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Catman's Analog Musings


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41 minutes ago, andyr said:

You said these were 'bypass capacitors' ... so I'm assuming not series caps in the signal pat

obviously I'm speaking on Felix's behalf, but I think that's a given - he added bypass caps around an op amp to stop oscillation - standard practice.

 

44 minutes ago, andyr said:

Shirley, by "properly used" ... you mean they didn't sound bad!!??  That's not the issue - the 'issue' is ... would the sound have been better if they had used film coupling caps instead of electros!

I must admit, I get caught up with this argument also, but the flipside is "could you hear a difference?"

The distortion created by a cap is related to the voltage across it. Decoupling caps will generally have very low voltage across them (very different from say passive Xover caps - but you and I don't run passive Xovers).

I choose not to use electro caps for de-coupling in DIY, but in a design such as Felix posted, I'd bet money no-one could hear a difference between electro caps and any other cap - there are far too many other elephants in the room.

 

cheers

Mike

 

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12 hours ago, andyr said:

 

You said these were 'bypass capacitors' ... so I'm assuming not series caps in the signal path?

 

But they are still in the signal path.  All signals flow through and from the the power supply.  Consider this diagram I found on the net.  OK, it's a valve circuit, but the principle is exactly the same.  The signal path in the output circuit, for example, is directly through the power supply caps (and the af bypass cap)

 

Image result for power supply cap signal path

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Something curious about the Schiit 'Mani' circuit.

 

G'day all, just trying to sort out the mess of audio wiring in here this morning and having my Schiit Mani connected and playing music, I happened to disconnect the inputs at one point and noted with interest that as the inputs were reconnected the music from the turntable do not return 'instantly' as is usually the case with my phono stages of 'normal' design. 

 

That can only mean one thing, and that is the inputs are likely coupled via a large capacitor to the active amplifier stage, and that is indeed interesting.  Giving that the 'Mani' is such a good sounding phono stage, the input capacitor seems to have no negative impact.  Looking at photos of the Mani circuit board online there does appear to be two quite large electrolytic capacitors near to the RCA inputs.  Mmmmmm.  Regards, Felix.   

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On 1/11/2018 at 9:12 AM, aussievintage said:

But they are still in the signal path.  All signals flow through and from the the power supply.  Consider this diagram I found on the net.  OK, it's a valve circuit, but the principle is exactly the same.  The signal path in the output circuit, for example, is directly through the power supply caps (and the af bypass cap)

 

Image result for power supply cap signal path

great little diagram - cheers

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Good points and bad points of my various phono stages. 

 

G'day all, instead of rigid technical analysis, I've decided to rank my various phono stages in purely verbal terms, i.e. good points and bad points.  This could be 'fun'!

 

Schiit 'Mani'.  Good points:  Heaps of potential gain, 100 pf input capacitance, good sounding, good dynamics.

Bad points:  Slightly more 'hissy' than possibly desirable.

 

QED DS1:  Good points:  Musical sounding, low noise.

Bad points:  Low gain at 31 db, it should be in the 40 db range. 

 

Lounge Audio LCR MK3.  Good points:  Good gain, low noise. 

Bad points:  Somewhat 'overrated'.  Not the clearest. 

 

Cambridge CP1.  Good and musical sounding, low noise.

Bad points:  220 pf factory input capacitance, too high for many 'typical' setups.  Overall gain marginal but generally adequate.

 

DIY ESP P06.  Generally excellent, superb dynamics and excellent gain (changeable), input capacitance changeable by constructor.

Bad points:  Slightly hissy but acceptable and some DIY modifications are worthwhile improvements. 

 

Akitika Phono z.  A technically interesting DIY design with generally superb (technical) performance and good dynamics.  Constructor adjustable input capacitance and filtering and gain options (quite useful in practice).

Bad points:  Not the most musical sounding, but endearing! 

 

Lucid Labs 'Catalyst'.  A good sounding budget phono stage, good gain and low noise and good dynamics.  Changeable input capacitance between zero pf and 100 pf (useful).  Generally excellent technical performance.

