TOPIC: How to create custom decay! It's possible?

The dude is the next!

I have create various "soundfonts" from nokia S40 5th edition, S60 3rd edition and Nokia Series 30 and the issue is samplers recorded have linear. decay and the standard sf2 decay is exponential

any form to create similar or same decay. because if possible my soundfont will be more precise!

Thanks!

It is not possible to say anything without the original wav sample or a minimal soundfont.
Maybe you should never interfere with the decay parameter.
Thus, the original decay remains constant.
According to what I see in the picture: it looks like you added decay to the original (natural) decay in the wav sample.

To supress decay from bass sample, i use the technique of compress and after compress i will find the loop. after create instrument the decay appear on exponential instead of linear.

An exponential release sounds more natural than a linear one in a volume envelop, that's why Polyphone makes it this way (to the opposite, the modulation envelop uses a linear release). There is unfortunately no options to select between linear or exponential. You might have a slightly different sound from you Nokia, but a better one