Building the Echo Base PCB

Started by Taylor, April 22, 2010, 11:26:18 PM

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midwayfair

I just built taylor's Tap Tempo Tremolo recently and it was a great build (in fact, it's the first tremolo to displace my Malekko on my board, which I swore would never budge). I'm planning on the EchoBase being one of my first delay builds and using this PCB.

I had a couple questions about the circuit before I get into it, though:

I have a PT2399 homemade pedal from someone else that I suspect is either the Echobase or based on it (I can't get at the guts without removing all the pots because the board is secured to the PLATE of the pedal) - it has a footswitch dub feature, tails switch, and all the right controls. I really like the sound of the first repeat and then ... splat. Big volume drop off. And turning up the feedback turns into runaway oscillation and volume increases (and another reason I'm pretty sure it's an echobase is because this happens at EXACTLY the same spot in the sweep that I see in demos of the EB).

I'd like to smooth things out so the decay is a little less extreme. I already have delays that can do really clean repeats. So I was thinking of using germanium diodes in an echobase build, even though it would result in distorted repeats*. This would reduce the clipping threshold quite a bit, right? Is there a way to compensate for some lost volume on subsequent repeats? I also plan on taking advantange of some of the mods that increase the time it takes to get runaway volume.

*This might make for an interesting lo-fi type thing, too.

Thanks for the help. :)
My band, Midway Fair: www.midwayfair.org. Myself's music and things I make: www.jonpattonmusic.com. DIY pedal demos: www.youtube.com/jonspatton. PCBs of my Bearhug Compressor and Cardinal Harmonic Tremolo are available from http://www.1776effects.com!

Marcvv

Quote from: Barcode80 on March 21, 2012, 04:30:00 PM
What IC are you using? I've found that LFOs don't like certain NE5532 chips I have, and I end up with the symptoms you are referring to.

Tl072cp is what i am using.

Marcvv

Quote from: Marcvv on March 18, 2012, 12:10:57 PM
I did the measurements. I noticed that sometimes when the lfo locks up on connecting power it starts working after a certain time.

These are the readings:
When it is working normally:
Ic1
1=4,98
2=4,95
3=2,49
4=0
5=4,95
6=4,98
7=4,98
8=9,52

ic2
1=3,97-6,05 (varying in between these values)
2=3,42
3=4,98
4=0,59-0,77(varying in between these values)
5=3,32
6=4,90
7=2,29
8=7,05-8,49(varying in between these values)

4066
1=2,85
2=2,85
3=0
4=0
5=0
6=0,79
7=0
8=2,10-2,49(varying in between these values)
9=1,86-1,89(varying in between these values)
10=2,85
11=2,85
12=7,79
13=8,98
14=9,52

and when the lfo is locked:

Ic1
1=4,97
2=4,97
3=2,49
4=0
5=4,96
6=4,97
7=4,97
8=9,51

ic2
1=6,12
2=2,11
3=4,98
4=0,86
5=3,32
6=4,98
7=2,27
8=7,86

4066
1=2,85
2=2,85
3=0
4=0,20
5=0
6=0,84
7=0
8=2,48
9=1,80
10=2,84
11=2,84
12=7,78
13=8,97
14=9,51

any ideas?

A polite bump

Taylor

I really can't think of a way that the bypass and LFO would interact like that. The only thing I can think is that perhaps for some reason the LFO is not oscillating until the bypass creates some slight imbalance in the ground/power, kicking the oscillation into action? Perhaps a different TL072 would be a solution?

Marcvv

Quote from: Taylor on March 22, 2012, 06:32:44 PM
I really can't think of a way that the bypass and LFO would interact like that. The only thing I can think is that perhaps for some reason the LFO is not oscillating until the bypass creates some slight imbalance in the ground/power, kicking the oscillation into action? Perhaps a different TL072 would be a solution?

Tried different TL072s with the same result. ???

Taylor

Do you have any mods to the pedal? Are you using the LFO kill switch? Any parts substitutions, for example the transistor in the bypass section?

