Echo Base - a new PT2399 delay

[slacker]

The CD4066 or CD4016 shouldn't be hard to find, I would think almost any electronics store would have them and there's plenty of places to buy them online. The place you are buying the PT2399 from will probably have them, Smallbear and Banzai definitely do.

If you really can't find any in theory you could change the pedal to use the stomp switch to instead of the CD4066, I can draw a modified schematic if you like. You might get problems with switch pop though.
Or you could use fets to do the switching instead, I haven't tried that though.

[Paul Marossy]

Hmm... I might have to build this one. I have another PT2399 based echo pedal, and it's a lot of fun with the tone control it has. I like the modulation feature on the Echo Base, though. It would be really, really cool if I could get something that does modulation and also has a tone control so you could get analog delay type sounds, too.

[carrejans]

Isn't there any webpage about this pedal, with all the usefull info bundled?
Or do I have to go through 30+ pages? 

this is just a tad ungrateful, please be respectful. this is a community, not a service. please don't complain about how such a great project is developed and shared, just enjoy the project!

I wouldn't call it ungrateful.  While I salute and respect the work others have put into this, it IS a bit tiring to go through so many pages for the information.  It would be great if the first post on any build thread was left for constantly updated information.  It could include the schematic/PCB layout (updated as it changes), parts list, troubleshooting tips w/ thread links, etc.  I think it would cut down tremendously on the constant posts for help with problems that were covered 2 or more pages ago.

Thank you EHman. That's what I was thinking too.
So Barcode; don't judge me. I wasn't ungratefull.
Thank you, slacker, for all your work. I just asked, because maybe there already was some kind of webpage or pdf, that I didn't notice.

Slacker, is it possible to use the part of the delay-tails on an AD3208?

[slacker]

Hmm... I might have to build this one. I have another PT2399 based echo pedal, and it's a lot of fun with the tone control it has.

Depending on where the tone control is on your pedal it should be possible to add it to the Echo Base, apart from the switching it's a pretty standard PT2399 circuit. Or you could add the modulation to your pedal, it will work with any PT2399 based pedal, I know some people have added it to the Rebote and PT80.

Thank you, slacker, for all your work. I just asked, because maybe there already was some kind of webpage or pdf, that I didn't notice.

No problem, no offence taken

Slacker, is it possible to use the part of the delay-tails on an AD3208?

It should be, you'd just need to decide where to put 4066 switches. Probably in between the first opamp stage and the SA571 and then after the second SA571 would be easiest.

[Paul Marossy]

Hmm... I might have to build this one. I have another PT2399 based echo pedal, and it's a lot of fun with the tone control it has.

Depending on where the tone control is on your pedal it should be possible to add it to the Echo Base, apart from the switching it's a pretty standard PT2399 circuit. Or you could add the modulation to your pedal, it will work with any PT2399 based pedal, I know some people have added it to the Rebote and PT80.

Yeah, the modulation part wouldn't be too hard. I don't know how I would add it to the pedal I have... I don't have a schematic for it.

I think this would be something to mess with on a breadboard using a building block approach and tweaking it as necessary to get the desired result.

[decc]

I got kinda bored and made up a tap tempo PCB off of the two IC's and schematic from the PTAP. Not sure if they are right, but oh well, maybe someone can see some fix. I don't know if there is a layout/PCB for it yet, but here is another one anyway. About 1"x 1.2", so pretty small. Could be smaller I guess. I put on the 5v reg because the notes say it should have its own, or it could introduce noise.

Just noticed that the connections for the 5V regulator are wrong. That could be trouble. Try:

[svstee]

So you don't have to look back a page, my voltages are:
PT2399
All normal, except:
7 and 8 are 3.3v instead of 0.5

4066
1 and 2 are 2.8 should be 4.6
3 and 4 are 0.0 should be 0.4
5 is 0.0, normal
6 is really weird. It should be 0.45 on 4.5 on, but I get .08 off, and when it is on and I touch it with the meter lead, the effect turns off.
7 is 0.0, normal
8 is 2.26 should be 9.0
9 is 1.92 on and 0.0 off should be 3.0 on and 0.32 off
10 and 11 are 2.89 should be 4.6
12 is 8.5 on, normal
13 is 7.5 should be 8.5
14 is 9.0, normal

TL082, top left of vero, U3
all normal except:
6 is 3.37, should be 5.0

TL072, bottom left of vero, U1
all normal except:
2 is 3.62 should be 5.0
5 stays at 4.12, should change.

Voltage regulator and all transistors work the way they should.

