Can Adding a Preamp (where there currently is none) Improve SQ?

Discussion in 'Audio Hardware' started by BIGGER Dave, Apr 10, 2019.

  1. heathen

    heathen Forum Resident

    This is obviously not true at the level of generality in which it's stated.
    Randoms, 62caddy and Mad shadows like this.
  2. SandAndGlass

    SandAndGlass Twilight Forum Resident

    I use a Integrated with the DAC on the SS side of my system.

    I use a tube preamp on the tube side of my system.

    I was using a Line Magnetic 845-based 518iA SET as the power amplifier of the A7's and I still used a 6SN7 based tube preamp, made by a division of Cary Audio. Even thought the 518iA is an integrated, I still far preferred the sound with the external preamp.

    Another thing that having a preamp in the system can do, is to give different independent sources, more of the same sound in your system.
  3. 62caddy

    62caddy Forum Resident

    Nor on any level.
    Mad shadows likes this.
  4. 62caddy

    62caddy Forum Resident

    Sorry but I don't agree with any of this. A preamplifier is not supposed act as a processor, otherwise neutrality is being sacrificed. And "processing of sorts" isn't necessarily going to be desirable with all material and speakers.

    Of course, we have no idea how these listening comparisons were made.
  5. Rubberpigg

    Rubberpigg Forum Resident

    I agree with you.

    Same question on another audio forum:

    I thought the job of a preamp was to be completely transparent (or as close as possible)... essentially just acting as a volume control for the whole system and managing the various inputs...
    So can a preamp really make a system sound better than if it simply weren't there?

    **** no.
    No device in a signal path will "improve" sound.
    It can only be passed or degraded.
    Euphonic distortion can be added, but that is distortion, per its name.
    Randoms, chili555, jtw and 2 others like this.
  6. 62caddy

    62caddy Forum Resident

    I wouldn't go so far to say that processing can never be beneficial. That would be equally wrong.

    But speaking for myself, I just assume the preamplifier influence the sound as little as possible - setting a "baseline" as it were - allowing any further processing to be used on an "as needed" basis. A preamp in which coloration is inherent to the design is something I would have no use for.
    Rubberpigg likes this.
  7. SandAndGlass

    SandAndGlass Twilight Forum Resident

    A nice tube preamp can bring out the richness an analog recording and take the artificial hard sound out of a digital source.

    It can also make both sources like they are part of the same system.
  8. Ralph Karsten

    Ralph Karsten Forum Resident

    St. Paul MN
    A preamp can in fact help things out. Here's why: A preamp has four basic functions
    1) control volume
    2) provide source selection
    3) provide any needed gain
    4) control the interconnect between the preamp and amp

    Of these, 3) might be the most problematic if you're using digital. But quite often the volume control in a preamp is better than the volume control in a digital system. So you run the digital system up to full volume and use the control in the preamp. Especially if the digital system employs a digital volume control, you'll get more resolution.

    The 4th aspect, cable control, is poorly understood by many designers. I've seen enough Oppos to know they didn't get this right either. If you've ever heard an interconnect cable affect the sound and had to audition several to get the one that worked best for you, then you know exactly what I'm talking about. A well designed line stage can help you out with this. I totally concede that there are poor line sections that actually make things worse in this regard; if they were all on a level playing field this conversation would never even come up. It does solely because there is junk out there.

    Now if your digital system had a proper line stage built in with a proper volume control we again would not be having this conversation. But such a device is a rare bird- if you have a volume control on a chip an old school analog control can beat it. So that's why a preamp can help out.
    Hymie the Robot likes this.
  9. TarnishedEars

    TarnishedEars Forum Resident

    Seattle, WA
    Have you ever lived with a really good tube preamp inside of your system? I've lived with SS Preamp, a Passive "preamp", a tube preamp, and no preamp. I agree that no preamp is the most neutral choice, and that it will beat a SS and passive preamp most of the time. But a good tube preamp can really make a system come alive, even if it sacrifices a tiny bit of transparency in the process. So I'm happy to live with this very minor tradeoff myself.
    HiFi Guy, nm_west and SandAndGlass like this.
  10. Hymie the Robot

    Hymie the Robot Forum Resident

    This. It will sound different for sure, better will depend on the synergy of the entire system.

