Passive vs. active preamps


I'm thinking of building a passive attenuator/preamp and would like to hear some opinions.
jdseno3aec
I have tended to follow "conventional wisdom" in my system set up in that I have used mono block amps with very short runs of speaker cable (4-5 feet) which requires the use of relatively long runs of interconecting cable (5-7 meters). The need to drive long runs of interconnecting cables makes passive preamps a concern to me in that I have been advised that passive preamps do not do a particularly great job of driving long runs of interconnects (more than 3 meters). Because this limitation has been a concern for me I have stayed away from passive preamps. Obviously your system may be different, but for me, in order to get the best out of a digital source, an active, balanced preamp is best.
I too have monoblock amps. I also have a passive pre-amp. I have read on Nordost's home page that you should use short interconnects and long speaker cables. Their reasoning being that the speaker cables carry much higher power. This of course contradicts the monoblock setup convention. I have also heard that longer speaker cables sound better. So many opinions... I have not yet purchased good cables. I would prefer to keep the monoblocks on the side of the room rather than next to the speakers. I will be purchasing nordost cables and interconnects. John
I have had a passive preamp for the past six years, and I have to tell you that they are very transparent. BUT, after a point I felt that they are also a flat and lacking that 3D quality the real music has. I have just purchased an Audible Illusions Modulus 3A with all the latest upgrades and for the first time in 6 years love the way my system sounds. Good Luck.
If you already have an active preamp that you're very happy with, then there's no harm in building a passive one, especially if you can do it on the cheap. I don't expect that you'll discover anything about passives that isn't already known, however. IF YOUR SYSTEM IS ALREADY TOO DYNAMIC (if that's possible), then a passive preamp might "tame" this. It will very likely sound more "transparent" than most affordable active preamps, and if "detail retrieval" is what you want more than "realistic dynamics", then GO FOR IT...I'm a firm believer in active preamps.
I have both active and passive preamps and drive monoblocks with short interconnects. Carl eber above nails the difference. My only caveat is that a passive attenuator like http://www.tweakaudio.com/ or and Adcom costs A LOT less than a reference preamp. So in my opinion if you are upgrading over time I would use the passive as a way to stretch my dollars.
I've often thought about building a passive preamp, but so many items are going thru my system now that I couldn't spare the time. Then there are my speaker projects...
If you decide to build a passive, I have advice since I have a design for one that sounds better than the line stage of a CAT SL-1 III. Get a pair of Shallco "true ladder" attenuators from The Parts Connection (part of Sonic Frontiers) and four good RCA jacks--I use Kimber Ultraconnects--and a simple chassi of some kind, do internal wire with fine Litz wire (not Kimber AGSS, for example--I used that first), plan on switching inerconnects to change from CD to tuner or other source. You'll love the transparency if your sources hve good enough outputs.
Sounds pretty good, but "better than an SL III" is kind of a glib assertion. What's super duper is if your CD player already has a volume control.
serious bang for the buck. $ for $ will blow away active preamps. very natural sounding. much less harsh and digital sounding. phenomenal power and drive. At least try it for yourself. please see my post under system matching "theil cs7.2 and levinson amp and preamp" 3-12-00. And when your done making your preamp can you post the results for all of us. Thanks.
I have a Creek OBH-10 passive remote control and use it between my Camelot Arthur (last version) DAC and my CARY SLA-70 Mk II and PARASOUND HCA-1000 A. The high output voltage of Arthur (4 volts) works much better with the 150K input impedance of the CARY. Of course, the sound is very transparent and more musically detailed (with E34L tubes) but not as dynamic as driven by my Dynaco PAS-4 Pre. When fitted with Sovtek KT-88's in passive mode ther is a big, big difference in dynamics but less sweetness (correctable with proper cabling). My speakers are Paradigm Reference Esprit Bi-Polars connected with Straight Wire Quartets. Best results with interconnect are MIT Terminator 2 and Belden StarQuad (home brew). The Parasound with its lower 30K input impedance is much better off driven actively. Any experiences to share? Manny