Your All Time Favorite Preamplifiers?

[Light Dependant Resistor]

I think active preamps are the only devices that provide the positive attributes of increased drive and dynamics I've described when placed between DAC and Amplifiers.
Passive devices, by definition, cannot and do not do this.

I disagree, as they ( passives ) can. It requires a power amp with sensitivity matching consumer line level , and to have shunt resistances and series independent of each other. In this scenario there is more than adequate if not bountiful dynamics and drive.

 

[bonzo75]

someday if i were to switch to something like horns and an SET amp then the EMIA Autoformer might be the way i would go.

So when tang moves to his vintage you are babysitting his Cessaro? They are sounding good so you can, and I guess you can have an arrangement that you can give it back if he wants it

 

[twitch]

Fond , fond memories of my Huntley 'modified' ARC SP9 mkII

 

[DasguteOhr]

Bartolomeo Aloia PST 200 many came, most lost, he stayed
Amazing tube preamp with phono

 

[Atmasphere]

Unfortunately, nothing, no matter what its design methodology, nothing approaches a straight wire with gain.

I have to pop the balloon idea of a straight wire with gain. A straight wire with gain would not work in most audio systems, just so we are clear

For example if an amplifier, can it double power as impedance is halved? No wire I know of can do that. If a preamp, what is its Common Mode Rejection Ratio? How accurate is its RIAA curve? I suppose you could put some of the wire before the RIAA network and some of it after; what impedances does the wire have so it can be driven properly?? The impedance could be an issue, since otherwise it might pick up noise and apply gain to that too.

Put another way IMO/IME this metaphor really shouldn't be used since it compares real life to something that could never work in real life if it even existed! This puts unreasonable exceptions by real world people on every preamp product made- nothing could measure up, but if this tech somehow existed, we might find its actually unusable.

 

[Light Dependant Resistor]

It helps to realize that consumer line level does not need changing upward, in the process where it, by amplifying further, introduces distortion. Rather attenuation is all that is needed, where power amps have compliance to consumer line level. In the case of RIAA these can be stand alone units, typically providing improvements with power supplies. Proving it can be done the UK amplifier, the Quad 306 has consumer line level sensitivity.

 

[musicfirst1]

It helps to realize that consumer line level does not need changing upward, in the process where it, by amplifying further, introduces distortion. Rather attenuation is all that is needed, where power amps have compliance to consumer line level. In the case of RIAA these can be stand alone units, typically providing improvements with power supplies. Proving it can be done the UK amplifier, the Quad 306 has consumer line level sensitivity.

I have to disagree with both your
last two posts. PASSIVE line stages, no matter how well matched to the amplifiers or upstream sources, cannot provide additional drive and dynamics without intrinsic gain.

 

[Ovenmitt]

Nagra HD and EMT JPA66.... I love 'em both.

 

[Light Dependant Resistor]

I have to disagree with both your
last two posts. PASSIVE line stages, no matter how well matched to the amplifiers or upstream sources, cannot provide additional drive and dynamics without intrinsic gain.

Yes they can, you can have all the dynamic content with utmost clarity you require, if you allow the shunt resistance to be independent of the series, so two quite different curves. This allows to adjust or shape the shunt resistance so as never to load the source component. Lower volume is catered by making the series resistance extremely high, circa 25 mega ohms or more at lowest volume, rather than the traditional shunt element.

 

[bazelio]

I have to disagree with both your
last two posts. PASSIVE line stages, no matter how well matched to the amplifiers or upstream sources, cannot provide additional drive and dynamics without intrinsic gain.

Some people don't want a line stage to provide additional drive and dynamics as that's coloration added by gear. I'd rather a line stage do as little of that as possible.

 

[Ron Resnick]

Some people don't want a line stage to provide additional drive and dynamics as that's coloration added by gear. I'd rather a line stage do as little of that as possible.

I think you're talking past each other. Of course he's not talking about drive and dynamics as a coloration.

People who like line stages providing signal amplification enjoy what they perceive positively as greater drive and dynamics from amplifying the signal on the way to the power amplifier.

 

[bazelio]

I think you're talking past each other. Of course he's not talking about drive and dynamics as a coloration.

People who like line stages providing signal amplification enjoy what they perceive positively as greater drive and dynamics from amplifying the signal on the way to the power amplifier.

No, I think the case is that resistor ladder passive attenuators often sound flat. This is not the case with TVC and AVC passives. Too many people lump all passive attenuators into the same bucket and assume that's the baseline. And I do think a lot of people actually like what active preamps add (as opposed to preserve) on the way to the amp.

 

[Gregm]

less is more.......until...........more is more.

at a certain point not having an active preamp will reduce energy and substance from the music. better sources and better amps deserve the better signal delivery that a top preamp can deliver. hard to define where that line is as far as dollars. but it's easy to hear.

