Mechanical vs. solid state

July 16, 2021
 by Paul McGowan

When we need to switch inputs on an analog preamplifier we use a switch. The kind of switch we use affects sound quality.

For years we had only mechanical switches from which to choose. Standard switch contacts in those days were nickel or tin-plated while the more expensive and better-sounding styles were either silver or gold.

These worked great and sounded excellent, but they had a problem. They were nearly impossible to remote control.

The customer's desire to control their systems from their easy chairs drove us designers to replace mechanical switches with electromechanical relays. Relays were available with the same contact materials though because they weren't self wiping (like mechanical rotary switches), their slap and connect operations produced a slight degradation in sound quality.

Relays are expensive and cumbersome.

Along came silicon switching. Low cost, quiet, reliable, and without the problems of contact degradation. Sonically, they fell into third place, but not too far behind relays.

Engineering is always a matter of compromise. We give up one thing and in exchange get something else.

In most of PS Audio's PerfectWave series of analog audio products, we rely upon a combination of electromechanical and electronic switching.

Common sense, practical, excellent performance.

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35 comments on “Mechanical vs. solid state”

  1. Back in the day I had a turntable, a tuner, 2 cassette decks (1xDAT) & a CD player
    ...that's 5 inputs.
    However now I have only one input... a CD player, & I yearn for nothing more.
    If I could be bothered I'd get my soldering iron out & bypass the inputs section of my amp & just make one input available straight through to the pre-amp section.
    Or I could go completely nuts & hard-wire my CD player to my integrated amp,
    thereby bypassing any & all input switches & contact points...
    maybe one day...
    when I'm really bored.

    1. **Off Topic**
      Sorry everyone, I don't mean to get political
      but this piece of news really cracks me up.
      So, I just heard that Vladimir Putin did, in fact,
      pull out all stops to interfere with the 2016
      American elections.
      His thinking was, to get Trump elected because
      Putin believes that Trump is mentally unstable &
      that because of said mental instability, this would
      divide America.
      I'm not a Putin fan, but if this is true then he's one smart cookie 🙂

        1. Since Jan 20, things have sure gotten better, haven't they? I challenge you to think of this administration building an audio system and what it would look like. An no, it cannot run on fossil fuel.

          1. I'm not aware that the previous administration listened to music at all. Well maybe Kanye and Kid Rock, and that was likely only because flunkies told him about them. From accounts, he mostly just watched a certain cable news channel that shall remain nameless and even they provoked his ire when they (rarely) drifted out of full tilt sychophant mode. I wasn't there (thankfully), so I can't say for certain. I never saw him at the Kennedy Center Honors broadcasts, though.

            Barack Obama has posted at least two summer music play lists (that I am aware of, maybe more) and hosted concerts at the White House. For your listening and viewing pleasure, I particularly recommend the two parts:



            Ain't nothin' but the blues!

            1. Hmmmm. YouTube says "Video Unavailable" for Part 1. It is. The link for Part 2 works and Part 1 does show up on the side bar stack of thumbnails/links. Erratic interface, maddening.

      1. All politicians, regardless of affiliation and (especially) type of governmental structure, are power pigs to a greater (mostly) or lesser extent. It apparently just goes with the turf. In the immortal words of Bob, "Don't follow leaders, watch the parkin' meters."

        And while i'm (yet again) quoting song lyrics, let's give Bruce a go:

        "Poor man wanna be rich [me], rich man wanna be king [Trump]
        And a king ain't satisfied till he rules everything [Putin, Xi, ad nauseam]"

        Not a fan of anarchy (in the UK and elsewhere), either. Balance is a tricky and frequently metastable thing.

      2. p.s. And a writer (and physician) best known for crime stories and a certain archetypal detective in particular, Arthur Conan, "It's a wicked world, and when a clever man turns his brain to crime it is the worst of all." Just substitute 'political power' for 'crime'.

  2. It might be interesting to mention another very special type of switching at this point, which is realized in the preamp I use (I removed the brand name here):

    (Cited from the product description)
    „Another unique feature is the design of the input selector circuit. It is realized without any interference of switches, relays, Fets or ICs. This input selector circuit is achieved by booting and power down of the heating voltage of the respective input tubes. This means that the input signal remains untouched and is neither sonically and metrologically limited nor affected by switches, relays, Fets or other components. This special circuit is unique in high end audio worldwide.“

    This means the circuit has one input tube for every input, which also means, one can use different tubes per input or compare them directly. When switching, signal is faded out and in. A really crazy solution to be able to switch without a switch in the signal path.

