[Mark Korda]

Dear Frank, I always thought that a passive preamp,(less is more) ,was the best way to extract the cleanest signal from an amp, forgoing the preamp,active. You said long ago in Audio Basics that the best thing you could do with your hifi system was to start with the preamp. Well, in the latest Stereophile, John Atkinson,the head honcho, confirmed your statement upon reviewing the Pass Laboratories XP-30 preamp, 16.500 bucks. In summing up he said: The XP-30 has rekindled for me the concept that the beating heart of an audio system is the preamplifier. I know it's not your Fet Valve preamp, 8 x's less in price,but Atkinson cemented what you said a long time ago, just wanted to let you know......Mark K.

[werd]

Dear Frank, I always thought that a passive preamp,(less is more) ,was the best way to extract the cleanest signal from an amp, forgoing the preamp,active. You said long ago in Audio Basics that the best thing you could do with your hifi system was to start with the preamp. Well, in the latest Stereophile, John Atkinson,the head honcho, confirmed your statement upon reviewing the Pass Laboratories XP-30 preamp, 16.500 bucks. In summing up he said: The XP-30 has rekindled for me the concept that the beating heart of an audio system is the preamplifier. I know it's not your Fet Valve preamp, 8 x's less in price,but Atkinson cemented what you said a long time ago, just wanted to let you know......Mark K.

Nothing can mess with a system more than a pre amp. But really the source is what you hear. Everything your hear through your speakers is the source amplified.  At the end of the day pre amps are just tweaks off the source.

[avahifi]

Werd, you are off base here, probably because you have not thought through what a good preamplifier is supposed to do (and that few actually do).

First, the obvious. It needs to be the switching and control center for your audio system so you can choose any source and feed an appropriate signal level to your power amplifier to match the efficiency and gain of the rest of your components no how varied they are.  That is the easy part.

Now comes the hard parts:

A preamplifier must be able to isolate the normally very poor load driving capabilities of your source components and drive the shit out of whatever cables and amplifier)s) you have downstream.  This requires a low output impedance and high drive current capability.

A really good preamp will also isolate the amplifier and speakers from out of band signal garbage so you amp and speakers don't have to amplify crud, which is much harder to amplify than music.

Finally the preamplifier's audio circuits must not screw up the source music or change it in any way (except for the use of tone controls if these are needed to help out lame speakers or horrid source material).

Note that a passive preamp cannot do any of the functions above.  However, a really good passive preamp might be more desirable than a ho-hum active preamp if you don't mind its significant limitations.

Note that a good preamp is not supposed to be a music tweaking device.  If it obviously changes the sound, it is not doing its job well.

Regards,

Frank Van Alstine

[werd]

Werd, you are off base here, probably because you have not thought through what a good preamplifier is supposed to do (and that few actually do).

First, the obvious. It needs to be the switching and control center for your audio system so you can choose any source and feed an appropriate signal level to your power amplifier to match the efficiency and gain of the rest of your components no how varied they are.  That is the easy part.

Now comes the hard parts:

A preamplifier must be able to isolate the normally very poor load driving capabilities of your source components and drive the shit out of whatever cables and amplifier)s) you have downstream.  This requires a low output impedance and high drive current capability.

A really good preamp will also isolate the amplifier and speakers from out of band signal garbage so you amp and speakers don't have to amplify crud, which is much harder to amplify than music.

Finally the preamplifier's audio circuits must not screw up the source music or change it in any way (except for the use of tone controls if these are needed to help out lame speakers or horrid source material).

Note that a passive preamp cannot do any of the functions above.  However, a really good passive preamp might be more desirable than a ho-hum active preamp if you don't mind its significant limitations.

Note that a good preamp is not supposed to be a music tweaking device.  If it obviously changes the sound, it is not doing its job well.

Regards,

Frank Van Alstine

Frank

The only component that manufactures the sound is the source. It plays the band and its why we have a vinyl market. Pre amps and everything else are tweaks off the source. Not to undermine technical aspects of what makes a good preamp or power amp. They just end up being tweaks off what we hear through our speakers.

[roscoeiii]

Very well put Frank.

And as with most components, in my experience a good power supply pays real sonic dividends. Not to be skimped on. IME.

[skifasterslc]

when i first started down this rabbit hole of a hobby I made the mistake others do of putting to much emphasis on speakers and amplifiers and the pre amp was secondary.  That was a big mistake.  Once I started to pay attention to the preamp my system improved by a large margins.  Ive had a few  passives and a couple of actives and agree with Frank.

Now I use ( and have for a number of years) a high quality preamp driving active speakers, each driver in my system has its own dedicated amplifier.

Now I have never had a quality Tubed preamp, that may be my next toy.
For now it's about time for some irish whiskey in light of st paddys day, tomorrow i will proudly be wearing ORANGE, so WHY will I be wearing Orange??????????

