Kegworth Show Information

The information for this year's show is now live at www.thehifishow.com or by clicking on the show banner below.

NON EXHIBITOR ROOMS NOW OPEN - Special Offer....Stay Saturday, join in all the build up excitement on Sat night and then gain FREE access to the show on Sunday

ONLY 4 EXHIBITOR ROOMS LEFT - BIG SYSTEM SPACES SOLD OUT - ONLY 2 NON EXHIBITOR ROOMS LEFT

Shadders

Wammer
  • Content Count

    312
  • Joined

  • Last visited

Community Reputation

93 Excellent

1 Follower

About Shadders

  • Rank
    Experienced Wammer

Wigwam Info

  • Turn Table
    N/A
  • Tone Arm & Cartridge
    N/A
  • SUT / Phono Stage
    N/A
  • Digital Source 1
    Dune HD Base 3D
  • DAC
    Audiolab 8200AP
  • Integrated Amp
    CambAudio Azur 650
  • My Speakers
    DIY Transmission Lin
  • Trade Status
    I am not in the Hi-Fi trade

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. Shadders

    Loudness Wars

    Hi, I wrote to a group (music) and had a reply from one of the band members. He said that they do not compress their music as per the loudness wars, and as per the dr-loudness website the figures were not correct. So, essentially the loudness or compression as indicated on the website has to be viewed with some scepticism, and maybe use your ears to determine if there is too much compression. Regards, Shadders.
  2. Shadders

    Speaker noise when tapping turntable??

    Hi, So, when you tap or knock the turntable, you get a noise through the speakers like a tap or knock to the turntable. The solution is, don't knock or tap the turntable. Which reminds me of the Etch a Sketch joke : Q: My Etch-A-Sketch has all of these funny little lines all over the screen. A: Pick it up and shake it. Q: How do I turn my Etch-A-Sketch off? A: Pick it up and shake it. Q: What's the shortcut for Undo? A: Pick it up and shake it. Q: How do I create a New Document window? A: Pick it up and shake it. Q: How do I set the background and foreground to the same color? A: Pick it up and shake it. Q: What is the proper procedure for rebooting my Etch-A-Sketch? A: Pick it up and shake it. Q: How do I delete a document on my Etch-A-Sketch? A: Pick it up and shake it. Q: How do I save my Etch-A-Sketch document? A: Don't shake it. Regards, Shadders.
  3. Shadders

    Chasing Distortion Measurements

    Hi George, Thanks for the text. It seems Bruno agrees with what has been said. First Paragraph : If sufficient feedback is not applied at high frequencies, the sound is brittle - so he advocates more feedback. This is known - using a capacitor in the feedback path to increase the feedback at high frequencies will compensate. Also using other techniques to counter high frequency distortion is possible. The second and last paragraph : Here he restates how important feedback is - and using it is a good thing. His statements indicate that it is the distortion that characterises the sound of an amplifier, which agrees with Bob Carvers experiment/proof. Going back to the D'Agostino Momentum Integrated - it does have relatively high distortion at 20kHz - compared to other amplifiers. If this distortion is even order - it will sound nice. So i expect this is "designed in" distortion to separate the amplifier from the others, and people like the sound, realise that there must be less feedback as they used given the THD measurement, and then associate that good sound comes from less feedback. Regards, Shadders.
  4. Shadders

    Chasing Distortion Measurements

    Hi, Ok - please provide the text from Bruno Putzey. Thanks. Bob Carver did prove that if you mimic an amplifiers distortion profile the two amp cannot be differentiated subjectively - nor objectively - he used the null testing approach : https://www.stereophile.com/content/carver-challenge-page-4 The relevant text states : "Disquieting Implications The implications of all this are disquieting, to say the least. If, after only four days of work, it is possible for someone—design genius or not—to make a $700 amplifier sound exactly like a state-of-the-art amplifier costing many times as much, what does that say for the cost-effectiveness of the latter?" Excellent components are cheap. As per the Bob Carver experiment - it does not matter if you use special components, as you can emulate another amplifier with the relevant equipment. Whatever the components, they will introduce distortion, and if measurable, the effect can be replicated. Regards, Shadders.
  5. Shadders

    Chasing Distortion Measurements

    Hi, In respect of the Bruno Putzey statement - this may be that no distortion means less "nice" sounding harmonics. The converse is true for the expensive/cheap amplifier and feedback. You can design a cheap amplifier and the design can be very good. It can be as good as an expensive amplifier costing 20x more (£2k -> £40k). I do not believe we can associate cheap meaning bad design requiring more feedback. If the two amplifier have the same harmonics at the same level, then they will sound the same. This is what Bob Carver proved. How you achieve that specific harmonic content is irrelevant, it is the level of the individual harmonics that create the distinctive sound. Amplifiers sound different even when they are both cheap (relative term). The big amplifiers - D'Agostino - use exactly the same components as every other amplifier. The casework may be exotic, but then so is the price. That is really what you are paying for. Regards, Shadders.
  6. Shadders