  3. I can't say I ever gave the issue of switches a thought. For all by 6 months of my audio-owning life (approaching 40 years) I've used integrated amplifiers. For me, the word "mechanical" implies servicing and eventually failing. I'll make an exception for mechanical cameras.

  4. My Creek 5350se is 100% mechanical with a motorized remote system and also passive. Over time I have to Deoxit the controls. Once cleaned it sounds great.

    1. I miss my Creek! Eventually the source selector wore out somehow and caused terrible noise. They said it couldn't be fixed easily, so I switched to a Rogue tube integrated, but I still have love for that 5350SE! Very satisfying click when you hit the button on the remote and the knob turns.

      1. It has beautiful sound. Was in Stereophiles recommended components class A integrated Amplifiers and for good reason. Everything can be repaired. I'm surprised they told you that. It probably just needed the contacts cleaned which is common with mechanical source controls. Worked for me.

        1. Yes, I was too! But that was from Creek tech support in England, so I threw in the towel. He said that in newer models they switched to a different part that didn't have this problem.

          1. The one negative about Creek is their customer service. Without looking at the unit or knowing whats wrong with it they are telling you the only solution is to buy their newer unit. They are also notorious for not keeping replacement parts on hand but some of the parts are still available from other sources if you get the part number off the part and search it. I know the volume control is available that way but they won't tell you. I have had vintage receivers that had dust or corrosion in their pots and switches that cut out the sound of a channel completely and after a proper cleaning all worked like new again. Your best bet is to find a place in the USA that services Creek rather than contacting the manufacturer in England once your warranty expires. But only after a good cleaning has failed and you cannot locate replacement parts and fix it yourself.

  5. "I can’t say I ever gave the issue of switches a thought"
    Same for me.
    As I see (hear) it, people who DO give this issue a thought are a tiny little bit neurotic.

      1. I totally agree Michael.
        In fact that is what I wanted to write in my 4:01 comment, but I forgot.
        I was referring to listeners, not designers.

    1. Can't say we audiophiles are not a bit nuratic. We all been to audio heaven and at some point after selling our gear for something new or moving into a new home it was snatched away from us. We either experimented with new gear replacing it until we nailed it again or improved on it, or we went back to the old gear, but we know where we need to be and we won't stop until we get there. Anything less is unacceptable.

  6. Interesting that things had to be developed because the ‘demand’ was for input switching.

    I for one have no issue with switches and the “better sound”. If you you listen to any sources that require ‘operator’ intervention then you have to get up and move…. Spinning anything…

    If you’re listening to streaming digital then maybe not. Then again there’s probably not a lot switching going on.

    Volume and muting functions on a remote may be in demand…

    Now that the issue has been raised, should the way sources are selected become a major factor when choosing a preamp, or an integrated with multiple source inputs? Common Sense at PSA prevails…. So maybe not.

    1. I am with you Mike on your comment.

      Besides, even if I was neurotic about my need for more and more new gear after all of the purchases I’ve made over my audio history, making a major change like this now would require a Go Fund Me Account.

      1. Thanks stimpy2. 🙂

        I’d like to think I’m not neurotic about thinking new gear. Just at a point where more than a simple incremental change may be required. (Especially since I’m entering the last 1/3 of my life expectancy) So while I can get by without a go fund me account for the gear. I may need one to build the appropriate hall 😀 in which to listen.

        1. Mike, we seem to agree about more than a few things with regard to audio. I’ll b e 75 next month but most people comment that I don’t look over 60 which is probably true.

          I never purchased a new component unless it was time or a new format (streaming) proves itself out. I’m not sure if I should label myself as a neurotic over these purchases but once I make my mind up I become obsessed with finding the best product that offers the proper synergy in my system.

          1. Hello stimpy2,

            Looking younger is great. Feeling younger than you are & doing the things you most enjoy is greater.

            As far as audio goes I feel honored that someone agrees with some of what I write 😀

            Replacing gear (I’m thinking primarily amp / preamp) is not because I have to, (thank goodness) but as you say, rather time, along with a fair amount of desire.

