Announcement

Collapse

HUG - here for all audio enthusiasts

Since its inception ten years ago, the Harbeth User Group's ambition has been to create a lasting knowledge archive. Knowledge is based on facts and observations. Knowledge is timeless. Knowledge is human independent and replicatable. However, we live in new world where thanks to social media, 'facts' have become flexible and personal. HUG operates in that real world.

HUG has two approaches to contributor's Posts. If you have, like us, a scientific mind and are curious about how the ear works, how it can lead us to make the right - and wrong - decisions, and about the technical ins and outs of audio equipment, how it's designed and what choices the designer makes, then the factual area of HUG is for you. The objective methods of comparing audio equipment under controlled conditions has been thoroughly examined here on HUG and elsewhere and can be easily understood and tried with negligible technical knowledge.

Alternatively, if you just like chatting about audio and subjectivity rules for you, then the Subjective Soundings sub-forum is you. If upon examination we think that Posts are better suited to one sub-forum than than the other, they will be redirected during Moderation, which is applied throughout the site.

Questions and Posts about, for example, 'does amplifier A sounds better than amplifier B' or 'which speaker stands or cables are best' are suitable for the Subjective Soundings area.

The Moderators' decision is final in all matters regarding what appears here. That said, very few Posts are rejected. HUG Moderation individually spell and layout checks Posts for clarity but due to the workload, Posts in the Subjective Soundings area, from Oct. 2016 will not be. We regret that but we are unable to accept Posts that present what we consider to be free advertising for products that Harbeth does not make.

That's it! Enjoy!

{Updated Nov. 2016A}
See more
See less

Amplifier selection for your Harbeths (general, not specific Harbeth models)

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Re: How a Leben amplifier would fit??

    Others may refute this but this is my observation.

    The C7es2 sounds very good with at least 50 watts tube amp. I've tried 15-30 watts tube amp, while it sounds ok at small to moderate volumes, i feel i could want some more watts. The sounds is a bit boxy with 30 watts below.

    However, when you feed this speakers with more wattage, (eg tried 140watts tube amp), wow, it even sounds better. More alive, another dimension opens up.

    In short, it would be great if you can try this first with the Leben 14 watts. Your mileage may vary.

    good luck,

    Comment


    • Speaker hum

      Alan and others,

      Now I just recalled that when I used Quad909power/99pre with my M30, every time when stand-by or when I switched the amps off, my speakers made light hums, now I am using Plinius 9200 integrated amp and Quad CDP, I am not aware of that hum from speakers totally.

      Would someone be kind to tell me why, do some amps make that hum while some do not?

      Thanks!

      Hu

      Comment


      • Re: Speaker hum

        Originally posted by Hu
        Alan and others,

        Now I just recalled that when I used Quad909power/99pre with my M30, every time when stand-by or when I switched the amps off, my speakers made light hums, now I am using Plinius 9200 integrated amp and Quad CDP, I am not aware of that hum from speakers totally.

        Would someone be kind to tell me why, do some amps make that hum while some do not?

        Thanks!

        Hu
        Hi Hu,
        I am using Plinius 9200 integrated with AH!njoe Tjoen tube CDP+ C7 ES2. Do you speakers make some hissing/buzzing noise from the tweeters and the midwoofers regardless of volume when put your ears close(about 10 inch). And some merchanic hum from the amp itself. Just want to know if this is normal. Thanks.

        Comment


        • Re: speaker hum

          Hi wlmdx,

          No, I have not heard any hissing/buzzing noise from the tweeters or the midwoofers no matter how close I stick my ear to them. In the beginning of using 9200, I heard very slight mechanic hum from the amp itself, but somehow that disappeared later, so I do not think that the noise from you speakers are normal. Wonder what others would say

          Comment


          • Re: Amplifier selection for your Harbeths - Lavardin

            I've been driving Compact 7ES-2 with the Lavardin IS Reference with terriffic results. Sound is detailed and clear, with great separation of instruments and a spacious soundstage. This amp is rated at only 35 watts / channel, but I've never felt the dynamics lacking.

            Comment


            • Re: BAT Amps compatibility with Harbeths

              Originally posted by ranyc
              I am actively shopping for amps and was highly recommended to BAT (Balanced Audio Technology) Amps and Preamps. Has anyone heard BAT electronics matched with Harbeths and if so, how would you describe the sound characteristics? I own the Monitor 30 speakers. Many thanks for your advice.
              I am planning to order the SHL5 to mate with my VK-75. I borrowed my friend's Compact 7 and drove them with the VK-75 and they sounded great!!! So much so that I've placed an order with my dealer for the SHL5 right away.

              The VK-75 is warm sounding so be careful. Everything else upstream of the VK-75 in my systems is very neutral.

              If your front end is warm sounding then you may want to try the VK-75SE as I believe this has a more neutral sound. One more caveat with BAT, I am told that you must use a fully balanced pre-amp to extract the full potential of the amp.