    My guess in this particular implementation is it will sound better but that is just a guess from my experience.
  11. 62caddy

    62caddy Forum Resident

    Yes, I've been down that road with a beautiful McIntosh MX110Z tuner preamplifier that I had completely refurbished at Audio Classics.

    Sounded lovely but I've never found it able to make a poor or otherwise "harsh" recording sound good, nor make a good recording sound any more listenable than the (SS) MX113 I have since replaced it with in my vintage system. I enjoyed the MX110 for a number of years but being a vintage tube model, it tends to need a lot of regular attention- not so much the preamp section, but the tuner which needed realignment every year or so.

    The MX113's tuner section is much more advanced and significantly better at receiving distant stations and hasn't needed to go back on the bench since its original servicing 2 years ago.

    To be brutally honest, between the MX110 and MX113, I don't think I'm missing a thing - except that is, for the service trips. :)
  12. Bananas&blow

    Bananas&blow Where the wind don't blow so strange.

    Pacific Beach, CA
    A preamp makes a huge difference in the sound quality of a system. Those who think it's just a volume control should check out the inside of one. I agree with the person who said it defines the sound of a system more than the amp itself. The preamp tubes affect the sound of a system more than the power tubes, that alone should tell you it makes a big difference. If you have separates, the preamp is the heart and soul of a system.
    SandAndGlass, SirMarc and HiFi Guy like this.
  13. Linger63

    Linger63 Forum Resident

    I thought there was no such thing as a "no pre amp" system.

    Isn't the Source simply doubling up as a pre amp in these cases?

    IME an OPPO 105......and later a 205....... were great as Sources but found to be lacking as pre MY system anyway.

    Would be interesting to hear a higher end Source connected direct for comparison......
    Something like the ( too many $$ for me!!) PS Audio DS maybe.
  14. Bill Hart

    Bill Hart Forum Resident

    It's hard to predict outcome with your system and components in the abstract. Several iterations of my system ago, I had a Steelhead phono with some fancy NOS tubes into a pair of tube amps driving horns and it just sounded threadbare- great bass, great high frequencies, but the midrange was too lean. (You could run the Steelhead directly). I added an active line stage- one that was solid state audio circuitry with a tube power supply and got far more fleshed out sound- not bloated or colored, just far more 'filled in'--
    I've made several component changes to that same basic system since then-- different phono stage, different line stage, changing phono cartridges, but the core elements have remained the same, including an active line stage.
    I had a discussion with Eva Manley about this step when I took it- the purity of no separate line stage v. the results I got from adding one. I couldn't disagree with her in theory, but the results in performance were more determinative to me.
    I'd say, before you spend money, see if you can get someone to loan you a good preamp. Even if it is a dealer with a higher price than an individual seller, the transaction coasts in the end may be a wash, particularly if you decide it isn't the route you want to take. And you won't have committed your money to something that is an entire unknown.
  15. 62caddy

    62caddy Forum Resident

    Actually it's the power amplifier's gain stage that is essentially serving the purpose (assuming the gain is variable).
    Bananas&blow likes this.
  16. avanti1960

    avanti1960 Forum Resident

    Chicago metro, USA
    I would never run without a preamp if I had separates. A good preamp will add muscle, life and dynamics to the system. Much in the way a good phono preamp or even the analog section of a DAC or CD player will add robustness to the sound. Get that separate transformer and power supply working for ya.
  17. TarnishedEars

    TarnishedEars Forum Resident

    Seattle, WA
    Most line-level sources put-out enough voltage to be able to drive a typical amp up to clipping. So all that is technically needed in most cases is attenuation, not amplification.

