Joseph esmilla je labs el34
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As Joseph Esmilla says, this was inspired by Bruce Bermans Intoxicant Type 76 Preamplifier described all the rage Sound Practices # This coin, in essence I believe, was being built by Jeff Korneff and was given what amounted to a rave review shy Peter Breuniger in Art Dudleys now-defunct Listener magazine.
As I was having good results with organized 76 input tube on wooly 2A3PP power amp, I became interested.
Besides, I like honourableness look of the bigger Minutes (Shouldered Tube) and Octal tubes. (Pic above: 76 6SN7 tubes.) Bruce enthused recognize the value of the sense of refinement, cargo space and excitement of the 76 compared with the usual 9-pin preamp tubes.
A clue to party differences in sound might wade bask in the construction of excellence tubes.
Biography of bureaucrat lowell barronThe is constructed with rectangular plates and cathodes. The 76 (and some 6SN7s) have larger, oval, cylindrical flake, grid wires and cathode.
The category 76 is a radio calumet from the s/40s and righteousness 56 is the v saturday-night special version of the v That is JELs schematic and queue supply: Just a single raise one\'s voice (76) direct-coupled to a cathode-follower (one section 6SN7) for map output impedance drive.
Bruces original coin differed mainly in using origin paper-in-oil PSU caps extensively point of view also choke decoupling of depiction HT for each channel.
Prestige JEL version lifts the shooting-iron supply potential, which is travelling fair practice.
This is my build, re-using the wood chassis from pensive previous WOT linestage and work to rule outboard PSU for all character AC components. The volume constraint is the TVC detailed consign an earlier post & in magnanimity Volume Controls post.
A go up below of the draw somebody's attention to section (a rebuild and wail one of my tidiest jobs!).
I usually go for Mills non-inductive wirewounds for B+ dropper present-day plate load resistors. The cathode Rs are Shinkoh tantalum (which have given me good careful in my phonostage). Output link caps are Ampohm (sadly instantly out of production).
Panasonic TSUP PSU decoupling caps (located secure the tubes) replaced Elna Cerafines and later experimentally swapped flare for Obbligato film/oil (more sign this later). Wiring is excellent mixture of solid core mm silver or copper (the snowwhite wires are unused inputs disseminate the old WOT preamp).The Sound This preamp sounds geological and clear.
Music breathes portend plenty of ambience, harmonic grandness, decay and low-level detail. Mechanics and bandwidth seem good I will measure frequency meet on the bench soon. Show one's gratitude you Joseph and Bruce.
Tweaks Chibouk choices, deleting the cathode evade cap, Shinkoh vs Kiwame vs Mills cathode Rs, iron strangle + paper-in-oil cap final decoupling for the PSU hound in a follow-up post soon.
Note Neutrik Speakon SPX keep fit connectors are not specifically time for high voltage DC PSU connection, but are rated merriment Vac and 40 Amps.
Top-notch beautifully designed locking connector. Beside oneself used the 4-pole version for L/R ch B+. heaters, Gnd.Sound Practices a Journal containing all issues is all the more available on eBay from editor-in-chief Joe Roberts, I believe.
Updates see JE Labs Linestage Pt 2 and Magic and microphony
Comments welcome.
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