2. amps-preamps
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Active vs Passive Pre amps

I know this is'nt a new subject, but I would appreciate your views folks. At the moment I am using a Passive Pre, equivelant to the Music First Audio baby reference, but built by an independent engineer. I use it into my ARC Reference 75 power amp, into Daedalas DA-RMa speakers. To be frank, I am very happy with it. The only drawback is the dual volume pots only have about 18 stops available, so you tend to go from too soft to too loud. When the dealer delivered the ARC power amp, he used it briefly with an ARC Ref 3 Pre and I preferred the passive, but it was a limited listen with a new, non run in Power amp.

The passive seemed more neutral and detailed, the ARC a little rich and lush. I know you are supposed to lose dynamics with a passive pre. The question I suppose, is whether it is worth trying to get hold of an ARC Ref 3 or maybe an LS 26/27 and comparing again? Do you think ARC power amps should sound better with an active ARC Pre, which are'nt cheap, even second hand? If I am going to stick with a passive pre, are there better options than the MFA baby reference?

Thanks
david12
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lak
4,650 posts
 
David,
I believe it's all a matter of personal tast. I agree with Brownsfan comments totally however for peace of mind you might want to once again demo a preamp in your home. I would think the dealer that you purchased the ARC Reference 75 power amp would be more then willing to bring out a preamp to demo or let you borrow one.
czarivey
5,946 posts
 
in reality it's very simple math instead of science:

passive volume control will vary resistance from valueA to valueZ where we can assume Z will be the the highest so to control the output voltage.

active volume control(active preamp) will have stable or fixed output impedance to supply variable input voltage to your amp.

by all possible and impossible means it means that supplied stable output impedance is preferable for best amplifier performance.

than you can do the rest of science to decide.
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drubin
3,274 posts
 
I have been on both sides of the active/passive debate over the years. I love the purity of passives and have never felt the need for more gain, or an expanded soundstage. On the other hand, I appreciate the added body, weight and drive an active can supply.

A year ago, I tried a Music First Baby Reference, the most expensive preamp I had ever had in my system. I felt, as Sam Tellig apparently did, that this was at last the preamp I'd been searching for, so I bought it. It was and is considerably better in my system than a number of other excellent passives I'd tried, including various Placettes, TVC and autoformer units from Bent, and the Lightspeed Attenuator, not to mention going direct from DAC to amp (for digital).

I think I might be able to do as well as the MF (perhaps better, I really don't know) with a truly great active, but I think I'd need to spend well north of $10K to get there without giving up what the MF does so well.
zd542
5,339 posts
 
"in reality it's very simple math instead of science:"

That's what I used to tell my professors in college. Unfortunately, they never saw it that way.

" I know you are supposed to lose dynamics with a passive pre."

That's not always the case. A lot of it depends on how good the output is on your source.
czarivey
5,946 posts
 
Zd, It's all regardless and nevertheless at the same time.

regardless of your output source, input sensitivity and impedance of your amp, it will benefit from stable output impedance of active preamplification.

nevertheless, there are benefits of passive with transparency, but with lower dynamic headroom and volume ranges.
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