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  »  New  More about step up transformers..  LOL...  Analog Playback Forum     4  40503  01-06-2005
  »  New  The last phonocorrector: “End of Life" Phonostage..  Big cap banks...  Analog Playback Forum     310  1990453  11-13-2007
  »  New  Phono stages with SU-1..  SU-1...  Analog Playback Forum     4  66438  11-23-2007
  »  New  Taking the mystery out of cartridge loading..  The phase in Step-Up Loading by Dave Slagle...  Analog Playback Forum     6  90046  02-26-2005
  »  New  Expressive Technologies SU-1 and cartridge output and i..  MV and Ohms...  Analog Playback Forum     2  33838  07-07-2011
  »  New  How to run MM-type cartridge into MC phonostage?..  Quite interesting....  Analog Playback Forum     6  67879  11-13-2011
  »  New  Expressive Technologies Model 1 preamp..  This is a full functional pramp....  Analog Playback Forum     6  45600  06-17-2014
07-24-2009 Post does not mapped to Knowledge Tree
Axel
South Africa
Posts 80
Joined on 07-18-2009
Post #: 26
Post ID: 11170
Reply to: 11168
SUT secondary loading is a very standard practice
fiogf49gjkf0d
Right, so it is. B U T it seems not the case, that the final load-value the cart sees is the same with non-SUT, as is the case with an SUT. Unless your experience is different - therefore my question.
If you look at Lyra's recommended loading specs it shows clear differences between SUT and non-SUT loading.
I know you do not use Lyras, fine. But Lyra is not so special about loading, I used their Dorian (J.Allaerts re-tipped with FGS/Boron) some time ago.
So is the different loading value BS, correct, or once again 'matter of taste'?
Axel
07-24-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,184
Joined on 05-28-2004
Post #: 27
Post ID: 11171
Reply to: 11170
There are no absolute loading values
fiogf49gjkf0d
Manufacturers do not recommend any specific loading, and it they do then they shell not do it. They recommend a region where most probable final loading value might be. In case a transform is use it make not difference; they just transfer impedance in reversed 2 power of their gain. If your Lyra gives you very firm specific resistor value to load then first you shell not treat this resistor value as some kind of absolute reference and second you need to reconcile this value if you use a step up. Sure if your cartridge has suggested to be loaded with 10R but you get proper result with 10K then it might be a good reason to review what you do but if you found that with your setup 40R would work for you better then 10R then I would consider it appropriate. I do think that with transformers in use the run off of lording might be even further as different transformers have different internal impedance of primary  but I do not see that it has any practical significance unless you use multiple transformers and try to advocate your found loading values and some kind of absolutely and universally right values. The right values of loading would be derivatives of many things and it is fine that in different installations they might be wary within a sensible limits.

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-24-2009 Post does not mapped to Knowledge Tree
Axel
South Africa
Posts 80
Joined on 07-18-2009
Post #: 28
Post ID: 11172
Reply to: 11171
SUT:cart impedance match 1:1 ?
fiogf49gjkf0d

Hi Romy,

of course, no manufacturer give one value only (non that I would know), but will spec. a range starting with some value e.g. >10ohm or say >100ohm and either putting a cap at 500ohm, 1k or nothing at all, meaning 47k (if that suits you). Lyra would give a start point of say >100ohm 'normal' (no SUT) and >10ohm for use with SUT.

You say: >> The right values of loading would be derivatives of many things and it is fine that in different installations they might be wary within a sensible limits. <<
Of course also fine, yes. I was hoping to get some specifics from you when looking at a BEST "impedance match" ~ 1:1 with the cart in use, and if you had figured out some ball-park value which then can be used as point of departure for listening test.

The smaller the DCR value of the cart (>0.3mV) the closer is the REAL impedance of the cart (20Hz - 20kHz) to that DCR value, because it will have a VERY small inductance, no?

