25 June, 2014

Review: Manley Neo-Classic 300B preamp

Click pics to enlarge. L: cramped interior of heavily regulated design; R: battleship!

Letter from NYC (36) 2014 (8): Manley
Review: Manley Neo-Classic 300B preamp 
Review: Shindo Monbrison (old version), Part II

Revised July 31, 2014

Background Manley has never been popular in HK, and often lacks representation. Not surprisingly for a company with a studio arm, the old looks were workmanlike and probably low in WAF. But personally I prefer the old looks to the new ones. I have had previous experience with some Manley products. An untouted old DAC was a sleeper. The Neo-Classic 300B SE/PP amp (methinks old looks better too) (input transformer is a luxury!) of Manley's wonderful and statement-level Neo-Classics series has received many reviews and much accolade; it was good sounding as I recall.

Neo-Classic 300B preamp
Strangely, the 300B SE/PP amp's companion preamp has had quite a low profile. There are no reviews from the major English audio press. You can find reviews from hometheaterhifi, Audio Video Revolution and Image HiFi (in German). I suspect this is because of its ungainly nature, built like a tank and resembling more a serious amplifier (necessary for ventilation of all those tubes). I ran into an irresistible bargain and acquired it brand new.

Design The official link is excellent and a must-read. This is a tube rectified design. While I think a single rectifier tube may just do the job, the use of 2 certainly is no-holds-barred and a luxury. The interesting thing here is Manley does not state preference for either direct-heated 5U4 or indirect-heated 5AR4 (Manley's own photo shows the latter). Mine came with stock EH-5U4GBs, and I am happy with that as generally I have always had a preference for the greater presence in the sound the direct-heated tube produces. But one would think the sound would be different, as the 5AR4 would generate higher B+, though in a reply to my email Eveanna Manley said due to the regulation the end B+ would be the same. The use of 0D3 for regulation is certainly a "retro" move - these tubes were commonly found in really old designs.  In fact, the whole design, including the use of large octal based 6SL7 (double-triode; but older designs usually employed pentodes), does have something old-styled about it - many studio-originated old classic preamps, like the WE106 and Langevin 102 that I have, are huge. Make sure your have enough room on your shelf.

300B as preamp tube Manley is not unique in using the 300B as preamp tube, but the design had been around a long time and Manley may have been the first to do so (Manley also has a history of using tubes not commonly used by other manufacturers). As far as I know, several Chinese manufacturers (Audio Space, Ming Da) make 300B preamps, and there is an intriguing kit from Bottlehead called the BeePre (informative on the challenges of using the 300B as a preamp tube).

My System As you know, I have 2 Reference Systems (always updated in sidebar to the right), but both use the same amp and loudspeakers, differing only in source and preamplification (Manley is used in System I; Shindo in System II). Part of the reason is to compare and contrast, so you shall see a little of that later. For the last 4-5 years, although the turntables and phonoamps have been constantly rotated, the digital front end, amp and loudspeakers basically have not changed. System as of this writing:

Digital: Ensemble Dirondo/Dichrono Hi-DAC
Turntable 1: Linn LP12/Ittok LV II/Air Tight PC-1
Phonoamp 1: Parasound JC-3
Turntable 2: Clearaudio Concept/Koetsu Black
Phonoamp 2: Fosgate Signature
Amp: Wavac MD-811
Loudspeakers: YL 4-way horns

Sonic Impressions and Tube Rolling:
  • General There is nothing much "retro" about the sound, which is thoroughly modern - quiet, transparent, wide and deep soundstage, excellent imaging, accurate tonal balance and extended frequency response. The bass, as you can expect for 300B, is tightly controlled. However, one reservation: with the mostly stock tubes, although microdynamics were reasonably good, I had wished for better macrodynamics (but read on to Tube Rolling/5U4). This also implied rhythm and pace that is not quite of first order.
  • Microphonics/Isolation Despite its size and weight, the unit is prone to microphonics. Make sure it rests on a sturdy platform (mine is unfortunately not). The 6SL7 tube in particular is susceptible. Personally, I don't like these metal Manley legs with rounded tips: they slide on polished surfaces and cannot be as shock absorbent as rubber feet; also, they look like they are joined to the chassis by hardware, which adds resonance-prone weak points. This "industrial design" gets a minus from me. Beauty is only skin-deep, and beauty is in the eyes of the beholder. Why try your best to design a good product and get it compromised by cosmetics?
  • Direct vs Transformer Out Some of the reviewers cited above made a meal out of the superiority of Direct Out; indeed the Manley website recommends it. In my case, I find, as some listeners note, the difference is not huge. Now, in my setting I use long interconnects between the preamp and amp, and that may favor the transformer output. In any case, I'd think this shows the output transformer is of very good quality!
  • Headphone Output I prefer not to use headphones, but I did test it out with my Audio-Technica ATH-AD700, and the sound was excellent.
  • Tube Rolling/6SL7 I have to confess I never used the stock EH 6SL7s. I don't like them (nor the EH 6SN7s, even worse). I have a large stock of old tubes and any one sounds way better (though some may be worse in microphonics than the new Russian tubes). Consider rolling old-stock 6SL7 a necessity! I'd think even a pair of humble JAN Philips should be way superior!

