Cartridge Experiments

 Expanded my bubble with a covid test and a visit for a weekend of listening to cartridge variations in DC.

Thus far the cantilever, diamond profile and suspension have been determined so the primary goal of this session was to confirm results of 10 different variations of tieback and coil winding materials. Comparing copper, silver and gold coil wires was interesting and a consistent sonic pattern of behavior is starting to emerge.  The system was Garrard based with my stacked quad57's and the tonearm for the primary swaps was a Schick and then ultimately the winner was installed in the 12" dymondwood "Chunk" and compared to the previous reference in the 16" magnesium "MegaChunk"

In order to do quick and effective swaps the head shells were all mass loaded to net the same VTF and in the case of the mono carts some substantial mass was required.  Zenith and azimuth were set electrically and the SRA was dialed in by ear for each cartridge to best isolate the variable being compared.  It has become abundantly clear that setup usually dominates the sonic results in comparisons like this so extra care must be taken to assure proper setup.  Once a general feel for the variable being examined was determined the pattern of results correlated nicely to the same set of tests in a different system.  The next step with this batch of cartridges is to repeat the comparison in a third system and then move onto coil formers and magnet types with the ultimate goal being a more finessed version of the field coil.

stay tuned.

Silver and Gold

 I've used this title before around the holidays and this time I'll take it 100% literal.

Being a huge fan of silver wound things and loving the sound of silver wound cartridges I decided to take my game up a notch and see what 0.9999 gold coils sound like. 

It has been posed to me by Dick Sequerra that it is the oxide semiconductor boundaries within wire that that make silver a better sonic choice since silver oxide is a more benign conductor than copper oxide which creates a diode.  Dick made the compelling argument a few months ago that since gold doesn't oxidize at all it should be the ultimate choice for the low level signals found in an MC cartridge coils.

Stay Tuned.

Franken-Schick

 I have been playing a fair bit with cartridge designs lately and have come to the realization that setup (mainly SRA) can have a profound impact on the sound of a cartridge.  When trying to make apples to apples comparisons of different suspension types or silver vs. copper wound coils, small changes in SRA will quickly swamp out the variable you are trying to isolate.  

My 12" Schick has been my goto arm for these comparisons since cartridges installed in headshells are a must for efficient changes. That means for these experiments my Schröder Reference sits idle.  The realization of the importance of matching SRA from cartridge to cartridge had me add VTAF to the Schick for quick and repeatable changes in VTA.  This left me counting turns and computing changes from a known thread pitch. Around four hours ago Jeffrey pointed me to a table he used at a show with a machinists indicator to read out VTA.  

I recalled that I had a similar indicator and to the cad/cam program I went. A few hours later I came up with something that would make my long lost uncle Rueben proud.  The end result tells me the VTA setting to the 0.001" over a 1" range which is just what is needed to dial in 5 different cartridges with different tie-back wire types for my next comparison.

When it comes to simple listening pleasure of a single field coil cartridge the Schröder gets cued up as  the daily driver.

Capital Audiofest

Another year, another sleepless weekend in DC.  Here are some pictures from the room and links to show coverage.  Pete Hutchison of The Electric Recording Company sent over a test acetate that he cut of Sonny Rollins Way Out West which was sublime.  We were running 301's, a Schick and a Schröder with lots of silver and mercury.  I'll let a few pictures do the talking and those that write professionally tell the tale.

https://www.stereophile.com/content/emia-re-visioned-quad-esl-57s-loudspeakers-garrard-301-turntable-shroeder-and-schick

We were also showing the 50 amps, Autoformer, LR phono and SUT's in the Refined Audio room.

https://www.stereophile.com/content/cube-audio-mini-nenuphar-loudspeakers-emia-audio-electronics-tw-acoustic-raven-gt-turntable

Jack Roberts blurb on the Audio Beatnik

https://theaudiobeatnik.com/caf-2019-the-emia-room-and-stacked-quads/

EMIA Permalloy 50 Amplifier

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rarely seen and never blogged, the EMIA 50's made an appearance at the warehouse for some final tuning and listening this week... two amplifiers are shown... one copper, and one silver... yes, silver interstage transformer and silver outputs... 

