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catman last won the day on April 24 2015

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About catman

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  1. catman

    Catman's Analog Musings

    G'day mate, yes all noted. Actually the bass response is largely unaffected by the track position, but the treble response certainly is. No I haven't tried the effect of the P99 recently but I have in the past, and in any case I have wound back the bass response of my P06 (as suggested by Rod Elliott), which largely removes most of the bass boost of the standard design. 'Excessive' lower bass roll off certainly gives a 'cool' bass perception. Regards, Felix.
  2. catman

    Catman's Analog Musings

    The bass end of phono preamps. G'day all, this an interesting one to me, regarding the bass end response of phono preamps. Around 1976 or thereabouts the IEC 'tinkered' with an additional bass roll off around 20 Hz, that was apparently later withdrawn. Some good information here: http://sound.whsites.net/project06.htm This additional bass roll off wasn't overly popular with manufacturers, but I am aware that quite a few present day phono stages incorporate it. From my own listening observations, phono stages incorporating this additional bass roll off tend to sound 'cool' to my ears which can sound pleasant enough, without sounding bass accurate per se. At least two of my own phono stages sound this way. However listening to a record this afternoon (a remastered mono pressing of The Beatles 'Rubber Soul'), it was immediately apparent that comparing different phono stages, one with this bass roll off and my own DIY ESP P06 (minimal bass roll off), that Paul's bass was much stronger on my DIY ESP P06! Interesting! Regards, Felix.
  3. catman

    Catman's Analog Musings

    Damn that ESP P06! G'day all, I haven't been using my DIY ESP P06 much at all lately as I have been required to fix a couple of faulty signal leads but today in an increasingly rare burst of activity I did the job and it was good to get the P06 working again, and wouldn't you know it despite being an all op amp based unit it sounds pretty good, and possibly as good as any of my discrete circuit based units. Oh well....I tried! Regards, Felix.
  4. catman

    Catman's Analog Musings

    Have I been wrong all this time? G'day all, I guess that this isn't quite a case of humble pie, but I am starting to wonder if discrete circuitry does sound better than op amp based circuitry, at least for phono preamps! Listening closely to my Rothwell Simplex (which is based solely on discrete transistor circuitry), and comparing it with others based on op amps, I do think that simpler circuitry based on discrete circuitry has a certain clarity unmatched by op amp based circuitry. I'm not saying that discrete circuitry is superior, and that op amp circuitry is 'inferior', but my ears do detect 'something' in favour of discrete circuitry. The difference is exceedingly subtle, but this does have me wondering. Regards, Felix.
  5. catman

    Catman's Analog Musings

    Phono stages that really 'grow on you'! G'day all, this whole post might be more psychological than anything else but although I have always liked my Rothwell Simplex phono stage, of late I've come to really appreciate its clean yet utterly 'musical' sound which in particular sounds so good with many genres of music, but seems to reproduce acoustic stuff very well. I guess another good word to describe its sound might be 'neutral'. I've paired it with several different cartridges without much noticeable tonal change, which is interesting! Many contemporary phono stages seem to favour some part of the sound spectrum, yet the Rothwell Simplex doesn't, but sounds great in nicely reproducing everything! Regards, Felix.
  6. catman

    Catman's Analog Musings

    G'day mate, yes one would think so, but even with one op amp the simple Heran design is simply stunning performance wise. Maybe that says a lot about just how good modern op amps are! Regards, Felix.
  7. catman

    Catman's Analog Musings

    Phono stages that sound like music! G'day all, this has been a common theme in many of my posts in the search for the ultimate in high fidelity. I have always believed that 'high fidelity' should always replicate the 'sound' of the real thing yet I have rarely approached this for possibly many complex reasons. I think that 'good quality sound' is easy to achieve, but beyond that, not so easy! Over the last few days I have been using my Rothwell 'Simplex' playing a lot of music that I wouldn't normally use with that phono stage, like Dave Brubeck Jazz, and I've been very pleasantly surprised with of the 'realism' with the Rothwell 'Simplex'....stunning actually. I'm hearing strange little sounds in the background like percussive sounds I would only hear in a good acoustic venue and performance! When I first bought the Rothwell Simplex I was impressed, but in all honestly I thought that it was a little overpriced! Well on the basis of my most recent listening, I see things differently. I think that the Rothwell 'Simplex' is a great phono stage. It sounds like music! Regards, Felix.
  8. catman