    Chasing Distortion Measurements

    Hi, For THD - this would not be sufficient, since it could be second order dominant, or third order dominant, but both have the same THD. What Bob Carver did was match the second order, third order and so on, distortions to meet the target amplifier. It is not the THD, but how the distortions are distributed across the frequency range which give the amplifier its characteristic sound. As such, you can purchase an amplifier at the cost of £2k, add the distortions to mimic the Momentum, and the amplifier will sound like the Momentum. There are obviously bounds to this - such that if the £2k has a peak current of 30amps, the Momentum will exceed this - but then, if the speakers impedance never requires this peak current - then it is not an issue. Example, peak current 30 amps is 60volts peak into 2ohms speaker load, which is an amplifier operating near its maximum voltage output. High peak currents can be obtained from low cost amplifiers, but in general - to achieve the peak current means driving the amplifier hard into difficult speaker loads. Regards, Shadders.
  7. Shadders

    Chasing Distortion Measurements

    Hi, Yes - yesterdays news - it was in the 1980's. Where does it say that Bob Carver regrets his challenge ? Current delivery is only needed when you have a difficult load. Again, a well designed amplifier - circa £2,000 with ample current delivery will sound the same, if the distortions have been matched. The D'Agostino Momentum Integrated amplifiers cost £42k as per Hifi News indication. The same "sound" can be achievable for 5% to 20% of that cost. Regards, Shadders.
  8. Shadders

    Chasing Distortion Measurements

    Hi, If you examine the measurements for the D'Agostino Momentum amplifier from Hifi News December 2014, it shows that the distortion from 20Hz to 20kHz is 0.018% to 0.11%. This is quite high considering the number of output transistors per channel - not stated, but pictures on the internet show a high number. What we can say about this, is that output crossover distortion will be reduced by the number of output devices. This then means that the high distortion is due to the other components of the amplifier and its topology. Essentially this will be the reduction of negative feedback to allow specific distortion mechanisms to be higher. If we examine Bob Carver's challenge - he was able to prove that his well designed low distortion amplifier, with added distortion to match that of any other amplifier, that the listener could not tell the difference between the two. (https://en.wikipedia.org/wiki/Bob_Carver) So the nice sounding amplifiers have higher distortion, which is preferred by the human ear (even order distortion, more musical). So, what if you purchased a cheap and well engineered amplifier, and added to that a DSP unit that copied the distortion mechanisms of know high end amplifiers. Hey presto, you have an exactly same sounding amplifier for a fraction of the cost. Regards, Shadders.
  9. Shadders

    General Question on Speaker Internal Stuffing

    Hi, I bought my wadding from Falcon Acoustics - reasonably cheap. My interpretation of the use of wadding is a trial and error approach - try and see what sounds best. For my current transmission line speakers i have just built, which has internal folds - there are 3 internal sides which face forward (back panel, and two internal panels) which have 30mm egg crate/convoluted foam (adhesive backed). Then all panels sides that face downwards have the same. The remaining panels (rear facing sides, upward facing sides, and left/right facing sides) all have 6mm acoustic foam. Then i have internal wadding along the entire length of the line. Cannot tell you how they sound yet since i am painting the speakers. Regards, Shadders.
  10. Shadders

    Slim floor-stander to active?

    Hi, For the driver performance - you can check some online sources - Voice Coil tests drivers and their distortion across the frequency band. https://www.audioxpress.com/categories/vc-testbench Another website is : http://www.audioexcite.com/?page_id=445 You can select from the menu which drivers - less choice here. Regards, Shadders.
  11. Shadders

    Rustling noise on one channel of my turntable

    Hi, Yes, grounding the shield will conduct any energy to the ground. If the tin foil is not connected to any ground, then the incident wave will induce a voltage, but will also reflect the energy. This is how a parabolic antenna works - energy transmitted by the amplifier is reflected into free space (assume satellite transmission) with a specific gain, based on the parabolic antenna size and the frequency of operation. The tin foil distance to the cartridge coils will introduce some capacitance, but the distance and dielectric (plastic cartridge shell, free space to coils) means that it is extremely low. As such, the majority of the incident energy is reflected. Regards, Shadders.
  12. Shadders

    Rustling noise on one channel of my turntable

    Hi, All earthing will do is reduce significantly the energy reflected. The tin foil will reflect any incident wave. Regards, Shadders.
  13. Shadders

    Rustling noise on one channel of my turntable

    Hi, Maybe wrap the cartridge in tin foil - not tight, to see if that stops the noise. Regards, Shadders.
  14. Shadders

    Why do i always seem to do this to myself

    Hi, What frequency range did you use for the room calibration ? If you used low frequencies to correct, then the speakers will have been driven at a much higher power at low frequencies due to their response. The smell may be components getting hot at the the low frequency pass. Is the TCP smell the enamel of the transformer windings getting too hot ? Regards, Shadders.
  15. Hi, I did a check - the S/PDIF uses biphase encoding. The Toslink Receiver specification for the receiver is maximum 7.5MBits/s with biphase encoding, which means that 24bit/96kHz is the maximum the link will operate at. (32bit/96kHz is possible as this is less than 7.5MBits/s). I checked with Farnell etc., and the receivers are difficult to obtain - and the ones available ate 10MBits/s maximum - and expensive - £10 approx - i paid £4.10 for Toshiba receivers 8 years ago - these are not sold any more. Anyway - current optical comms will be 24bit/96kHz maximum for standard audio. Regards, Shadders.