and check out those ridiculously giant nickel outputs... no, not 49% nickel... actual Permalloy - 80%.... sometimes I forget how much I love the sound of nickel... especially when coupled to a globe 50... not sure it gets any better than that... different maybe, but not better... a true classic... 

and speaking of rarely seen in public together, last night this happened:

Nick Mason played all 1970 and earlier Pink Floyd tunes... so wonderful to hear all of those Syd Barrett songs... and they brought the swirling chaos as well... Astonomy Domine... Interstellar Overdrive... Saucerful of Secrets.... and Roger Waters came out to sing the only song I wanted him to sing:  Heart of the Sun.... just perfect..   oh! and on the way out I found the Saucerful of Secrets:

I love me some liquid lights!

peace,
me

GM70, Silver and Nanocrystalline

Just finished these up for a GM70 amp Jeffrey is building for a customer.  They are wound with 0.9999 pure silver wire on big nanocrystalline cores.

The silver winding wire is brought out for direct connection to the circuit.  While I am a firm believer that it is the amp designers responsibility for the ultimate packaging aesthetic, I do have some 125mm cubed aluminum covers that will cover them if needed.

After many years of insisting that doing multiple taps only adds to the compromises I want to avoid in a design, I have finally come up with results that I deem acceptable.  Below are the plots of a similar transformer wound with the ability for 4, 8 and 16 ohm taps.

For behavior below 100hz I look at the inductance plots to make the best choice of inductance vs. current for the intended application and set the air gap accordingly.  The plots below were taken with the equivalent of a 16W excitation voltage @ 50hz.  Pink would be suitable for a parallel 300B,  Brown an 845 or GM-70 and something inbetween green and blue could be chosen for a 211.

dave

Silver Elmaformers

This is a new version of the elmaformers which uses a 47 position switch and seamlessly goes from -51.25dB to +5dB in 1.25dB steps.  It is essentially a linear version of the Chapman remote modules.

 It all starts with the weakest link and that is the pesky circuit board.  This isn't your everyday board but one made with .9999 silver and the traces are cut on a CNC milling machine.


The 4 deck 47position Elma switch mounts directly to the board and the wiper contacts are the silver of the board.  I have already run some boards through 20,000 switch rotation cycles without any issues so I am confident in the longevity of the units.

The silver boards are very time consuming to produce and will be reserved for the silver wound units.  For the more pedestrian copper wound units I am getting quotes for the hard gold boards per Elma's spec and will have them in the very near future.

a sweet permalloy pea wrapped in silver.

On the micro level here are a set of silver LCR inductors ready to be put in their pod to ship.

 Once in their pod they look like this.

 Now consider some may want pods with different flavors.

As much as I like peas filled with silver, most of the time permalloy peas are copper.

Now that the phono correction is taken care of for customers in three different parts of the world... lets add the attenuation pods in silver.

I broke the mold with the 6X box and regret it.   I had to go find an odd-pod friendly box.

46 silver peas and 20 copper peas ready to go into 3 bigger pods to ship.

Precious Metals

 

My newest investment strategy is moving away form cash under my mattress to silver on my shelf.  Given the worth of the US dollar, I hope it is the correct move.  Pictured above is about 8 pounds of high purity silver magnet wire in assorted sizes.  These sizes will allow me to do a small number of autoformers and some nice low ratio SUT's for a handful of customers that have been pestering me for years for silver.

 First up are 6 pair of the chapman/bent modules to go to Korea with some Step-Ups to follow.  Next a few samples go out to some OEM's and family members to try.  If all goes well I may try to do what the Hunt bros. couldn't accomplish in the 80's.

As a final note,  in the next day or so we should crack the 100,000 pageview threshold and JJ and I want to thank you all for putting up with out antics and coming back for more!  I'm sure the content is about to increase a bit in the next weeks with Munich on the horizon.

Silver and Gold.

My favorite UPS man left me my X-mas present a few days early in the form of a large box filled with gold.

Add a few pounds of silver and you end up with something special.

Without a size reference it is hard to tell exactly what you are looking at but let me just say that is a very large 80% nickel 5K output transformer that will do around 3W full range!

For reference, most people consider moving one size up from the autoformer size is a big 80% core.  Well these babies are 6 sizes up and sounding wonderful with a 2A3 playing Elvis's Christmas.

Happy Holidays to all!