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Cartridge response - pink noise test
"Don Pearce" Apropos of some stuff we were doing a while ago, here is the pink noise track from th HFN-RR test disk played on my system, which is: Systemdek IV SME 3009ii arm AT-OC9 microline cartridge http://81.174.169.10/odds/dspkr/atoc9.gif It shows an essentially flat response from about 12Hz, with a slight lift at 10kHz, then returning to the proper level above that. The recording is made at 96kHz sampling, and it is clear that the test record cuts off sharply at 20kHz. The cartridge claims to go to 60kHz (ahem!) ** What the heck is this REALLY a test of ?? Certainly NOT the PU cartridge's response. That test record is a huge unknown. Is not a RIAA pre-amp involved too ?? More room for error than you can poke a stick at. ......... Phil |
Cartridge response - pink noise test
Don Pearce wrote:
On Thu, 19 Oct 2006 00:41:58 GMT, (Don Pearce) wrote: On Thu, 19 Oct 2006 00:36:37 +0100, "Keith G" wrote: "Don Pearce" wrote Forgot to add - for this test it is vital that there is no clipping - that would screw the measurement utterly. The clip is on its way to you direct. Courtesy of Keith we now have a pink noise track of a Shure V15/5. It has a smooth if slightly depressed top end, rather wavy midrange and rolled off bass. Interesting! Again I have added the "nominally flat" line for comparison - I've tried to put it in a sort of average position. http://81.174.169.10/odds/dspkr/v15pink.gif d Actually, the rolled-off bass may be to do with the amplifier. Many phono stages incorporate a high-pass filter to remove subsonic bass. This can help power handling by preventing the speakers from flapping with unheard sounds. d Which phono was that Keith, I must admit, that curve looks very like the spice model I have for the WAD phono. I must get a new test disk, I have found traces I did several years ago, with different arm/cartridge/deck and phono stage that still shows the HF inbalance that the response I posted shows. -- Nick |
Cartridge response - pink noise test
"Don Pearce" wrote Actually, the rolled-off bass may be to do with the amplifier. Many phono stages incorporate a high-pass filter to remove subsonic bass. This can help power handling by preventing the speakers from flapping with unheard sounds. Ah..... http://www.apah69.dsl.pipex.com/show/oops.jpg Second clip is on its way to you as I type - rumble filter *out* this time!! :-) |
Cartridge response - pink noise test
"Nick Gorham" wrote Actually, the rolled-off bass may be to do with the amplifier. Many phono stages incorporate a high-pass filter to remove subsonic bass. This can help power handling by preventing the speakers from flapping with unheard sounds. 'E's not daft that Don....!! ;-) d Which phono was that Keith, I must admit, that curve looks very like the spice model I have for the WAD phono. That's the little Pioneer SA-510's own onboard (SS) phono stage - my 'computer setup'..!! I must get a new test disk, I have found traces I did several years ago, with different arm/cartridge/deck and phono stage that still shows the HF inbalance that the response I posted shows. The HFS75 disk I have is the most *offcentre* pressing I have ever seen and thus came to me virtually unused!! |
Cartridge response - pink noise test
In article ,
Keith G wrote: And apropos of nothing at all, here is a nice little melody from Senor Coconut And His Orchestra: http://www.apah69.dsl.pipex.com/show/Melody.mp3 - A fairly new (2006) release on 12 inch 45, just to show where vinyl is these days in a *dynamic* sense and what it sounds like on a 30 quid deck with a 300 quid cart....!! Enjoy! :-) Dynamic sense? It's pretty well all electronic samples with the dynamics of a wet sponge. And yes - there's no mistaking vinyl. ;-) -- *Red meat is not bad for you. Fuzzy green meat is bad for you. Dave Plowman London SW To e-mail, change noise into sound. |
Cartridge response - pink noise test
On Thu, 19 Oct 2006 10:42:37 +0100, "Keith G"
wrote: "Nick Gorham" wrote Actually, the rolled-off bass may be to do with the amplifier. Many phono stages incorporate a high-pass filter to remove subsonic bass. This can help power handling by preventing the speakers from flapping with unheard sounds. 'E's not daft that Don....!! ;-) d Which phono was that Keith, I must admit, that curve looks very like the spice model I have for the WAD phono. That's the little Pioneer SA-510's own onboard (SS) phono stage - my 'computer setup'..!! I must get a new test disk, I have found traces I did several years ago, with different arm/cartridge/deck and phono stage that still shows the HF inbalance that the response I posted shows. The HFS75 disk I have is the most *offcentre* pressing I have ever seen and thus came to me virtually unused!! The latest V15 plot is here now, with the rumble filter gone. It has flattened out all the lower mid bounciness, although there is still evidence of a low end cutoff - just not at frequencies anyone is going to worry about. The top end is interesting - it has grown a peak which I think I can explain. I believe that removing the rumble filter has changed the capacitive loading on the cartridge considerably, and what we are seeing is what I predicted from my maths - extreme sensitivity of the top end to resonance from capacitive loading. I produced plots that looked exactly like this in my musings. This is all very interesting. The general dropoff above 1kHz looks almost like a mis-set tone control. http://81.174.169.10/odds/dspkr/v15pink3.gif d -- Pearce Consulting http://www.pearce.uk.com -- Posted via a free Usenet account from http://www.teranews.com |
