Passive vs Active preamp.... probably a stupid question in here....

Eddieedwards

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Evening All

When compared to a passive pre, does an active simply provide additional gain, or is there more to it than that?

I've tried comparing mine in both modes, but it is difficult to make an accurate judgement as volumes always differ. In A/B tests I've done, I always seem to prefer active as it seems to sound fuller, deeper with more presence and scale. Are my ears deceiving me and am I kidding myself? :doh:

Cheers

Eddie

 

rabski

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No. In my experience, your ears are not false.

It is doubtless colouration and doubtless 'wrong', however, I personally think this is one area where wrong is right.

Sorry to all those who believe, but I have had various reasonably good components in my heap of mayhem over the years. Pre amps that I have owned include a Puresound L300 and an SJS Arcadia and I have had Phil's Kondo M7 here. I have tried a number of passive stages and I'm sorry, but all have sounded as flat as a witch's tit to me. Dead. Lifeless. Horrible.

I like the colouration and 'drive' that an active pre brings to the party. I don't care whether it's coloured and false, it simply sounds better.

 

bonzo

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I have tried comparing Townshend's passive pre with conrad johnson pre and AR pre - by replacing the respective pres into the respective power amps. Did not work at all. Except in the case of the lampizator which I am buying that has a built in pre

 

Eddieedwards

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Cheers for the replies gents..... as always, a fan of your work Rabski, (especially your car park rants)..... "flat as a witch's tit" haha.

 
V

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No. In my experience, your ears are not false.It is doubtless colouration and doubtless 'wrong', however, I personally think this is one area where wrong is right.

Sorry to all those who believe, but I have had various reasonably good components in my heap of mayhem over the years. Pre amps that I have owned include a Puresound L300 and an SJS Arcadia and I have had Phil's Kondo M7 here. I have tried a number of passive stages and I'm sorry, but all have sounded as flat as a witch's tit to me. Dead. Lifeless. Horrible.

I like the colouration and 'drive' that an active pre brings to the party. I don't care whether it's coloured and false, it simply sounds better.
horses for courses then. :^

 

rabski

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Sorry, I speak as I find. Or in this case, as I hear.

I have tried a couple of quite serious passives and found them not to my taste at all.

"fuller, deeper with more presence and scale" is exactly how I would describe what an active pre brings to the party. It's what I like. Doubtless a passive is more accurate...

 

SergeAuckland

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Active pre-amps can provide gain and possibly tone correction, but their most useful attribute is that they provide a high input impedance and a low output impedance, which allows the use of long cables. I disagree with Rabski in that I don't find that in a domestic HiFi situation there's any sonic difference between a good transparent active and a passive, given that even with a passive, up to 5 or 6 metres of cable to the power amp/active 'speakers doesn't provide any problems due to a higher than normal output impedance. Unlike Rabski, I take the view that if a pre-amp has a sound, it's not fit for use.

I use an active pre-amp as I want it to be controlled by the same remote control as the Tuner and CD player, I used to have a home-made passive for several years with no problems. Resistive passives are the best solution for transparency provided that the input and output impedances are suitable for the system.

S

 

greengoblin

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I don't really understand why passive preamp is deemed to be more accurate and transparent, while active pre is coloured and wrong. That's only true if we assume what comes out of your CD player is the total 100% true interpretation of the recorded music. Sorr y but I just don't buy that, since I can often tell difference between different cdp. Signal leaves the silver disc and is being processed all the time downstream.

For me a little extra processing via my active pre adds "fullness, depth, presence and scale". It sounds more like the honest live performance I'm looking for

 

SergeAuckland

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I don't really understand why passive preamp is deemed to be more accurate and transparent, while active pre is coloured and wrong. That's only true if we assume what comes out of your CD player is the total 100% true interpretation of the recorded music. Sorr y but I just don't buy that, since I can often tell difference between different cdp. Signal leaves the silver disc and is being processed all the time downstream. For me a little extra processing via my active pre adds "fullness, depth, presence and scale". It sounds more like the honest live performance I'm looking for
A passive pre has zero distortion and provided the impedances are OK, the frequency response is flat throughoutbthe audio band. A good active preamp can be equally transparent although some active preamps aren't, but there's no reason for a preamp to be anything else unless deliberate.

If you want transparency either will do, if you want your preamp to have a character of its own, then that normally will require active circuitry.

S

 

RobHolt

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I can happily live with either, though my liking for tone controls, buttons, lights and dials tends to push me into the active camp.

When I've heard passive sound poor there have usually been plausible impedance matching issues. Either the source component doesn't properly drive the attenuator load, or the attenuator is feeding a low impedance load.

Clean active is the safest bet IMO - properly buffered in and out so that loading is never a concern.

 

SSM

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I don't like flat tits either, so I'll take Rabski's word as gospel and not explore the passive pre option. :dunno:

Startled to read that bonzo found that Townshend pre did not do what it said on the tin. Two weeks ago, I was thinking of ordering one, that's £1.8k saved. Did I almost pay that for a box that's as sturdy as an empty biscuit tin. :shock: :p

SS

 

john dolan

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If a system is put together with a passive preamp in mind with the input and output impedances and short cables are used then a simple passive is as good as it gets and will have practically no audible degradation of the source.

If you place a passive into a system that has less than ideal impedances it can and will sound flat and lifeless.

The best compromise imo is the TVC passives which seem to be as transparent as a normal passive but don't suffer the compatibility weakness issues they have but system matching is still important what ever type of preamp you use.

 

awkwardbydesign

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I have both, and the active I am using at the moment has too much gain, and so is noisy. The passive TVC is silent. Mine has 6dB of gain and that is plenty for me.

When the speakers are finished I will compare them directly and decide which to use.

 

greengoblin

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It shows variability as I have esoteric and I distinctly prefer +12 db gain over passive for same reason.....fullness, depth, presence and drive. Passive sounds nice, pretty and clean....just like hifi while active mimics life music in my room better. (still not even close to real thing though)

 

ERICLIMPIT

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I like both active and passive pre amps, both can be great (and not great for that matter) in the right system but if I had to choose one? then its the TVC type passive for me.

 

Kev

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I've tried passive pot in a box, passive TVC, active valve and active SS. My preference in my system is TVC. This is because I have sufficient gain and low output impedance out of my DAC. Input to my power amp is 50kohm so a good high impedance. Given those circumstances, flat as a witches tit does not apply. It's dynamic and has deep deep bass.

On the other hand does anyone want to bring an Esoteric C03 for me to play with:love:

 

Sir_Franc

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I don't really see any point in standing up for one varity of pre amp over another. They are just like any other peice of kit and really down to personal taste.

 

Tenson

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So what's the difference between a potentiometer buffered by an op-amp at the input and output of the box, compared with a potentiometer fed from an op-amp in the CD player and feeding an op-amp in the amp?

 

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