Marcvv

Quote from: Taylor on March 23, 2012, 09:40:24 PM
Do you have any mods to the pedal? Are you using the LFO kill switch? Any parts substitutions, for example the transistor in the bypass section?
No mods, no substitution and no lfo kill switch.

claytushaywood

Quick Question here-
I have never built musicpcb boards... but these help forums are somewhat alarmingly long...they are pretty complex pedals though i suppose.

anyways, I just recently finished the D'Lay project from guitarpcb.com (pt2399).  I love the tone of the pedal, it sounds very aweseomely analog.  But the noise on the repeats of the delay are unacceptable when the delay times get longer--- and not long- around 300ms is unbearable to me- it's just like a static noise that doesnt come in on the dry initial notes, it just comes in for the repeats.  so annoying that i will get rid of the pedal if I cannot solve it by upgrading components or trying to mod it.

just wondering if this echo base pedal has similar noise issues with its pt2399 base.  I mean I know it's not gonna be crystal strymon clear... This noise that comes in on long delay only on the repeats is driving me nuts though.  I cant handle it!!!!  anyone have this problem here?

musicpcb looks to be a supremely awesome pcb site... this is the only site i've found where i want to build everything they have... board mounted pots everywhere!  woohooO!  whoever would have thought a board mounted meat "sphere"?!?!?  wow... please give me a board mounted mutron iii too!

StereoKills

The PT2399 is inherently noisy in it's longer repeats 300-500ms or so in my experience. If you want a clean delay, digital is the way to go. That said I was really happy with my Echo Base, pcb was great quality, and I had no build issues. I don't really play super clean anyway so unless I drive my EB really hard I don't notice it.
"Sometimes it takes a thousand notes to make one sound"

snarblinge

will tweeking the LED resistor have any adverse effects?

I usually keep my values low to keep LEDs nice and Bright. But then I usually (read always) build true bypass.

I have dropped the 50k to 1k but the modulation has reduced in effect. delay still the same??? have I hit something else I missed in swapping this one out? everything was sweet as prior to the change. the only nearby sensitive component is the 4066 I would think i'd have far greater issues if that was toast.

thanks
b.

snarblinge.tumblr.com

slacker

Yes making the resistor smaller could reduce the amplitude of the LFO waveform, giving less modulation. You could compensate for this by making the 240k resistor between the LFO and the mod depth pot smaller. I recommend using "super brite", "ultra bright" or whatever LEDS, that way you can keep the resistor big.
The other thing that can happen is making the resistor smaller puts more current through the LED, this can make the flashing less obvious, depending on the LED it might even stop flashing. This could happen without actually affecting the amount of modulation.


slacker

Quote from: Marcvv on March 24, 2012, 01:06:47 AM
Quote from: Taylor on March 23, 2012, 09:40:24 PM
Do you have any mods to the pedal? Are you using the LFO kill switch? Any parts substitutions, for example the transistor in the bypass section?
No mods, no substitution and no lfo kill switch.

Try temporarily removing the LFO led, and see if that makes it work properly.

snarblinge

hmmm, is there anywhere else to easily shoehorn a bypass indicator LED?
b.

snarblinge.tumblr.com

Scruffie

Quote from: claytushaywood on March 29, 2012, 01:15:40 AM
Quick Question here-
I have never built musicpcb boards... but these help forums are somewhat alarmingly long...they are pretty complex pedals though i suppose.

anyways, I just recently finished the D'Lay project from guitarpcb.com (pt2399).  I love the tone of the pedal, it sounds very aweseomely analog.  But the noise on the repeats of the delay are unacceptable when the delay times get longer--- and not long- around 300ms is unbearable to me- it's just like a static noise that doesnt come in on the dry initial notes, it just comes in for the repeats.  so annoying that i will get rid of the pedal if I cannot solve it by upgrading components or trying to mod it.

just wondering if this echo base pedal has similar noise issues with its pt2399 base.  I mean I know it's not gonna be crystal strymon clear... This noise that comes in on long delay only on the repeats is driving me nuts though.  I cant handle it!!!!  anyone have this problem here?

musicpcb looks to be a supremely awesome pcb site... this is the only site i've found where i want to build everything they have... board mounted pots everywhere!  woohooO!  whoever would have thought a board mounted meat "sphere"?!?!?  wow... please give me a board mounted mutron iii too!

