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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
celander's avatar
celander
1,503 posts
 
@tweak1 there you go again with the snarky remarks. I’m not going to post anymore Q’s to you. I’ll just make two statements to suggest you are deceiving yourself with your equipment choices and rebuttal remarks to others. 

First, a 600 ohm increase in input impedance (3.5% overall) by increasing your amp gain will not restore anything magical to your setup. It’s still an impedance-mismatch for the Hattor. 

Second, there is no such thing as an amplifier being overpowered for any set of speakers. Period. Musical transient peak demands typically can require 100’s of watts to the speakers. I doubt your class D amp of 125W RMS is up to muster. 

Over. And. Out. 
tweak1 OP
3,679 posts
 
well, considering you're still pushing 100% PURE BS, it's about time you stop
kalali's avatar
kalali
1,977 posts
 
"I like to listen during the day as background music as well as go to sleep listing to music, meaning system is on 24/7. "

I think most folks here tend to evaluate the quality of their gear more critically. If most of my listening to music was as background, I would have probably invested a lot less time and money in picking the gear. Not saying anything wrong with it but I think the level of expectation would be very different, at least for me. 
tweak1 OP
3,679 posts
 
WOW, just WOW

Do I really need to include "critical' listening? 

Mind is officially blown now
atmasphere's avatar
atmasphere
11,928 posts
 
Second, there is no such thing as an amplifier being overpowered for any set of speakers. Period. Musical transient peak demands typically can require 100’s of watts to the speakers. I doubt your class D amp of 125W RMS is up to muster.
Actually there is, but if the speakers are only 94 db and the amp only 125 watts, the amp isn't too much power by any means! If a class D amp, I would want more power just to make sure I never got near clipping, a fundamental difference between tubes and solid state (including class D).

Too much power in most cases means that the amplifier is operating in a portion of its low power region where its distortion is actually higher than at higher power levels (typically this is about 5-7% of full power with many push-pull amps). The only amps that I know of that don't have this property are SETs and the OTLs that we make, where the distortion linearly reduces to unmeasurable as the power is decreased. Its that first watt that's the most important!

Regarding critical listening, my amps are on all day and a good portion of the night as well- and I can't say that all that is spent in critical listening. But I've come to expect a certain level of competence out of the system and if its not doing it, my listening gets pretty critical real quick! So tubes all the way (at least for now- we have a class D amp we're brewing up; its got a pretty high bar to meet).

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