Phono Preamp. With transformer or fully active

@intactaudio I don't see you commenting about the transformer loading in your post. I know that this bit is problematic:

If you take a 2Ω cart and use a SUT designed for 40Ω, the LF extension will be down into and past record warp and tonearm resonance and the low impedance drive will cause an underdamped top end (HF peak in response)

-because our phono sections go down to about 2Hz, yet there are no problems with record warp and the like. Loading the transformer is well-known to control issues in the high end- the 'underdamped' part to which you refer. So while the inductance of the cartridge certainly plays a role, its not that hard to come up with the correct loading for the transformer to make it work.


However I agree that in most cases this is beyond most audiophiles, but this does not change what I wrote. An SUT made for a specific cartridge was probably made at the behest of the cartridge manufacturer; they would probably not be happy if that transformer were used with some other manufacturer's product. So its not surprising that they don't publish loading charts for other cartridges. But if the manufacturer of the transformer doesn't have a dog in the fight, then things are different- and I point to Jensen Transformers as one of the best examples of that. One glance at all the cartridges they list shows they've done their homework!

The Jensen Transformer website contains or used to contain some excellent white papers on transformer loading, as per the subject of Intact's and Atma's posts.  They show how and why to load down the secondaries to compensate for the effects mentioned.

Dear @lewm :  A dedicated external SUT is not builded exactly the same as the transfortmers used in phono stages where the designer knows that the customer can have different MC cartridges ( needs a gain/impedance selector/alternatives. ) and their designs take in count that issue.

R.

@atmasphere 

Are you the guys who do OTL amps?

I loved your setups with classic & their horn speakers

Do you do “ just” phono pre’s ? 
Jeff

Are you the guys who do OTL amps?

Do you do “ just” phono pre’s ?

We do the OTL amps, but so far have avoided stand alone phono sections as we are convinced that they work better when they are integrated into the same chassis as the line stage, this due entirely to how the output of the preamp is connected into the line stage. When the connections are short and soldered, they seem to sound better.