Axel
07-24-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,184
Joined on 05-28-2004
Post #: 29
Post ID: 11173
Reply to: 11172
Are you reviewing different phonostages/cartridges, or what?
fiogf49gjkf0d
 Axel wrote:
I was hoping to get some specifics from you when looking at a BEST "impedance match" ~ 1:1 with the cart in use, and if you had figured out some ball-park value which then can be used as point of departure for listening test.
  
It is not the way how I see it. What you are saying might be useful for some who use different step up transformers and try to evaluate how the specifics of a given transformer (DCR of primary, impedance of cartridge and etc…) might impact the results of sonic assessments against another transformer.  I do not do it for a quite a whale, so my take on it is following: to get a phonostage that you like (fully active or with transformer), fine a cartridge that you like, find a proper loading for the given cartridge and the given phonostage. If you wish to change cartridge or phonostage then you need to review the loading but I do not necessary feel that your loading number with one phonostage/cartridge it relevant to another phonostage/cartridge. In some cases phonostage/cartridge are more and in some cases they are less sensitive to loading. I truly do not feel that any rules might be built in there. Sure it is possible to find a pattern in it but the question why would it necessarily?  To play with loading resistor is very simple if one knows what to listen foe. We do it only when we change phonostages/cartridges. How frequently you do it? I do not change phonostages and I try to use my stereo cartridges to be of the same loading. My mono cartridge wants to have way another loading, so I use a different phonostage for it….

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-24-2009 Post does not mapped to Knowledge Tree
Axel
South Africa
Posts 80
Joined on 07-18-2009
Post #: 30
Post ID: 11174
Reply to: 11173
Not a reviewer, only single SUT & multiple cart user
fiogf49gjkf0d
OK, this is useful also, in that you have not noted a "pattern" as you say. My point is closer to your suggestion, that I do change cart --- and sometimes buy new ones,  B U T I do not buy other SUT (at least I try to avoid it). I'm currently waiting for the return of my new Ortofon Windfeld (the old one developed a problem with wrong VTA of cantilever) so they give me a new one after MUCH waiting time. (I rings a bell with what your Jubilee did, as did my previous Jubilee!!! also exchange because of split open body).
So, I'm getting ready to hock up the new (I hope now correctly working one) with my FR XF-1 type M SUT. With that messed up Windfeld (riding almost on the bottom) I found that primary loading sounded best and 10ohm! Maybe the new one will be happy with it also, but maybe not - I will see. Using primary loading is more 'uncomfortable' because of the resistors having to be soldered into the primary side of the trannie ---- and getting good resistors is also a pain (I use Shinkoh Tantalum, other R sounds crap as you'd call it).
So, that's some background to my question.
Axel
07-24-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,184
Joined on 05-28-2004
Post #: 31
Post ID: 11175
Reply to: 11174
Secondary vs.primary
fiogf49gjkf0d
 Axel wrote:
OK, this is useful also, in that you have not noted a "pattern" as you say. My point is closer to your suggestion, that I do change cart --- and sometimes buy new ones,  B U T I do not buy other SUT (at least I try to avoid it). I'm currently waiting for the return of my new Ortofon Windfeld (the old one developed a problem with wrong VTA of cantilever) so they give me a new one after MUCH waiting time. (I rings a bell with what your Jubilee did, as did my previous Jubilee!!! also exchange because of split open body).
So, I'm getting ready to hock up the new (I hope now correctly working one) with my FR XF-1 type M SUT. With that messed up Windfeld (riding almost on the bottom) I found that primary loading sounded best and 10ohm! Maybe the new one will be happy with it also, but maybe not - I will see. Using primary loading is more 'uncomfortable' because of the resistors having to be soldered into the primary side of the trannie ---- and getting good resistors is also a pain (I use Shinkoh Tantalum, other R sounds crap as you'd call it).
 
