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
I also tried TEO s overpriced passive
Yes over priced for just 24 switched resistor position, do you know what value it was? 10 20 50 or 100k, and if it was a series, ladder or shunt switch resistor passive? As of yet I can’t find out, I’ll look harder tomorrow.

This sort of thing leaves me https://www.emojirequest.com/images/CrossEyedEmoji.jpg
" Judciously placed vibration control materials are located within the case of the Liquid Pre for the purpose of tuning, as the performance of the Liquid Pre is so refined that everything matters. In fact the center foot on the bottom of the unit is interchangeable for the purpose of voicing the system in which it is used: soft to hard. Even placing a thin item such as a business card under the center foot can tailor the sound. Similarly, one does not want to place anything on top of the Liquid Pre such as a book, as it will be detrimental to the performance."


This tech page of theirs might is no better might as well have been written by a tech word bot.
http://www.teoaudio.com/technical/

Cheers George
To whom it may apply: "I" started THIS thread, NOT George. 

The impedance issue between my recently acquired Hattor XLR and my EP amps/ Audio Alchemy stereo amp has turned out to be a blessing. To get to the bottom of the impedance issues, I bought a AA Dac/Pre, not for the dac, but for the pre. I thought I was satisfied with my Oppo 105s internal dac for redbook. LOL

My intention was to use it while I got my Hattor XLR fitted with the OpAmp George suggested, which was going to take some time and additional cost $350 + shipping, if I attempted it myself.

AA: after 24 hours and the standard wall plug for power I was hearing music that finally combined detail with warmth.

Late on day 2, I decided to connect my WireWorld Toslink cable (which I used between my Pioneer PD 65 (inverted platter), modded by Musical Concepts, with outboard PS as a transport to some dac, and I still have it!) so I could listen to SACD/DVD-A discs, but first I compared the AA redbook dac to my 105, which was spinning Tony Bennett Duets. WOW, warm, texturally rich music,bordering on 3D, at least when the music was easy, less so when the music is complex. I reread the Absolute Sounds review, which tried the wall wart briefly, then inserted the PS 5 outboard power supply to complete the review.. So Im on a quest to locate one

Back to my Hattor: If I move forward (and I might as it is dual mono wit better separation) it means I also need to add a dac and another power cord and use the Oppo as a transport, or use the 105 for SACD/DVDs only and my Pioneer to the AA internal DAC. Of course all that takes money, and by the time I add it up I am within reach of the Tortuga XLR.. FYI Morten says he will have a ss opamp soon

Will someone please make me an offer I can't refuse for my Hattor?.
@tweak1 congrats to finding a setup that allows you to enjoy the music!  I’m sure the Hattor will sell quickly if you offfer it up on the main site. 
@tweak1 If you are finding some of the Tony Bennet recordings " wow ", listen to some Elvis Presley recordings, and realize the expert technical aspects of the recording and mixing engineers, as well as the King’s voice. Enjoy ! MrD.
To whom it may apply: "I" started THIS thread, NOT George.

Sorry Tweak, it’s hard not to respond to others that are asking off topic questions.

For $350 I would just go the Hattor mod with opamp, you have the Hattor and it’s very nicely made, the OPA2134 has a very nice musical sound not etched and sterile. It’s part of Texas Instruments/BB "Sound Plus" range which have always been good. As is my favourite dac chip, the PCM1704

Cheers George