DAC DIRECT IN TO AMPLIFIER OR TO PREAMPLIFIER

Paul; Here is my most recent experience on topic:

I used an Audio Research SP15 as my preamp, an entry level DAC (Suncoz) to smooth my CD and hard drive inputs. I was dissatisfied.

I bought a PS Audio Perfect Wave DAC/streamer which is also a fine quality preamp. In fact Paul McGowan touts it as a substitute for the necessity of a preamp in some of his daily videos. I was excited about the front end of my system being a state of the art source / DAC and preamp. One less component, 3 fewer tubes, a lit less heat, etc. 

The CD sound was fantastic- truly revolutionary. The streaming sound was meh most of the time but wonderful when the material was well mixed and of a high quality uncompressed nature. I had achieved the impossible- tube sound with an all in one front end. I was ecstatic..until:. 

Poor volume control.  The PS Audio preamp just couldn't give a strong enough signal to my amps to make a loud DB presentation. Full volume was about the same as loud talking. It sounded fantastic but I couldn't push it to the level my speakers and amps would support- and some music needs to be played LOUD!

Given my particular components my conclusion is this: With a high end preamp a  first quality DAC is improved- not sonically per se but in overall control of the sound. 

Update:

In my case the pre-amplifier made a noticeable improvement in sound quality- more than I thought it would. The Lumin volume control was fine, but adding a preamp confirmed my suspicion that I was missing out on something. This made the difference I needed from my system. I’m satisfied with my gear now and will be focusing on room treatment moving forward. I only listened to streaming and my NAS. I haven’t rewired the turntable for XLR yet, but will in the next couple days. I can imagine that results for a preamp will depend on the preamplifier being used. This might be where the "your results may vary" and "system dependent" comments come from. There’s no going back for me. If I had to describe the difference between running direct from the Lumin S1 compared to running through the preamp: with the preamp- more depth, better separation of instruments, more full sound, and better focused center image. The only downside I’ve noticed is it does make a little hiss with volume all the way down from the speakers, but it’s minor. I’m thinking this is normal since it’s a tube preamp. It’s still less noise than my old tube amp made though. I hope you find this information helpful.

A low hiss is not normal from a good quality or better tube preamp. Deed quiet is the mark.

Low hiss, can you hear it from your seat? If not… not a problem. Even if does, does it go away at low volume? Tube stuff is never gonna be DEAD quiet IME.

On the topic of tube hiss. I have all-tube cj gear: hiss evident at idle, although not loud enough to spoil my enjoyment of music. Replace factory-supplied tubes with some NOS Westinghouse and GE pre-amp and amp input tubes (not power output - couldn't afford that) from Vintage Tube Services. System now dead quiet at idle. Based on my experience, tube equipment can be quiet - all depends on the tubes, and the equipment of course.