Thanks for the responses everyone – learning a lot.
The point about utilities being the secret sauce of modular is interesting. I guess, like Nick said, its hard to grasp at first because unlike oscillators, samplers, filters, envelopes, LFOs etc, 'utilities' don't really exist in the conventional world of music and are unique to modular (to my limited knowledge).

They are mostly hidden

I'm pretty committed to 2 x 84 HP, just because I don't have a lot of space, and want to keep the arrangement of gear on the desk relatively flexible. Also I don't plan on building a massive collection of modules, I'll probably buy/sell stuff until I have a setup I'm happy with, but who knows... If I do eventually want to go bigger I'll probably just get another 2 x 84. Also I think I want to stick with eurorack because I'm not too interested in building a conventional synth – I like the range of unique stuff in eurorack.

104hp is 10cm wider - depending on the case a mantis may only be 8cm or s wider as it has very thin sides

I live in Australia which has unbalanced mains power. How much of a factor is noise? I've read that modules tend to put out a pretty hot signal, but yeah I might just follow Jim's advice and try without, then attenuate, then balance. I'm only running it into either an octatrack or external soundcard.

good luck!!! - are the inputs balanced or unbalanced on the octatrack and sound card????? if so then you may want a balanced output!

hot doesn't have anything to to with balanced - it just means the peak to peak of the voltage is higher than line level


Re VCAs: what's the difference between a VCA and an envelope/LFO module? also VCA vs attenuator?

a VCA is a voltage controlled amplifier, although most only have unity gain, so are technically attenuators and not amplifiers

you send a signal (audio or cv) through the VCA and control the amount of the signal let through with an envelope or lfo

attenuator is manually controlled - vcas may also be able to be manually controlled

"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia

Utility modules are the dull polish that makes the shiny modules actually shine!!!

sound sources < sound modifiers < modulation sources < utilities