Recently, I was in a very similar situation. I was looking for a nice pre amp, but actually ended up buying a Placette passive volume control - which will arrive sometime this week. Before jumping at the Placette, I was doing some extensive research here on Audiogon and especially on the Audio Asylum web site, where you can find a lot of information about what a passive pre amp will do (or better: will NOT do) to your music. In general, passive pre amps require a reasonable output voltage from the source together with low output impedance. The power amp, on the other hand, should have a high input impedance, which seems to be true for most tube amps (OTL amps might be an exeption - not sure, though, someone correct me, if this statement is wrong). So, if you don't run obscenely long interconnects (stay around 1 m), you shouldn't run into any problems with a passive unit. If you want to get the Legends pre, anyway, you can still put a passive volume control (i.e. the Placette) in the signal path and it should do next to nothing to your signal. If you want to go with a high quality passive unit, you can get the Placette passive pre (which has 3 inputs, Placette's remote volume control just has one) or the Audio Synthesis Passion Ultimate (which also comes with an optinal MM/MC phono board). If you want to get a turntable later, you can always get a phono pre amp (you need one, anyway, if your pre amp doesn't have one built-in) and plug it into the passive pre. Good luck. |
I can't disagree with anything Pipetman said, but could add that I'm using a DIY passive with OTL amps with no problems. Placette looks very good to me but if you're a DIY type at all, you can make a world-class passive using Shallco switches, Holco resisters (Michael Percy Audio has kits) and good input and output connectors, RCA or (better) XLR, for about 1/3 of a Placette's price. But will it be as detailed and transparent as a CD player with a good digital volume control? In my experience, with an Accuphase DP-75 going into my OTL power amps, definitely not. There's little in a good passive to degrade the signal--but in a refined system even a little degradation can be clearly heard. Bu the way, there's a recent post on passives you might want to look at. |
Of course you understand that any signal coming out of your cd player has to be attenuated, whether it be passive, active or digital. The quality of the attenuation is the key.
I use a Placette, because like yourself I like the remote volume control. I like passive preamps because I believe that the less you do to the music signal they better; less is more. Active preamps seem to give the music a "processed" sound (some give the music more life and dynamics than it actually has), the good ones do this much less. This is not always a bad thing, so I keep a tube preamp when I want this effect for certain types of music. The problem with really good active preamps is that they are more expensive than a really good passive preamps or simple resistor controls that you can stick on the back of your amp, as the above post suggests.
I cannot comment on the Accuphase above, but digital attenuation is accomplished by removing information in the signal. So, as the music gets quieter there is less information. If you go this route definitely listen before you buy.
The cd players that you may want to look at with really good built in analog attenuation are: Levinson 39 (might actually have active attenuation), Resolution Audio 50 and 55.
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Ultrakaz- re: active attenuation, would not the Audio Aero Capitole have it as well? (mine has analog volume control). Must admit though- I have often wondered if adding a quality passive could benefit things at all... |
Thanks for the info. I am not a DIY person, so would want to buy my passive. I think I will buy my source with a volume control(probably ML or possibly Audio Aero) and try it first that way, then move on from there to a passive if I feel the sound can be improved upon. Then if I don't like a passive, I will know that I need an active pre-amp. I want to play records, so will need a pre-amp eventually anyway. I just don't want to degrade the sound of my system. It's hard to demo a pre-amp, especially where I live. Thanks again for the input |
I assume that the author of this thread has triode monoblocks from Legend Audio and I dare do dissapoint the author that these amps will loose some of its performance if driven by passive stage. These monos have low sencitivity and relatively low gain. The great deal of detail and dynamics may dissapear if the source with high output(~3.V on the output) isn't used.
