Have Passive Preamps Finally Come of Age?


Back in the late 90s (eons ago) I tried a variety of passive preamps (PPs). The most musical was an autoformer, but back then my system was not balanced. For the last decade I have been using active preamps, both tube and solid state, but finding a quality balanced preamp under $4K is damn near impossible. Enter the Parasound P5 (2.1), which in addition to having balanced I/Os, it has a separate bass management circuit (MSRP $1095), and I was hoping it would provide better control over the built in class D plates incorporated into my 2 SVS powered subs, whose volume controls are STUPIDLY sensitive: when barely cracked from zero they overwhelm. Alas, no bueno. 

Recently i watched a PS Audio YT video that was emphatic about NOT connecting powered subs with interconnects; instead he recommends speaker cables piggybacked off the main systems amp/s. I had a spare set of DIY flat copper cables, and was shocked how much better they sounded, but doing so did not change the  volume control problem and unfortunately this id not bypass the SVS amps whose class D chips are now ancient. Thinking there could be an impedance problem led me to revisit PPs.

I sold my P5 and was using the XLR outs from my Oppo 105 (upgraded power supply and IEC/wiring to the power supply) direct to my Emerald Physics 100.2SEs (class D). The noise floor dropped tremendously, allowing me a much better view into the music. My Core Power Technologies 1800 PLC had more than a little to do with this, but...  

Days of PP research later, I came across LDRs, which seem like the ultimate PP option, but XLR versions are ~ $2K and up, with the Tortuga coming in at $2700, seems like a true SOTA bargain, just not in my current budget. Scouring the' for sale' sites I came across a Hattor XLR (MSRP $995) which was in my price range. Hattor's www had links to 2 reviews both were extremely positive: one used it in combination with a class D amp. Bingo! I snapped it up.

It arrived late yesterday, although Hattor's www pictures look awesome, they do not compare to seeing and touching it. The metal carrying case was an indication of the designer's dedication. This is an etremely well made piece of kit, but how does it sound? Alas it came with no manual and Hattor's site does not have a PDF. How hard can it be to hook up? Well, after a couple scary minutes, I discovered that it would not light up until I connected the 105. 

Stone cold, the first thing that shocked me was a further reduction in noise floor and an incredibly wide and deep sound stage, but as can be expected, it was dry. Fingers crossed, in about a half hour I began to be rewarded with texture as well. Tis only got better as the night wore on

I hope somebody chimes in with their Tortuga experience, or any other high quality PP information.that goes under the reporting radar. 
tweak1
@atmasphere 
FWIW dept: our MP-3 preamp can be ordered as a balanced tube buffer with no active gain stage.
That is interesting Ralph, I wish I had heard the no-gain version back when - I may not have sold my MP-3.   Now I have a great sounding SS unity-gain buffer by Steve McCormack so don’t have the need for another.  You should get the word out.  With today’s high output DACs, that might be just the ticket for many.

I might be missing something, but for as long as I can remember, the dacs I have owned, the cd players I have owned, the tuners I have owned ( and some tape machines ), have all been 2 volts output, or more. I also remember early passive units from way back. So none of this is new, with maybe the buffer circuit being new. Of my hundreds of amplifiers passing through my doors, all could be driven to full output with 2 volts in ( I am not talking about the impedance here, just the output voltage ). I do understand the importance of impedance matching. Enjoy ! MrD.
Correct MrD, as Nelson Pass says, today we have way to much gain (voltage) with the sources we have.
That’s why if you can do it with the source that has a volume control, go direct from source to poweramp.
If no volume control put one there "a passive" so long as the impedance’s are right, and in most cases they are.

Cheers George
George said (7/15): It may sound good, but I don’t want to burst your bubble, you should have asked, if your still using your Hattor passive, you didn’t heed what I said about your EP 100.2 amp being only 19kohm input impedance, and not the best match for your Hattor passive. (How can I 'heed; when I don't know the right questions to ask? Impedance matching is new to me, and I am not a techie

Now you confuse me by saying (7/25):  Now we’re looking at what the Oppo can drive

I don’t know the impedance of your Hattor or is attenuation method, series, ladder or shunt.

so, how can you know it is/isn't the best match? " not the best match for your Hattor passive."

Morten Sensor of Tortuga sheds some light on the subject of Passive V active in an article he wrote. Link on his www.
Correct MrD, as Nelson Pass says, today we have way to much gain (voltage) with the sources we have.
He's not the only one to say that- its been a beef of mine for years. Whoever came up with the Redbook specs at Phillips and Sony blew it on this one, since any amplifier made will be clipped by a source that supports the Redbook spec. IMO it would be better if they dropped the output voltage, even by a little bit, since the less you have to knock down the signal to make it useful for an amplifier the better.