This is very strange. What voltages do you get on pin 1 of the LFO opamp and what voltages do you get on the base of the transistor with the mod depth pot on maximum?
If you turn the delay time pot to minimum what sort of length delay do you get?

It appears mod depth has NO affect on the voltage of either pin 1 of the LFO opamp or the Base of the transistor. speed however, in addition to affecting speed, also effects voltage. On pin 1 with speed at max, voltage is 4.5-5.56. with speed all the way down, it is 3.2-6.0, and changes faster. same thing with the Base.

As for the delay pot, the minimum is about 300 milliseconds, max is about 1 second, and slightly distorted. Feedback start to self oscillate about halfway up.

I replaced to 2339 chip, with no effect.

[Vitrolin]

The CD4066 or CD4016 shouldn't be hard to find, I would think almost any electronics store would have them and there's plenty of places to buy them online. The place you are buying the PT2399 from will probably have them, Smallbear and Banzai definitely do.

If you really can't find any in theory you could change the pedal to use the stomp switch to instead of the CD4066, I can draw a modified schematic if you like. You might get problems with switch pop though.
Or you could use fets to do the switching instead, I haven't tried that though.

hi i think ill build it true bypass, since i have no idea how to make the fet shifting and i a future when i get my hands on a CD4066 ill build in the tails feature.
and the PT2399 i got when i mail ordered for some trans and switches, they send me 4 of them and i never ordered any lucky me.
i dont order very often, i have to save up, and i live in chile so shipping is expensive, and components are expensive in comparision to your standards.

[slacker]

It appears mod depth has NO affect on the voltage of either pin 1 of the LFO opamp or the Base of the transistor. speed however, in addition to affecting speed, also effects voltage. On pin 1 with speed at max, voltage is 4.5-5.56. with speed all the way down, it is 3.2-6.0, and changes faster. same thing with the Base.

The voltages on pin 1 of the LFO opamp look correct. If the mod depth pot isn't having any effect on the voltage on the base of the transistor It sounds like the mod depth pot isn't wired correctly or you have a bad pot. When the mod depth pot is turned all the way down you should have 0 volts on the base of the transistor. Double check that the CCW lug of the mod depth pot is connected to ground.

[svstee]

IT WORKS! I did not have the depth ccw hooked to anything 
I really like the chorus on this thing, the vibrato is a bit extreme for my tastes, and the way they can be combined with delay is great...

[slacker]

Cool, glad you got it working. With the depth pot not connected to ground the voltage on the base of the transistor would be too high, permanently turning the transistor off so that's why there was no modulation.

If the modulation is too extreme you can reduce it by making the 240k resistor before the mod depth pot bigger.

[svstee]

Good to know.

Thanks a lot for all your help with the debugging, and for coming up with the project in the first place. You, sir, are a gentleman and a scholar. 

[kristoffereide]

I just built this, but it didn't work. Loads of noise, and 10% guitar sound. No delay at all. I've checked all the solderings and I've got all the parts right. Any ideas?
BTW: I use the vero layout I found somewhere here, is there a new and corrected ( if it was wrong)?

Not even the LED lit up!

[Barcode80]

if the led didn't light up, first think i would suspect is a bad/blown 4066 chip. That could also cause the other problems...

[kristoffereide]

ok thanks, I'll switch it for a new one.
If that doesn't work I'll go through the voltages.
Not familiar with debugging digital circuits though...

I guess I'll find what I'm looking for if I backtrack the posts

[slacker]

voltages are on page 4 of the thread.

[kristoffereide]

ok, so I put in new chips, I switched the 2399 aswell, and now I at least get an echo to the noise. So it getting better. The tail/boss-switch is working fine, but the bypass has no effect ( that I can hear). It oscillates like crazy at high feedback, so I know I've done something right at least ...
Still no light, still no guitarsignal, still loads of noise and hum

[kristoffereide]

Im getting very strange voltages but all the parts seem correct.


f.eks the LED+ 0,34V (4066 pin 13)

The PT2399 pin 7 and 8 are 4,5V!!!!) all the other vary with about 0.1V

Any ideas at all???

Now I get a clean signal through, but the delays are heavily distorted and controlled by the feedback-pot

[svstee]

Well, after spending some quality time with it I really feel I owe Ian another big thumbs up. This thing is really GREAT! The interaction between the controls is amazing, I really don't need much else on my board for modulation. The chorus, slapback echo, vibrato and delay are all superior to anything on my board now. Keep up the great work!

[exterm]

hi !

my echobase doesn't work!!!
i've got dry sound when the pedal is in and out, the led works
i change all the IC's, i check everythings but...

so there is some pictures, if you see something wrong!