+1 for Source Audio Collider. Based on the built-in effects in MicroMonsta 2, I bet Doctor A would also be quite nice (I have listened to demos, but don’t have direct hands-on experience).
Uhm not sure if it makes sense for your setup, because it‘s available as a plugin too – but for roomify‘ing a harmonic sound I‘ve been enjoying the Eventide Micropitch lately a lot.
For certain settings it can make a strongly modulated reverb ‚splash‘. It‘s actually working like a chorus/flanger, but the pitch shifting can make it sound much more complex. Nice stereo width and tone control too!
It doesn‘t have many different algorithms or whatever but it does its one thing pretty well and versatile.
Zen Delay is easily my favorite delay. And the Mercury7 my favorite reverb. But I’ve got to call out Doctor A because more and more I don’t set the other two up and just use it instead. It’s somehow alway what I need when I need it.
Earlier I set out to refute this and in the recent transactions history on Reverb there was a unit marked “excellent condition” that sold for $450. So it is possible. But it would take some work and agility. I would say $600-700 is more realistic, which is twice the new price of some of the units mentioned. Of course you get a lot more than just delay/reverb. But while the A4’s effects are quite good, I don’t think they have as much diversity or character as a specialized unit. It really depends on the ambitions of the OP. One other advantage of the A4 is that it can supply four CV sources to the Subharmonicon, driven by that excellent sequencer, including its arpeggiator.
Whoever got that, it was a gift!
Certainly couldn’t state you can get an A4 for $500 routinely. $700 perfectly normal.
Anyway, I’ve got a Ventris and Nemesis sitting on my desk that can be had new for less than a used A4 and crushes it’s reverb/delay in every category. I imagine the Collider is a steal for that same duty.
Like you said, unless the OP needs another synth/sequencer.
I’ve gotten two A4s for $600 and $550 respectively. You’d be surprised at how many people sell them cheap in hopes to raise money because of a new case of gear acquisition syndrome. I’d have three right now if I didn’t trade one for a DN.