              Comment


              • Re: Amplifier selection for your Harbeths (general, not specific Harbeth models)

                I have Compact 7s in a 2500 cu.ft room, and I listen in the nearfield (approx 7 feet).

                I have been using Cary 300B LX-20 single-ended triodes (rated at 20W) and they clip only rarely - and very gracefully. For my listening tastes (classical, often period-instrument recordings) the trade-off of power for sound quality has been well worth it. The purity, timbral truthfulness, dynamics and soundstaging are simply remarkable in my system - and confirmed by other listeners. And I get satisfying in-room levels (85dB) without even opening up the preamp all the way.

                I would encourage others with similar listening tastes - if you're looking for ultimate sound quality more than unrestricted power - not to shy away from lower-powered amps.

                Frank
                http://www.franklarocca.com

                Comment


                • Re: Speaker hum

                  Originally posted by wlmdx
                  Hi Hu,
                  I am using Plinius 9200 integrated with AH!njoe Tjoen tube CDP+ C7 ES2. Do you speakers make some hissing/buzzing noise from the tweeters and the midwoofers regardless of volume when put your ears close(about 10 inch). And some merchanic hum from the amp itself. Just want to know if this is normal. Thanks.
                  Hi wlmdx,

                  My Plinius SA 102 arrived, now I heard some hissing/buzzing noise from the tweeters and midwoofers, especially when I put in its class A mode, with A/B mode just very slight noise, nearly cannot hear. Now I just mailed dealer, have you ever contact to the dealer? Those noises are quite big. I did not hear merchanic hum from the amp itself, just from the speakers.
                  Thanks!
                  Hu

                  Comment


                  • Re: Speaker hum

                    Originally posted by Hu
                    Hi wlmdx,

                    My Plinius SA 102 arrived, now I heard some hissing/buzzing noise from the tweeters and midwoofers, especially when I put in its class A mode, with A/B mode just very slight noise, nearly cannot hear. Now I just mailed dealer, have you ever contact to the dealer? Those noises are quite big. I did not hear merchanic hum from the amp itself, just from the speakers.
                    Thanks!
                    Hu


                    Hu,
                    Did you try to follow the procedure here?
                    http://www.pliniusaudio.com/questions/index.asp#09

                    First disconnect all powercords and interconnects and then reconnect back one by one start from poweramp, it will help to you identify which part of your system causing hum.

                    Good luck!

                    Rdgs,
                    Kevin

                    Comment


                    • Re: Speaker hum

                      Originally posted by kevint
                      Hu,
                      Did you try to follow the procedure here?
                      http://www.pliniusaudio.com/questions/index.asp#09

                      First disconnect all powercords and interconnects and then reconnect back one by one start from poweramp, it will help to you identify which part of your system causing hum.

                      Good luck!

                      Rdgs,
                      Kevin
                      Thanks, Kevint!

                      I will try that to find out. Yesterday the dealers brought different source, pre amp and interconnects to try with Plinius SA 102 and Harbeth M30, they found the noise, later when I connect my own source, pre amp and so on, the noise is still the same.

                      Regards,

                      Hu

                      Comment


                      • Re: Speaker hum and electrical safety

                        Originally posted by Hu
                        ...they found the noise, later when I connect my own source, pre amp and so on, the noise is still the same.
                        I think you need to be absolutely clear about the source of this problem: is the hum noise generated in the electronic circuit of the amp (or CD or whatever) or is actually an artifact of the mains supply wiring in your room?

                        For example: I have been playing with different power amps at home in my tiny 3 x 4m listening room recently. I noticed that there was a small hum on the left channel of one amp (right channel was clean, just the usual tiny hiss). I could live with that hum, no problem. On the next amp, there was a hum on both channels. Actually, it was not a hum, it was a buzz; I could live with this since it was only audible when I put my ear about 3cms from the bass unit. On the third amp, there was a strong hum on both channels.

                        It turns out that there were several problems and I had to tease them apart. First point to resolve was that the amp was plugged into a mains wall socket that was on the other side of the room. You may think (as I did) "so what? It must be served by the same electrical ring-main, and what is a distance of only about 5m between wall socket A (powering the CD, and preamp) and wall socket B, (powering the power amp)". Both the preamp and power amp were mains grounded.

                        But you and I would be wrong. There is a microscopic difference in the potential of the earth pins in wall sockets A and B due to the finite resistance of the bonding earth cable between them. To put this into perspective, that small a voltage is about the same as the voltage from your TV aerial that reaches your TV receiver: very difficult to measure but obviously there! So, the potential difference between socket A and B may only be millionths of a volt - surely insignificant - but it confuses the amplifier which will amplify the difference and then delivered to the speakers as a low-level hum or buzz.