    I own a DS, and I definitely prefer the sound with a preamp in circuit. But the unnecessary gain from the preamp can be annoying at times as I'm almost always running with my volume control down between 8 and 9 O-clock.
  18. Ghostworld

    Ghostworld Forum Resident

    I rolled a CJ PV5 into my system and it never sounded better.
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  19. BIGGER Dave

    BIGGER Dave Forum Resident Thread Starter

    As it turns out, I have an inexpensive tube preamp I completely forgot about. At least ten years ago (probably more like 15 years), I built a Bottlehead Foreplay preamp. I used it for a while, then put it in the closet and forgot about it. I just pulled it out of the closet, hooked it up between the Gungnir MB and the Dynaco ST-70 Series 3 amplifier. The Foreplay preamp immediately gave me LOTS more usable volume (as expected). There was also an increased amount of (for lack of a better term), “slam”. The increased slam is probably due simply to higher sound pressure levels. But overall, I liked what the Foreplay was doing.

    I’m going to pursue looking for a good quality preamp, preferably tube. Remote volume control is a must. I’m not totally set on the Audio Research L25, so I’ll be doing some more research. Thanks to everyone that chimed in. More to follow.
    Last edited: Apr 13, 2019
    SandAndGlass and billnunan like this.
  20. Ron Stone

    Ron Stone Offending Member

    Deep Maryland
    Years ago, I did many listening tests with local audiophiles, comparing active preamps with a passive unit then receiving raves. I forget the name but it employed a stepped attenuation volume control.

    I never preferred the sound of the passive unit, nor the sound of the variable output of the CD player used as a single-source preamp. Always the active preamp. And, yes, we level matched with a dB meter.
    Ghostworld likes this.
  21. Bananas&blow

    Bananas&blow Where the wind don't blow so strange.

    Pacific Beach, CA
    Get the ARC preamp. I just got an LS 17 SE this week. Sounds great. Haven't heard much bad about ARC, ever. If you don't like it, you can flip it and get your monies back.
    Ghostworld likes this.
  22. Ghostworld

    Ghostworld Forum Resident


    Yep. SH started a thread “audiophiles don’t like neutral and don’t want neutral” or something to that effect.
  23. Ghostworld

    Ghostworld Forum Resident


    Dynaco and ARC used to be a great match. Fast forward forty years... :confused:
  24. Randoms

    Randoms Aerie Faerie Nonsense

    These are excellent, and in my opinion, honest observations (and facts).

    A few years ago, there was a very long discussion regarding the need for a pre-amp, or not on the Linn forum, after the introduction of the Linn Klimax DSM.

    Not having a lot of personal experience of this, I haven't got strong opinions, but would probably believe sometimes, but not always.

    For anyone interested, here is a link for a pdf to the White Paper that Linn wrote regarding the evolution of the pre-amp. Whatever your opinions, it is an interesting read and obviously follows a lot of investment, measuring and listening.

    The Linn Klimax pre-amp, was a mutiple award winning design in several markets.
    Last edited: Apr 14, 2019
  25. rjpjnk

    rjpjnk Active Member

    Bolder CO
    That is a really tough question Dave, and one I've wrestled with myself over the years. For phono inputs the answer is clearly yes, since a preamp is essential because you need 40dB of gain for the fragile cartridge signal and a huge RIAA equalization correction. So that is a no brainer.

    But for the line stage things are not as clear.

    Most, if not all, modern sources (CD players, iPhones, DACs) already have output levels at standard line level, and very low output impedances with plenty of driving capability. Technically speaking there is no way adding an active preamp can ever improve the signal quality of a signal like this that is already at a sufficient level to drive your power amp to full volume. No matter how expensive the components and how perfect the circuit, the overall SNR, frequency response, and any other electrically measurable figure of merit will certainly be worse with the preamp in the circuit than without. (Assuming you don't have problems with impedance miss match or too long interconnects here)

    That said, I do use an active line stage preamp because I like the sound, and I also like the convenience of input selection and volume in one box. Notice I say I like the sound, not that it is "higher quality". I know it cannot be higher quality having passed through more electronics. My theory is that the preamp, being the first stage to process the signal, has the earliest opportunity to electrically define it's sound signature. I say it is all about pleasant coloration of the signal. Many will disagree and say a good preamp should never "color" a signal and should be sonically invisible. To those I suggest using a wire instead (a short one at that). My opinion is that all electronics color signals, and it is really about choosing the color you like best. I like the sound of tubes, and so I use a tube preamp. A special one.

    I may change my mind as I listen more and learn more, but that's what I think for now. Hope it helps.

    I say try one.
    TarnishedEars and Melvin like this.

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