Wednesday, February 28, 2024

More Teasin'

can one ever have enough 80% nickel? 




Saturday, May 27, 2023

which one arrived first?

 Sun Ra did not use the term "birthday" - he referred to "arrival day"... 

so which of the following "arrived" first?



the Western Electric 555...



or Marshall Allen?


the answer below the scroll..
















Marshall Allen arrived first! ... in 1924... 

the first 555 drivers were made in the BTL lab in 1926....


fwiw, the two go well together... 


(and see, Iain, I can post!)


peace,
me

(the other one)




Sunday, March 26, 2023

work in progress tease

 something that is creeping from the back of my mind into reality....  more to come (and at the rate we add content here....)


Sunday, January 15, 2023

Why nickel is so yummy.

 Here is a simple set of low frequency plots of steel (red) vs. nickel (blue) with applied signal levels.


This clearly shows that for low level low frequency information retrieval, steel takes a certain amount of energy to "turn on".

Sunday, November 27, 2022

Sequerra Auction

 Up for auction is the last system Dick Sequerra built and was listening to when he passed away a year ago.   No connection other than he was a friend and I am trying to help the estate.  Please spread the word.


https://www.auctionninja.com/hamilton-grp/sales/details/sequerra-audio-system-stamford-home-furnishings-collectibles-more-16.html?Page=1#items




Thursday, August 25, 2022

Your Brain on Reggae

 Matisyahu.  Born Jewish... rebelled... followed phish.... found reggae... became Hasidic...  released "Youth".... went off my radar.... just resurfaced to me...






My favorite line of his came in an interview asking if he had ever performed on the Sabbath.  His response was along the lines  that he did a show on a Friday night in Alaska.  He then added since it was summer, technically the sun never went down.




Tuesday, August 23, 2022

Happy Birthday!

 


Twenty-seven years ago today this little 8lb 14oz baby was born.



Thursday, June 23, 2022

Dick Sequerra's last speaker.

 Here is a cell phone pic of what Dick was working on before he passed last fall



Monday, May 23, 2022

fry baby fry

 A friend asked me the best way to use his Hagerman Fry Baby  to burn in his tonearm cables.  After a few minutes of thought I figured an old denon 103 body would be a safe approach since it will secure the delicate cartridge wires in place and greatly reduce the chances of a possible "Oops" 


I had the thought to put the plastic body back on but we all know that denuded 103's sound better.

Friday, July 23, 2021

Herculean DIY Autoformer wiring.


 They say a picture is worth 1000 words... well how about how about around 180 wires and 820 solder connections?  Brad from the Boston contingency wired 6 of the 28 position autoformers up for Caroll's home theater system.  I often joke that more than half of the $200 autoformers I have sold sit partially wired in a box on a shelf and this picture might explain why.

Sunday, June 20, 2021

blink blink blink


 I mentioned the Feral Eye a number of years ago and the fate it met from Hurricane Sandy.  It  was brought back to life by steve berger as a PP 10 amp with a 49% nickel phase splitter and last night I got to hear it with a quad of mesh 10's from 1929.  
I'll be he first to admit that historically  I have not been a fan of either push pull or 10's and these days my daily drives are PP 300B's direct feeding stacked quad 57's and last night has me considering revisiting the 10.
The days events were to listen to cartridge variations and the mesh came in at the end of the evening as a treat for a hard days work.

Wednesday, April 28, 2021

Another Early Strain Gauge

 I came across this cart on the 'bay and it is from an Admial 6F10



One interesting thing about it is the way the cantilever and stylus appear to be formed from a single piece of bent metal.



The other quirk is that it has three terminals with rather high resistances.


The end to end resistance is 150kΩ and the center pin is 100kΩ and  50kΩ to the outers. "Tweaking" the stylus makes the resistance change by 1-10kΩ+ so it really seems to be a strain gauge  and with a date of "Pre-1952" that would make it an early one.  The idea that the three terminals all seem to be connected to gauges has me puzzled an I haven't fully digested the schematic so have at it.






Monday, March 22, 2021

Autoformer Frequency Response

 Had a customer ask for details about the frequency response of the autoformers and while I honestly believe a picture is worth 1000 words,  I'll add a few comments.  My general statement about the high frequency behavior is they behave to 100kHz without the need of any sort of loading network.  I like to show plots that cover the areas where a device misbehaves so a pattern of behavior can be identified.  Lots of people will just show a random well behaved sweep and call the device perfect.  I want you to see the squirrels.  Unfortunately plotting around 50 steps in 1dB increments creates an incredible mess so I picked a random sampling to get these plots.


Around 20 years ago I showed a similar set of plots from a step up transformer to Frank Schröder and he commented how the behavior was unacceptable @ 20kHz to which I replied "check the scale" at which point he realized he read 200kHz as 20kHz and his opinion changed. 

The other set of plots that shows important behavior involve the low frequency end of the spectrum and for this it helps to pick the worst case scenario with the +7dB gain setting of the remote autoformer.



The above plot shows the +7dB setting driven from 100Ω, 500Ω, 750Ω, 1000Ω and 1500Ω.  This represents the worst case situation for the low frequency response an with a 1500Ω source the -1dB @ 20Hz is borderline.  It is also interesting to see how the top end extension is also compromised in the +7dB position with the 1500Ω source but if you then move down to the +4dB position things look better and from unity and below all is well. I could have simply showed the Red sweep above from 20Hz-100kHz and called the device perfect but alas perfect transformers do not exist.

Thursday, March 4, 2021

Unsafe At Any Speed

Apologies in advance to Ralph Nader for a wee bit of appropriation.  



 

Wednesday, February 17, 2021

Garrard 301

 I know the inerwebs are filled pictures of beautiful Garrard 301's and by that standard this one is a bit pedestrian.

If you take a step back and see that it is partnered with a vacuum tube based phono stage and amplifier things get a bit more interesting


another 20 steps back reveal that this is then paired with a pair of Tannoy Westminsters in a Japanese restaurant in NYC and suddenly that first picture isn't so pedestrian any more.

Makes me really want to exit my bubble and be one of the lucky folks who gets a table during the 25% seating capacity phase of the pandemic.

Thursday, February 11, 2021

Laser Zenith

 I have recently found the need to adjust Zenith by small repeatable increments and it seems that hot glueing a laser to the side of the cartridge proves to be quite effective.


 The need for this type of repeatable precision was so I can plot the change of IMD against Zenith angle and the results are telling.




dave


Wednesday, January 6, 2021

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.

Wednesday, December 30, 2020

Boptura

 Random said number 5


boptura needs to get me an address.


Wednesday, December 23, 2020

Festivus

 It is that time again.  Everyone air your grievance below in an identifiable comment and before the year ends Random.org will pick a winner of a pair of the Slagleformer Modules.  We will cover shipping worldwide.



peace.... 

us.

Wednesday, December 9, 2020

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.

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