DIY'er in Brooklyn, NY USA

J Epstein

Member
2002-02-08 7:24 pm
Hello diyaudio!

I was asked to introduce myself by the person who introduced me to this interesting forum - dice45. So I shall.

I am Jeremy Epstein, 41 years old, from Brooklyn, NY USA. I have built almost my entire audio system myself and I have a web page for my audio gear at:

http://home.earthlink.net/~ellenoler/audio.html

Please be sure to look at the Music page also, since music is what this is all about.

http://home.earthlink.net/~ellenoler/music.html

I am always unhappy being identified as an audiophile, and I usually correct that to music lover. I have been chasing after records (and later, CD's) with great sounds on them since my teens, and I enjoy a wide variety of music as a result.

I'd describe my audio interests as narrow but deep. The things I understand, I understand well, the things I don't understand comprise the majority of the subject. The same with music.

Thanks to dice45 for inviting me to look in here. It seems like a lot of interesting, unusual activity is going on among these DIYers!

-j
 
Welcome, Jeremy









the crowd of hardcore SET amp freaks grows slowly, but grows :)









Didn't scan your site for quite a while ... is this a Denon DL103 on your Teres TT? Cannot believe! how is the cooperation with the Ladegaard arm? And how is the sound?









From smart guessing i would never have believed that a cartridge with a small screwdriver's compliance would get alive in a low pressure/ high flow linear tracking tonearm.









Dtopic,




have you finally found a proper replacement for your Lundahl LL1660 "plate choke" used for your free lunch's 6C45pi? What a waste! What a misuse! :) BTW, Lundahl manufactures plate chokes, too :)
How does you free lunch sound with the Audionote T-144?





My pair of LL1660 PP finally has arrived and i hope it will serve me well as my differential preamp's output. Measured the sheet metal thickness, it is 0.1mm !! Although the unit looks like crap (as usual for Lundahl), i am sure it is one of the finest trannies made; i recently learned Per Lundahl uses nickel for his cores, atleast for the better ones.
 

J Epstein

Member
2002-02-08 7:24 pm
I have "stepped up" to the Denon DL103D, and I like it A LOT. It works perfectly in that arm. The sound is very extended and it tracks well. I am using Altec 15095 (microphone mixer application, 10:1) octal plug-in transformers as step-ups and they work well.

I got in on a purchase with Thomas for some Lundahl chokes - 1668/40mA, so I use those now instead of the interstages. Surprisingly they only affected the sound very slightly, there was really little difference froom the IT. But now I can use those ITs for something more interesting.

2A3 PP maybe?

I swapped the Audio Note T-144 (which worked very well, especially at the price) for some transformers Kurt Steffensen is using and doing OEM with. They are good 2K7:8 units, sort of ugly but they sound slightly better - smoother - than the Audio Notes did.
 
Jeremy,





fine the DL103 works so well, then there is hope i will try out mine on the LT-1. Obviously your Ladegaard exerts a lot of guidance. If i look at the width of your slider, yes, then it appears plausible to me.





How do you judge to possiblity to invert the bearing, to feed air to the slider (yanno, 100% nozzle coverage, only 4 nozzles needed, precision nozzles affordable) ? and then, a VERY simple LT-1-like VTA adjustment could come within reach :)





LL1660: i bet it is a superior plate choke, just, what a waste :)


Good you now have LL1668/40mA. I also have a pair of them, the 25mA variant. Was meant to be the plate load for my line stage before i switched to standard PP topology and now the LL1660 is my preamp's OPT. 2A3 PP certainly will work. I use the 12B4A for my preamp's line stage which historically is the granddaughter of the 2A3 and has similar parameters, just the base is Noval/9pin and the tube is indirectly heated and cheap and available in quantities for matching.





AudioNote T-144: rumours tell there is not only praise on cheap AudioNote units. Heard of complaints .... Peter H. loathes them for their performance on the bench.
 

J Epstein

Member
2002-02-08 7:24 pm
How do you judge to possiblity to invert the bearing, to feed air to the slider (yanno, 100% nozzle coverage, only 4 nozzles needed, precision nozzles affordable) ? and then, a VERY simple LT-1-like VTA adjustment could come within reach

Well, the biggest problem I had with mine was the side force exerted by the wires, so I would say that you would have to come up with a very clever way to prevent the tubing from exerting side force for this to work well. The difference between 5 (L+, L-, R+, R-, earth) strands of 30 AWG copper with Kynar insulation (too stiff) and 5 of 40 AWG silver/teflon was very significant.

With the Kynar wires I was constantly playing with them to get them into "neutral bias." With the silver wire I never have to worry about it, it is a complete non-issue. Mis-bias had a bad, audible effect on the tracking - exactly as you would expect, like having the anti-skate too much or too little as we heard in Arhus.

I can't imagine that the air tubing (under pressure!) would be softer than a thin strand of wire, so there would definitely have to be some thought given to solving this problem. Perhaps two hoses in opposition/equilibrium?

Any clever ideas?

-j
 
Jeremy,





what you report is as i would expect it. If the air hose can act as an enemy, it also can act as a friend.


The air tubing i intended to use is silicone insulation tubing. Not much air flows if the inner diameter is kept low so for a low pressure / high flow design a compromise must be taken. The smaller the tubing diameter, the more pressure it can stand and the less it stiffens with pressure.





I made experiments on an improvised airbearing and found that the force exerted by the wires (enamelled copper wire of 0.1mm diameter, two loosely twisted pairs) and by a thin silicon hose at 4 bar pressure is just about equal, the wires being even a bit stronger. Wires and hose were hanging from 30cm height and pulling the assembly.


Hose and wires hung along a "chain curve" which is very close to a x=y^2 function.





This is what i want to have: slight too low antiskating. You remember Aarhus? Well, barely enough AS was way more enjoyable to listen to than slightly too much. In a perfectly balanced airborne linear tracker one always has slightly too much "AS" as the stylus pulls the slider unit. So let's hassle out how the air hose can help to pull and take the bigger part! :) then we have "barely enough AS".





Have something to report: my compressor is up and running. Was a kit of a JunAir airbrush compressor and sat for 15 years in the dust, had no idea whether the thing would explode or electrocute me :) now it runs fine.
 
Bringing something back from the past

I have "stepped up" to the Denon DL103D, and I like it A LOT. It works perfectly in that arm. The sound is very extended and it tracks well. I am using Altec 15095 (microphone mixer application, 10:1) octal plug-in transformers as step-ups and they work well.

So you are using a 15095 as a step up transformer for your MC cartridge? How are you doing your RIAA equalization?