I may have posted this elsewhere, but I've had a few octavers and this is what I've found,I've included some rough guides to the used prices 😁
Purely my opinion of course,I'm sure others may disagree.
BOSS Oc2/ 3/
Very synthy and warm sound,the benchmark for octavers. Doesn't track well but has that sound,which is great for synth tones or even the classic 80s "Pino tone" with the clean up full. - approx £80-£200 depending on condition or year.
OC3 is a digital version and tracks very well, has an OK tone (not like the OC2) poly mode is useless on bass and the distortion is awful - approx £60-80 used.
I haven't tried the OC5 but I think it's still digital even in vintage mode. Sounds close to the OC2 in the demos to me,enough to make me want to try one. The octave up is a nice touch,once again poly is useless- approx £120 ish
Valeton - OC10
inexpensive and very small clone of the OC2. Even the colour and design is the same, only very small (not far away😂) for me gets 90% of the tone, it's just not quite as plummy or deep. Tracking as per the OC2 as well as overall low volume from the unit. Sadly discontinued, these used to be cheap, maybe not anymore. Approx £35+
EBS Octabass- one of my faves! Tracks really well and has a smooth,deep,natural tone and 3 modes for Tonal variation (I've had 4 😂)approx £70-120 depending on condition and version (there are now 5)
MXR bass octave Deluxe
Nice small size and tracks very well. Has two voices meant to replicate the OC2 and EBS these can be mixed,however found thst one tone always dominates the other,so really only two viable tones. Has a very cool mid boost to add punch. This model has a well documented issue (which I can confirm mine suffered from) in that it has a constant subsonic warbling noise when switched on,not noticeable when playing though. Reason given by the company was that it was so sensitive it picks up noise. I got rid as it annoyed and it's a massive shame as it's tracking and tone are excellent. - £75-95 (amendment- I got another of these, and no noise issue, so try not to get an early one, fantastic clean octave)
MXR vintage - small size and based on a vintage OC2 earlier units still have the noise problem, I believe this has been sorted. - £100-120
COG T16/65/70
The T16 is a tiny enclosure and features a filter on the octave so it can sound synthy and aggressive or deep and clean.tracks fairly well about as well as an oc2 I'd say (this can cop an OC2 tone very well with the filter) V1 has a volume issue on the filter,this was sorted on V2.
T65 is the same only has an additional octave up. Thus isn't the same as a POG as the octave up is analogue whereas it highlights the 1st order harmonics and adds some dirt really. Very dirty sound and fantastic for synth,however even with the octave up dialled down it still sounds dirty,and the tracking is not the best (strangely I found the T16 tracks better) It also has a very useful parallel loop,so it can run in parallel with other effects. It means your octave sound is clean underneath fuzz/filter etc
T70 is basically 2x switchable T65S with a third sub only channel (to get the classic OC2 sub trick)I do feel the T65/70 is more of a synth engine than an octave.
T16- approx £80-100
T65- approx £100- £130
T7O-£180-200
Cog is currently not building,so you don't see these so often, prices are likely to go up.
Aguilar OCTAMIZER
The one octave thst is all things to all men. It can do synthy or super fat and deep with the filter switch. It also has a useful tilt EQ (this can be used as an effect in itself with the octave turned down)built like a tank and sounds fantastic. Unfortunately IMO it's the worst tracking octaver I've ever used (I know this will open a can of worms)approx £80-120
Digitech Bass Synth Wah
On top of it's various synth and filter modes, it has a synth octave. The synthy tone can be dialled out,leaving it as a digital octave. Tracks very well and sounds great,although not as fat or organic as Analog octaves. Approx £35-75 depending on whose selling😂
EHX POG
A digital pedal with a very unique voice,it's very "organ" like. It tracks well but has a very synthetic sound,which can sound cool in certain situations. Approx £80-120 depending on model/condition etc
Emma - Okto Nojs
A dual pedal with seperate octave and fuzz, just referring to the octave. Has the usual modern octave feature of a filter on the octave signal, can can get deep and clean to dirty and edgy. It reminds me a bit of the Cog T16, tracks fairly welk if you play up high (which I always do) decent octaver with nothing out of the ordinary, but missing it with the dynamic fuzz, yields very synthy results a great fun pedal. Used approx £100- 130 (amendment- the octave does not track well at all with active basses, unless played right up in the dusty end,No issue with passives)
Iron Ether -Subterranea
Not pedal you see everyday, however I'm now on my second one of these, and for completeness, I'll mention it.
A boutique Octave/synth, no two look the same and the enclosures are a work of art. At its heart it has an Analog Octave with the filter as others have, so the octave signal can go from smooth and deep, to dirty and edgy. Once again this can be set to sound OC2 ish (Very close I think). It has two additional synth voices, one in unison with your signal and one an Octave down. It has two three way switches so you can set these voices to square/pulse/triangle wave making for some very interesting tones, for some reason the uni synth doesn't track well at all, but used sparingly it adds a great edge on certain waveforms, the octave synth tracks fine. I've found the tracking on the octaver isn't great (No worse than the OC2),however as the sound has a glitchy lofi kind of vibe with the clean signal off, it just sounds incredibly cool and I've a lot of love for it. Used (If you can find one) £150- 200
There is a modern digital version called the Dubterreanea which i haven't tried, but seems to have improved on some aspects (2nd footswitch for the synth voices, very handy)
Sorry for the novel,Just thought I'd share my thoughts on my favourite effect.
Apparently the 3 leaf Octavbre is fantastic,but I haven't owned it, and it's £££££