    Catman's Analog Musings

    A specific phono stage for different genres? G'day all, I assume that any good phono stage should make every genre of music sound great, and I guess that the cartridge and stylus play their part too! I guess that is probably expected, yet I have noted occasions when a particular phono stage seems to perform particularly well with a particular music genre or artist. My Rothwell 'Simplex' always seems to reproduce Hendrix' electric guitar with quite apparent 'excitement'. Why? Has anyone else ever noted anything similar? Regards, Felix.
  9. catman

    Catman's Analog Musings

    G'day mate, a long while ago I asked Rod Elliott about input buffering in his P06, and he told me that it was 'built in' and done in the first op amp stage following the phono cartridge! Regards, Felix.
  10. catman

    Catman's Analog Musings

    G'day mate, in all honesty I am not sure what your point is! A great many typical modern phono stages utilise exactly the same general circuitry and 'input buffering' simply isn't an issue. As far as I understand, the input buffering is done within the op amp and again yes the cartridge connects directly to the op amp non inverting input via a 'standard' 47 k input shunt resistor. I honestly don't see any problem. Regards, Felix.
  11. G'day all, thank you for all comments. Most interesting. Certainly the 'Muffsy' is a well regarded and popular kit phono stage. Certainly my own builds are quiet and whilst passive equalisation can be problematical the 'Muffsy' appears to be well designed overall. However one thing concerns me possibly needlessly in that the gain setting resistors appear to be earth referenced from the feedback loop of that op amp. I am no expert with op amp design but such of an arrangement seems possibly wrong to me technically. Regards, Felix.
  12. catman

    Catman's Analog Musings

    G'day mate, yes you are correct however my system is optimised in terms of buffering etc, so no additional circuitry is needed. Regards, Felix.
  13. catman

    Catman's Analog Musings

    Is one (dual) op amp stage enough for a typical phono stage? G'day all, for an hour or so this morning I tried to do a wiring repair on my DIY ESP P06 which has lost a channel and whilst doing it I fired up my DIY Bruce Heran single op amp phono stage and listened to Dave Brubeck's greatest hits. Whilst I listened I realised (again), what a good sounding and performing that little phono stage is, and how it uses only one OPA2134 dual op amp, where my DIY ESP P06 uses two in separate stages and I wondered if two were really necessary given that the Heran design works so well with only one! I have seen it written that any phono stage using op amps using two op amps in separate stages will always be better than one using only one, and I used to agree with that but now I'm not so sure given the general performance of the Heran design. Yes it is true that high quality phono preamp applications require a high quality op amp, but that isn't an issue things days. So then why make circuitry more complex than it really needs to be? I do wonder. Regards, Felix.
  14. G'day all, I've actually built two of these but rarely play them much, but tonight I did, and assuming correct assembly to my ears it sounds good, but 'punchy', almost 'compressed'. Any comments on this? Regards, Felix.
  15. catman

    Catman's Analog Musings

    Phono stages of unusual design. G'day all, of the phono stages that I have at least two of them might be considered of 'unusual design', my ANT Kora 3T SE all FET design using FET's made for 'industrial applications' and my Lounge Audio LCR MK III phono stage. I would venture to guess that many phono stages these days, at least of the less expensive variety anyway, are very likely to be op amp designs based around RIAA feedback eq, and I have a few of those too, and one or two of them sound excellent! Yet I'll concede that no particular design approach is sonically superior (to my ears), which is actually slightly disappointing to me in all honesty! I really wish that I could define what makes a really fine sounding phono stage, but so far, I can't! Regards, Felix.