I've built the guitar, built the amp, and next.......

[ecca]

I've timed it up but it sounds a bit fast to me.
101,199,278,353.... ish.
Still troubled by racket.

2399pattern.JPG

(80.62 KiB) Downloaded 4581 times

[rogera]

Ignoring the noise that is causing a problem, I notice that the 4th repeat at around 360 msec is slightly less than the others whereas it should be larger.

[ecca]

Thanks Rog !
I'll attend to it.

[Detailed Infinity]

Hi Eric--good progress. Regarding the noise problem you're experiencing is there some way of incorporating a noise gate into the circuit either onboard or post signal?

You don't need me to say what a noise gate is however here's Wiki for those who don't http://en.wikipedia.org/wiki/Noise_gate

Bri

[ecca]

I will be putting a sound sample up soon and may gate it post recording but I don't want to incorporate it into the design if I can help it, I'll persevere trying to get rid of the noise in the first place.

[ecca]

I'm on the edge of giving up.
It's just so noisy and I don't seem to be able to cure it.

[Detailed Infinity]

No Eric don't pack in. Give it a few days and have another head scratch. I for one would love to see you succeed.

As an aside, I replicated your timings using Sound Forge's mulitap echo and It is a do-able sound at those timings.

Bri

[ecca]

Here's a link to a recording I've made of the various noises from the 2399 echo unit.
Watch the volume, the speaking is quieter than the sounds.
The recording was done using a Zoom H4 recorder right in front of the amp.
Feedback is taken from 'head' 4.
Each 'head' is a 2399 chip.

https://www.box.com/s/67c4df82241714fd3c9c

[fenderplucker]

Hi Ecca,

It sounds to me like the interaction between the clocks of the 2399 chips bleeding into the audio signal. If you haven't already got it, you need a steep cutoff low pass filter between the 2399 stages, something like 6-7 kHz cutoff and at least 24dB per octave. Also pay attention to filtering of the supply lines at each chip and a robust earthing system.

Hope this helps,

Paul.

[ecca]

In practical terms....... how ?