Echo Base - a new PT2399 delay

[junkwork]

Hi everyone I'm anonymousfacelesscoward. I prepared sound samples of my EchoBase.

http://warehouse.nusutto.jp/diy.html

[Filament]

In case no one else has done so, let me say THANKS! 

[gutsofgold]

Would you say this is on par with the sound quality of a Boss DD-4 or DD-5 I've tried a few different things to get my Rebote 2/2.5 sounding better (cleaner sounding delays, less treble roll off, more real sounding) and I've been unimpressed. I might give this one a try instead of buying the Boss.

[slacker]

It has a lot less filtering than the rebotes, as I wasn't trying to get an analogue delay type sound, so it is brighter/cleaner sounding. Having said that it's not as clean as a DD3 especially on longer delays, I guess it's somewhere between the two.
The sound clips in the first post give a pretty good impression of what it sounds like.

[zyxwyvu]

Have people found that the depth control works well? It seems odd to me that the LFO output is centered around +5V, but the depth control is tied to ground. This means the bias on the transistor will change as you adjust the depth. Maybe there should be a cap off the output of the LFO?

[slacker]

Here's how the modulation works hopefully this will explain the depth control. The resistance of the PNP transistor is proportional to the voltage on its base the greater the voltage the greater the resistance. With 0 volts on its base the resistance is so small that it doesn't affect the delay time of the PT2399 the maximum resistance is set by the parallel resistance of the transistor and the 39k resistor across the collector and emitter.
The depth pot is connected to ground so that when it's turned all the way down there is 0 volts on the base of the transistor which turns the modulation off.
Like you said the voltage of the LFO is centred around 5 volts and swings between about 3 and 7 volts. It then goes though the voltage divider made up of the 240k resistor and the depth pot which lowers it. If you turn the depth pot all the way up the base of the transistor swings between about 1.8 and 2.6 volts and the resistance sweeps from something low up to the maximum so you get a large change in the delay time.
With the pot turned almost all the way down the voltage on the base swings between much lower voltages say between 30 and 40mv so the resistance is much lower and only changes by a small amount so you only get a small change in the delay time.

Hope that makes sense

[zyxwyvu]

Here's how the modulation works hopefully this will explain the depth control. The resistance of the PNP transistor is proportional to the voltage on its base the greater the voltage the greater the resistance. With 0 volts on its base the resistance is so small that it doesn't affect the delay time of the PT2399 the maximum resistance is set by the parallel resistance of the transistor and the 39k resistor across the collector and emitter.
The depth pot is connected to ground so that when it's turned all the way down there is 0 volts on the base of the transistor which turns the modulation off.
Like you said the voltage of the LFO is centred around 5 volts and swings between about 3 and 7 volts. It then goes though the voltage divider made up of the 240k resistor and the depth pot which lowers it. If you turn the depth pot all the way up the base of the transistor swings between about 1.8 and 2.6 volts and the resistance sweeps from something low up to the maximum so you get a large change in the delay time.
With the pot turned almost all the way down the voltage on the base swings between much lower voltages say between 30 and 40mv so the resistance is much lower and only changes by a small amount so you only get a small change in the delay time.

Hope that makes sense

I think that does make sense. Thank you.

[mth5044]

So, where did you source most of your parts? I've never seen caps like that before. I try to order from mouser but even the resistors are confusing (like what size and stuff, I just dont know). Also, what size board is that? Did you get it from DIYStompboxes store? Any help would be great  I think I'll start building it soon.

[Filament]

So, where did you source most of your parts? I've never seen caps like that before. I try to order from mouser but even the resistors are confusing (like what size and stuff, I just dont know). Also, what size board is that? Did you get it from DIYStompboxes store? Any help would be great  I think I'll start building it soon.

I believe most people etch their own PCBs but I can tell you that John Lyon's will etch one for you and at a very fair price. 

As for resistor sizes, typically you'll want to order 1/4 watt resistors.  Hope that helps.

[Boogdish]

I bought stripboard from Aron (diystompboxes) to build this, but it was the wrong size, I had to tighten up slacker's layout a little bit to make it fit.  It was a good learning experience for me, but I think I'd definately get a pcb if I was ever going to build another one of these..

I used all 1/8watt metal film resistors in my build.  I do the search and then sort by price and get whatever's cheapest and always get extras.  If you're building on perf using slacker's layout, I'd try not to get all boxed film capacitors (the little colored square capacitors) because they usually have short leads and can't be flexed too much.  I think the only onboard component I wasn't able to get from Mouser for this was the PT2399, and I got that from Small Bear as well as the enclosure, switches, pots, knobs, jacks, led/bezel.  I'm sure some of that stuff could be gotten from Mouser, but the price isn't that different between the two.

[Barcode80]

futurlec and others (digitech, mouser, allied) sell larger vero boards, although kudos for supporting aron!

[davent]

So, where did you source most of your parts? I've never seen caps like that before. I try to order from mouser but even the resistors are confusing (like what size and stuff, I just dont know). Also, what size board is that? Did you get it from DIYStompboxes store? Any help would be great  I think I'll start building it soon.

I believe most people etch their own PCBs but I can tell you that John Lyon's will etch one for you and at a very fair price. 

As for resistor sizes, typically you'll want to order 1/4 watt resistors.  Hope that helps.

Echo Base PCB for sale

[John Lyons]

Thanks for the plug Joe and Dave!
I do still have some Echo Base boards for sale.

John

[rm -rp ./Matt*]

So can someone tell me whats the difference between this delay and the PT-80 delay on tonepad or ggg? Deciding which one to make, which ones better.

[Barcode80]

i'm all out of .1uF!!!!!! i'm also out of tlo72. I will trade an etched echo base board to anyone who can give me a bunch of .1uFs and a bunch of tl072...

[~arph]

So can someone tell me whats the difference between this delay and the PT-80 delay on tonepad or ggg? Deciding which one to make, which ones better.

..modulation.

 I'd say start reading page one and listen to the samples

[Gila_Crisis]

i'm all out of .1uF!!!!!! i'm also out of tlo72. I will trade an etched echo base board to anyone who can give me a bunch of .1uFs and a bunch of tl072...

where are you from??

[Barcode80]

i'm all out of .1uF!!!!!! i'm also out of tlo72. I will trade an etched echo base board to anyone who can give me a bunch of .1uFs and a bunch of tl072...

where are you from??

USA, TN

[sean k]

I've problems with my Echo base but after seeing the demon delay, or something like that, I've realised that in my hurry to copy, and not properly check, my original schematic drawing I put a 100 nano cap between pins 13 and 14 instead of a 1nano. No wonder theres no output on pin 14. I think I said I had a bigger output on 12 than 14 and know I know why. From here on in I'll be double and triple checking my drawings.

[Tuemmueh]

Hi..it is possible to add a loop send-return between the 20K resistor and the 100n cap across the pin 2 of the feedback pot? In this way, connecting an effect in this loop, this effects influences the repeats always more..right? If we use, for example, an octave up in the loop, the first repeat would be 1oct up, the second would be 2oct up, etc.. (obviously the feedback pot should be set low, with a few of repeats, otherwise the pitch grow to much)

Another question: why there are 2 1N4148 across the feedback pot?

thanks so much!
Dimitri

I'm sorry to pull out this older post, but I'm not sure if I understand this one correct ... Am I right assuming that the loop should be inserted between the 20k connected to the Feedback-pot lug2 and the 100n following this 20k? Or should it be inserted at pin3 of the Feedback-pot? I've seen talking of both ways and am not sure which one is the right one or if both are working the same ... thanks!