Low gain dac!

@gryphongryp,
I had a similar situation years ago of having excess system gain. Anything above 9 o’clock volume control setting was too loud. I used attenuators that were effective and didn’t cause any noticeable sonic degradation. Harrison Labs and Rothwell were both good choices. Fortunately not a problem with my current audio system. 

@cat_doorman is right, in certain cases with some components there can be potential impedance matching issues. I understand your desire to have reasonable volume control range in order to have the ability for finer gradients of the volume control knob. 6 to 7.5 is unnecessarily too limiting/restricted.
Charles

@gryphongryph OP

Wow!! this setup needs a passive pre, if ever one did.

Primare Dac30: 100ohm output impedance, 4.7v output. (it's a good dac)
Belles SA 30 : 100kohm input impedance, and needs only 0.7v in for full output.!!

Just get a Schiit Sys for $49 as cat_doorman said, get far better sound this way, more transparent, less noise, less distortion, better dynamics
Sell the Supratek pocket the money and never look back

Nelson Pass,
"We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.
Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.
Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.
What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.
And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp."

Cheers George

The Supratek is a high gain preamplifier.  Passive is a viable option for this system. Depends on what sounds best to the OP.
Charles 

Thanks for the advice, but I like the sound of tubes, and just to be clear, my system got so much better when I got the Supratek, will never sell it I suspect, it makes the artists stand in my living room so to speak, my dac is good, but I suspect there are better dac’s out there today, I think the Dac30 is from 2012.
It is not that I don’t find a good listening level either, it just would be nice with a bit more adjustments range, and as I was looking to change my dac I thought it this would be a good place to ask about this, as there maybe was someone that had experience something similar.

Try a $49 Schiit Sys as you can send it back

But at the moment you would have so much distortions/noise because your shunting >90% of the dacs signal down to ground, only then the re-amplify it again noise/distortion and all.
Cheers George