Echo Base - a new PT2399 delay

[fuzzo]

SOmeone put a "tone" pot like Carl martin did on its  red delay on these PT2399 delay ?

Some people complains about the dark tone of rebote delay  and watching the schema , there's a filter after the delayed signal path , maybe SOmeone has already tried to play with ?

[WhenBoredomPeaks]

SOmeone put a "tone" pot like Carl martin did on its  red delay on these PT2399 delay ?

Some people complains about the dark tone of rebote delay  and watching the schema , there's a filter after the delayed signal path , maybe SOmeone has already tried to play with ?

I breadboarded the example circuit of the PT2399 (basically the Rebote 1.0) and its repeats are really noisy so thats why it sounds dark imo because the noise filtering is taking away the treble too.

if you are interested in, i've a layout (for stripboard ) of the echo base without the other effect -just the delay section- and true bypass.
it's not verified, but i took it from another verified stripboard layout (by GilaCrisis) of the complete echobase.

Thanks, but i can remove it, but i think i gonna left it there, the more possibilities, the better.

[cpm]

going for a higher order output filter can help with the noise, and the steeper rolloff allows for a higher cutoff freq. (resulting in a less dark tone)

[fuzzo]

SOmeone put a "tone" pot like Carl martin did on its  red delay on these PT2399 delay ?

Some people complains about the dark tone of rebote delay  and watching the schema , there's a filter after the delayed signal path , maybe SOmeone has already tried to play with ?

I breadboarded the example circuit of the PT2399 (basically the Rebote 1.0) and its repeats are really noisy so thats why it sounds dark imo because the noise filtering is taking away the treble too.

Ok I thought that was desinged espcially for that kind of analog sound . The noise is really present on rebote delay ?   

[Taylor]

I have spoken to Ian and I may do a run of professionally manufactured Echo Base PCBs. These would be quality double sided boards with silkscreen and soldermask. I would most likely do PCB-mounted pots to cut a lot of the offboard wiring down. This will make for a nice clean and leisurely build. 

I will be looking through this thread to check out all the variations and mods everyone's come up with since I built my Echo Bases last summer. But it would be helpful to hear from you guys what variants seem to be the most popular, so that I can include as many as possible into the PCB. It's always a balancing act between the flexibility to build different versions and an easy build. The more options you add the harder it is for someone who just wants to build the thing stock.

So what would be the top mods you think should be included?

[sinner]

Hi Taylor, that's great! I'm up for a couple strait away

I think double chip mod is good idea, also I would like to have FX loop and tap tempo in mine...
Thanks
Pawel

[Taylor]

The double chip does the 2 chips in series for longer time, right? Not ping pong?

Would the tap tempo be for time or the LFO? Both might be a tall order... 

[sinner]

The double chip does the 2 chips in series for longer time, right? Not ping pong?

Would the tap tempo be for time or the LFO? Both might be a tall order...  

Hi, yes, double time, or simply cleaner repeats also tap tempo for time is what I was thinking of..

Other mods that we can do is switch that cut the speed in half like in Cornis T.E.S.. But it's offboard mod and easy to make, all you have to have is stacked pot and switch

[cpm]

Taylor i have posted somewhere how to control the delay time of 2 chips only with one pot, instead of setting the 2nd chip with a fixed time. This may be worth adding

[sinner]

Taylor i have posted somewhere how to control the delay time of 2 chips only with one pot, instead of setting the 2nd chip with a fixed time. This may be worth adding

Another way I've never seen done, but which works pretty darn well is to change the speed pot to a dual speed pot, both sections half the original resistance, but put in series. Each section contributes half the "slowness". By shorting across one, the speed doubles.

[Taylor]

I could be wrong, but it sounds like RG is talking about a single delay chip in that quote...? I think cpm and RG are talking about different things there.

[mth5044]

So for the circuits with 2 pt2399's, can you just smack the LFO onto each delay pot and have one modulation controlling multiple chips?

