Bent Audio Autoformer vs Tube Pre

Don't you own a TRL Dude? At least that is what I have seen you post previously. Surely you must know Grannyring owns one given the TRL family is pretty well connected.

I'm guessing you probably know where I stand on this subject as well given my very open opinions about passive preamps. Although I have not compared any passive preamp to The Dude, I have compared them to many active preamps. You could do a lot worse than the Bent modules, but your system has to be optimized for it. Just for ha ha's contact Audiogon member Dgarrettson. He implemented an LDR volume control in his Atma-Sphere MP-3 preamp. Could give you the best of both worlds.

What amplifier and source(s) do you plan to use with the Bent? I have tried many passive preamps and currently still use them in my system. One is balanced and the others single ended. From my experience I will say that with the right set up a passive preamp will help you achieve outstanding sound for little investment. Typically an autoformer or transformer volume control will be easier to match up with system components, but that shouldn't rule out potentiometers or resistor passive designs. In fact, a real sleeper is Roger Modjeski's pot in the box that uses a simple but high quality Noble potentiometer to attenuate the signal. LDR attenuators are also very good if built properly.

The four key specs you need to really evaluate how a passive preamp can be used in your system are the output voltage and output impedance of the source and the input sensitivity and input impedance of the amp. Neither Lynx or ATSAH provide these specs although I will go on the assumption that the Lynx outputs at least 2V and has a low enough output impedance since it is a solid state design. I do see the amp has 26 db of gain which might indicate an input sensitivity high enough (ideally below 1.5V) but the input impedance would be the more critical factor and should be greater than 50k ohms, the higher the better.

If the specs do not line up properly it is still possible to build something using the Bent modules and remote, but you might want to consider buffered outputs that would allow for better matching to the amp. Perhaps you can check with the manufacture to see if they can give you the specs.

Well if you have the specs figured out and a balanced unit with remote is what your desire the Bent modules are going to be your best bet. In addition to a Lightspeed and Warpspeed (balanced) I built an autoformer volume control using the Slagleman units co-designed by John Chapman and Dave Slagle. All are very transparent and while I would give the nod to the LDR units for their increased transparency and purity in transferring the signal, building a balanced unit and one with a remote on top of it is not nearly as feasible.

I have considered building a balanced version using the Bent modules as well and may ultimately get around to it someday, but first I am having a custom direct coupled balanced preamp built that will serve as both a phono and tape head preamp with all the gain in that portion of the circuit and unity gain and buffered output in the linestage portion of the circuit. It will be interesting to compare this to the passive preamps I have.

Just for the record for those who could not gather it from my previous post Atma-Sphere is building the custom preamp I mentioned. While I firmly believe in the benefits of a passive preamp, one of my amps is an Atma-Sphere S-30 and after many conversations with Ralph decided that it would be worth hearing the preamp for both technical and synergistic reasons. I am moving from digital to a completely analog front end with turntable and reel tape deck, the latter taking the output directly from the tape head. Given the phono catridge is inherently balanced as is the tape deck I needed a solution that could handle the balanced designs of my sources. The convenience of getting this in a one box preamp was also influential in my decision. So for the first time in a while I will have an active circuit in my preamp. I look forward to the comparison.

Andrew, yes the idea is to withdraw from digital completely. I will probably miss a handful of CDs but have already become more familiar with my vinyl collection which has many more nuggets than my CD collection. I am also building up my tape collection and while I understand your situation, IMO getting into tape as big a commitment either financially or time wise as some may make it seem.

DSD has piqued my interest but I have to draw the line somewhere...