Renegadrian PT2399 LoFi Delay build question?

[Jasonmatthew911]

Hey guys, I know many of you have built this simple circuit...Anyways, I just breadboarded Renegadrian's PT2399 Lo-Fi Delay, and I'm basically just getting crazy random oscillation noises when I move the 2 pots....I connected my guitar to the input, and it seems like the guitar signal barely gets through the circuit, once in awhile when I move the pots to a certain position, it seems like the guitar signal kind of gets through for a bit and activates a different noise oscillation....So, is this how this circuit is suppose to work or should my guitar signal always be sounding through the circuit?....I know it's a Lo-Fi Delay, but I'm mostly getting noise and oscillations with some kind of delay...The noises are actually pretty cool, but I was expecting more guitar sound being delayed with a Lo-Fi quality sound I guess....Can you guys just clear this up for me?...I'm not sure if I have a problem or if this is how this circuit works?...Thanks

[Jasonmatthew911]

I even tried connecting an Oscillator device I made with 4 oscillators, just to see if the circuit reacted anything like the You Tube videos I've seen of the GetLoFi PT2399 Delay....When I move my oscillator knobs of my other device it doesn't do anything really...The PT2399 LoFi Delay is doing all the noise and oscillation on it's own, it's like there is almost no point in having an input jack for an external source right now, so I think something must be wrong, which I find odd, since I breadboarded this twice just to make sure, plus it's such a simple circuit, yet I have no idea what the issue could be with the input source...Any help?

[Jasonmatthew911]

Nevermind about me thinking my build had an issue...I just tried it with an Atari Punk Console Square wave oscillator and now it works just fine like the videos on you tube....I guess you need a simple waveform for this circuit, it's no good for guitar....Can anyone tell me the simplest PT2399 LoFi Delay that could work good for a guitar signal?....I'm trying to fit this in a very small box, so I need a very simple delay that works (Least parts as possible), I don't mind if it's not the best fidelity.

[rousejeremy]

I never had luck getting it to work with guitar either. I suggest Madbeans Cave dweller. You could fit it in a 1590A!

[reverberation66]

    I don't think the lo-fi delay as posted by renegadrian is supposed to work as a stand alone guitar effect.  It needs something to boost the input signal, that's why it works with apc and not guitar.

[Renegadrian]

Yeah I did the layout just for the lulz! I built it and didn't have a decent sound with guitar...

[Jasonmatthew911]

Yeah I did the layout just for the lulz! I built it and didn't have a decent sound with guitar...

Have you tried the circuit with a pre-amp stage before it or do you think it's worth it, just to see how it sounds with a guitar?

[Renegadrian]

Actually I didn't - btw check their site,they recently updated the schem!!! You will find the layout there...They say it works with guitars too...Else I'd say check the first version of the rebote, it had a buffer before the 2399 input.

[Jasonmatthew911]

Actually I didn't - btw check their site,they recently updated the schem!!! You will find the layout there...They say it works with guitars too...Else I'd say check the first version of the rebote, it had a buffer before the 2399 input.

I'd like to try building that new PT2399 LoFi Delay on GetLoFi, but there is no schematic or layout on the page...They only have kits for sale it seems....Is there any way to get that schematic?

[Renegadrian]

[Jasonmatthew911]

Thanks...Just 1 question...What pins of the PT2399 do the 2 traces on the top and the 2 traces on the bottom go to?...I can understand all the traces except for the ones that just seem to be going into the middle of the PT2399 on the top and the bottom, I can't follow those traces to any specific pin....Do you know what pins those 4 traces are connected to?

[rousejeremy]

I kinda wondered the same thing when I first saw this. Are there any trace connections under the IC? It's impossible to tell without a schematic, but I bet if you looked at the datasheet for a PT2399 you could figure it out.

[Renegadrian]

pin 6 is going to delay time 3

[Jasonmatthew911]

Thanks...I looked at another schematic...So besides lug 3 of Delay pot going to pin 6,  Lug 1 of 20K Repeat Pot should be going to pin 16, and at the Top part of the chip we have a GND trace and pin 14 for Output trace...I think I got it now....I'll give this a try one of these days, and report how well it worked for guitar...

[Renegadrian]

that should work - please remember to report back with pictures too!!! 

[timd]

Old thread - sorry. Was there any updates on this one? The OP stated that no/little sound was coming out of this thing, but it worked with the Atari Punk Console. Could the original layout work with guitar if the 2399 opamps were utilized to drive the circuit?

[deadastronaut]

Hi Tim, i never got the thing going, and im not surprised, if it did get going i,m pretty sure it would suffer from locking up...

i would go with another pt design.

[petey twofinger]

me too .

[bean]

Nevermind about me thinking my build had an issue...I just tried it with an Atari Punk Console Square wave oscillator and now it works just fine like the videos on you tube....I guess you need a simple waveform for this circuit, it's no good for guitar....Can anyone tell me the simplest PT2399 LoFi Delay that could work good for a guitar signal?....I'm trying to fit this in a very small box, so I need a very simple delay that works (Least parts as possible), I don't mind if it's not the best fidelity.

I'll plug the Cave Dweller too. You can etch your own board. It's lo-fi. It fits in a 1590A. Or, if you want a challenge, the same doc has the "dub" edition which gets you about 1 second of delay (2 PT2399s) in a 1590A. Etching artwork also available.

http://www.madbeanpedals.com/projects/CaveDweller/CaveDweller.pdf

[timd]

Yeah, I'm going elsewhere for this one... I did find it curious that the "revised" layout in the picture mentions starting with both pots fully clockwise for the sound processing to start. What? Why? Does this have something to do with lock up? What causes this chip to lock up?