with the rate knob if you want it.

The middle two are Space and Smooth: Space basically controls the duty cycle of the LFO signal, how much it is on versus how much it is off in one cycle. You can look at the LFO LED to see what it's doing to the waveform. This is a really useful control, it really changes the choppyness and smoothness of the LFO, the Smooth knob doesn't really do that much but I just included it because it's in the original Tremulus Lune LFO. When the rate is low it seems to control how fast the signal peaks and decays. When the rate is pretty fast I can't hear much of a difference there, just slight. I used 240k resistors in my build, the original LFO has 220k resistors so this could be a major factor in why mine isn't so noticeable.

Finally there's the time knob, it controls the nominal delay time. With modulation, the LFO signal rides on top of the voltage set by the time knob.

Okay, that was a huge response, but hopefully it answers some questions, I'm sure it'll raise even more...

Maybe I'm confusing space and smooth. One of them is really useful and the other doesn't do much like you said, I just figured people would freak if I took it out of the Tremulus Lune LFO.  :icon_rolleyes:

Ben N

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I'm not proud of myself for asking a "sounds like" question, believe me  :icon_redface:, but WTH, is there one of the PT2399+modulation pedals that gets closer to the Memory Man magic?

ForcedFire

I'm not proud of myself for asking a "sounds like" question, believe me  :icon_redface:, but WTH, is there one of the PT2399+modulation pedals that gets closer to the Memory Man magic?

Well I'm not very proud to say I've never played one  :icon_lol:. I'll look into it though....

ForcedFire

Please disregard what I said here:

Quote
You are right about my build with the true bypass and tails switch. I have noticed the same thing about hearing the effect in the background. I think this is due to some feedback from the delay configuration. I just took half of the BYOC Ping Pong delay and used that and didn't put the tails switch in until the very end. When I was working on the breadboard I was just using the delay level knob to turn off the delays instead of a switch so I never noticed this. To remedy this, you need to use another pole of the 3PDT (delay tails switch) to cut the path at either R21 or C24. To do this, remove either of those two components (the resistor is cheaper to replace usually) and put a pole of the 3PDT switch in series with the resistor or capacitor you took out and wire that to the pads where the component you removed was. This will ensure nothing feeds back to the input of the delay. If anyone doesn't need the delay tails, just put a jumper across the pads for the delay tails switch. Use the delay level knob to turn off the delay in this case.

I am still on holidays and haven't actually done this. I don't think it will work. I'll work on the tails switch wiring when I get back to my apartment...

niopren

Please disregard what I said here:

Quote
You are right about my build with the true bypass and tails switch. I have noticed the same thing about hearing the effect in the background. I think this is due to some feedback from the delay configuration. I just took half of the BYOC Ping Pong delay and used that and didn't put the tails switch in until the very end. When I was working on the breadboard I was just using the delay level knob to turn off the delays instead of a switch so I never noticed this. To remedy this, you need to use another pole of the 3PDT (delay tails switch) to cut the path at either R21 or C24. To do this, remove either of those two components (the resistor is cheaper to replace usually) and put a pole of the 3PDT switch in series with the resistor or capacitor you took out and wire that to the pads where the component you removed was. This will ensure nothing feeds back to the input of the delay. If anyone doesn't need the delay tails, just put a jumper across the pads for the delay tails switch. Use the delay level knob to turn off the delay in this case.

I am still on holidays and haven't actually done this. I don't think it will work. I'll work on the tails switch wiring when I get back to my apartment...

ok thanks..


my Magnus is 99,9% finished
pictures soon

ForcedFire

Awesome!

I might try putting a 1 transistor buffer between the delay output pot and the output buffer/mixer to avoid the dry signal coming back into the delay input through the feedback path when using the tails function.

Looking forward to your pictures niopren!

niopren


Looking forward to your pictures niopren!

some pictures from my cell phone.


« Last Edit: January 12, 2009, 02:27:41 PM by niopren »

John Lyons

Looks good niopren!

I still have some boards to sell if anyone is interested.


$20 total with shipping
Basic Audio Pedals
www.basicaudio.net/

runmikeyrun

anyone try this on bass guitar yet?  My PT-80 doesn't sound nearly as good on bass as it does on guitar and i'd hate to spend lots of hours on this project to find the same thing.  I also have problems with clarity with guitar oriented chorus effects too.  If anyone could run a bass through theirs and report back (or post a sample  ;) )that'd be awesome.
Bassist for Foul Spirits
Head tinkerer at Torch Effects
Instagram: @torcheffects

Likes: old motorcycles, old music
Dislikes: old women

Hey all, long time listener, first time caller etc etc  :icon_cool:


Been building pedals for 6 months or so and fell in love with the Magnus Modulus project as soon as it was posted up by FF_Pedals. Seemed quite complicated with my limited experience but, while I'm still in kindergarten theory-wise I can triple check things and follow a plan with the best of them ;)

I finished the enclosure last year prior to getting the board from the US and ordering the parts. Started on the innards early this month.

I'd intended a fully polished finish, something different from my usual painted approach, with a label on top. Well, I spent hours and hours filing, then sanding and finally polishing the box and eventually got it looking like chrome. Unfortunately, after I'd stuck the decal on and begun adding the final polyurethane coat, all that shine went south. It's ended up as a sort of burnished, slightly greenish metal finish that I'm still pretty happy with so all's well.

It's the most complicated pedal I've built and yet, due to Nathan's / FF_Pedals excellent documentation, the most fun. Oh, and it fired up first time, thank God I didn't have to debug this bad boy.

Some idiot accidentally ordered a couple of capacitors suitable for use as part of the national grid and yet was determined to make them fit as a personal challenge... see if you can spot which ones  :wink:


It sounds fantastic and is a lot of fun to play with, working out what dial interacts with what. I'd always assumed that I'd be using it pretty clean but found that quite a fast tremolo rate coupled with a nice scuzzy fuzz pedal sounds brill. Lots more to discover.

I decided that this pedal was going to be built practically rather than prettily and so went for stronger stranded wire rather than the more easily positioned solid core stuff and also made each run long enough that I could hinge the board up and get at the underside to tweak things if need be. I have slightly more background hiss introduced by turning the pedal on than I'd like so need to look at isolating that problem and minimising it but, frankly, I'm having a lot fo fun just playing it at the moment, so that can wait.













Just seen the pics, nice job niopren.
What are the extra LEDs you've added there for?

John Lyons

Mothercruncher

That build looks very nice!
The layout of controls and switches is a little chaotic but there is a lot to fit in a BB size box.
What type of sticker did you use?

John


Basic Audio Pedals
www.basicaudio.net/

Cheers John, I must get into this "waterslide" business people talk about but, for now, I'm just printing stuff out onto photopaper and using photo mounting spray to stick it down. Coming from a graphic design background it's all stuff I've got to hand. The main downside of that approach is that, in order to get a good durable print, you need to use thick paper and if you then want to try to hide the edge under the lacquer then that's a LOT of spray layers and wet sanding.

niopren

Just seen the pics, nice job niopren.
What are the extra LEDs you've added there for?

thanks, your pedal is great.

the extra led is "D2" for the LFO.