Why does my GE7 sound worse with a power supply?

[Killthepopular]

I bought a crappy old second hand GE7 last year and it's given me loads of trouble. It's got a black label and is made in Taiwan.

When I first got it it wouldn't work with a battery. I decided that the power jack might be defective in some way and was permanently breaking the circuit to the battery even when no power supply was plugged into it. So i ordered a new boss style power socket and soldered it in place of the old one and that seemed to do the trick. It now worked on battery power.
Another thing I did was replace the 3 IC chips with TL072s to get rid of that weird hiss that a stock GE7 (the old ones anyway) seem to put out.

That's all just a record of the pedal and the mods I've done. They may be unrelated to the actual issue I'm having. When I plug in a power supply the LED doesn't light up and the sound is different somehow, it's thinner, duller, murkier, maybe a bit fuzzier like there's less headroom. It's a subtle difference, not night and day but it's enough to make it sound weird. When running on battery power the LED lights up nice and bright and the sound is crisper, clearer and maybe slightly louder.

So that's the issue. It seems to me like maybe something is disrupting the power line so that the circuit isn't receiving the full 9v but I dunno, I'm guessing. Any ideas why the battery would work but the power supply sounds kinda saggy? Or any suggestions on how I can diagnose the problem?

[intripped]

maybe this article will help
http://stinkfoot.se/archives/726

[cab42]

maybe this article will help
http://stinkfoot.se/archives/726

That explains a lot!

Back in the day I solved this by making a battery clip adapter for my power supply. I thought the dc input was broken.

[Killthepopular]

maybe this article will help
http://stinkfoot.se/archives/726

Yep, that was it. I had to remove and jumper d1 and r1 and now it works fine. Seems a weird policy for boss to make devices that ran on 9v but wouldn't work with 9v power supplies. I'll have to keep this in mind if I buy any more old boss pedals.