06 July, 2015

Langevin 102 Preamplifier


L: Langevin 1961 Catalog, from internet (Preservation Sound); R: system upstream. Click pics to enlarge.

Letter from NYC (42) 2015 (4): Langevin 102 Preamplifier - My Reference System III
Review: Elekit TU-8500, Part VI Use as Buffer Amp
Review: Lepai 2020A+, Part II

Links relevant to this article:
Reviews of Lepai 2020A+, Part I; Dayton B652, Part III; Almarro M1A
Phonoamp Shootout (with Parasound JC3, Part II)
Elekit TU-8500 Review Part I (with links to II-V)


Casual got Serious
Compared to years past, I had less spare time during my stay in NYC this year, and what time I had were piecemeal. My large systems (see equipment list in sidebar) saw relatively little use compared to my "Casual System". This left me to ponder a drastic upgrade of the system to reference status - "casual" should also mean quality!

Acquiring the Vida, which can hook up two turntables in Reference System II, freed up the Parasound JC3. Also, I have long wanted to set up my professional Langevin preamp, which has enormous gain and . So I got the idea of using my Elekit TU-8500 as buffer amp, to control the listening volume. All sources are connected to the TU-8500 System is now as follows:

Digital: Sony XA-5400ES SACD/CDP
Turntable 1: Clearaudio Concept/Ortofon Kontrapunkt C
Turntable 2: Audio-Technica AT-PL120/Raos MC Mono
Phonoamp 1: Parasound JC3
Phonoamp 2: Elekit TU-8500
Buffer Amp: Elekit TU-8500
Preamp: Langevin 102
Amp: Lepai 2020A+ or McIntosh MC-2200
Loudpseakers: Almarro M1A or Dayton B652

Click pic to enlarge.

Langevin 102 preamplifier

Considering the innumerable roles audio play in our lives, it is appalling how poorly audio history is documented. Which is why we all should contribute a little.

History The best known Western Electric is the best documented, but its various spinoffs are less fortunate. Langevin is the most important of these (actually incorporated much earlier and long supplier to WE), but its history is barely documented on the internet. Its very close ties with WE is immediately obvious from the similarity of its products (at its peak in the Golden Era) to WE. The products are superior in every aspect, and deservedly escalate in value.

The professional world in which most Langevin products are used provide tidbits of information (see here, here, and here). Langevin products and consoles were widely used in recordings. The company lasted into the transistor age, and its name was later acquired by Manley, which did not seem to do so well by it.

Documentation Descriptions and Schematics on the 102 series (A-G) are available in original Langevin literature from vintagewindings. My unit looks to be the 102-B/F fitted with the optional 103-B (for more info on 103 A-C, see vintagewindings) input panel and has a matching 201 Power Supply. Also, from the technicalaudio site, you can get more useful Langevin info: Description of Various Line Series; 1952 Catalog.

Acknowlegement: most sincere thanks to the folks who selflessly put these valuable info on the internet for free. Salut!

Design and Tube Complement The 102 is similar to the more famous WE 106 preamplifier, which employs the famous WE 348 and WE 349 tubes. The 6SJ7 is electrically identical to 6J7 except for pinout. Mine was re-wired for 6J7 (with its top-cap), hence enabling use of WE 348. And WE 349 can be used in lieu of the output tube 6V6. Output is similarly transformer-coupled. The 103B panel is not used. Right now, I am not using WE tubes, instead Sylvania 6J7 and National Union 6V6. The 201 Power Supply can use both 5Y3 and 5U4 types. I have used both but settled with the Tungsol 5Y3 for less heat, as sonically it is as good as the We 422. My unit was restored by Master Huang 臺北黃老闆 in Tapei, who has restored numerous WE units, including a pair of WE 124 that I have. He has very high praise for the unit.

Gain Like the legendary WE 106, these being professional equipment not originally designed for home use, the gain is enormous. I am not sure of the spec but the 102A is in the vicinity of 55 db! My unit thus is configured for both fixed and variable outputs (I use the former). Hum is therefore a potential problem, especially with high efficiency speakers. It would be interesting to try out this for phono direct in (after only RIAA application and sans phonoamp)!

Setup and Sonic Impressions
  • Settings The setup has three volume knobs, and setting is somewhat aribitrary, arrived by listening. The lepai 2020A+ was used as an amp, with volume around 12 o'clock. The volume of the Langevin (fixed output) was around 11 o'clock. With these settings, the volume knob of the Elekit TU-8500 hovered around 10-12 o'clock. The interconnect from the Elekit output to the Langevin input is very long (not desirable but of necessity), around 15 feet.
  • General Sound I first listened to the system using the dirt-cheap Lepai amp, and the result shocked me, that is how good it is. I would think most of this is attributable to the excellence of the Langevin 102. The sound has strength in every department. Most importantly, it is superbly lively. Indeed, it gives my Reference System I (always cooler than reference System II) a run for its money, lacking only power and bass heft.
  • Langevin 102 Particularly impressive is the pristine high frequency. A miracle, in fact, considering the input is through a very long interconnect and a buffer amp. I think there is not a little of the single-ended 6V6/349A quality here. You may want to know older Chinese vintage tube lovers dubbed the 6V6 tube 琴王 the king of string instruments. The sound is very similar to my WE 106 (in which I use WE 348A/349A), and that is the highest accolade. In passing, note too Shindo used to use the WE 349A in his Giscours. As with the 6V6, the sound can turn lean with bad recordings, but with most material the midband and bass are beyond reproach.
  • Elekit TU-8500 I rolled in RCA 6201 black plates and the sound was so good I let them stay. So users should try 12AT7 family tubes too! Set to unity gain (actually 1.1), the Elekit performed flawlessly as a buffer amp. Its neutrality allowed the full flavor of the Langevin to emerge. Commendable! Too bad I do not have the iFi iTube on hand to compare (next year perhaps). Not surprisingly, it also functions very well as a phono amp for the Raos MC Mono cartridge (shall be covered in a coming article). With this, I think I shall conclude my series on this gem.
  • Parasound JC3 As mentioned in my last article (roll down), with an Ortofon Kontrapunkt C, I played Willy Deville's Miracle (acquired after hearing it played in Audioarts) and was compelled to listen to the entire side, a luxury for me these days. The high gain of the JC3 is not needed in this setup (indeed a detriment) but its quietness was again proved in this very high gain setup - remarkable!

Article finished in HK.

3 comments:

Anonymous said...

Hi there. Was wondering how you'd compare our friend the Elekit to the Croft preamp you wrote about a while back if using both as line preamps. Both of them are priced around the same and both seem like giant killers based on your writings. Some head to head (if your auditory memory serves) would be really helpful!

doctorjohn said...

The Croft paints with a broader stroke, the Elekit more detailed and modern sounding. Given that the Elekit has more features (cans serve as buffer unit or phonoamp), I'd go with it.

Anonymous said...

Okay- fair enough. I'm sure both are impressive pieces of gear. To be even fairer, I heard the micro basic pre is no longer made so it's only the somewhat pricier micro 25 (with or without phono) that's now in the running... The fact that your Elekit can hang with such a high dollar system as your 'A' gear is remarkable though!