Cartridge response - pink noise test
On Thu, 19 Oct 2006 10:17:38 GMT, (Don Pearce)
wrote: On Thu, 19 Oct 2006 10:42:37 +0100, "Keith G" wrote: "Nick Gorham" wrote Actually, the rolled-off bass may be to do with the amplifier. Many phono stages incorporate a high-pass filter to remove subsonic bass. This can help power handling by preventing the speakers from flapping with unheard sounds. 'E's not daft that Don....!! ;-) d Which phono was that Keith, I must admit, that curve looks very like the spice model I have for the WAD phono. That's the little Pioneer SA-510's own onboard (SS) phono stage - my 'computer setup'..!! I must get a new test disk, I have found traces I did several years ago, with different arm/cartridge/deck and phono stage that still shows the HF inbalance that the response I posted shows. The HFS75 disk I have is the most *offcentre* pressing I have ever seen and thus came to me virtually unused!! The latest V15 plot is here now, with the rumble filter gone. It has flattened out all the lower mid bounciness, although there is still evidence of a low end cutoff - just not at frequencies anyone is going to worry about. The top end is interesting - it has grown a peak which I think I can explain. I believe that removing the rumble filter has changed the capacitive loading on the cartridge considerably, and what we are seeing is what I predicted from my maths - extreme sensitivity of the top end to resonance from capacitive loading. I produced plots that looked exactly like this in my musings. This is all very interesting. The general dropoff above 1kHz looks almost like a mis-set tone control. http://81.174.169.10/odds/dspkr/v15pink3.gif d -- Pearce Consulting http://www.pearce.uk.com Should have added - the red trace is a sample of pink noise generated in Audition for comparison. The blue is the cartridge. d -- Pearce Consulting http://www.pearce.uk.com -- Posted via a free Usenet account from http://www.teranews.com |
Cartridge response - pink noise test
"Don Pearce" wrote The latest V15 plot is here now, with the rumble filter gone. It has flattened out all the lower mid bounciness, although there is still evidence of a low end cutoff - just not at frequencies anyone is going to worry about. The top end is interesting - it has grown a peak which I think I can explain. I believe that removing the rumble filter has changed the capacitive loading on the cartridge considerably, and what we are seeing is what I predicted from my maths - extreme sensitivity of the top end to resonance from capacitive loading. I produced plots that looked exactly like this in my musings. This is all very interesting. The general dropoff above 1kHz looks almost like a mis-set tone control. Not on the amp - the tone controls are/were all set 'flat' - although, I would mention the amp is no spring chicken, I believe if first belonged to Oliver Cromwell when it was new....??? :-) http://81.174.169.10/odds/dspkr/v15pink3.gif (I'm ruling out nothing atm - the pickle I got into with filters, bias settings, record levels and playing/recording different records at different speeds and forgetting to reset the speed afterwards &c....!! ;-) |
Cartridge response - pink noise test
On Thu, 19 Oct 2006 12:22:35 +0100, "Keith G"
wrote: "Don Pearce" wrote The latest V15 plot is here now, with the rumble filter gone. It has flattened out all the lower mid bounciness, although there is still evidence of a low end cutoff - just not at frequencies anyone is going to worry about. The top end is interesting - it has grown a peak which I think I can explain. I believe that removing the rumble filter has changed the capacitive loading on the cartridge considerably, and what we are seeing is what I predicted from my maths - extreme sensitivity of the top end to resonance from capacitive loading. I produced plots that looked exactly like this in my musings. This is all very interesting. The general dropoff above 1kHz looks almost like a mis-set tone control. Not on the amp - the tone controls are/were all set 'flat' - although, I would mention the amp is no spring chicken, I believe if first belonged to Oliver Cromwell when it was new....??? :-) No, I don't think it actually is the tone control - you can see it was set to flat, and there isn't a failure mode that I know of that would bugger both channels simultaneously by the same amount. http://81.174.169.10/odds/dspkr/v15pink3.gif (I'm ruling out nothing atm - the pickle I got into with filters, bias settings, record levels and playing/recording different records at different speeds and forgetting to reset the speed afterwards &c....!! ;-) Well, me Cyrus II has no tone controls or rumble filters; about the only thing I can do wrong there is forget to set the Tape Out switch to phono. d -- Pearce Consulting http://www.pearce.uk.com -- Posted via a free Usenet account from http://www.teranews.com |
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