I am not big fun of using resistor on primary. There is something non kosher in it, even the resistor is properly recalculated from secondary to primary. It is not to mention that in your loading assessment the cable after the second is not involved. Even if you have 3 inch cable after the transformer than with 1:25 ratio the coil of your cartridge would see almost 3 feet of cable… Also, I do feel that loading of primary and loading of secondary affects loading differently and damps the coil differently.  Some transforms makes offer separate options for loading of primary and secondary, the Kondo transformers for instance. I played twice with this transformer and one time I change the load but it was only secondary. I have in a past a very prolog debate with Kondo transformer owned who swear to me that primary loading affect sound differently then secondary. I do not argue it and would concur it. However, when I was asking his what type of Practical Sonic Impact he is able to inflict with primary loading that he is not able to inflict with secondary loading he really was not able to come up with any sensible description.
 
I use Vishay 102S and RN60 for loading and load only on secondary and at extreme proximity to the grid of the input tube. I do not change loading in fly as I was not able to find a transparent enough switching for this level of currents. I kind of do not need a lot of play with it as I for all of my 3 phonostages (2 actively use now) respectively use the same dedicated topology of cartridges that more or less have the same loading. For instance when I moved from Shelter 901 to Otofone Jubilee I did not feel any need to change my loading and it is not loaded to 36K RN60 on secondary right at the input tube’s leg
 
The Cat
 

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-24-2009 Post does not mapped to Knowledge Tree
Axel
South Africa
Posts 80
Joined on 07-18-2009
Post #: 32
Post ID: 11176
Reply to: 11175
Loading details secondary vs. primary on XF-1
fiogf49gjkf0d
First of all, thanks for additional detail.
As mentioned I can speak only for my Fidelity Research XF-1 (30dB).
Loading it on secondary as you mentioned, it ALSO damps the trannie - result in my case: less resolution.
Primary loading is MUCH more sensitive to start with, but only cart damping takes place, the SUT is not 'directly' involved.
As for the secondary's cable going to the phono-pre --- sure! Capacitance is reflected back to primary, and in the case of 30dB, 1000 times for any capacitance of what is the case on secondary, cable and all.
XF-1 has no connectors only one short (~18cm) low capacitance cable to the phono-stage.
I have the phono-pre INSIDE the pre-amp and when I did secondary loading it was done DIRECTLY on the phono-modules (SS)

Now, in case of a 0.3mV cart and 30dB trannie with secondary loading, best result was to load with 18k resistor parallel with 47k (phono-pre) = 13ohm reflected to primary. Loading on primary 18ohm resistor to achieve the same 13ohm was not as good as a 13ohm resistor = 10.18ohm for the cart to see (i.e. parallel with 'natural impedance' of 47ohm reflected from 47k input impedance of phono-modules).
In my case I got more resolution with primary loading, BUT it gets very quickly too bright with even small changes, sounding all wrong. The 18k on *secondary* sounded fine, but was missing some more detail that I know from connecting the cart straight with no SUT and using full 78dB gain of phono (60dB + 18dB raised input gain of pre-amp).

Why I used SUT? More tight really powerful bass, better upper-mid-bass (German for once shorter: "Grundton"), more "hall information" better "live feel" (there-ness) compared to all MC in general. When in my rig most of the time MC without SUT sound a bit skeletal. NO SUCH PROBLEM WITH MM RIGHT NOW! The Windfeld will have a hard time to replace Shure V15 III xMR.
Axel
07-24-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,184
Joined on 05-28-2004
Post #: 33
Post ID: 11177
Reply to: 11176
The strange phrases....
fiogf49gjkf0d
 Axel wrote:
In my case I got more resolution with primary loading, BUT it gets very quickly too bright with even small changes, sounding all wrong. The 18k on *secondary* sounded fine, but was missing some more detail that I know from connecting the cart straight with no SUT and using full 78dB gain of phono….
 
