Passive pre with Bryston 7B ST??


I am wondering whether the Bryston monoblocks are suitable for passive attenuators/pre while the Bryston preamps (are said) to be the weak link of this pre/power combo. As the Brystons are pretty well known I'd gues that someone would have tried it with a passive pre (FT Audio LW1 for example)

The Brystons have a high sensitivity (0,8 volt) and a high input impendance. My cd-player (Musical Fidelity Nuvista 3D) has a low impendance 2 volt output according to the red book standard.

Any comments?
nanning
While I can't speak to the 7B amps I did try a Reference Line passive with my 4B-ST and while I found the sound to be clean I thought my amp was best served by an active preamp. Seemed to my ears to work better with the BP-25 and even better with the Rogue 66 but thats another issue (tubes vs SS)...
Agree with Rdg. I have tried Reference Line Preeminance 1A with 4BST and later on 7BST's driving a pair of Maggie 3.5Rs. I gave up and went to active preamp. Try a tube preamp for your 7BSTs...
...that's how it's suppose to work. Having sencitivity of .8V and the source output of 2V you won't need any extra gain.
Try it with Creek OBH14 and it'll smoke Bryston BP25 in your case.
How many sources are you running? If only one, you might consider the EVS attenuators--they go right on the power amps and save a cable and some connectors. But in general, I don't see how a 10K ohm passive could fail to work with the 7B ST's. The passive/active debate will surely never end, though in a recent post almost everyone liked passives best. Is there any way to try a passive risk-free? I've had high end active preamps--e.g. a CAT SL-1 III with its signal path factory-simplified, and prefer a DIY passive. But such knowledgeable reviewers as Martin Colloms believe that even a top CD player offering digital volume control sounds better through a top active preamp. In the end, it may be a matter of what aspects of the sound matter most to you--though I don't feel I'm losing anything with a passive.
As an alternative you may want to try an Adcom GFP 750. It's a Nelson Pass design, runs either active or passive, and can run balanced in/out. You can pick them up under a $1k here on audiogon but make sure you ask questions. At one point there was a run of bad ones, which the factory cheerfully rectified. High input impedance in the Bryston and true balanced input is a beautiful thing....when you go passive.
I have 2 passive amps, the placette and the EVS attenuators.
I also have had the BAT, Thor TA-1000, Cary slp-50 and now the blue circle BC-3 Galatea line stage.
The passives need to be matched with the right source and amps. You have to drive your amp to life. I could not get either passive to drive my Bel Canto SET40 to my liking. There was volume, but no life. Yes it had bass too, but it was missing something. Paired with the Evo, the sound was very detailed but on the lean and sterile side. Very detailed, but to the point of distraction.
The way to go is with a quality active linestage. The BC BC-3 did it for me. The stepped attenuators, simple circuitry and great design make music. The sound is detailed yet doesn't distract. The bloom and presence are all there.
Great pace and it sounds alive. A drum kick is felt, not just heard. Vocals have air, depth and a pleasant natural presence.
There is no right or wrong in what you prefer. Everything matters in the audio chain. Keep things as simple as possible when dealing with the source signal. An active linestage is a great way to manage the type of sound you are looking for.
Look for a simple design in an active linestage. The Cary SLP-50 is a good eample. The BC-3 is more refined with a very well designed power supply. Don't ignore the volume control. You would be amazed how many $8K preamps use a $25 volume control. Go with a stepped attenuator setup if possible.
mike
Thank you very much for your answers and personal experiences. In the past I once used a passive attenuator (Qed) with PS Audio Delta250 monoblocks as as my budget coudn't stretch to buy the accomodating preamp with it (audiophiles and budgets ;-). It too sounded the way people (negatively) describe passives: lifeless, less dynamics and kind of subdued in the extremes.

As I was looking to replace my Conrad Johnson Premier 3 all (9!) tube amp, which sounds closed in, non-3D and not transparant enough in this setup, I came across some pages describing the passive matter (FT Audio LW-1) again which was said to overcome these problems.

I think now that this is too good to be true. I am thinking of going with the Bryston BP20 now which I can pickup for a decent price, go balanced and have time enough to look for a next preamp upgrade as I believe this is a very important component. The Musical Fidelity 3D deserves a good one I think!
Interesting comments from Mikem as I had similar experiences with a couple passive preamps into my CJ Premier 11a tube amp. The Adcom GFP-750 was "lifeless" in passive mode and was somewhat better running active. I still didn't care much for the Adcom's relatively weak air & soundstage compared to some tube preamps plus it seemed a bit bright to me.

I tried a used McCormack TLC-1 passive/buffered preamp earlier this month and the McCormack is much better in my setup running in either passive or buffered modes. Either setting on the TLC-1 was better than the Adcom in its best mode. The TLC-1 is very neutral but not boring. I tried the Adcom GFP-750 with various solid-state and my tube power amp but it didn't cut it for me. I still have the McCormack TLC-1 and plan to keep it. A true bargain at about $400 used (but not remote controllable).

I picked up a used Conrad-Johnson PF-R solid state preamp just this weekend and so far, it's more to my liking being somewhat neutral with extended frequency response yet it has a wee bit of midrange sweetness that I enjoy. And yes, it's able to bring my tube amp to "life". I've gone through many preamps in the past year, solid-state, tubes, and passive. Right now I'm leaning toward solid-state so long as it has some signs of "life" especially in the midrange and isn't too neutral or boring.

I do love the soundstage, air, and midrange sweetness of some tube preamps but I haven't found one (yet) that has the low frequency extension (bass) of a good solid-state preamp. Still looking and open for suggestions.
Although I haven't tried any passive attenuators with my
Bryston 7Bs, I tend to agree with the majority of the peanut
gallery that an active pre-amp is the way to go. I use a
Golden Tube Audio SEP-3 tube preamp with my Brystons, and I
find the sound dynamic and extended. I think that with passive attenuators, you'll lose some of the dynamics and drive, depending on what music you listen to. I would hazard a guess that, unless the CD player was designed to drive an amplifier,( i.e. Wadia/Krell w/ digital volume control and humongous power supply and regulation) the rest of said CD player circuitry would be penalized by the output
attempting to drive an amplifier through passive attenuators. Either way, good luck in your search.