Recommendations for a tubed preamp

I’ve used both a Trafomatic Reference Line One and Trafomatic Lara with an S5.5 and No.8 Coda with amazing results.  Both preamps are outside of your price range unless you can find a used Ref Line One.  They do however have a Head2 which is a dual purpose headphone amp / preamp in or near your price range.  I haven’t heard it personally but being from Trafomatic will be very high SQ - with the downside of it not having a remote that I’m aware of.  That being said the Aric preamps especially the Motherlode XL (while a bit outside your price range) from what I’ve read / watched are a great match with Coda amps.  Check out the Jay’s Iyagi review on YouTube.   

Please be aware the OP is in Europe so brands like LTA, Backert, etc. that aren’t available in Europe aren’t applicable here. 

There are Tube Pre Amps that are going to influence the End Sound.

It is important to know whether a design is to influence the produced sonic with a quite discernible rich tone, rich tone, or transparent for a Valve.

No point spending monies on a device that influences in a way that can quickly become a detractor when the sonic of the device becomes quite noticeable.

EAR produce Tube Pre's that are a injection of a Rich Tone, one model has been demo'd in a system that is familiar to myself and was very much liked.

A friend who owns the EAR Acute and others who own their Power Amp's have proven the EAR designs responds very well to tube rolling. 

Tube rolling is a area worthwhile budgeting for when shaping the upstream sonic for the system.  

As you are in Europe I would look into the well reviewed Icon Audio LA4 Mk III.

https://iconaudio.com/pure-valve-line-pre-amplifier-la4-mkiii

I heard the top-of-the-line Allnic tube preamp on my system which has a CODA #16 amp in the mix. This thing cost $33k and for the first time I found a preamp I liked better than the dead neutral Benchmark LA4 preamp. 

I did some research on the designer, and he seems like a bit of a genius. I cannot afford the Allnic preamp and I am very happy with the Benchmark.

The reason I mentioned this expensive preamp is that this company has other lower end models and I see them listed on USAudiomart in the price range requested. 

One thing I am looking for with Allnic products are ones that have OTL/OCL design. I hope to get a DAC from them with this design. Phenomenal detail and beautiful holographic sound. I would not be interested if the detail was missing.