 

Bad points:  Sadly no longer in production.  A curiosity: prone to oscillation at low capacitance setting with open inputs. 

Continued!

ANT Kora 3T SE.  A most interesting all FET phono stage and a personal favourite.  Very 'organic sounding' and good gain, if slightly low.  Input capacitance is 'acceptably' low.  A very 'nice' sounding phono stage.

 

Bad points:  Again apparently out of commercial production but may be available as a kit.

 

Various versions of the DIY Bruce Heran simple op amp design.

 

Good points:  A real giant killer, stunningly good for such a simple and basic design!  Great sounding and as it is a DIY design, tweakable to constructors needs.  Excellent general technical performance. 

 

Bad points:  Seems to perform best with the OPA2134 dual op amp.  Regards, Felix.

 

Rothwell 'Simplex'.  Somehow I'd completely forgotten about this one!  Good points:  An all discrete transistor design, low noise and good gain, 'acceptable' input capacitance'

Bad points:  When new, there was a tendency to noticeable stridency and occasional 'roughness', however with use all of this tendency has disappeared.  At least in this case break in use has helped enormously! 

 

Observations and comments:  Although this thread was intended mainly as a listening analysis, certain vaguely technical things have come to light which are interesting and indeed fly in the face of many popular audiophile 'upgrades' like op amp improvements.  In fact many of my best sounding and lowest noise op amp based phono stages use the now old and 'antiquated' NE5532 dual op amp. 

 

It may date from the 1980's but it is still an excellent op amp stage for top notch phono stage applications.  In addition, I've realised that a few of my collected phono stages use input (electrolytic) capacitor coupling, and all these phono stages sound excellent.  Yes capacitors do have their limitations especially when heat is a factor and with passing time in general (yes they have definite lifetimes), but sonically they are fine, and dare I say it, a lot of audiophools, especially the non technical ones, are just fooling themselves.  Some things are real and some things are completely in the mind.  Yes I really think so.  Regards, Felix.    

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  1. Felix, when you rate the sonic performance of the ANT 'Kora' ... is this with a wall-wart SMPS ... or using SLAs?
  2. you haven't listed your 'Phantom Audio' discrete BJT phono stage.  Haven't you been able to sort out the problem in one channel, yet?
  3. ESP P06 - when you say 'slightly hissy' ... do you mean you hear sibilance on (female) vocals ... or it is noisy?

 

Andy

 

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G'day mate, point one, very good with the supplied wall wart (not an SMPS, but a linear transformer based design).  SLA's are slightly cleaner but only marginally.

 

Point two, no I'm still working  on the 'Phantom Audio' preamp'

 

Point three, the ESP P06 is just noticeably 'hissy' at high volume, dependent somewhat on the op amps used, and OPA2134's are the most hissy, but interestingly enough the Schiit 'Mani' is actually more 'hissy'.  Regards, Felix.    

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4 minutes ago, catman said:

Point three, the ESP P06 is just noticeably 'hissy' at high volume, dependent somewhat on the op amps used, and OPA2134's are the most hissy,

 

Have you ever tried the  OPA1642? I ask bcoz the guy who designed the 8-channel, digitally controlled analogue volume control ('ReliaXed') that I have just taken delivery of says this is his preferred audio opamp.

 

Andy

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23 hours ago, andyr said:

 

Have you ever tried the  OPA1642? I ask bcoz the guy who designed the 8-channel, digitally controlled analogue volume control ('ReliaXed') that I have just taken delivery of says this is his preferred audio opamp.

 

Andy

Might give that a try at the moment the best I've tried is Burson opamp v5

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Just now, mloutfie said:

Might give that a try at the moment the best I've tried is Burson opamp v5

 

Mahdie, they are SMD opamps - so you need to solder them to a 8-pin backing 'plate' which then goes into a standard opamp receptacle.

 

Andy

 

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  • 2 weeks later...

