Thanks Timlub (and everyone) I'm thinking my system may not be high end enough to take advantage of the high quality of some of these recommendations. I suppose if I had really good stuff, properly matched, proper room treatments and perfect ears, (that's becoming more and more of an issue) than I would have no need for any tone controls. That's why I was hoping to find something with that capability, and substantially better than what I have. |
No. I think that question was raised in the Lightspeed thread, and it sounds to me that it cannot be done with LDR approach. The Endler/EVS approach is one for of passive I have not tried, though several users on the LSA thread have. |
Does Lightspeed make a mono model that plugs directly into the amp(s), like the Endler or EVS attenuators? In my limited experience, doing away with that output cable offers a significant sonic benefit when going passive. |
Hi Ghoeper,
No none of the pre's I mentioned have tone controls. I can give you some lower priced units with tone controls, but you lose remote. It seems to me some of the newer B&K units have remote, but they are mid fi. The units I mentioned are all very nice and would be at home in a high end system. |
Though there groups of committed activists and pacifists, I will say that there are folks using passive that have made that choice coming from very expensive active line stages in the mid to high 4 figure range - for some, not active can beat a passive in the right system context (source - passive - cables - amp). I am a fairly committed pacifists at this point, for the past 3 years or so.
I use the $450 Lightspeed Attenuator, which I prefer to any of the resistor/TVC/AVC passives I have also tried - limit? one input / one output. |
There are a variety of preamps that are called "passive." If the only criterion is no gain stage, then you have;
Discrete resistor units like Placette, Goldpoint, Endler and EVS attenuators, Khozmo and others (Luminous falls in this catagory but uses a pot),
Buffered passives such as First Watt B1 and McCormack TLC-1,
TVC preamps such as Music First, Django, Promitheus, Sonic Euphoria and others that have no active buffer or gain stage, but can often provide up to 6dB gain, and finally
hybrids such as the Pass L1 and McCormack VRE-1 that run buffered passive to a point and then can add up to 6dB gain.
I have a balanced Goldpoint passive and Endler attenuators here and they certainly sound different from each other, but both sound better than I remember from the GFP-750 - perhaps because the Goldpoint and Endler units use high quality discrete resistors and the Adcom uses an Alps pot, which IMO is way inferior to discrete resistors for attenuation.
The length and capacitance of the cable coming out of the passive also makes a big difference. In the cases of Endler and EVS, they offer the benefit of no exiting cable.
Stereophile said about the GFP-750: "In passive mode, the signal sees only input switching and the attenuator." This implies the passive mode is unbuffered and only sees the switches and the Alps pot. One issue with running the Adcom passive could be that since it is an active preamp, many will put it in their racks in a typical position where the exiting cables may be longer than if it were set up as a passive preamp where most would try and keep exiting cables as short as possible. That may be why I didn't like it, although I don't remember my cables being any longer than 1.5M in the set-up I had at the time I was using the Adcom. I remember it being somewhat bright and harsh in active mode, and less bright but also less dynamic and somewhat boring in passive mode.
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Mitch2/ghoeper
When you say that the gfp750 is bright, I take it that you were using it active. If so, that's why I recommend a passive unit. As for the dull sound running it passive, that's not always the case. The better the component, the better the output stage (usually). It's up to the amp in the source component to power the signal all the way to the amp. Your Cambridge 840 is a very well made CD player. Using that for your source, I can't see how you can go wrong with a passive. Also, you don't have to limit yourself to Adcom. The 750 is excellent but there are other companies that make passive preamps at a very reasonable prices, as well. I have used passives from Creek and Channel Islands with excellent results. I do prefer the Creek but both are great. |
I owned the GFP 750 and even after having the Black Gate cap upgrade performed, I couldn't get beyond the sorta bright and electronic Adcom sound. Replaced it with the MUSE unit mentioned earlier and found that to be much better sounding, and not bright. I am sure there are other good ones in the general price range too like the Classe mentioned or the Quicksilver tubed linestage.
I found the passive circuit on the Adcom to be dull and lifeless sounding. The best true (unbuffered)passive I have heard was a pair of Endler attenuators - but ergonomically they are not for everyone. |
The GFP750 would be a very good choice. I'm pretty sure it has no tone controls. Also, if I remember correctly, it has an active line stage as well. You can switch back and fourth between active and passive. I would check, though, as I am not 100% sure. |
Thanks for the additional explanation. It makes more sense to me now. I will definitely research this option further.
Timlub, I have considered the Adcom GFP750. Are you able to control Bass and Treble with this. Somewhere I got the idea you couldn't. Also, is there really a big difference between the "Blue board" version and any other? Thanks or your help. |
Ghoeper
The lower the voltage, the harder it is to make something that sounds good. In an audio system there are several power amps besides the amp you use to drive your speakers. For example, a CD player needs to send the signal to a preamp. Inside the CD player, there is a very small power amp that is used to drive the signal through the interconnects. The amp in the CD player is basically the same thing as your big power amp but much smaller.
It is much more difficult to design the small amps in your cd and active preamp.The weaker the signal, the more sensitive it is to work with. Small changes at that level have a very big effect on sound quality.
When you use a passive unit, there is no amp inside it like an active has. It just controls volume and input selection (if you have more that one input. Because an active preamp is harder to design, it costs to make. Generally speaking, active preamps don't out preform passives until you get to around the $3000 price range. My opinion is that if you can't get a really good active preamp then don't buy one at all.
I hope this info helps you out. If you have any more questions, just post. |
Correction, the c-d player in the initial description of my system is a Cambridge Audio Azur 840-C (not Z) My apologies. |
Audio Research LS9
Muse 3 signature
Classe Five
Coda Windows Continuum 4
Adcom GFP750
These are all winners, Nice sounding, balanced or single ended, remote
The Audio Research really needs to run balanced (low gain on single ended) |
Thanks for those recommendations, I'll check them out further on the net. I own an Aragon 18-K with the penny and giles volumn upgrade. I wonder how that would pair up with the Ultracurve pro DEQ2496 that Xxqq250 recommended. I see it gets good ratings on the net. |
you can find a cambridge 840 pre within your budget; nice piece and aesthetic and operating match for your cdp. parasound 2100 and arcam fmj (which i'm partial to) seem to meet your criteria. |
Thanks for the response. I'm curious though, if a $300 plus unit can do the job, how come I wouldn't be able to find an active pre-amp for anywhere near $1000 that will. |
I would do this a little different than the way you are going. Since you can't get a good active preamp anywhere near $1000, I would go passive. It will eliminate the problems you run into with a cheap active. You can find one well within your budget. After that, I would buy an EQ. If you are going to use tone controls, you might as well do it right. You will probably be happy with a behringer Ultracurve pro DEQ2496. These 2 pieces are well within your budget and should sound a lot better than the active unit. |