CD players with volume control can have a sufficient output voltage for your amplifier but won't you use different components as well? |
Yes, I have triode monoblocks, but didn't know the sensitivity etc, since everything is boxed up right now. Thanks for the input, though. I'm waiting for the new format to settle in somewhat before I buy a cd player, but am thinking of a ML or Audio Aero or something with a volume control. I want to get a turntable in the future, so eventually I will have to get a pre-amp but just wasn't sure which one to get. I don't want the sound from the Legends to change because of the pre-amp, so I thought I might get a passive, but I guess that won't work. What about a volume pot (EVS)? Or what pre-amp would you suggest if I don't go with the Legend (no remote volume)? |
There are several options for you:
Pass Aleph P(hard to find though) that has switchable gain and can be used as an active and passive preamp as well in case if you will have high output source(can be a phono too).
BAT VK50 is one of the best preamps for the money spent. It's excellent performer with triode and SET amplifiers and has a remote.
EVS volume pot or even Creek OBH12 passive remote stage can also be coupled with existing non-remote preamp. |
Get the Placette Line Stage, which is active but has no gain. It will give you everything you wanted from a passive without the downsides. If you need gain, he can build it in, but you probably won't need it. This is a tremendous product. |
I believe you can try the Placette risk free for 30 days from the manufacturer. Sounds like that might be useful in your situation. Best of luck.
Tim |
I have been an advocate of passive preamps for years. I have been using a Stan Warren buffered line stage for about 8 years. I recently upgraded my amp to a CJ MV-60 and was uncertain if I needed to upgrade my preamp. I only run a CD player, so I started to look at options, including a CD player with variable output. Budget is an issue, but not so much if I find a sound that is so wonderful that it sticks in my head and will not leave. I also spoke with Bill Conrad who said that the inteconnects will be an issue with a passive set up because they will act as filters. The CJ and buffered line stage are amazing, even with old Audioquest Ruby interconnects and some prototypes from another manufacturer. I have done ABs with Creek OBH 12 and OBH 14 and EVS Ultimate Attenuators. The issues are ease of use, access to controls and wires too heavy for device, more than sound. In all cases the sound does change, but ever so slightly. So, it becomes a mood thing more than the fact that I cannot live with the sound. The Creek does something to the sound that makes it nicer. I asked Stan Warren about this and he relayed a story of a recent A/B between the Creek OBH 12 and a BAT 20? or 30? at a recent Chicago Audio Society meeting. The outcome? Everyone liked the Creek better, even with a slightly narrower sound stage. I like the Creeks a lot because theys sound good and are more convenient than reaching around the back of a hot amp sitting under a rack. The EVS does nothing to the sound which I like. I A/Bed the EVS versus direct CD-amp. It is a tough call. My recommendation is try the Creek and, as Tim said, the Placette on a risk free basis. The cost of used Creek OBH 12 is risk-free. Besides it has growth potential and you can just put it away for a rainy day. If you are happy with your current CD player, then the better option may be to take the less expensive route until the industry decides what it wants to do with CDs and use the money somewhere else. If you want to go into this in more detail send me an e-mail. Cheers! |
I'm the passive folk too but there are certain conditions must meet before you'll get into no-preamp listening. Most of SET and Triode amps have a low sensitivity and will loose a great deal of dynamics when coupled directly with the source. There is one more condition but usually it's the only consearn for solid states which is impedance compatibility. There are a few technical differences that I want to describe as a former engineer:
Triode amps need in average 4...5x higher input voltage than tetrode push-pulls due to a lower gain. If insufficient voltage is applied to the input(lower than offset) the triode enters non-linear operation and will operate with the great deal of distortions(especislly on low volumes)
Tetrodes have their characteristics more linear and usualy more sencitive amplification components. On most of tetrode operated amps the input voltage of .4 volts is enough to drive them. If the specs say that input sencitivity of the tetrode amp is 1.2V and you will drive it with just .4volts on input most-likely you will just loose the rated power of the amplifier with remaining linear non-distorion operation.
To my experience SET and Triode amps should be best driven with 20dB gain amps not excluding the solid state(MOSFET) or hybrid designs.
