Thursday, April 2, 2020

FREEkerFormers





Ok... poor play on words.  I just updated the Speakerformer page with some more fake news on why you need them.  I also added a "Rshunt" calculator and two new tapers.  One is a middling version that does -6 to -15.5dB and an "I don't know what I need" version that does from -1 to -20dB in 1dB steps.

Up for grabs is a pair of the 1dB per step versions pictured above just wash your hands for 20 seconds and leave a comment with your name or some sort of identification and random.org will pic a winner in a week.

stay safe


Wednesday, March 25, 2020

The worst resistor ever?



I wound some 2KΩ copper wire resistors for DHT Rob a few years back and he used them to bias a 10.   He reached back out to me to do some 1300Ω to bias an AD1 @ 35ma.  


These got the slightly nicer package pictured above @ 25mm X 25mm. One of the biggest problems with the copper resistors is the value is not stable with temperature.  My solution to this for this case is to let them make some heat to stabilize them when in operation.  These units have a cold DCR of 1140Ω when cold and 1302Ω after an hour at 35ma.   Since these are intended for cathode bias it must be noted that the tube will run a bit hot initially before the temperature comes up and things stabilize.


The units are wound to be non-inductive and that results in a fair bit of parallel capacitance.  Since there will be a bypass cap in parallel with the resistor anyways, that is of little consequence.   In a crazy world one could use them unbypassed to compensate for loss of HF info elsewhere in the amplification chain like Kondo did with the Ongaku.

The other use for this idea is the loading of MC cartridges.  Since the proper way to load a cart is at the primary of the SUT, the values are typically much lower.  Knowing that it is also at a point where linearity of value across the audio band is a concern.  Here are some units that I wind onto an RCA plug for ease of termination and use.


These have much better bandwidth and are flat through the audio band.  Unlike the 1300Ω units which go capacitive at high frequencies, these go slightly inductive. 


The big question is why go to these insane lengths when there are plenty of off the shelf options are available?  Well if you look at it on the most basic level a resistor is simply a really crappy conductor. Given the extremes we go to for the quality of our signal wiring it isn't beyond reason to me that a longer length of a superior conductor with all of the baggage that it comes with may be better than an alloy specifically done to impede conductance.  Or you could just listen and damn if they don't sound good.

dave

Wednesday, March 4, 2020

Sincere thank you for the write-up, Eddie!




We also had a lot of fun... glad you could make the trip....


peace,
me

Thursday, February 20, 2020

For Sale: very early Altec Lansing 604 in "furniture cabinet"

.

as Lisa knows.. I have a problem... I just cannot pass up beautiful and well-built items from the past... I love them... listen to them.. learn from them... but Joe warned me about this... long ago warned me... "Jackson, do not accumulate these things that belong in museums. You will be beholden to them." .. and how often is Joe Roberts wrong?  well, do not ask Joyce that question... but I am now far off-topic...



this beauty used to sit at one end of our dining room... the 16a sat at the other.... and it was what we listened to during family dinner.. or if one of us was sitting at the old farm table working on a project... but it has not been used in several years.. and that just is not right... so it is time to move it to a new home.. 


I love so many of the details on this... the pillows!!  and that wrinkle paint... sets my heart aflutter... 


the original label that is on the rear of the cabinet


one "oops"... from loading it... the veneer flaked up.. could be fixed by any woodworker, if desired... it is small.. and I tend to let old things just be.. 


but pretty clean for 1947.. that is seventy-three years old!


and look at that... 16a making a sneak appearance in the background... 


more pillows!


and then the driver in all of its minty details


"voice".. holdover from "field" days?  I dunno... 


20 Ohms.. Hollywood, CA

model 604... not 604B... or later... 


the driver has never been removed.. and I am not about to crack those screws.. 


N-2000-B crossover... and shockingly little dust for a 73 year-old..


original wiring.. they twisted and taped the wiring..


paper accordion surround... yep, early.. 


original cone (duh)


and that patination on te screws.. clearly untouched in a long time.. 

I think I am going to slowly just put things up on the blog... I will try not to make it a used hifi store, but focus on things that are blog worthy in themselves... 

oh, yeah.. I used to drive this directly from the headphone output on my phone... yes, seriously.. 

available unless marked sold.. 

US$4k, but accepting offers.. pickup in Rhinebeck is preferred, but I will drive this baby to a good home if needed.. and build a proper crate for shipping if I must.. 

experiencemusic@hotmail.com

peace,
me






Monday, January 27, 2020

Hens Teeth.


We spent the day soldering up some LR Phonos  and took a break to see how the 4304 compares to its daddy.  Alas Pops had what appeared to be an intact filament without continuity and even a removal and reflow of the base didn't save it.

other winter news here in the north involves snow, ice and sand.   I was moving the bigfuns around and forgot why they were so heavy.





 It seems 20 years ago somebody had the brilliant idea to mass load them by filling the voids with play sand which came in very handy in navigating the uphill path of ice to the storage shed.




dave

Wednesday, November 27, 2019

Marantz 7T

Alas the "T" stands for transistor and not triode but this one was personally modded by Sid Smith.






The insides...





and in case you didn't notice, it happened to be sitting on by far the most beautiful piece of gear ever.


Tuesday, November 19, 2019

ETF 2019 Sunday...

and this time I am positive what day it was...  I could hear the church bells... 


first we said goodbye to our lovely house... and the lovely field... and the French cows... 


verification of Sunday.... 


then I walked over to finally see Marc Henri... I had not yet had a chance and he was still setup... we have similar tastes... and he listens.. so it sounded exactly as I recalled... very nice... very open... and very French -  it was sweet.. hard to do with horns... 



we then walked the streets of Bellême... 



and admired the colors again... 


but the stupid Americans had their loud pull cart luggage... you can spot and hear them a mile away... 



the Yellow Vests were relatively quiet... so I talked the crew into a side stop... I am quite certain they all were grateful... I have read books about this place... and I will apologize for the low quality photos... the place was stunning... everything I had hoped for and more.. google around for Chartres Cathedral.. read some about it... just incredible... and to imagine them building this is mind-boggling... 





and the rose windows... these things are so large and so beautiful... and survived massive shelling during WWII as teh French buried them in the surrounding fields... 



man... those photos were worse than I recalled... oh, well.. you should really find a way to go for yourself... and they were cleaning quite a bit of the statuary inside... being such pure white really changed the feel of the place... it was nuts... 

oh.. and we waked by this really creepy doll shop... actually, it was rather interesting... glad that such places exist...



lastly, this:



grateful for the French team... thank you...


peace,
me


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