Hello all,

first of all, I apologize if the topic has been addressed already on the forum (I haven't found anything about it).

I'm working on a personal DIY project (a synth based on a FPGA) and have been struggling to get the kind of sound I like (even when just playing a single PCM wave).

I'm using a typical I2S-compatible DAC with a built-in 1/8" output that sounds pretty good (very clear sound, excellent SNR).

So far, so good.

However, I'm not 100% satisfied with the sound. To my ears (and to my taste), the sound is bland and I think the output is not hot enough (I always need to raise the gain control on the mixer).

When I play a Korg M1 (hardware version) or an AKAI sampler, I find the sound is much closer to what I expect from a digital synth (especially how transients sound). Why do those old instruments sound way better than modern ones? I suppose it's a combination of different aspects (the kind of DAC, the preamp circuitry used for the output, etc. but I'm not sure the role that each single component has in the final shape of the audio).

That said, I would like to improve a bit the output of my synth. I have considered several options, among them:

-buy a pre-built preamp breadboard (connected to the output pins of my current DAC). I have seen some interesting options on Internet, but I'm not sure if they will improve the sound in some way. Some of them even have balanced outputs:
https://www.aliexpress.com/item/1005001858181700.html

-buy a pre-built DAC + preamp board (same as the previous point, but including a I2S-compatible DAC).

-copy the preamp circuit of a synth a like (e.g. Korg early workstations). Here the problem is that my skills in analogue electronics are VERY limited, and also some components are likely deprecated or unavailable nowadays.

-design a whole preamp circuitry and use the DAC's output pins as the input for this circuit. The problem is same as the previous point: my skills in analogue electronics suck big time.

In any case, what aspects should I especially pay more attention to? Should I seek for any specific op-amp IC (or any components I should avoid)?

(I prefer "musical" sound over "technically perfect" sound, by the way).

I hear you guys.

Thank you in advance.