Nostradoomus
Well-known member
yep
Sea Horse Mods
- Thread starter Chuck D. Bones
- Start date
Chuck D. Bones
Circuit Wizard
That's what I did.
Matopotato
Active member
Just wanted to say thanks a lot for this @Chuck D. Bones !
I tried all five, but in the end I only choose the last/Shape mod. I felt some of the others changed the basic character of chorus/vibrato a bit more towards delay with modulation, but still happy to have tried them.
I read elsewhere (doc for Vector by Aion FX + A thread at diystompboxes ) about issues with PT2399 and how to reduce unwanted noise by adding a green clear/transparent 3mm LED from pin 7 to ground (in parallel to the 100nF cap already there). Aion FX recommended a Vf of 2-2.3V, which I couldn't find any one LED that matched, so in the end I put a diffused green LED in series with a BAT43 to reach about 2.1V. And I felt that had a good impact on potential noise. (Fairly hot humbuckers, hitting base strings quite hard. Full Volume etc). 1.9V from LED only reduced it some, but not quite, and 2.5V clear one didn't seem to change much, so I will add the diffused green LED + BAT43 for my PT2399 builds from now on, if needed.
I tried all five, but in the end I only choose the last/Shape mod. I felt some of the others changed the basic character of chorus/vibrato a bit more towards delay with modulation, but still happy to have tried them.
I read elsewhere (doc for Vector by Aion FX + A thread at diystompboxes ) about issues with PT2399 and how to reduce unwanted noise by adding a green clear/transparent 3mm LED from pin 7 to ground (in parallel to the 100nF cap already there). Aion FX recommended a Vf of 2-2.3V, which I couldn't find any one LED that matched, so in the end I put a diffused green LED in series with a BAT43 to reach about 2.1V. And I felt that had a good impact on potential noise. (Fairly hot humbuckers, hitting base strings quite hard. Full Volume etc). 1.9V from LED only reduced it some, but not quite, and 2.5V clear one didn't seem to change much, so I will add the diffused green LED + BAT43 for my PT2399 builds from now on, if needed.
Chuck D. Bones
Circuit Wizard
You're welcome.
The LEDs are supposed to cure distortion issues. My experience with distorting PT2399s is that there are good ones and bad ones. The LED fix doesn't help if the PT2399 in question is a "bad one." I've breadboarded quite a few PT2399 delays, flangers & choruses and didn't need the LED fix on any of them.
The PT2399 has limited headroom and if you overdrive them, they will distort. The fix for that is to reduce the volume going into the PT2399 and then amplify it by the same amount coming out. One can tailor the attenuation and amplification to de-emphasize and then re-emphasize the bass frequencies since those frequencies have the higher signal level.
The LEDs are supposed to cure distortion issues. My experience with distorting PT2399s is that there are good ones and bad ones. The LED fix doesn't help if the PT2399 in question is a "bad one." I've breadboarded quite a few PT2399 delays, flangers & choruses and didn't need the LED fix on any of them.
The PT2399 has limited headroom and if you overdrive them, they will distort. The fix for that is to reduce the volume going into the PT2399 and then amplify it by the same amount coming out. One can tailor the attenuation and amplification to de-emphasize and then re-emphasize the bass frequencies since those frequencies have the higher signal level.
Matopotato
Active member
Is there a "stripped down (?)" Way of testing PT2399s? Or better.off socket them in some build and run through the ones you have?
Chuck D. Bones
Circuit Wizard
Look for a very simple delay circuit, such as the PPCB Seabed Delay.
The PT2399 datasheet also contains some example delay circuits.
The PT2399 datasheet also contains some example delay circuits.
Matopotato
Active member
Thanks, have the Seabed so I can use that to test out.