High-bandwidth Decouplers?

[nightcap]

Hi everyone

Soon I'll be swapping/upgrading caps in a SS MC phono stage and have resolved most technical issues already.

One aspect, though, has drawn mixed opinions from experienced circuit designers, viz, adjacent decouplers to high-bandwidth, high-gain op-amps. I'm aware of the need to minimize inductance in these caps and the logical, technically-astute option is stacked polyester (Epcos 0.1uF 250V at the ready).

However, I've read that some DIYers are pleasantly gob-smacked by the use of Black Gate's in "L cancelling - super e cap" decoupler format. I also have some BG NX 0.1uF at the ready.

One circuit designer is absolutely resolute in his opposition to BGs in this situation, as there "will always be some small level of residual inductance and one cannot consider electrolytic decouplers for high-bandwidth op-amps". Meaning oscillation or worse I wonder?

So who's compared stacked polyester and Black Gate as decouplers in this situation? Any clear sonic evidence to support one over the other?

nightcap

[Jonathan Bright]

can't help on that specific comparison but I saw an article E&WW(and I can't remember when) that was adamant that a 10uF electro' cap between the +ive and-ive lines was v.helpful in addition to the conventional power supply to ground. Might be worth investigating. I also recall that Analogue Devices (and prob' many other) manufacturers have good application notes on decoupling. Still I suppose you've done that already. Not under water are you?

[nightcap]

Thanks Jonathan.

Yes, this subject seems to raise its hoary ol' head every other day, and elicits multiple opinions. No doubt after completion of my A-B testing I'll add to the maelstrom!

Only slight risk of drowning down this way (thus far), but mould, rust and mud loom large. Long range forecasts indicate El Niña effect remains dominant......isn't Queensland beautiful one day, perfect the next?

nightcap