Interconnect recommendations

Regardless of which interconnects you select, I recommend burn in. I recently purchased a Hagerman fry baby. There is notable improvement in terms of depth and vividness. 

Lots of advice here.  I do agree in the big picture that buying a better DAC is a good move.  That said, I like the Qutest a lot, especially used with an upgraded power supply and the green filter engaged.  Not suggesting this should be your end point, but if you are waiting a bit to allow your finances to recharge for a truly next level DAC, you might consider better cables for an instant boost with your current gear.  I auditioned some interconnect cables recently and landed on the Anticable Level 7.3 RCA Analog Interconnect.  These sound very good both with the Qutest and with an ESS Sabre DAC I have in another system.  So good in fact that I bought a pair their Level 6.3 RCA cables for my analog front end.

I purchased both pairs of Anticables used, so they were at least partially broken in - my understanding is that like Nordost cables, Anticables need a lot of time to settle down.  If this says anything, I bought one of the pairs from a reviewer who was using them as his reference cables and replaced them with some significantly more expensive Kubala Sonsa interconnects.  In any case, my experience indicates these cables are an excellent match for the Qutest, supporting its inherent good timing and detail retrieval without sounding the least glaring or bright.  Voices are rendered especially well.

Here is a pair available right now for very little money if you can make due with 0.5m length. https://www.usaudiomart.com/details/650257674-anticables-level-73-rca-12-meter/

kn

op

your current system is quite nicely assembled

you have gotten a lot of input already (maybe too much as it is)

I would suggest two things

1. remove the bhk tube pre from the system and replace with an equivalent level solid state pre ... I think the perceived system clarity will increase quite a bit, although there will be some tradeoffs involved, I.e. some recordings may sound harsher/crisper

2. try a 5v linear power supply on the qutest in place of its factory smps...  I feel it improves the sound some

your cables are fine, but you can mess with some silver or silver blend cables if you want a little more sheen on the treble and upper mids

good luck

signaforce OP

I am admittedly an newbie to high end audio. Over the course of this thread, your responses have completely changed my strategy.

It’s taken me only 10+ years to dial in my system for ’my ears’ and ’my room’.  I thought that buying a battery-operated tube DAC would help hasten the process.   It did and it didn’t.  It showed me the potential.  The journey has been a fun learning experience. 

@knownothing @jjss49 I have the Sbooster mkll plus the ultra upgrade running at 6v (extra volt required for the Ultra). My system sounds very nice.
The RCA cable upgrade from DAC to pre & XLR from pre to amp was my intention at the start of this thread. Thought about the distortion from my BHK tubes, but will stand pat on that. Thanks!