If I correctly understand what you're asking, the Lumin network streaming DACs with upsampling will do that. You can permanently turn on upsampling in the options, with different upsampling options. But when you switch to MQA it will use that, and it will still accept whatever bit-rate and sample-rate you want to feed it from Qobuz/Tidal or local files.
The Lumin T2 will fit in your budget. We carry the Lumin product line because they work great, sound great, are built to exceptionally high quality, and are easy to use.
If you still want to feed into the Mytek, the Lumin U1 which only has digital outputs also supports upsampling, to even higher bit-rate and sample-rate formats, and fits in your budget as well.
The Lumin T2 will fit in your budget. We carry the Lumin product line because they work great, sound great, are built to exceptionally high quality, and are easy to use.
If you still want to feed into the Mytek, the Lumin U1 which only has digital outputs also supports upsampling, to even higher bit-rate and sample-rate formats, and fits in your budget as well.