  • Tube Rolling/300B Although my ultimate aim may be to roll in really old WE 300B (not the inferior re-issue WE), here for me the stock EH 300Bs are good enough. In my other 300B amps I have always preferred  Russian 300Bs to almost all other currently manufactured (more airy to me). I did briefly try Cetron (darker) and Golden Dragon (slower), but I preferred the stock EH. Keep in mind a good period of burn-in is necessary for best performance.
  • Tube Rolling/5U4 Every time I shifted to my Shindo front-end I developed the nagging feeling that the Manley sound was just a little too controlled, even polite. As noted above, macrodynamics was too reined-in for my taste, and not impressive enough on my horns. This time around, I decided to swap out the stock EH5U4GB rectifiers for a pair of old-stock Sylvania 5U4GBs. I played my Saint-Saens CD and I was dumbfounded by the difference. Now, that is macabre! The improvement in dynamics and rhythm and pace is so miraculous that I'd consider rolling in better rectifiers a MUST. The sound is simply bigger. I am a little surprised here: my experience with EH's coke-bottled 5U4G has always been positive, but I had never tried the straight-bottled (GT) EH 5U4GB before the Manley. The cheaper 5U4GB should have a slightly higher rating than the 5U4G, but the preamp has 2 rectifiers and won't need the margin. Use of straight-bottled tubes (ditto the 5AR4) though would allow more room for ventilation as the 2 rectifier tubes are close together. Considering how much real estate there is, not finding more room for the rectifiers is regrettable.
Manley vs Shindo Monbrison
  • Design Both use tube rectification (6X4 in Shindo) and tube regulation (6BM8 in Shindo), but the Manley is on a larger scale, necessary due to use of larger and direct-heated tubes. Manley also uses a lot of transistors in regulation, which Shindo eschews. Manley uses only triodes for amplification, whereas Shindo also employs pentodes (I don't know whether they are used as such or triode-strapped in some cases). Of course, the Shindo as a superlative phono section!
  • Parts and Stock Tubes Except for NOS OD3s (cheap) Manley's are current production tubes, whereas Shindo's stock tubes are good NOS. Similarly, Manley uses good modern parts whereas Shindo uses mostly NOS parts (like AB resistors), which are more expensive.
  • Sound The two preamps are very different. At its best (with NOS tubes), the Manley's sound is excellent, but it would not be easy to distinguish it from other high quality modern preamps (despite use of 300B). The Shindo possesses that elusive je ne sais crois quality, and is just more special. And despite the use of vintage parts there is nothing "retro" about its sound either - it is also quiet (a little less so than the Manley) and transparent (but warmer than the Manley) and it conjures a big soundstage (bigger than Manley). Its special appeal is harder to describe, and you may want to read Art Dudley's Stereophile writings on it. The Shindo just sounds big and sinuously full, and it takes you to the venue and goes right to the heart of music. Its dynamic expression and rhythm and pace are superior. A rough analogy: Manley is to panel loudspeakers as Shindo is to horns. At this moment I have to say I prefer the Shindo even if I have spent more time on the Manley to improve the sound (I haven't even rolled the 0D3). Of course, most importantly, the top-flight Shindo phono section is at least as good as any of my reference phonoamps that I use with the Manley (would be nice to try the well reviewed Steelhead one day), and that makes this one-box preamp a formidable rival (and a relative bargain) for whatever I could put together at Manley's end. Keep in mind the Manley is still excellent, just that as an analog man I have always preferred full-function preamps for convenience and integrated sound.

6 comments:

  1. AnonymousJuly 14, 2014

    Hello there,

    thanks a lot for your detailed review!

    I've ordered the Manley 300b preamplifier and I was reading with interest your comments about tube rolling. Do you know if it is possible to swap the rectifier tube for a 274B? I was thinking to Sophia Electric or the 1:1 WE Replica from PSVane.

    Thanks a lot for your attention any advice will be more than welcome :-)

    Have a nice day,

    Ben

    ReplyDelete
  2. Hi Ben, you can surely use the so-called 274B, but their coke-bottle shape means the 2 tubes will be close together, and the area will be quite hot. Make sure you have good ventilation.

    I'll also try some coke-bottle OD3's too. They are cheap on Ebay.

    ReplyDelete
  3. AnonymousJuly 15, 2014

    Hi Dr. John :-),

    thanks a lot for the advice.
    The preamp is on a top shelf so ventilation should not be a problem,
    I'll have a look on ebay in regards to the choke-bottle OD3.
    I'll post some comments as soon as I receive the preamplifier (It should arrive by the end of the month)

    Thanks again for the good review and the adivices :-)

    Have a nice day,

    Ben

    ReplyDelete
  4. AnonymousJuly 21, 2014

    I have the Ming Da MD300APS, using Genelex Golden Lions for the 300Bs and Shugang Golden Treasures for the 6SN7's. It's very nice, tho it can be a little "crackly" until the tubes heat up. I've been thinking of upgrading to the Manley....

    ReplyDelete
  5. Dear Dr. John,

    I remember your great review on EAR 912.....any comparison?

    Thanks
    Ken

    ReplyDelete
  6. Hi Ken, again it is hard for an analog man like me to compare a full function preamp (EAR) with a linestage (Manley). Also the EAR is fully balanced and the Manley is single-ended only.

    If I only compare the single-ended linestage, and this is from memory only, I'd say the Manley is likely just a little sweeter.

    With its exceptionally versatile analg section, and balanced features, the EAR seems much better value.

    ReplyDelete