To me it is one of the indications of problem to load primary. By loading you damp the coil of cartridge; you do not EQ the cartridge’s output. Sure the frequency response changes but it shell not be changing drastically, it is not the capacitive loading of MM cartridge. It is like selecting VTA – you shell not use “brightness” as criteria. If adjusting loading on primary “gets very quickly too bright with even small changes” then it is a wrong place to change damping of the coil. Also, I am not convinced that what you say is truly “more details”.  In many cases an insufficient loading gives a sense of hyper-resolution that I do not like. It is like loading the plate of SET amps – go too idle and it begin to fracture sound with micro-particles giving an impression of what they call “resolution”. I do not say that it what happen in your case but I would never use the phsase  “too bright” or “resolution” or “details” when I think about proper loading

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-25-2009 Post does not mapped to Knowledge Tree
Axel
South Africa
Posts 80
Joined on 07-18-2009
Post #: 34
Post ID: 11180
Reply to: 11177
“too bright” or “resolution” or “details” with SUT primary loading
fiogf49gjkf0d
yes I understand your take with regard to those phrase, now what a about "too dull" or "not resolved" or "lack of detail"?
Those would then be equally 'incorrect' for initial sound determination. If I use a different cart to my current V15 xMR, say Empire S1000 ZE/X with elliptical stylus (i.e. not micro ridge as the V15) I have to resort, at least initially to the same 'avoidable' expressions of the different sound?
I use the word 'initial' on purpose, because there is of course a lot more to it, like e.g. timing, phase?, etc.

With the second cart mentioned, sounding more like secondary loading, I do get a lot of positive results but always something seems to be not there, e.g. like when a coil is over damped --- what would you call this other then "dull" or "unresolved" or "loss of detail"?

I am aware that we have all some form of our own 'ear equalisation' too, and when used to the 'over-resolved' fake bright sounds we often can hear it MAY become something we expect to hear. I do not think I'm talking about this, as primary loading is still somewhat subdued when compared to not going with any SUT.

In fact the case with a good transformer can be made, that it does NOT need any damping of its own, because it would only start to resonate far, far, above the audio frequency band say 200kHz --- so why bother to damp the trannie coils?

Next issue the cart coil. If a cart has, as my initial example, 0.3mV and 4ohm DCR AND has a quoted >=10ohm minimum damping, then these 10ohm would/should? be very close to the 'true' cart impedance for the audio band. Recall that DCR 4ohm is a 0Hz only.

Assuming we are not to way off, next thing is to follow the idea of electrical 'impedance matching' going back to MY original post. Impedance matching occurs when current is doubled at the expense of voltage dropped. So, using 10ohm primary loading to impedance match ~ 10ohm cart impedance would create the best possible 'power transfer' from the cart to the primary. And IF the transformer has no need for any audio band (or beyond) damping then we have a case for primary loading.

The sensitivity, when primary loading, is of course exactly due to this 'impedance matching' as it ONLY occurs in a VERY narrow impedance band/window, in the example at ~ 10ohm. Going to 9ohm or 11ohm will already be outside the window. This with a 30dB SUT and the square of the 1:31.6 winding ration means 1000 times bigger R on the secondary and makes it thereby 1000 times less sensitive.
Axel


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   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  More about step up transformers..  LOL...  Analog Playback Forum     4  40503  01-06-2005
  »  New  The last phonocorrector: “End of Life" Phonostage..  Big cap banks...  Analog Playback Forum     310  1990453  11-13-2007
  »  New  Phono stages with SU-1..  SU-1...  Analog Playback Forum     4  66438  11-23-2007
  »  New  Taking the mystery out of cartridge loading..  The phase in Step-Up Loading by Dave Slagle...  Analog Playback Forum     6  90046  02-26-2005
  »  New  Expressive Technologies SU-1 and cartridge output and i..  MV and Ohms...  Analog Playback Forum     2  33838  07-07-2011
  »  New  How to run MM-type cartridge into MC phonostage?..  Quite interesting....  Analog Playback Forum     6  67879  11-13-2011
  »  New  Expressive Technologies Model 1 preamp..  This is a full functional pramp....  Analog Playback Forum     6  45600  06-17-2014
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