This is exactly my experience as well. Before one reaches the top preamp level, one is best served by an excellent passive. I am wary of s/ware based attenuators, because they shed bits -- which in turn begs the question: is losing some bits at (low volume) worse than the linear & non-linear distortion introduced by an inadequate active pre?

Back to the original question, my favourite experiences were with a CAT Ultimate (30? yrs ago), a FM Acoustics 102 (25? yrs ago), the Dart of about 15yrs ago (and my current one).

 

[Gregm]

No, I think the case is that resistor ladder passive attenuators often sound flat.

True, but they won't if they are correctly matched to the load (the amp's input impedance). Having a source with a powerful output also helps.
My little DAC has a hefty output and drives the amp quite happily (i.e. dynamics etc are OK) via the passive volume control

 

[tima]

I have to pop the balloon idea of a straight wire with gain. A straight wire with gain would not work in most audio systems, just so we are clear

For example if an amplifier, can it double power as impedance is halved? No wire I know of can do that. If a preamp, what is its Common Mode Rejection Ratio? How accurate is its RIAA curve? I suppose you could put some of the wire before the RIAA network and some of it after; what impedances does the wire have so it can be driven properly?? The impedance could be an issue, since otherwise it might pick up noise and apply gain to that too.

Put another way IMO/IME this metaphor really shouldn't be used since it compares real life to something that could never work in real life if it even existed! This puts unreasonable exceptions by real world people on every preamp product made- nothing could measure up, but if this tech somehow existed, we might find its actually unusable.

Of course this is correct I am hereby duly chastised. In a review I once referred to your your M60 amplifiers as "as close to a straight wire with gain as my system has known." And you let me get away with it!

 

[tima]

I did not read each post in this thread with care but what I am not seeing is anything about the so-called 'proper' definition of 'preamp'.

Yes once manufacturers starting dropping phono-sections in their errant belief that the phono era was being displaced they started creating the 'linestage'. Telling us we were saving money! ha!

And yes some manufacturers still label their linestages as preamps, Lamm for example. Audio Research has the category 'Preampliers' under which the explicitly list 'Line-stages' and put their 'Phono Stages' under 'Sources Analog'. It seems a given that forum participants use both 'preamps' and 'linestages' interchangeably, as we see in this thread.

I think a 'true' preamp has a phono-section and another active gain section. but I'm kinda old school with names.

 

[christensenleif@msn.com]

I´ve ran passive/TVC for 20+ years and when people come here to listen, the last thing they think about is lack of dynamic drive or control, or even what could be accomplished by some hiend cables
to me it seems meaningless to amplify a source component to maybe 10-20 volts to have to dampen it in a volume control....most poweramps need between 1 -5 volts to be driven to full output, a task any source components is fully capable of as long as impedance matching is taken care of

 

[tima]

I´ve ran passive/TVC for 20+ years and when people come here to listen, the last thing they think about is lack of dynamic drive or control, or even what could be accomplished by some hiend cables
to me it seems meaningless to amplify a source component to maybe 10-20 volts to have to dampen it in a volume control....most poweramps need between 1 -5 volts to be driven to full output, a task any source components is fully capable of as long as impedance matching is taken care of

Interesting perspective. If I ever visit Ainola (Sibelius' house) I'll come hear your fine system.

 

[AMR / iFi audio]

One of the most intriguing preamps I have heard was a DIY from Pass:

The BA-3 as preamp build guide

Using the BA-3 gain stage (“Front-end”) as a line stage preamp. A mini build guide. :) PCB - P-BAGSN-1V20 - Burning Amplifier Gain Stage for BA-3 (Requires bias boards and output stage; Makes 2 channels; Rev 2.0) - Circuit Boards BA-3 as preamp thread -...

www.diyaudio.com

It was made by my friend and it sounded amazing. Exciting, engaging and detailed sound.

Besides that, I have a thing for preamps from Accuphase. They really tickle my fancy.

 

[kjartanb]

I used a passive volume pot for many years together with PSE 2A3 amps and Lowther horns. Changing my passive to a Slagle Autoformer volume vas a great upgrade and a great solution for that very revealing but bass limited system.
With Altec 604 I then used a Leben RS-28CX with several different power amps mainly tube (PP kt88 and SE 300B) but also class D amps. That was a nice preamp, bass could be rather bloated with SE 300B but it revealed wonderful inner detail in voices and instruments. However, it could be a little tame on rock, thus the class Ds.
Currently, I have 2 preamps (plus the passive Slagle which I still own). A DIY Aikido using 6CG7 which I like with my Altec A5s and DIY first watt amps and a DIY first watt B1 Korg which I use on Carlsson OA51 with a DIY Modulus 86 chip amp (the distortion profile of the Korg pre can be tailored according to personal preference).
I would say that the Leben was the nicest preamp from a build quality perspective. The passive slagel autoformers where great where more gain was not needed, but extremely revealing and could be quite tiring if the source material was not tip-top. I like my Aikido and use it a lot, but the best of the lot and most flexible is probably the inexpensive DIY B1Korg.