Step Up Transformer Question

@rmdmoore As stated in a earlier post in this thread and in another thread very recently.

I am a user of Valve equipment who much prefers the end of a Valves produced  Sonic that leans heavily towards transparent.

This has made me inquisitive and searching for items that assist with keeping the sonic where I prefer. As stated, I have been demo'd numerous SUT's across many years and state with full conviction in my system and in other systems, SUT's add Richness to the Sonic being produced.

In some cases it is a subtle underpinning of the Sonic, and at the other extreme, the sonic can be Bass Laden and very very loose in its shape and roll off.

My 'Gut Intuition' strongly leaves myself feeling the use of a Nano Crystalline Core has reduced the perception of Richness using a Copper Winding to the least I have detected it. Also the impact it had on the Cart' was quite something, the sense of effortless function and the projection of the sonic, had one feeling the system had gone through a very expensive upgrade. The system it was demo'd on has been via a Valve Phon' close to my own in use design, a Pre Amp' that shares very similar design to the Model I am having produced, EAR Valve Power Amp's and ESL Speakers. This system has similarities to my own inclusive of the ESL's.

As stated the Nano Crystalline Core with the Silver Winding that was not a ideal match for the Cart' in use, was equally impressive for other reasons. This had the most voluminous Sonic, extra pumps of Volume were seemingly added to the Soundstage. I am no stranger to this perception, but using older experiences and recollection this came at the expense of a undesirable colouration, one that is way beyond what I seek. The Structure A Silver Winding, offered all this Voluminous perception, as well as maybe being the most Transparent SUT ever heard.

Hence, this Brand is Shortlisted for Home Demo's.

It is good to see that other Companies have become aware of the value of adding the nano crystalline cores to their range and individuals like yourself have become interested in the notion of adding it to a SUT.

All SUT users, who prefer the Transparent End of the sonic that can be produced, will have to wait for patiently for the time when PC Triple C Wire Wound Tranx's are being made, to get to the next exciting level of sonic that can be created.

I'm hoping for Cart' Coils, Lead Out Pin's, Wand Wire (Already Achieved), SUT Windings to be produced in PC Triple C Wire. My World of interest in Audio will become a place with new enthusiasm to encounter such items. 

Interconnects, Power Cable, Speaker Cable, Internal Speaker Wire and Internal Hook Up Wire are all uses for PC Triple C Wire that I have now experienced in use.

Internal Speaker Wire being the only device not able to be A/B compared as a Demo' to a Typical version.

PC Triple C Wire has proved as a result of Demo's to be the correct choice made as a Copper Wire.                

@elliottbnewcombjr I use WBT locking connectors, but they still need a wiggle or a jiggle every now and then to decrease resistance caused by accumulated crud. (I guess they might be gold plated but it is impure gold!)

My question is where do I go from here? Bob's makes the sky 30 which is switchable from 1:15 to 1:30 which I like because I can play with the gain tubes in my preamp and potentially go to a quieter 12au7 than the 12ax7 that's currently in there. Will that be a real improvement?

@rmdmoore We've worked with SUTs a lot over the last 40 years. @lewm's suggestion of Jensen Transformers is an excellent one- they make some of the very best in the business at any price.

One thing you learn very quickly is that you want the least amount of step up possible so as to work with your cartridge. The more step up you go for, the more issues the transformer can introduce.

If you have 0.2mV you really only need 60-65 dB of gain if you have a regular line section in your preamp. So you should be using the MM input, not the LOMC input. 

The other thing that is tricky about SUTs is loading. The loading does not affect the cartridge (other than measurably and audibly limiting its high frequency bandwidth; lewm already linked to the thread on the Steve Hoffman forum that shows what is really going on), but loading is critical for any SUT!

If the SUT is improperly loaded it will either 'ring' (distort, so adding brightness) or be rolled off if loaded too heavily. Jensen transformers has published a pdf file that shows the correct loading for their transformers when used with most known LOMC cartridges. Mot SUTs made for a specific cartridge are designed to be loaded at 47KOhms with 100pf of capacitive loading (which is about the capacitance of the tonearm cable 1 meter long); IOW they are designed to be plug and play.

But if you use a different cartridge with such an SUT the loading will be off and it won't sound right! That is one reason I like to work with Jensen since they did their homework, figured out the loading values and so their transformers work with almost any cartridge.

@atmasphere Ralph, thanks so much for your input. Yes, the plan is to use the MM input and which has about 45-50db of gain with the current tube complement. I should really only need about another 20db which, if I understand correctly, would be a 1:10 transformer. That's what is in my unit on the MC side according to the designer. Seems like that's really all I need then. There are some good deals on recently discontinued Hafler SUTs that had Jensen transformers in them. Anybody have any experience with those? 

@rmdmoore This is why Jensen. You can get transformers from them that are only 1:4 or 1:8 which allow for greater bandwidth. There's no point in having more gain than you need since there are always performance tradeoffs to get the greater gain.