Hi,
Probably, this question already came up in this forum already. But the topic is also quite subjective.
I’m looking to extend my setup, which currently consists solely of the ST. I’m making almost exclusively techno music and wonder what gear would accompany the ST best.
I think a sampler is a part that would enable more opportunities. Does anybody have experience with the DT/OT or SP404?
Then, also a wavetable synth will join sooner or later…
Thanks for your input!
I’m in the same boat. Was going to get the sp404 new but have seen a good deal on used Digitakt. See what happens lol
Welcome to the forum!
Indeed. What features are you looking for in a sampler?
Purely from the perspective of getting two boxes to change patterns in perfect sync when receiving program changes, I would recommend sticking to another Elektron box.
I’ve got an MPC Live and an OP1 and I can still see the benfit of getting a Digitakt or OT, just for that workflow similarity.
Hell, if the Digitakt MkIII is stereo and plays multisample instruments, I might drop the MPC altogether
Hydrasynth, Waldorf M or Minifreak.
That will be a budget decision I think 
Maybe Korg Modwave… Or Argon8
I’ve had an MPC One but never connected to the sound and feel of the device. Although, I see its benefits and the sheer amount features.
I understood that the SP404 is superior to the DT in terms of sample handling like slicing and time stretching if that is correct?! It feels like the DT would have too much feature overlap with the ST. Also, I heard that the effects of the SP404 are quite nice.
The OT is probably the fitting piece, but much more expensive and has a lot of overhead in its complexity.
What I think I need as an extension to the ST is Sampling and maybe some end-of-chain effects.
I have the Digitakt and Digitone along with the Syntakt and all three play really well together. But I have also linked it up to the UNO, BSII, MPC One, MPC1000, and Minitaur without any issues. Just depends on what you want from the sampler.
I use the OP-1f. Great for recording to tape and arranging/adding later on the field. Samplers are great too and I also use it as a looper.
I’m using an SP. I think it compliments the Syntakt quite well. It’s super fast and easy to use and doesn’t have any overlap. Plus it’s super cheap.
Never considered a MPC ? I got a MPC One and it can do so much. There are adding loads of plug-ins too, lately they added a Moog Model D replica.
If you can, get an OT. Such a wonderful device.
Can’t go wrong with Elektron samplers. DT or OT - pick your poison 
With OT CUE out sent to ST inputs ST back to OT with feedback you can get cool fx, like pitched delay with analog drive and filter…
Easy stereo sampling of loops, synced to ST. Other samplers may need editing.
Easy recording of sample chains of (layered) drums with different settings.
Additional FX
Crossfader’s magic
I wasn’t expecting this answer from you. 
I started my Elektron journey with a Digitone, fell in love with the workflows and picked up a Digitakt as a follow-up. Once I confirmed (within a day) that the Digitakt was everything I had hoped for, I sold my MPC Live as being “too much” for what I wanted to do with hardware-based music creation. Picked up a Syntakt when it was released to “complete” the setup.
Me, I love the consistent workflows and complementary sound generation between these three units, but you’ll need to decide: do you want to keep with the Elektron Way, or do you want something completely different like the 404? And if Elektron, do you want the relatively easy transition to the Digitakt that literally has the exact same layout and almost identical sequencing as your Syntakt, or are you ready for the deeper challenge of an Octatrack?
Most importantly (from my perspective, YMMV), what are your specific musical/workflow goals and which sampling device best meets them in a way that is satisfyingly similar or different than the Syntakt and that you can grow with over time?
I personally LOVE the Digitakt with the Syntakt (and Digitone), but others also swear by the Octatrack/Syntakt pairing, which does seem beastly.
Just some points to ponder. 
By the sounds of it, you want more of a performance sampler, something that can catch loops and maybe add FX to what you’re putting out from the Syntakt…
SP404 or the Octatrack if that’s the case.
If you’re looking for a proper ‘sampler’ sampler, as in being able to record the sounds/output of the Syntakt and manipulate them into fully fledged instruments, then probably an Akai MPC of some description would be the best match.
Also, the Akai Force is a really good combination of both types of approach, and a great match for a Syntakt… all the real-time performance you could want, plus the ability to create your own Drum Programs and Keygroups from the Syntakt.
I sent my A4 MKI today.
OT and ST only after a few Elektrons. 
(Waiting for an HS E) 
Nice!
What’s that?
Yeah OT is probably the go-to. But still expensive. Has anybody experience with the 1010music blackbox?