                        I decided that I'd bundle up all three amps and send them back to their manufacturer's excellent service dept. (total cost ?400 to repair, check and calibrate). I then brought all the equipment mains to ONE point; this killed the ground (hum) loop.

                        Moral of the story:

                        1. As I have said here before, amps do age. The big smoothing caps (made with a wet paste) do dry out, and they let mains hum through onto the speakers. Only solution: replace them periodically - say every 10-15 years or so.

                        2. Always - always - connect all your audio equipment to ONE wall socket (or a pair of sockets if they are together on the same moulding).

                        3. Never, ever, remove or tamper with safety earths as a way of breaking ground loops. This could be FATAL. If the equipment is double insulated and does not have an earth connection that's fine, but if the equipment has an earth pin it needs one to ensure that the case is safe sould there be a mains leakage inside.
                        Alan A. Shaw
                        Designer, owner
                        Harbeth Audio UK

                        Comment


                        • Re: Speaker hum and electrical safety

                          Very interesting, Alan...
                          thank you !
                          Anyway, have you read my email about Monitor 30 birth year?
                          bye

                          David

                          Comment


                          • Re: Speaker hum and electrical safety

                            Originally posted by A.S.
                            I think you need to be absolutely clear about the source of this problem: is the hum noise generated in the electronic circuit of the amp (or CD or whatever) or is actually an artifact of the mains supply wiring in your room?
                            Thanks Alan,

                            I tried to disconnect the interconnects between power amp and pre amp, only switch the power amp on, still heard the hissing/buzzing noise from M30s, with Class A mode more, with A/B mode less.

                            The dealer tried in his shop, the same noise from his West Lake speakers. I am not sure if he connected all his audio equipment (probably Goldmund preamp) to ONE wall socket, I did at home.

                            Hu

                            Comment


                            • Hiss, hum, buzz and standards of perfection in amps .....

                              Originally posted by Hu
                              I tried to disconnect the interconnects between power amp and pre amp, only switch the power amp on, still heard the hissing/buzzing noise
                              Ok, noted. It's very important that you use just one mains socket to power everything as I explained.

                              Now, I am not trying to make excuses for any equipment, but as I have some experience designing active speakers which include power amps I am aware of how difficult it is to totally eliminate all and every hiss, hum and buzz. Because the circuitry is in the same case as the mains transfomer there will always be some interference between the magnetic field generated by the mains transformer and the circuits. This is inevitable. There will also be some hiss generated by the circuits. This is also inevitable and to a large or complete extent, predictable by a mathematical analysis of semiconductor (or tube) electron flows - far, far, far beyond my pathetic maths ability. There will also be a buzz associated with grounding inside the case and outside due to the connection to other equipment.

                              These unwelcome and unwanted noises are exceedingly difficult to eliminate during design and construction of an amp (which is why really good amp designers are so rare) and in the case of the M40 it has amazed me that every single active amp unit has its own very subtly different sonic signature - some have a tiny little hiss: some are absolutely silent etc. etc.. Why? I don't know. The circuit is the same: the layout is the same: the case is the same and yet there are these tiny differences in hiss, hum and buzz if you put your ear on the tweeter.

                              I have spent tens of hours playing with wires, tracks, grounds and so on and driven myself nearly (or more) mad to understand this. But - reality check - 'can you hear it at 50cms away or more'? Answer: no. All these noises are masked by the aircon system, the traffic noise, the TV next door and of course, the music itself. So why chase a standard of perfection down at the noise floor? It's just not necessary - or is it?

                              In my humble opinion, having recently become much more aware of the gurgles, groans, heart beat and spurious quasi-tones from inside my own body (and ears) when meditating in a quiet room just before sleeping, it seems to me that this sets the threshold of a worthwhile signal to noise ratio in the electronics. I should add that comparatively speaking, the problems with speakers - even good ones - are so gross and so ghastly that all this amp stuff pales into relative insignificance. And I'm not proud of that.

                              Lastly: it is not fair to judge an amp (pre or power) when the input is 'open circuit' because the input will pick-up and amplify aircraft, taxi, mobile phone, TV, computer and other rubbish noise.

                              To be fair to the amp you need to short circuit the INPUT i.e. connect the INPUT plug's hot pin to the input plug's ground or connect it to a preamp that is turned off.
                              Alan A. Shaw
                              Designer, owner
                              Harbeth Audio UK

                              Comment


                              • Re: Hiss, hum, buzz and standards of perfection in amps .....

                                Originally posted by A.S.
                                . So why chase a standard of perfection down at the noise floor? It's just not necessary - or is it?
                                Thank you Alan for your very considered reply.

                                One other point which I have thought about from time to time is the relationship of these noises to speaker sensitivity. e.g. If the noise source is in the amp then switching to more sensitive speakers would make the hum/buzz more obvious.

                                Seems logical but is it?

                                Comment

                                Working...
                                X