catman

Members
  • Content count

    1,632
  • Joined

  • Last visited

  • Days Won

    1

About catman

  • Rank
    1000+ Post Club
  • Birthday 12/14/1962

Uncategorized

  • Location
    Queensland
  • Country
    Australia
  • First Name
    Felix

Recent Profile Visitors

9,245 profile views

Display Name History

  1. G'day all, a bit of a vent! Today was our second annual record fair in our town. As I did last year I went along and ended up buying four LP records. Two things were apparent, the number of vendors was less than last year, and secondly one of the vendors was selling 'all' his records at one (very) premium price. One might even say an exorbitant price, however his range was very good and I did hand over my cash for two records. What was worse than his prices was his 'attitude', that I personally found quite offensive. Essentially it was, no negotiation on price and if you don't want to buy, 'go away'. I was not impressed at all. If I'd been feeling a little more confrontational, things might have become somewhat more heated, but I restrained myself thankfully. This chap was clearly cashing in and milking the present renewed interest in records for all that he could. The other vendor was much more pleasant and reasonable and was a pleasure to deal with. It was an 'interesting', shall I say experience. Regards, Felix.
  2. The Human Mind Aspect. G'day all, this may end up being just another long ramble of mine, but of late I'm getting the impression that at least when it comes to matters audio, the human mind and its perceptions (accurate or not), have a much greater effect on general opinion than many would think. Coming from a long term work technical background I would like to think that I am not subject to such things, but alas, significantly I am. Whilst my hearing acuity is good I know that 'little things' will affect my audio perceptions, things like physical appearance to the thoughts of others on given subjects and even my own pre-existing judgements and prejudices. Reading the 'reviews' of others on the many audio online forums can both be enlightening, and indeed the opposite. Based on what I know and have personally experienced and observed I can see that quite a few reviews, although possibly heartfelt, are affected my a general lack of subject matter knowledge, misunderstandings, and indeed ignorance and the really sad thing is, in my opinion, such reviews can be quite influential! The whole range of life experience can be similarly fraught! Even my own audio perceptions have changed to a degree over time! For example, the subject of 'op amp sound'. For many years I regarded the OPA2134 highly for its perceived musical 'sound' as well as being a very well designed and 'hardy' high performance dual audio op amp....and it is, however in recent times I've found a renewed admiration/respect for the general sonic qualities and general performance of the 'good old' NE5532 as well. It is still an excellent op amp for many high quality audio applications despite its age! Speaking of component ‘sound’ and such, reading the pages of the various online forums I cannot fathom all the supposedly ‘expert’ commentary on all aspects of component ‘sound’, much of this written convincingly by audiophile people without much of a clue, in my humble opinion. Over the years I have dabbled in some of this sort of thing myself and whilst it is true that components do have measureable electrical differences between types, this does not mean ‘audible’ differences, but again such ill-informed commentary can 'influence'! For what it is worth I do use polypropylene dielectric capacitors in some applications such as cartridge loading, in place of frequently used ceramic capacitors. Ceramic capacitors do have their value and use in RF and some 'bypass' applications, but potential non linearity and microphony make their use in audio applications a little suspect! Base your decisions on technical fact and reality! In the end this whole discourse is all about the way that the human mind can be misled and there are many possibilities, and some of them are very sneaky and insidious! Here’s to clear thinking without blurry/misleading influences! Regards, Felix.
  3. G'day mate, yes that's a good point! Regards, Felix.
  4. Power supplies, noise filtering and all that stuff. G'day all, as I mentioned in another thread yesterday, I was somewhat shocked by how effective a rudimentary low pass filter on a DC power supply could be at significantly reducing mains borne 'crud'. My eyes have been 'opened' as it were. Yes in the past I have seen the value in the battery powering of phono preamps, for example, however my most recent experience has proved to me that the mains supply is not necessary perfectly 'clean', and even basic filtering can improve the subjective quality of audio gear as a result. This is not that hard to believe as in the end any preamp or power amp is merely 'modulating' its power supply at an audio rate, and any uncorrected issues with the power supply will be evident on the output of the audio device. Maybe a true and pure DC supply (batteries), is the only 'way to go'. Interesting indeed! Regards, Felix.
  5. G'day mate, no I don't have that phono stage....way too many already! I was genuinely surprised by how effective this simple low pass filter network is, and the overall sound quality is particularly good too! More things to investigate. Regards, Felix.
