Hissing PT-80 input buffer

[cardsharppro]

Hello!
I've built a PT-80 delay but i'm fighting hiss on the input buffer. I read all topics about it but got no answer..
This is what i've done:
-Removed all other ICs
-Tried different power supplies
-Replaced TL072, and tried other OPAMPs
-Replaced components

All resistors are metal-film. I also simulated the freq response of the input buffer and it shows 18db gain on higher freqencies, so i raised 470pF capacitor to lower the gain in the 10-20Khz range. Some beneficts, but still lot of hiss.
Any idea about? Reference schematic is the one of GGG

Thanks

[R.G.]

Hissing is often caused by bad contacts or by RF oscillation.

Is your circuit showing RF oscillation?

If you don't have a scope to tell, how well is your power supply bypassed?

[cardsharppro]

Thank you for the reply RG!
Yes i do have a scope, i did a check and everything seems ok, i only get the switching spikes of my PSU, but well above audio range.. I use separate supply for digital and analogue supply, and both are 100uF + 100pF bypassed. Same thing for Vdd/2 reference.
Tried with RC4558, AD712 but nothing changes..
I plug my delay on the HI input of my jtm45 so the hiss comes out a lot. Component values are ok, i also tried to raise the 1K feedback to 10K but i loose top and doesn't solve the problem.
I don't get this behaviour...

[cardsharppro]

I solved, lowered the gain at input and compensated at output buff to not color the dry signal