4 pt2399's in series / long clean delay..

[deadastronaut]

no they don't... you should have bought her some earplugs for xmas.. ...

[deadastronaut]

UPDATE:

well the design has gone through some major changes to this..

i am now using the rebote 2.5 in out section..

the delay time of all 4 pt2399's  is controlled from the first pt..

and the repeats/level is controlled from the output of the 4th pt...i had to re-evaluate it as there was a fair bit of background hiss , even before playing anything....and i'm not having any of that old bollox.. 

and now have the repeats nicely above unity if i like...which i do, without it being a noisey bugger..

i have to alter my lfo now as its a bit on the extreme side, but that's a relatively easy thing to adjust ..

but its looking way better than before now..i'll have to redraw out a schemo once ive sorted the lfo, and then i'll add on the 'chip jumping' again..which were very cool options.

anyway...back to the grindstone...

[~arph]

thanks loylo, i'll have a good read through that.

hopefully arnoud 'arph' will chime in on his experience/knowledge with the pt's too...

cheers..

w00t hey! missed this thread.. ( I've been away from DIYSB for a while.. too cold in the shed to do any projects)
As for hiss. I started on a redesign, but never really finished it. I believe one of my main sources of noise was the mixing opamps. They should be non inverting or inverting only. (one of the two is much noisier then the other, non inverting I believe). And yes, I used a downward expander IC (SSM2166) , but I think I'd drop that now as with the right opamp mixer topology and relative short delays plus some filtering at each PT2399 the noise was OK.

For the Binson swell sound you mix the output of all four PT2399 together and take the repeats from PT2399.

[deadastronaut]

@arnoud: cool glad you caught this thread...

so non inverting then...hmmm...the rebote is isn't it?..

ive yet to try this through my amp, but it seems ok at the mo, the repeats overunity introduces some hiss though, but i guess thats par for the course..

but used as i would normally use a delay its fine...so far.  

[~arph]

see, there you go. I believe non inverting is the LOW noise option.

The rebote is non-inverting.

It only starts to matter when you mix multiple playback heads

[deadastronaut]

righto, cheers man...i'll crack on then..

[deadastronaut]

https://dl.dropboxusercontent.com/u/7464107/4ptdelay.mp3

clips of what i have now....jumping chips, and self oscillation/modulation  etc...

i love the chip jumping, really adds depth to it, rather like a reverb in the trails...very nice.

ive made the level of delay able to go way over unity...which is cool for sequency style stuff..

just want to tinker with the lfo a little more, and re test the fet switch a little ...but its nearing the final schemo stage...thank f...

it won't be a build for the faint hearted, with 5 toggle switches 5 pots etc...

these clips were all in short delay mode...but there will be a switch that kicks in an additional 1M resistor to the delay control for uber (but noisier lofi) longer delays.

[jimilee]

I needs one!!!!

[deadastronaut]

^ yeah me too...i can't wait to box this beast up, it'll definately be a keeper for sure

i'm having my first crack at doing a schemo in eagle (i usually just knock up pcb's in diylc) ....it's a huge learning curve in one or 2 days , but its almost there surprisingly....

apart from finding out i should have used 'nets' instead of @#$%ing 'wire' ... luckily before i got too far with it.  ...( a few more tutorial vids to get through though i think)

anyway, some minor adjustments to get this lfo just right, and i'll be a happy bunny..

[Tony Forestiere]

anyway, some minor adjustments to get this lfo just right, and i'll be a happy bunny..

Happy Bunny. (No relation to Marc. I think?)


*edit* Poo! I forgot to say how nice and clean it sounds. That weird up/down warble is seasick neat. Good clips.

[deadastronaut]

cheers tony..

i think marc has the same ears..



yes it's getting there ...mrs astro is sick of it, so thats a good sign.. ...but it has been a few months of tinkering, i'll get her some headphones for valentines day.... 

[Jdansti]

Just listened to the demo - Awesome! 

[jimilee]

^ yeah me too...i can't wait to box this beast up, it'll definately be a keeper for sure

i'm having my first crack at doing a schemo in eagle (i usually just knock up pcb's in diylc) ....it's a huge learning curve in one or 2 days , but its almost there surprisingly....

apart from finding out i should have used 'nets' instead of @#$%ing 'wire' ... luckily before i got too far with it.  ...( a few more tutorial vids to get through though i think)

anyway, some minor adjustments to get this lfo just right, and i'll be a happy bunny..

killer man, delays are like candy!

[bluebunny]

Happy Bunny. (No relation to Marc. I think?)

As you can imagine, there are *lots* of bunnies.  Could be related.  Might not...   

i think marc has the same ears..

Yeah, they cast a shadow... 

i'll get her some headphones for valentines day.... 

You need to get Mrs A. a "Big Muff":

   

Anyway, bad jokes aside, looking forward to the final push, Rob.  Great job!

[deadastronaut]

 

cheers man..

[deadastronaut]

ok, had a bit of time out on this...its almost there now..

the only thing that is bugging me is:

the repeats difference when on and when in bypass...(fet switched)


say i have 8 repeats when on...

when bypassed i get a lot more... (same switching as merlins small time delay)

any ideas on how to make this more 'equal'' ?..

[samhay]

It's probably an impedance mismatch again. Got a recent schematic?

[deadastronaut]

hi sam, yep here ya go..





EDIT: btw the switching is lovely and silent, i turned my reverb on my mixer up fully wet and couldn't hear a peep out of it...very cool.

[deadastronaut]

bumpety bump...

[samhay]

Haven't had a proper look over the entire schemo yet - it is indeed quite a beast.
As a starting point, have you tried setting up the repeats and mix pots like Merlin's Small Time? He uses smaller pots and has a couple of additional resistors, which might help to reduce their interactivity.