[Audiovista]

With virtually unlimited flexibility of Phono-1 MkII preamplifier (http://www.audiocircle.com/index.php?topic=114404.0), it only makes sense to offer some guidance on optimum gain and load settings. I will be doing that, hopefully with support of the AC community. It will apply to any phono preamplifier, not only Vista Audio. Some discussions will be very relevant to other equipment too (examples of power amplifiers will be used).

I was wondering if there would be interest in going just a little beyond the very basic - "if that is your cartridge, this is the optimum seeting", and outline why is the loading important, how it affects performance and how can we tweak it to our liking.

If I promise to keep math out of discussions, and illustrations simple (sometimes little crude and handwritten), would you be interested in such a topic?

The most critical thing is cartridge loading, and we can start with an explanation of what a squarewave is and why is it important. We can then continue with imperfections, how they get introduced and how are they perceived. Then we can look at specific examples and start building the list. I see this as a collaborative effort, where everyone's participation is very welcome.

Let's run the poll for four days, so we can get started around the weekend, or sooner in case of overwhelmingly positive response 

[jimdgoulding]

Yes, of course, indubitably.  I have that option to a degree on my phono pre.

[poseidonsvoice]

I'm your pupil. Please teach us.

Best,
Anand.

[Devil Doc]

You bet. This stuff has always been a mystery to me.

Doc

[WireNut]

Absolutely, Lets do it 

[Audiovista]

Great! I'm not planning to give a lecture, everybody here is experienced and pretty much knows what works and what not. I hope to give some starting points and then let discussion have life of its own. We'll all get little richer in the end...

[WireNut]

 The one thing I don't understand is about 100-200pf loading. I've been reading about this but my Technics SL-D3 table has hard wired interconnects so I have no idea what I've got at the phono preamp input. I could Mod the TT with new RCA's and make my own interconnects but I still won't know what I've got at the phono pre inputs. 
 

[Audiovista]

The one thing I don't understand is about 100-200pf loading. I've been reading about this but my Technics SL-D3 table has hard wired interconnects so I have no idea what I've got at the phono preamp input. I could Mod the TT with new RCA's and make my own interconnects but I still won't know what I've got at the phono pre inputs. 
 

Typically, when loading is discussed, it is referenced to what is inside the preamp. But you are absolutely correct that interconnects add to the total capacitance that is seen by the cartridge (they also add resistance and inductance). Capacitive loading is more critical with MM carts, where it can seriously impede frequency response. With MC carts, it is not nearly as relevant - yes, it can help, but the capacitance need to be so high that it is not practical. We are going to dig into it little deeper. I have started preparing materials to open the optimization topic.

[tomytoons]

I notice some of this is discussed back in 09.

I always knew it was a balancing act. Since speaking with Boris I made some setting changes on my Monolithic Phono. We will see or hear how these effects compare to the MKII. Just because the Monolithic is 12 years old does not mean it cannot compete in today's offerings. It is extremely good actually superb for the used price I got it for with the HC1b power supply. It will kick the crap out of Black Cube SE, RS and others at one quarter of the cost.

On a HO MC I always left things in the 47k loading. On advice form Boris it does sound better kicked gown a bit.

I'll be reading with interest of course.

[rollo]

I'm in very good idea Boris.


charles

[woodsyi]

I vote yes.

[Audiovista]

Fantastic! 

I will have to ask for a little patience when I get into talking about boring old squarewave, but I promise it will be worth it in the long run. It is an excellent tool to quickly assess performance of any preamplifier, or amplifier (and other signal sources), for that matter. Anomalies in the sqauerwave signal can predict how the unit will sound.