My personal design briefs for MM phono stages.

 

G'day all, having recently listened to a lot of my phono stages and whilst they pretty well sound subtly different I really wish some aspects were 'standardised' as these things may well affect listening perceptions unduly!  Firstly I would like to see 40 db as the standard for moving magnet cartridges.  Lower gain than that can start to be a little problematic for various reasons.  Indeed, slightly higher gain 'might' be perceived' as better, with the Schiit 'Mani' being an example at around 43 db!

 

The other thing that annoys me is the varying input capacitance of commonly available commercially made phono stages.  Even now I get the strong impression that many vinyl people still do not appreciate the effects of (high) input capacitance on the upper frequency response of many typical high inductance moving magnet cartridges.  Some are 'very badly' affected, like the OEM  stylus M97xE!  100 picofarads should be the industry standard, a workable standard, and it is always easier to add input capacitance than lower it, if necessary.  That's all!  Regards, Felix.     

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13 minutes ago, catman said:

My personal design briefs for MM phono stages.

 

G'day all, having recently listened to a lot of my phono stages and whilst they pretty well sound subtly different I really wish some aspects were 'standardised' as these things may well affect listening perceptions unduly!  Firstly I would like to see 40 db as the standard for moving magnet cartridges.  Lower gain than that can start to be a little problematic for various reasons.  Indeed, slightly higher gain 'might' be perceived' as better, with the Schiit 'Mani' being an example at around 43 db!

 

Agreed, Felix.  I think 43/44dB (the Hagerman Cornet is 44dB) should be standard - not 40dB.

 

Quote

The other thing that annoys me is the varying input capacitance of commonly available commercially made phono stages.  Even now I get the strong impression that many vinyl people still do not appreciate the effects of (high) input capacitance on the upper frequency response of many typical high inductance moving magnet cartridges.  Some are 'very badly' affected, like the OEM  stylus M97xE!  100 picofarads should be the industry standard, a workable standard, and it is always easier to add input capacitance than lower it, if necessary.  That's all!  Regards, Felix.     

 

Absolootely!  I can't see any reason why 100/110pF can't be the standard (it's what I use on my Muse).

 

And, yes, I suggest many 'vinyl people' have NFI about how the loading on their cart - MM or MC - affects the sound! :(

 

Andy

 

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In the right mood?

 

G'day all, something that I think is of underestimated importance when 'listening' to high quality audio gear is being in the 'right mood'.  Over the years it has been all too apparent to me that one's mood can really affect the way one hears and interprets any particular piece of gear, especially strangely enough, phono gear!  For me it has been nothing short of embarrassing at times, that on one day a given piece of gear might sound fantastic and on other days....rubbish, and that difference is mostly 'mood'.  How utterly bizarre, yet it is often true.  One of the foibles of being human I guess.  It is hard to be completely objective 100 percent of the time, although some people claim to be! 

 

Just on phono gear, there have been times when usually pleasant sounding phono stages sound strident and essentially unlistenable and when that happens it is best to just switch everything off, and come back later!  Again this seems to be primarily a 'mood' thing, although it must be admitted that many phono stages can sound slightly 'brightish', if that makes any sense.  Perhaps when we are not in the 'right mood', this can exacerbate this perception.  Gotta think about that!  Regards, Felix.     

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1 hour ago, catman said:

In the right mood?

 

G'day all, something that I think is of underestimated importance when 'listening' to high quality audio gear is being in the 'right mood'.  Over the years it has been all too apparent to me that one's mood can really affect the way one hears and interprets any particular piece of gear, especially strangely enough, phono gear!  For me it has been nothing short of embarrassing at times, that on one day a given piece of gear might sound fantastic and on other days....rubbish, and that difference is mostly 'mood'.  How utterly bizarre, yet it is often true.  One of the foibles of being human I guess.  It is hard to be completely objective 100 percent of the time, although some people claim to be! 

