Schu Posted November 24, 2016 Share Posted November 24, 2016 I am curious about passive preamps... if you've dabbled in passive preamps, what is your impression versus tube based preamps? So far I have had a great time rolling tubes in my preamp, but I've already been thru many many variants, and really, only one sounds the best. Ive ordered a tube amp, and now I am very curious about a clean signal passive preamp... I am also curious as to why they cost so much if there are only few parts in them. Quote Link to comment Share on other sites More sharing options...
Honeybadger Posted November 24, 2016 Share Posted November 24, 2016 Passives certainly have their place in the world, because they do not color the sound. I have had a couple different passives, and have to say are not my cup of tea, I prefer a tube pre. Passives an get very pricey, just a good gold point attenuator is $$$ HB Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted November 24, 2016 Share Posted November 24, 2016 Passive line stages (calling them a preamp is a misnomer) can offer amazing performance and don't have to cost much at all. Most importantly, they have to be considered in combination with the amp with which they will be used. High input impedance tube amps usually do extremely well with them, if the former has a high enough input sensitivity to allow your source to drive the amp to around its full power output (or at least enough to satisfy your loudest listening level). For example, take the Eico which I discussed in the tubes section a while ago. It has an input sensitivity of a little over half a volt for full output and an input load of 500k ohms. Such an amp is made for a passive line stage (except that it doesn't need one since it has its own volume controls). On the other hand, a SS amp with an input load of only 10k, and needing 3V to provide full output won't do so well. It is not necessary to use a stepped attenuator (and don't forget that the steps offered may not provide the increments of loudness change which you like- it can be too low with one step and too loud with the next), with its often very high cost, to achieve pristine sound quality. It's possible to make a passive line stage in which the entire signal path consists of a single resistor (and you can choose any "audiophile grade" resistor you wish and it still won't cost much). Regardless of what you choose, it's important to use low capacitance interconnects and keep them as short as possible. And, remember, there isn't a preamp in existence which doesn't add something to what you hear. It is simply not possible to build one which produces zero noise (whether it be from the p/s or other factors) as is the case with a passive device. Maynard 1 Quote Link to comment Share on other sites More sharing options...
mike stehr Posted November 24, 2016 Share Posted November 24, 2016 Quote Link to comment Share on other sites More sharing options...
Deang Posted November 26, 2016 Share Posted November 26, 2016 Very good post by Manyard. Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted November 26, 2016 Share Posted November 26, 2016 I've always had my eye on one of these, just never enough need to justify getting it. http://www.tisburyaudio.co.uk/mini-passive-preamplifier Quote Link to comment Share on other sites More sharing options...
richieb Posted November 26, 2016 Share Posted November 26, 2016 I always swore by passives as they are cheap and for the most part very functional. I agree with all the above but after acquiring a couple decent tube preamps my system has more drive and body or as the English say PRAT. I find them very clean sounding but like Maynad I'm sure they inject some color of their own. And with Klipsch speakers (some) a bit of reduced top end sparkle can be a good thing. I used my B1 with Threshold Class A monos and it was a bit too much too clean, too exact, not a lot of "character" you might say. Like wdecho I too have a FW B1. Technically it is a buffered passive with a buffer circuit either before or after he volume pot(s) and is plugged into the wall to power the buffer circuit. My other passives required no external power source. I think both have their place and work wonderfully with the right choice of power amp. Quote Link to comment Share on other sites More sharing options...
Schu Posted November 26, 2016 Author Share Posted November 26, 2016 I see some passive that are hundreds of dollars... nearly $1000. And some that look good and are well under $300... like mikes example. Quote Link to comment Share on other sites More sharing options...
russ69 Posted November 26, 2016 Share Posted November 26, 2016 A pre-amp is the heart of a system. It's very important to the overall sound of a system. My experience has always been that a good pre-amp sounds better than no pre-amp (a passive). Some of this is system dependent however, it's entirely possible that some combinations might work best with certain passives. Quote Link to comment Share on other sites More sharing options...
mkane Posted November 26, 2016 Share Posted November 26, 2016 Put this together a while ago and like it alot. It's a TVC by Intact Audio. Quote Link to comment Share on other sites More sharing options...
richieb Posted November 26, 2016 Share Posted November 26, 2016 Well, I'm shocked. After finding something astray with my George Wright tube preamp (worked fine last time used, (today both speakers sounded like a transistor radio, no drive at all - ideas?) I thought I'd try the First Watt B1 buffered passive on my Quicksilver Horn Monos. And this after Mike Sanders of QS told me that due to the gain structure of the Horn Monos designed specifically for horn speakers that a passive Will Not drive them. Well the B1 drives them, and quite well, and with volume pots at only 9-10 o'clock. This exercise also showed me how quiet the monos are - as in graveyard quiet. And with the B1 with its L-R volume controls this is now a true dual mono system with one volume control for each amp. I'm giving it more time but the first CD sound every bit as full and rich, with drive, as with my tube preamps. Quote Link to comment Share on other sites More sharing options...
seti Posted November 30, 2016 Share Posted November 30, 2016 Dave Slagle autoformer volume controls are the bomb. If you have enough gain don't look back just do it. http://www.intactaudio.com/atten.html http://www.itishifi.com/search/label/Autoformer 1 Quote Link to comment Share on other sites More sharing options...
mkane Posted November 30, 2016 Share Posted November 30, 2016 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 30, 2016 Share Posted November 30, 2016 On 11/25/2016 at 6:32 PM, Deang said: Very good post by Manyard. We've come to expect nothing less! Quote Link to comment Share on other sites More sharing options...
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