[slacker]

Yeah one LFO can drive more than one chip. Using the Echo Base method you just need a separate PNP transistor for each chip, then you can either have one depth control hooked up to both transistors or hook 2 depth controls up to the LFO, so you could have different amounts of modulation on each chip.
You'd get some pretty mad sounds if the 2 PT2399s were in series though, because the modulated signal from the first chip would then get modulated again by the second chip, might sound great might just be a complete mess.

The reason

Taylor i have posted somewhere how to control the delay time of 2 chips only with one pot, instead of setting the 2nd chip with a fixed time. This may be worth adding

Yeah that's definitely worth looking at, the reason I did it with a fixed delay was that was the simplest way to do what Valoosj wanted, which was just more delay time.

[mth5044]

Yeah one LFO can drive more than one chip. Using the Echo Base method you just need a separate PNP transistor for each chip, then you can either have one depth control hooked up to both transistors or hook 2 depth controls up to the LFO, so you could have different amounts of modulation on each chip.
You'd get some pretty mad sounds if the 2 PT2399s were in series though, because the modulated signal from the first chip would then get modulated again by the second chip, might sound great might just be a complete mess.

Well that sounds easy enough. What if the cap/resistor set up was used? Would it be just repeat the 4.7u/4.7k combo for each chip?



FWIW, I still play my stock echo base just about every day. I absolutely love it 

[Taylor]

I get a kick out of seeing my goofy schems posted around the place...  For some reason I used 2 different symbols for resistors in that one. 

Let me comment by saying that I don't see any point in doing the modulation on both PT2399s if you have them in series. You will get modulation and double time just by sending the mod signal into one of them. If you're doing the ping pong thing I guess I can see it.

[mth5044]

It will be for parallel (with the optional series, of course )

I'm doing a pseudo echorec with 4 pt2399's.. so I'm trying to get that sliiight warble, but having the ability to take the mod deeper like in the echo base. I'd rather do the resistor/cap thing as me and transistors never get along  

I might as well ask, also, what's the point of having 8v on the TL072? Wouldn't be easier to just apply the 9v onto it?

Also, scratch that last question, as I think I found the answer. Pins 3 and 6 need to be half off the supply right? so if I supply the TL072 with 12v, I can connect 3 and 6 to 6v?

[~arph]

I'm doing a pseudo echorec with 4 pt2399's.. so I'm trying to get that sliiight warble, but having the ability to take the mod deeper like in the echo base. I'd rather do the resistor/cap thing as me and transistors never get along  

Nice then we're working on a similar project. Are you having the PT2399's in series or parallel?
If in series you'd only have to modulate the first PT2399 to get the warble.
What are you doing with the post delay filtering for each of the PT2399's?

Regards,

Arnoud

[slacker]

I might as well ask, also, what's the point of having 8v on the TL072? Wouldn't be easier to just apply the 9v onto it?

Also, scratch that last question, as I think I found the answer. Pins 3 and 6 need to be half off the supply right? so if I supply the TL072 with 12v, I can connect 3 and 6 to 6v?

If you mean the LFO, powering it off the lower voltage is to isolate it from the main power supply, the theory behind this is that it helps stops noise from the LFO getting into the audio. If you're running it off 12 volts, you might get away with connecting pins 3 and 6 to 5 volts like I did or use 6 volts.

[Vitrolin]

hey what would be a suitable replacement for the 2N5089 i cant find it here, could it be mpsa18, 2n3919, 2n3904, bc547, 2n2222, bc172 

and i remember having seen a schem showing how to bypass the modulation and one how to make the led show the mod rate, i went through the 39 pages and didnt find any of the two 

i hope someone can help me

[slacker]

Any NPN transistor should work instead of the 2N5089, I would just use a 2N3904.

The schematic for the mod switching is in another thread http://www.diystompboxes.com/smfforum/index.php?topic=81668.msg676920#msg676920