 

Just on phono gear, there have been times when usually pleasant sounding phono stages sound strident and essentially unlistenable and when that happens it is best to just switch everything off, and come back later!  Again this seems to be primarily a 'mood' thing, although it must be admitted that many phono stages can sound slightly 'brightish', if that makes any sense.  Perhaps when we are not in the 'right mood', this can exacerbate this perception.  Gotta think about that!  Regards, Felix.     

 

Amen to that Felix, the other night I wanted to listen to some new purchases but for whatever reason could not get into the groove and everything I put on sounded "off". Next morning i needed to have another listen as I was beginning to think something was faulty but this time the magic came back. Some might argue it was a "power" related issue however I think it was more to do with my mood at the time.

 

Wonder how many have spent money on "upgrades" due to mood.....

 

 

 

 

 

 

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Totally agree with mood changing perception, I had to turn the music off for a few hours on Saturday for that very reason, just didn't seem to work.

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Totally agree with mood changing perception, I had to turn the music off for a few hours on Saturday for that very reason, just didn't seem to work.

Absolutely believe in this. Has happened to me on a number of occasions. Stupid moods!
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I too agree with the 'mood' thing, Felix.......many a time I have thought my system sounds like the 'bees knees' and at other times I am super critical and less than satisfied. It is easy to conclude in these latter times that my mood is just not conducive to full enjoyment of what's emanating out of the speakers......I'm with @unclemack here, stupid moods!!:angry: Likewise, I am less inclined to even play music on nights where I work the next day and more inclined to play and enjoy music on nights where I have the next day off or on those days off, ie: when I'm obviously in a better mood.:) Finally, do I ever put on music when my mood is down with the intent of it putting me in a better mood? Of course.....but with mixed results, sometimes it works and it lifts me up, sometimes I give up and try something else to achieve the same goal. Stupid moods! Life and audio appreciation can be a bit like a 'yo-yo' at times!:(:):(:)

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A curious N97xE stylus fault.

 

G'day all, a curious fault with my existing N97xE stylus last night, and a new one for me.  Playing a record, something didn't sound right almost like the tracking weight was way too light, and not making proper contact with the groove. 

 

Examination of the stylus cantilever and tip looked normal but withdrawing the stylus out of the cartridge body 'felt' like something was 'catching'.  Anyway I quickly installed a spare N92E stylus that I had on hand which fits perfectly and after resetting the tracking weight for the new different stylus assembly (1.25 grams), all was back to normal. 

 

Although the N92E stylus is supposed to be a lesser stylus that the N97xE stylus, to my ears, it sounds great and with excellent treble!  I don't know what was wrong with the original stylus, but something was clearly amiss with the stylus cantilever/magnet assembly.  Interesting!  Regards, Felix.   

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Not too much time for records this week!

 

G'day all, with all the heavy emotional stuff happening to me of late, I haven't had too much time or inclination for records, although a few tracks have been played on occasion.  One interesting thing though, the other night I wrote down a list of things important to me and yes, records were on the list!  So there you go!  Regards, Felix. 

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Have I been wrong about the Shure M97xE?

 

G'day all, well partially anyway!  The other night I listened to the Steven Wilson remix of Jethro Tull 'Aqualung' (a brilliant remix), with my Shure M97xE body and Shure N92E stylus, and that combination sounds fantastic all with the traditional M97xE excellent bass and midrange, and the N92E's 'unsoftened' upper treble.  Shure I think has been a bit misleading regarding the sonic qualities of the N92E stylus, and to my ears it is a perfect match.  To be honest, I couldn't be any happier, and my DIY ESP P06 phono stage sounds pretty excellent too!  Regards, Felix. 

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The difference between 1.25 and 1.5 grams in terms of record wear?

 

G'day all, one of the things that I really like about the Shure M97xE is the 1.25 grams tracking weight (recommended) and my other favourite cartridge the Ortofon Super OM10 tracks at 1.5 grams (recommended).  Subjectively 1.5 grams feels a lot heavier, yet in terms of general record wear is there much difference?  Regards, Felix. 

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