  6. G'day all, a bit of a surprise for me this afternoon. Using one of my DIY kit phono stages I realized that the 'whistle' that normally comes from the switch mode power supply air conditioner unit in here was largely absent, compared to other mains powered phono stages that I use in here. Looking closely at the circuit I realised why, the preamp uses a simple RC first order low pass filter on the plus and minus DC split rail input. Simple, but quite effective at filtering out the crud on the mains. Most interesting! Regards, Felix.
  7. G'day all, this is an interesting scenario. Based on what I have personally observed, setting overhang alignment precisely takes some skill and understanding of what is involved. Sadly I have seen turntables leave the factory (as one possibility), with cartridges just bolted on with no attempt at correct overhang set up. Sadly, it does happen. I will admit that it took me a number of years to properly work out the intricacies of the Baerwald two point protractor! Regards, Felix.
  8. Lies, Damned Lies and Specifications....Grrr! G'day all, yes this is a bit of a hobby horse of mine but why can't manufacturers please tell us the real technical truth about their products? This really gives me the pips! Listening to my NAD PP2e this afternoon, and even mated with my Ortofon Super OM 10 (with no absence of highs with that phono cartridge), the PP2e sounds 'warm' and very likely rolled off in the treble. I pretty well proved this by substituting it with several other phono stages that 'all' sounded brighter and restored the lost treble. I can see how some might 'enjoy' the 'warm' NAD PP2e 'sound' yet the official specs for the PP2e say 'RIAA accuracy is within .3 db'. I doubt it! My ears tell me that it is 'voiced' (apparently deliberately to reproduce the 'vinyl' sound), so why can't NAD please tell us the technical truth? I know that NAD aren't the only audio equipment manufacturer guilty of being 'careless with the truth', but why please? As John Lennon would say, 'all I want is the truth....just gimme some truth'. Grrrrr. Regards, Felix.
  9. G'day mate, yep it goes against my nature too, but with that Hendrix track, I'll make an exception! Regards, Felix.
  10. G'day all, I'm of the opinion that distortion as a deliberate part of the music is not the same as equipment playback distortion although the two can mix and enhance one another, as it were. I can think of certain Hendrix tracks that sound better once the amplifier reaches the point of hard clipping, eg, 'Voodoo Chile (slight return)'. However soft electric guitar distortion applied tastefully without any additional playback distortion can sound wonderful, a notable example, Collective Soul's 'Shine'. Regards, Felix.
  11. G'day all, in the real world all audio gear produces some distortion with the lowest as possible being desirable in most cases anyway. Yet some distortion of the 'right' type is often considered 'sonically' a good thing. As a technician from way back, I would prefer all distortion to be as low as possible from a theoretical viewpoint, yet some distortion is definitely considered ok with the perceived 'sound' of certain gear like SET amplifier designs. Interestingly enough I've had a phono preamp with higher than expected distortion figures of the second harmonic variety, which was apparently part of that design's 'good sound' and reputation. On a different tact maybe even low values of distortion sound bad and maybe this is a function of the harmonic structure of the type of distortion. I have several DIY hi fi AM detectors that all sound great to me but one of them, the diode based 'voltage doubler' detector sounds the nicest and clearest to my ears. Why? Does it have lower overall distortion than my others? Possibly! Several technical references that I've read on this circuit have all extolled the low distortion of this circuit. However the other designs I use such as the FET and bipolar transistor based infinite impedance designs are also called 'low distortion' designs, but how low? Is the difference the absolute level of distortion or the type of distortion. I lack the test gear to determine this question. I think this subject is more complex than it first appears. Regards, Felix.
  12. G'day mate, yes but I was referring to the NAD PP2e which has an already too high input capacitance of 220 pf (done in tiny surface mount capacitors), and 'impossible' to work on. Regards, Felix.
  13. G'day all, this page specifically mentions Denon MC cartridges but there is a lot of very useful general information. http://www.rothwellaudioproducts.co.uk/html/step-up_transformers_for_denon.html Regards, Felix.
  14. G'day all, as night time falls on this North Queensland Autumn evening I was just listening to the Drive program on ABC Classic FM on my Tivoli One radio, and really enjoying it and I realised that I always seem to enjoy listening to music on evenings during the Autumn/Winter period. To be perfectly honest I'm not really sure why, but there is just 'something' about these beautiful evenings that seems to enhance the pleasure of listening to music. Any comments? Regards, Felix.
  15. G'day all, I'm trying to find a way to eliminate the effects of a higher than acceptable default input loading capacitance without physically removing the capacitors in a phono stage for MM cartridges. I have heard of circuits that claim to be able to do this, but I was thinking about using some form of input 'buffer' stage, something like op amp voltage follower or FET buffer or transistor emitter follower. Any thoughts on whether this idea is feasible? Regards, Felix.