            Since auditioning becomes a major chore for me because of commute times / distances… I’ve been putting things off and living with what I have. (This past week that changed) Like you I like the planar ribbon dipole sound and happen to have Apogee’s. So if I stick with the speakers I have then it’s a matter of finding electronics that drives them, will be robust enough to last, and have the musical synergy I’m looking for. If I change all things then my choice are Maggie’s. Let the obsession and games begin ✌️ 🙂

            1. Apogees are phenomenal speakers and so are the new Maggie 3.7‘s, 20’s or 30’s. I would step up from my 3.6’s but for the reasons I stated they’re gonna remain in my system for as long as they stay in great shape.

              I might also stay tuned for the release of the FR-30’s.

  7. I don't know when they started this, but they did.
    Mcintosh started in around 1998 or so, using these gas fealed tubes for switching purposes.
    At first, these tubes were used in their preamps.
    But after a good while, they came out with the MA-275 integrated tube amp.
    They used those gas fealed tubes in it too to preform switching chores from one source to another.
    You can't even tell that it got switched from one source to another just by listening.
    I mean, they were that quiet.

  8. I use a conrad-johnson preamp. I am not sure what they use to switch input selection, however, it can be done two different ways. If I am using the remote then it is a simple press of a button to get the desired input ( i.e. phono, tuner, cd, etc. each has its own selection button on the remote ). If I am at the unit and want to change inputs then I must press a single button that moves the selected input cyclically through the five possible input choices. All I can say is I have never noticed any change in the sound of the preamp based on how I change the input selection.

    Today's post has made me think of something I have wondered about that is related to how the operating system of a piece gear is programmed. This is somewhat off topic, but not completely off topic. 😀 I am fortunate enough to own what is the best ( or at least one of the very best ) sounding SACD transports in the world. This is the new PS Audio Perfectwave SACD Transport ( PST ). The sound of this unit is very special. I own a second one box disc player that is in my video system. It is the renowned Oppo 205, their last hurrah before pulling the plug. While it is a world class bluray player it is not in the same class as the PST / DS DAC combo when it comes to sound.

    There is a strange difference between the two units when you are operating them, which I have wondered about since there was a time in my career that I wrote machine code to program gear in my lab. With the Oppo when I am finished watching I press the eject button, remove the disc and then press the off button ( which should really be labeled standby ) and the unit closes the disc drawer and goes into standby. With the PST if I do the same thing when I am finished listening the unit goes into standby, but leaves the drawer sticking out. This, of course, is bad because the drawer could be damaged when it is left out. Thus, I have often wondered why the PST is programmed this way.

  9. Thanks for the quick review of the PSA CD transport. You seem to make quite a few excellent choices to complement your system. If I ever have to purchase another component it will probably be my Wadia CD player which I still love. I know that before Paul designed his first transport his videos used to show a Wadia in his office system. The only reason I would switch if my player goes down is because the Philips transport is not available anymore. I had a lengthy conversation with NP about his Wadia and he told me that he would’ve not replaced it if he could have located another Philips transport mechanism that failed on him. He uses an Oppo player now as well.

  10. Working on ships I often got asked by the crew and officers to repair their radios, tape recorders, cassette players etc. Some of the kit was bought from lesser known manufacturers and internally were very poor. For example a sliding on/off mains switch was a copper strip with paint on one end (to be the off position). Sooner or later that paint would wear off! Of course the well known manufacturers kit was a delight (mostly) to work on.
    Music was a great comfort on very long voyages like crossing the pacific so most had their own players.

  11. Silver? Or, gold? Tin?

    What do we call manufacturers products who manufacture the same boring and unexciting sounding audio year after year?"

    Call it ..... "Staid of the Art."

  12. Back on topic, cheap pots and switches are the bane of existence. Well, they are a major nuisance for music reproduction purposes. For a number of years, I used and enjoyed an Advent 300 receiver as a phono/line preamp and FM tuner feeding a Hafler DH-200 amp. The Advent 300 has the initial implementation of the well regarded Tomlinson Holman phono circuit, but it was definitely built to a low price point. It worked satisfactorily for a number of years, but things got to the point where any adjustment to the controls was greeted with a burst of static. TV tuner cleaning spray (Radio Shack?) would help for a while, although I am not at all sure of the inhalation safety/carcinogenicity of some of the ingredients.

    I eventually replaced it with an Arcam A65+ integrated amp, dating back to the day when their kit was still made in England. The company literature touts "The solid state switching is immune to the wear and tear that affects mechanical switches." . . . "The parts we use are not over stressed and are designed for long term reliability." This may be just p. r. hyperbole, but I can say that after about 15 years, I remain satisfied with the sound quality and the ergonomics. Not state-of-the-art, of course, but far more than adequately good.

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