Rebote 3 delay time question

[cparx]

Hey, I just completed building the Rebote 3 from TonePad.  Great board as usual! 

Has anyone else built this thing?  I have a very slow rate and a bit of background garble, I know the pedal was supposed to have a long delay, but does that exclude being able to do a fast delay?  I have done a few rebote 2 and the rate knob on that allows for some awesomely quick delay.  I guess I'm trying to figure out if this is how the effect works or if i might have something wrong.

Also...

I cut the trace between R4 and C13, bridged R4 to IC2 as in the fix on the website.
All values are the same as in the schematic.

[deadastronaut]

i havent seen the schemo for it...

but i'm guessing there are 3 transistors coming off all pin 6's yes?..(to accumulate the 'time' of each pt2399 to make a long delay)

you should be getting fast and slow i would think.

schemo link?..

[cparx]

Sorry about the delay, and thanks for getting back with me about this. 

it's a tonepad project - http://tonepad.com/getFile.asp?id=156

and it does look like all three chips have transistors coming off of pin 6.  any ideas as to what might limit the delay speed?

[ElectricDruid]

Having three PT2399's in a line will limit the minimum delay time quite a bit. The datasheet for the PT2399 gives a minimum delay of around 30msecs, so three of them is going to be 90msecs - nearly a tenth of a second, and not what I'd call a really short delay.

People have messed with the PT2399 to try and get shorter delays out of it (for chorus, for example) but it's not meant to go really short, and cascading them for longer delays just emphasises that.

T.

[deadastronaut]

when i used 4 x pt2399's in the abductor delay i had to use a 2M pot to get fast and slow delays...

[cparx]

Would r25 be the pot to tweak if I were looking to try a higher value like you did?

[deadastronaut]

R32 controls the delay time..

the bom 10k seems very small....try a 1M on there to start with ok.

[cparx]

I tried switching out that 10k pot with a 1meg, as well as a few other values - they're not getting me any closer to a quicker delay. 

i've built a few  effects but have no e.e. knowledge - could there be a resister somewhere in this circuit that might be limiting my delay time. 

As of right now this thing is fun for tooling around on, but it seems like my delay really wants to be a lo-fi looper.

Thanks for the help!

[peterg]

Cparx - were you able fix the delay time issue? I'm running into the same problem. The rate knob doesn't seem to do anthing.

[sajy_ho]

Yeah me too, the same problem!! I think tonepad.com even didn't tested it before posting the project file. I've searched the whole web and didn't found even one demo of Rebote3 delay. previous version(2.5) worked well for me but this one, not at all!
Does anyone have a project file from Deadastronaut's Abductor delay?

[karul]

Demo:

[peterg]

Karul - what does the rebote rate knob do on your build?

[karul]

peterg,

I haven't build one yet. I just found the demo and I've share it over here, that's all.

[peterg]

Ok. Thanks

[slacker]

What voltages do you get on the bases of the transistors? You should get between 0 and about 2 Volts depending on the position of the delay pot.

[peterg]

Ian - I get about 1.87 on the base with the delay pot set at 12:00. Removing IC1 from it's socket doesn't effect the sound at all so somehow something is preventing it from being engaged. Seems consistent with some other builds.

[slacker]

Does it go down to 0 volts? That's the crucial bit. Forgot to mention before this should be done with depth at minimum.
The LFO is copied from the Echo Base so will suffer the same problem in that it will stop working if the supply voltage drops too low, make sure your supply is at least 9 Volts. If you want to see if the LFO is working hang a LED and current limiting resistor off pin 1 of IC1, it should flash with the speed controllable by the rate pot.

EDIT: probably a stupid question but you have fitted C16? I notice for some reason it doesn't have an outline on the layout.

[peterg]

Thanks Ian. I will do further testing tonight. I noticed C16 wasn't on the layout but I have installed it.

[peterg]

Ian. The led doesn't flash no matter what the rate knob is set at. The depth setting does not affect the transistors' bases. The reading at the bases is between 1.93 and 2.48. Any suggestions?

[DimebuGG]

I made this for curiosity sake  . Designed and used my own layout. Well, it's working except that DIRTY "lo-fi" long delays similar to those single PT2399 circuits . BTW, I used 20K-A pot for delay knob(...don't have 10K on hand).