MFATGG are the world’s best cover band, and that is a scientific fact.
Back on track, PWEI’s version of Sigue Sigue Sputnik’s ‘Love Missile F1-11’ is vastly superior.
I’ve used both the lh500 and lh1000 - sometimes it was mine, other times it was the back line at festivals and I’ve never found them lacking in anything.
The only real difference (apart from an extra 500W) is that the LH1000 can be bridged to run at 4ohms.
Do you have a spare 9v output on your 'isolated' supply? you could buy a 'current doubler' which effectively runs 2 9v outputs in parallel (still 9v, but twice the current, so effectively a whole amp).
sounds like you're drawing too much current from your power supply. Digital effects are notoriously Amp-hungry.
Check that your supply can deliver the required amount of current through each of the outputs.
Also some supplies don't like reliving current to a mix of analogue and digital devices at the same time.