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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
tweak1 OP
870 posts
 
Reading back through, I have a couple comments

1. I believe NPass is speaking to a perfect electronic interface world, which would necessitate building ones system around a PP, as opposed to trying to insert one into a active preamp system

2.. A quality PP, such as the Hattor, is a high powered microscope, exposing whether there is/are problems/issues elsewhere in the chain. 

I feel that my Emerald Physics amps are the next step in my progression,  I am close to pulling the trigger on a Nord Two SE Power Amp (newest class D tech), and .I  have the next model Emerald Physics Speakers (3.0) with cap upgrade and WireWorld internal wiring on the way (I think, as they were supposed to be hear almost 2 weeks ago) 
georgehifi's avatar
georgehifi
4,966 posts
 
1. I believe NPass is speaking to a perfect electronic interface world, which would necessitate building ones system around a PP, as opposed to trying to insert one into a active preamp system

I believe it does, and that "perfect electronic interface" is available in systems much much more than not.

1: If the source has more output voltage than the amp has input sensitivity to give full output. This is maybe in 100% of cases.
(I have yet to see a source with less output voltage than the amp needs input voltage to make it clip) 

2: The ratio of output impedance to input impedance, of the source to passive and from the passive to the amps,  are both 1:10 ratio or more, this also would be in at least 90% of cases. 

Then you have what you call,  that "perfect electronic interface" for a passive to work as it should, which is getting the source signal to the amps in the most transparent, undistorted, uncoloured, unhindered way.

Cheers George  
tweak1 OP
870 posts
 
and how is one assured of that?
georgehifi's avatar
georgehifi
4,966 posts
 

and how is one assured of that?


Quite easy, just look at your specs of your source and your amp. Or if you have difficulty in doing that just post the brand and model of your source/s and amp up here, I will look them up for you. A I’ll give in detail what they are doing.
Cheers George
johnk's avatar
johnk
1,490 posts
 
Its all about achieving system synergy active passive buffer all can be used in proper system and can achieve synergy but I would say passive types take more thought and also have more chance of disrupting synergy. At this time I have a art audio pre its active or passive I have the cheap schitt and a costly line magnetic trans based about. If passives synergizing you get a bit less colored sound with improvements to image and detail if active you get improvement in bass drive and dynamics. I have owned a good num of other active pres and passive types and I tend to prefer a trans based if rest of systems up to it. 
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