Cheers ! --- Mark

[Diamond Dog]

I understand the logic of the "less is more " concept but my own experience comparing using my digital source to drive my amps directly vs. running it through my
( active ) preamp is that I really prefer the sound with the preamp in use. I don't think that it's so much a matter of the preamp providing some sonic colouration which I happen to prefer - it's more that the sound seems is more dynamic and more open. My source has a built-in digital volume control and with four 32-bit DAC's per channel, the theory is that there shouldn't be a loss of resolution but...

D.D.

[Mark Korda]

Skifastersic, I'm not trying to get off this subject tonight, it has raised a small ruckus, but what kind of corned beef do you prefer today,it's 2 in Maine, the bright red kind, or the traditional gray? Also,to get the cabbage down, do you pepper it with vinegar like I do?.And last but not least,Spicy Gouldens mustard, or Grey Poupon on the beef? It's the only day I ever eat a turnip. Frank VanAlStines answer about anything audio is God with me,but to cause more debate, what if you use a passive preamp with a combined sub woofer which will handle every thing from say 100 hz or so down.Do passive preamps roll off the highs that actives do not, using short cables?....thanks for all the info you guys...always have questions.....Mark K.

[G Georgopoulos]

Werd, you are off base here, probably because you have not thought through what a good preamplifier is supposed to do (and that few actually do).

First, the obvious. It needs to be the switching and control center for your audio system so you can choose any source and feed an appropriate signal level to your power amplifier to match the efficiency and gain of the rest of your components no how varied they are.  That is the easy part.

Now comes the hard parts:

A preamplifier must be able to isolate the normally very poor load driving capabilities of your source components and drive the shit out of whatever cables and amplifier)s) you have downstream.  This requires a low output impedance and high drive current capability.

A really good preamp will also isolate the amplifier and speakers from out of band signal garbage so you amp and speakers don't have to amplify crud, which is much harder to amplify than music.

Finally the preamplifier's audio circuits must not screw up the source music or change it in any way (except for the use of tone controls if these are needed to help out lame speakers or horrid source material).

Note that a passive preamp cannot do any of the functions above.  However, a really good passive preamp might be more desirable than a ho-hum active preamp if you don't mind its significant limitations.

Note that a good preamp is not supposed to be a music tweaking device.  If it obviously changes the sound, it is not doing its job well.

Regards,

Frank Van Alstine

Hi Frank,I agree with you on the easy part,for the hard part the only thing that can do is only gain ,and with
todays say source levels is not needed (gain),if needed it's ok,if not it's ok too.

kind regards 

[werd]

I understand the logic of the "less is more " concept but my own experience comparing using my digital source to drive my amps directly vs. running it through my
( active ) preamp is that I really prefer the sound with the preamp in use. I don't think that it's so much a matter of the preamp providing some sonic colouration which I happen to prefer - it's more that the sound seems is more dynamic and more open. My source has a built-in digital volume control and with four 32-bit DAC's per channel, the theory is that there shouldn't be a loss of resolution but...

D.D.

It's because the pre amp in your dac sucks. You can fix it though by using a TPV passive pre amp. The tpv houses transformers, a primary and secondary winding with a volume control in the middle. Set the pre amp volume to full and use the dac volume. This buffers the impedance between your dac and amp which is what's wrong with it. You get the impedance matching of the TPV and the active sensation of a power volume control from your dac. You also get excellent isolation between your dac and amp.

Something to try and it still may not be as nice as your Manley. But it maintains the sound of your dac.

[avahifi]

I am wondering how a single dual triode can provide exact RIAA equalization.  It can't be an RIAA feedback loop design because the highest gain tube available that I know of will run out of closed loop gain at low frequencies.

A passive EQ should be way beyond the drive capability of a single dual triode tube too.

And of course then the single triode design will have to drive loads downstream too, and the load and cable capacitance will modify the RIAA curve too.

I would really like to see a schematic of your single dual triode phono preamp design.

Frank Van Alstine

[CrazyBlue]

Rollin'   

So, what about DAC's with analog output sections (preamp) and volume controls that don't suck?

In researching gear for a high-end (ish) dedicated system, I'm running up against this same question again and again.  More than one High-end DAC manufacturer asserts that a preamp is not needed and the sound quality is in fact better driving amps directly with their DAC.  Now, if this is true, it might save a guy some money in building a system, while yielding better sonic results.  In theory at least. 

Of course, only if you have no need for analog inputs, such as from a separate phono stage.

I guess my question would be:  How much do you have to spend on the DAC / Pre for this to actually be true?  $4k (Perfectwave II)?  $6k (Overdrive SE)?  Or would spending about the same on say, an FET - Valve DAC and Pre yield better sonic results?  Or upon auditioning, might a guy prefer the sound of the Vision DAC and T-8, which cost significantly less? 

I think discussion and debate, with its inherent subjective opinion based on either experience or (sometimes) bullshit, is great, but at the end of the day, you have to listen for yourself and decide which combination of gear you prefer.  Unfortunately, this is difficult and time consuming to do, and something I would like to make my new career. 

"What do you do?"

"I audition audio gear and speakers."

"Really?  How's the pay?"

"It sucks.  But I get a big hard-on every day at work."

