You are unlikely to ever see a square wave test record. The max freq of 20k-40k will prevent that. More to the point, to get a square wave out of a record + RIAA the signal of the disk looks nothing like a square wave (not that thats the point of what Neal is doing).Maybe there is a SW record out there somewhere?
phono load resistors
#31
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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Paul Barker
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#32
Oh yes of course.
Such perspective changes the whole issue.
you would have to complete the whole chain by recording a SW onto vinyl (OK with bandwidth limiation so an odd looking SW non the less) then tweak you entire chain to achieve the best approximation of a SW at the output after the RIAA correction. If you like ensure you use a perfect RIAA and then only play with transformer and cartridge loading. but whole chain necessary to meaningful solution.
As you say doesn't mean what Neil and Morgan are doing is not helpful in some way.
Edit: Just ignore me. It's a pointless extension of the excercise unlikely to bear fruit. I think what inspires me to question the method is that zobel networks on transformers don't sound as good to me as transformers left to ring. But maybe I have't yet got a zobel network right.
Cartridge loading iss something that has to be got right however. So SUT transformers since they affect this issue are a special case, and Morgan/Neals ways are likely the means to one solution.
Wouldn't it be nice if EC8010 would find this and comment?
Such perspective changes the whole issue.
you would have to complete the whole chain by recording a SW onto vinyl (OK with bandwidth limiation so an odd looking SW non the less) then tweak you entire chain to achieve the best approximation of a SW at the output after the RIAA correction. If you like ensure you use a perfect RIAA and then only play with transformer and cartridge loading. but whole chain necessary to meaningful solution.
As you say doesn't mean what Neil and Morgan are doing is not helpful in some way.
Edit: Just ignore me. It's a pointless extension of the excercise unlikely to bear fruit. I think what inspires me to question the method is that zobel networks on transformers don't sound as good to me as transformers left to ring. But maybe I have't yet got a zobel network right.
Cartridge loading iss something that has to be got right however. So SUT transformers since they affect this issue are a special case, and Morgan/Neals ways are likely the means to one solution.
Wouldn't it be nice if EC8010 would find this and comment?
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
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Neal
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#33
I've now made the two Zobel networks switchable and added switchable loading. The loading now only affects gain, switching just slugs the o/p...reduces the gain, the higher the loading the lower the gain, there's no change in SUT ringing, bandwidth etc. With secondary loading not only does it slug the gain but also slugs the SUT ringing so what is it really affecting? OK yes the cartridge load but its the affect on the SUT that is more noticeable I think.
Having spent the day listening on and off to it I really prefer it, some albums that always sounded just too bright and sibilant have been tamed, the overall bright character of the recording remains but that feeling of pierced ear drums and the urge to put something else on is greatly reduced!
There is a fine line I've found though go too far with dampening the SW and it kills the sound...better to have a v.small leading edge peak than completely round it off.
Having spent the day listening on and off to it I really prefer it, some albums that always sounded just too bright and sibilant have been tamed, the overall bright character of the recording remains but that feeling of pierced ear drums and the urge to put something else on is greatly reduced!
There is a fine line I've found though go too far with dampening the SW and it kills the sound...better to have a v.small leading edge peak than completely round it off.
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IslandPink
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#34
Thanks Neal , this is great information and goes a good way towards explaining the different character of the sound with primary and secondary loading. I guess what I heard with unloaded secondary and primary loading could have been that ringing putting higher harmonic distortion into the upper frequecies - intermodulation essentially. That could cause the dreaded 'HiFi' sound . The component values you've worked out would be a good start for other cases .
"Once you find out ... the Circumstances ; then you can go out"
#35
Just reading with interest these posts and especially the later ones from Neal. I tend to agree having played around with loading for some months now, that that once past a certain point, the load affects the SUT response more than the cartridge sound.
I've tried loading my SUTs on the primary and secondary (I use 12K8 2ndary or 128R primary) and the measured frequency response in theory should be the same yet the result always seems to be smoother response if the 2ndary is loaded.
I guess that tranny performance in terms of leakage inductance and capacitance are a factor but HF performance seemed smoother using secondary loading.
The main thing to remember though for people starting out to play with values, is that one of the primary reasons for the load resistors is to prevent the cartridge drawing too much current through it's windings, so providing that the manufacturer recommended minimum loads are met, then that's a good place to start, as long as that value is at least 10 times the cartridge self impedance (rule of thumb).
Anything more I have found to have less of an effect on cartridge response that on SUT response.
I've tried loading my SUTs on the primary and secondary (I use 12K8 2ndary or 128R primary) and the measured frequency response in theory should be the same yet the result always seems to be smoother response if the 2ndary is loaded.
I guess that tranny performance in terms of leakage inductance and capacitance are a factor but HF performance seemed smoother using secondary loading.
The main thing to remember though for people starting out to play with values, is that one of the primary reasons for the load resistors is to prevent the cartridge drawing too much current through it's windings, so providing that the manufacturer recommended minimum loads are met, then that's a good place to start, as long as that value is at least 10 times the cartridge self impedance (rule of thumb).
Anything more I have found to have less of an effect on cartridge response that on SUT response.
