Value of a preamp?

Do it. Get the preamp. Just make sure it’s not a crappy one as those will make things sound worse instead of improving the situation- like a good preamp should.

I've also tried direct from DAC/Streamer using LUMIN's LEEDh volume control. It was ok, but the preamp with some good NOS tubes made a big improvement over direct connection from DAC to amps. 

 So then, an active preamp is actually 'adding something'  to the signal, (whatever that something is) but a passive attenuator is not.

So when all the impedance values are matched up correctly with a passive attenuator, then a more true to the source sound is being heard.

Really then, active preamps can be like tube rolling when you actually think about it !

So when all the impedance values are matched up correctly with a passive attenuator, then a more true to the source sound is being heard.

@scm So then it becomes, when are all those pesky impedance values matched up correctly?  Impossible to know, so just use your ears.

I just knew Deep Audio was behind preamps.

@ddgtt

"I have discovered some great preamps out there and I’m happy to recommend them should anyone be interested."

I’m interested in hearing what you recommend. Are there preamps that you think will work with a variety of amps, or do specific preamps need to be matched to certain amps?