Harbinger One issues

[Manc]

Right good people.
Been a lurker for some time here, and got inspired by fellow forum members to step up my game and try my hand with something actually complicated....
I've built a Harbinger One and it fired up first time around 
Only it was way too tame, so I did a bit of searching here on the forum and swapped R45 with a 4.7K resistor. It did the trick!!!
Now to the issues: compared to my Fulltone Minidejavibe2 the sound is quite darker, the "intensity" pot doesn't seem to have a big impact (B50k pot) same as the "offset" trimmer (250k).
In fact the depth of the effected sound is quite shallow.
Could it be the cap I used to cover the bulb&photocells combo? I used a plastic cap covered with black electrician tape. Could some reflective aluminum tape on the inside of the cap make any difference?

I'm still quite chuffed I pulled off this build  ... I'd love to address these minor points tho.
Thanks all for your input!

[Manc]

Should have mentioned I built the 9v version and I'm using a regulated PS (Gator Bus G8). It puts out 1700mA according to the specs... I will purchase some reflective alu tape and report back.
Cheers