Where did your PT2399 come from? I think some of them have been found to be of poor quality compared to others.

Quotewow... please give me a board mounted mutron iii too!
Check madbean pedals in the coming months  ;)

Taylor

Quote from: snarblinge on April 01, 2012, 04:20:22 AM
hmmm, is there anywhere else to easily shoehorn a bypass indicator LED?

If you don't need it to flash with the LFO, then you can just wire an unused pole of your bypass switch (if you're using a DPDT or 3PDT - which most people will since you'd have to go out of your way to just get a SPST stomp switch) to light the LED as you would with a true bypass effect.

snarblinge

From memory ( a mate of mine has the pedal) I'm using a dpdt to incorperate the clean kill, may have to swap it out to a 3pdt, but was trying to avoid that. might pop a trimmer in there and find a sweet spot between brightness and effect. LED could do with an updrage also. everything else is working sweet as, great pedal.
b.

snarblinge.tumblr.com

snarblinge

#416
EDIT** problem sorted
b.

snarblinge.tumblr.com

aballen

Well I just built my pcb, stock, no mods, and I'm debating on modding the hell out of it, or keeping it standard.  Quite a decision, because they layout of my case will depend on how may pots and switches I'm adding.

I want to try to get his right the first time, so I have a few questions I hope are not redundant, I read most of the thread(hopefully I did not miss anything)


  • Is there any tone sucking without true bypass?  I'm seriously considering setting mine up true bypass.  Hard-wiring tails on, and using the on/off switch as a second stomp, so I can have true bypass and then tails(when not in true bypass)  Is it worth the trouble? True bypass is religion to some people, all my pedals are true bypass, but I'm no zealot, if this pedal does not suck tone, I don't need to do it.
  • Is the humbucker mod required for all humbuckers or just really hot ones?  I have guitars with both single coil and humbuckers, I'm not sure if I need the mod or not
  • What is the affect of the humbucker mod?  I imagine if there was no negative affect, it would not be a mod, just part of the standard build
  • The LFO waveshape mod seems really cool, is it that noticeable? worthwhile?

Also thanks for such a slick board, I got mine soldered up in like 2 hours... just waiting for shipment #2 with the remaining parts... I'm pretty pumped about my echo base.
So many builds, I just can't list them anymore.

Vince_b

I'm gonna answer to your questions based on my experience with my echo base.

I never noticed any tone sucking with the bypass of this pedal so I don't think that it's worth it to make it true bypass.
To me the humbucker mod is useless. I don't hear any difference when I turn it on/off, even with hot pickups. But others may have a different opinion on that.
The LFO waveshape is noticeable so yes it is worth it if you like to have one more parameter that you can tweak.

Some other mods that you have not mentionned but that I found really useful are a dry signal kill switch, an effect loop, and the "dub madness" mod on a momentary footswitch.

slacker

#419
Quote from: aballen on April 07, 2012, 10:10:17 AM
  • Is the humbucker mod required for all humbuckers or just really hot ones?  I have guitars with both single coil and humbuckers, I'm not sure if I need the mod or not

If you set it to give you say 3 or 4 repeats and notice a nasty distortion on the repeats with humbuckers then do the humbucker mod and or the diode lift mod, if it sounds fine to you with your guitars then there's no need to do it. The humbucker mod just reduces the volume of the signal going through the PT2399, the only negative to this is you have to turn the level and feedback pots up more to get the same sounds as without the mod.  

I don't think it tone sucks, but I don't think Boss pedals do either, some people swear they do. The only way to tell is to use your ears, if you can hear it tone sucking then it might be worth true bypassing it, if you can't then don't worry about it :)