    

[Mark Korda]

Hi Werd, this is a picture of a home made TVP volume control I made with a small article  out of AudioXpress. I used 10K Goldpoint pots and transformers from Electroprint (PVE-3) from Jack Elliano, Jan.05 issue. I used an old Dyna PAM-1 chassis,which has holes already drilled for more switchability later on, like when I get to it. I don't  own a DAC yet,but have had it hooked up to my Dyna-35 and it sounds pretty good to me using cd's. I got a better picture of the finished TVP, but I only know how to put a picture on one at a time. Cheap Jack, the way I interfaced my passive preamp with my subwoofer is without a crossover. I do have an old Ace 5000 and a Shadow Mark4 a Audiomart pen pal made,the prototype.Parts Express gave me the answer. Y-cables. From the outputs of my cd player I attached 2 Y-cables, Monster,not that exspensive. One pair goes to the Dyna-ST-35, and the other pair goes to my subs amp, a Canadian BASH sub,not much over 100 bucks. The BASH, Parts Express,has a built in low or high pass filter,I don't know which is correct, to cut out anything to the sub from 50 to 150 hz. It is adjustable. So the only thing in the path of the great sound of tubes is a nice clean extra Monster cable, not a exspensive crossover. My favorite cd for sub listening is the Wicked, the broadway hit. It explodes with music right from the start. Frank, when the economy gets a little better for me, save one of your preamps for me,your stuff always sounds stunning! I'm still trying to get those PAM's running and until,I got a PAS-2,the Last PAS mod version,to put in a good 250k volume pot and gold jacks for the back. Then I can make my own musical comparison with passive vs. active. Thanks you guys for all the info I'm learning. Now it's off to the boiled dinner. I have already consumed a loaf of Irish soda bread in 2 days. I feel like a human biscuit. After today it's back to Sparta, my roomate used to say that when he'd go back to the gym.Thanks loads....Mark K.

[Diamond Dog]

It's because the pre amp in your dac sucks.

Werd:  Not sure that's actually the case or the problem. Correct me if I am mistaken but it's basically a digital volume control, no ? I suspect that because a lot of the music I listen to is mastered "hot" and compressed, I can't really open the taps on the attenuator and keep listening volumes at a comfortable level.  Using the K-03 on its own running direct to the amps rather than putting my active pre into the chain doesn't sound bad, it just doesn't sound as good.  I'm going to have to try comparing using some less- compressed source material and see what I come up with. Again, I don't think it's a question of this pre adding an undue amount of colouration- I have a nice SS preamp here as well and the Manley with it's current tube configuration is more neutral-sounding by a healthy margin. You would be surprised at how little that unit resembles the stereotypical "tube" sound in this system. Perhaps the digital volume control, like a passive pre, doesn't bring some of the benefits to the table that Mr. Van Alstine has mentioned earlier in the thread in promoting the use of a quality active preamp.

c-J: No response required or requested. Thank you in advance for your consideration.

D.D.

[SJ David]

I get lost in these "true-to-source" discussions. Lack of bandwidth, I suppose. Just how many stages, conversions, manipulations, phase changes, and who knows what else does a middle C on a piano go through until it excites my eardrum? Not from the source in my system but from the microphone and room in which the sound was recorded to my speakers and room the sound is reproduced?

Since that original C note went through so much processing from room to room, does it follow that removing one electronic stage in the total chain will materially enhance the reproduced sound of the C note? If yes, then in all applications, most applications, or some applications? If yes in all cases then why are so many in the audio component industry so wrong by designing line stages? If only some times, does that explain the preponderance of line stage pre amplifiers over passive pre amplifers?

[Tone Depth]

Does the output stage from a standalone high output DAC amplify the analog signal? Is the output stage functionally a built-in preamplifier in the DAC?

Is there a difference between a high gain output stage, as compared with a lower gain output stage and a standalone preamplifier?

Aren't each of them amplifying the signal to a level that can effectively drive a power amplifier? 

[roscoeiii]

Ugh, why must these threads on preamps always devolve into having to address "no preamp is best" or "passive is best" arguments?

Best is to actually listen to as many combos as possible. And don't forget that these claims for superiority of one over the other are being made by folks with different gear and musical tastes (both in terms of content and the qualities of music that are most important to that individual).

For me, no passive (incl the Adcom 750, Dodd tube buffer) or DAC with volume control (Wyred4Sound DAC2, Weiss DAC2) has approached the qualities of my active preamp (Musical Fiedlity kW). IME, the active pre provides better drive and dynamics that lacking an active pre cannot match. Though in lower priced active preamps, this can come at the expense of detail retrieval.

[SteveFord]

I'm with roscoeiii so that would make it double Ugh.
The preamp is the heart of the system, the amps are the muscle and the speakers are your ex's mouth!

[medium jim]

I have to agree that the preamp is rather important.  I presently have a simple tube Linestage pre, a Bottlehead Foreplay that has all the tricks and really cleaned up my sound. I sort of agree with Steve, but also feel that a good amp can be both musical and be the muscles.

Simple is better as goes a good preamp.

Jim

[roscoeiii]

...and don't skimp on the power supply, like with most else in audio.