Small Time is a PT2399 delay designed by the Valve Wizard. This delay has tails. This allows the delay sound to continue after the pedal is bypassed.
My first built worked well and wounded good. The tails was not as exciting as I thought it would but it is interesting and a small bonus. The effect not very pronounced unless you have a loud delay with lots of repeats.
This PT2399 delay is well balanced. The sounds are as good as any other short delay and better than most of the DIY delays.
It is buffered. This a requirement to get the tails to work!
I recreated the schematic in Eagle PCB.
Bill of Materials
- * R7 is shown as 0r or 0 ohms. This can be a jumper or omitted. The reason for this is that some PT2399 chips have problems if pin 4 is not grounded to pin 3. Some chips don’t have this issue.
- ** R16 is shown as 10K at this value the pedal will not self oscillate with repeats at max. If you want self oscillation you can decrease this. I used 7k5 and got oscillations around 4 o’clock on the repeat knob.
- *** J201 is a JFET transistor. It has characteristics that make it a really good choice for guitar pedals. Sadly this part is hard to find. Here are some ideas.
- Guitar PCB has J201 at a reasonable price
- Small Bear Electronics has J201
- AionFX sells a tiny PCB with a surface mount version of this part at a reasonable price.
- Mouser stocks J201 but the cost is high.
From there I designed a board in Eagle PCB and had these manufactured at PCBWay.com. I have been using this service a lot. The website is easy to use and the prices are great for prototyping.
I designed this board with 1/8 watt resistors but it could be built with 1/4 watt resistors if you stand them up.
The off board wiring is a little different from the usually wiring due to the buffered bypass.
I built the first board up and it didn’t work. Debugging with my multimeter I quickly found that there was no power at the op-amp! I had forgotten to connect pins 1 and 8. I run a couple jumpers on the backside of the board and everything started working!
I milled a black powder coated box and assembled everything. Since the buffered bypass scheme only requires a SPDT switch I used an old Carling switch I had on hand. You could use pole of a 3PDT switch since these cheap and easy to source. You could also use one of these (not the momentary!).
This circuit as presented here doesn’t self oscillate. R16 controls the feedback/Repeats, bringing this down to 7k5 (from 10k) gets it to self oscillate when the Repeats knob is past about 4 or 5 o’clock.
Here are some pictures of the completed build.
Would I build this? For sure! It sounds as good as any of the cheaper delay pedals. Delay is a great effect that makes everything sound better, including my mediocre guitar playing! Delay is also an area where there has been a lot of innovation. If you’re looking for fancy delay sounds you might buy or build something more complex. If you’re just looking for something to add some ambience or just need a simple slap back effect this works well.
How does the trails work? They work pretty good. I thought it would be more noticeable than it is. In the right situation you can really hear it, the rest of the time it’s a subtle addition.