Creek OBH12 is indeed a nice product for the price and can be a great addition to any non-remote preamp. |
Thanks for the input, it's actually been very helpful, especially Marakanetz. I will probably buy the Legend pre and get the Creek OBH 12 or the Placette for the remote volume. I was also thinking about getting the Hovland pre, but will have to look into that further. Thanks again for the input. |
I hope you rethink that - Drubin has got it right in my opinion. |
I will contact Placette and talk to them about my system and see what they have to say. If I can try it and return it if I don't like it I don't have anything to lose, so will be contacting them shortly. Thanks |
i have the placette volume control with cary audio 805C monobloc sound great, before i have a Hovland100-pre |
Smw- Marakenetz has some good points- that guy knows what he is talking about! That being said, My Audio Aero Capitole CDP has I believe ~ a 4v output- quite strong actually. It is driving my 300B's nicely (although they have been totally rebuilt and insanely modded) there is no 'sluggishness' in these babies whatsoever- using a gutsy tube like the KR 300BXLS helps as well as a very efficient speaker...
Must admit to being curious about the Placette though- can adding a passive preamp actually give me any benefits?? hmmm..... |
I don't believe so Sutts. I have the Capitole and a Placette passive (just the insides actually, not the official box - anyone want it?) and there is no way it improves things. It just does the job with minimal damage. The active Placette is another thing altogether, and I highly recommend it, but not as a way to improve the Capitole. |
I have decided to go with the Legend pre-amp and if I absolutely have to have a remote volume, I will try the Placette passive remote volume control. I have put a lot of thought into my system before I bought each piece of equipment, and decided from all the information I received, that this would be the best course of action. My speakers are not real sensitive (Dahlquist 20I - I think they are 88 or 89 decibels) and they are supposed to be hard to drive, so I think I better have a pre-amp. I will have to get a phono pre-amp when I play records, but that will be a ways down the road. Thanks again for the input, it was a big help. |
I have owned the Creek OBH-12, McCormack TLC-1, Adcom GFP-750, Classe CP-35, CJ PF-R, CJ PV-12L, CJ PV-14L, ARC LS-16, and BAT VK-20. My CD player is the Cary 306/200 and my amp is the CJ Premier 11a tube amp.
Of the passive preamps, I like the McCormack TLC-1 the best(but no remote), the Creek OBH-12 next, and lastly the Adcom GFP-750 (in passive or active mode). The McCormack produces the least coloration without upsetting the soundstage. The OBH-12 is quite good, much better than the Adcom GFP-750. The Adcom sounded flat and lacking dynamics in passive mode and was somewhat bright and irritating in active mode. However, in my system, an active preamp seems to be a better fit for my listening enjoyment. The active preamps do seem to produce better dynamics and soundstage.
Of the vacuum tube preamps above, the ARC LS16 was the most neutral sounding and had the best bass authority but not nearly as good as the ss preamps. Ultimately, I prefer a ss active preamp and find the CJ PF-R to be outstanding with good dynamics while retaining that nice CJ midrange. The BAT VK-20 (which is in my system now) is more neutral than the CJ PF-R and it has great dynamics and soundstage while having the best user interface I have ever experienced. I still haven't decided which I like better and for now it's a toss up between the CJ PF-R and the BAT VK-20, both priced about the same on the used market. I'm keeping the McCormack TLC-1 and I continue to experiment with the CJ PF-R and the BAT VK-20.
I'd love to try a Placette preamp or a Pass Labs preamp someday. |
Abe- re: the Pass & Placette- they are the same ones I would want to try as well. A dealer I know up here in Canada still has an older Aleph L (no remote, single-ended only) lying around- a passive/actuve hybrid- ingenious design.
Red- thanks for the tip. Another dealer up here has a used Placette Remote Volume Control for ~ $600 USD. How do you think adding that to the Capitole would be? |
