Review: Manley Laboratories Neo-Classic 300B preamp Tube preamp

Category: Preamps

My Troublesome Love Affair with a Manley Neo-Classic 300B preamp...but we live happily ever after..well..short of!

I have always been fascinated by 300B tube based gears for quite some time now, mostly because of the legend of the 300B tube itself and also the rave from other users and reviewers. Owning a pair of Avalon Acoustic Opus Ceramique speakers with 87 db sensitivity prevents me from even thinking of trying 300B tube amps in my system until one day, during an net-surfing session, i came across a link from in which a really short thread mentioned a Manley Neo-Classic preamp that uses a pair of 300B tubes in it driver/output stage. I was immediately struck by the idea of trying this preamp in my system.

Perfect ! If i cant have 300B tube amps, then why not a 300B tube preamp ???? I started to search for more information on this preamp, and i have to admit that i was a little disappointed because there was just too few information could be found. Given that the Manley 300B pre got an award from Image Hi FI from Germany, except for the info and two reviews i found in Manley Labs website (one from the Inner Ear Report, and the other from Home Theatre High Fidelity), there were only two or three posts on some audio website which were started a few years back. Honestly, beside the idea of auditioning the preamp for myself, i tend to like reading feedbacks from actual users than reading reviews from "professional reviewers" because i have had bad experience with gears that got great/rave reviews but presented many problems which never got mentioned in reviews (i.e I went through 3 (yes, three) new Aesthetix Rhea phonostages which all went dead on one channel in just 2 weeks, and the problem was not tube-related).

With that in mind, i made an attempt to contact some of the authors of those posts asking for their experience with the Manley 300B preamp. Luckily, some of them replied to me and said that they love that preamp, and with the right tube selection to improve the frequency extremes (i.e AVVT or TJ 300Bs), it is a keeper. A few days later, I decided to call Kevin Deal at Upscale audio asking for a demo and he was super nice to let me borrow his demo to try it in-home with my system !!

Being only 1.5 hr away from Upscale Audio, I was able to make the trip and later that evening, a BEAUTIFUL, unique looking Manley Neo-Classic 300B preamp already graced the center of my system !

To be honest, i was never much interested in Manley gears' look. I think they look more like studio gear rather than audiophile stuff. Take for an example, I own a Manley Steelhead because of its functionalities, its sound and reliability but not its look (To me, look is also very important, though not much as how it sounds, but nonetheless a big buying-decision factor), BUT something is sooo special about the look of this preamp that i love so much !! I cant explain just looks so classic, so elegant to me (in a retro way, ofcourse).

Upon the first listening, there was an undeniable sweetness but natural quality of the sound through this preamp which i did not have with the Air Tight ATC-3 preamp i owned at that time. The Air Tight ($3,300 retail )is, to me, a very good preamp, really quiet, very transparent, extremely dynamic and excels at frequency extremes but could be a little bright on some discs when driving the BAT VK-150SE and Avalon Acoustic Opus Ceramique speakers (which are also very dynamic, quiet, and great at frequency extremes). Compared to the Air Tight, the Manley 300B preamp was softer in the hi frequencies, but it has a more natural and beautiful midrange that i really like, though the bass was not as tight as the Air Tight. Also, with the Manley 300B preamp in the system, the soundstage was deep, deeper, and the most important improvement was the instrument layers of orchestra which , again, I could not have with the Air Tight. With the Manley 300B preamp, i can hear different instruments placed in different spaces of the soundstage more clearly in LPs like The Firebird - Stravinsky/Antal Dorati, Song of Nightingale - Stravinsky/Fritz Reiner/, Lieutenant Kije (RCA, Mercury Living), Mahler's 5th & 7th Symphonies /Thomas Tilson & SF symphony orchestra.

After a few days of listening and carefully considering the trade-offs between the Air Tight and Manley, I decided to sell the Air Tight and ordered a new Manley 300B preamp to fulfill my lust for having a 300B -sound in my system.

One thing i did not like about the stock Manley 300B pre was its stepped volume control. Personally, i found it difficult to dial in the perfect loudness with stepped volume control, so I emailed EveAnna Manley at Manley Labs and asked her if there was any way they can build my unit with a smooth volume control. She, very promptly, replied that they could, and the good new was that they had a brand new 300b pre in stock but it would take a few days to replace the volume control because the factory was closed for Winter Holidays (from Dec 23rd to Jan 4th, i think).

Being as compulsive and obsessive as i am, i called Kevin Deal at Upscale Audio (The best Manley Labs dealer) to fill out my special order for the Manley 300B preamp, and also emailed EveAnna again, urging her to push her guys at the factory to work on my unit the first thing in the morning of the day they come back from Winter break because I REALLY wanted it and also i knew they would be very busy getting prepared for CES, which was like a week later .

After all that was done, I tried to settle myself down with the though of having that 300B preamp sometime next week, and that was not easy for me at all *grin* ( I HATE waiting !!!)

The next day, in the early evening, Kevin Deal called me up on my cell and said: Hey, your amp is ready. I was about to curse at him for playing with me in such a way then I realized the urgency and excitement in his voice, and then i knew he was NOT joking!!!!!

Perhaps she was able to understand my obsessively desperation for the wait, the wonderful EveAnna Manley somehow, someway got my unit ready in just ONE day during the factory Winter Break and she personally dropped it off at Kevin's place for me. Thanks A LOT, Kevin, and guys ROCK!

The next morning, I got it!!!

As i wished, the volume was now the smooth turning type just as i wanted, and I got that preamp, no.. MY preamp installed in my system in less than 15min...all up and running.

The music was almost as gorgeous as i remembered when listen to the demo..since this one was a brand new it might take some time to sound its best. Then it was time for me to check out other functions of this preamp like headphones, direct and transformer output modes.

Even though i do not listen to headphones a lot, but i do own a pair of Sennheiser 650HD, so i took them out to try the Manley 300B pre headphone outputs. After putting the cans on and switch the output mode to "Headphone", to my surprise and disappointment, I heard a pretty loud buzz on top of the music playing!!! But wait!!! The buzz was apparently loud but it seemed to be coming from...kinda far my speakers!!! Pulling the headphones was confirmed that the buzz was coming out from my speakers, not in the headphones!!! Weird. What was going on here..why was the buzz coming from the speakers while the 300B pre supposed to mute the output??? Grounding problem? Nah...Hm...Why none of the other users or reviewers mentioned this ??? Was it just because of my own system??

After a few hours trying to play around with grounding, and switching the preamp in different modes, i was pretty sure that something not quite "right" of this unit. I called Kevin Deal and reported this issue, and he gave me some suggestions like playing more with grounding via using cheater plugs (2 to 3 pins to float the amp's grouding and grounded the preamp only). I rushed to a Lowes near buy to get those cheater plugs before it closed and install 'em in my system. A good hour later and all failed, i decided to let Kevin know and also emailed Manley Labs to report this issue. Kevin was very nice, patient and supportive to my problem and assured me that i'd be well taken care off.

That night i went to sleep, restlessly.

Early the next morning, while i was still sleeping, Kevin Deal called me on my cell and said something like "...she wanna come to your place and help you out with the buzz problem...blah..blah.."..and i was like...huh?? what?? while trying to wipe the sleep off my eyes. He laughed and said: You havent checked your email right? it right now and let me know." I reached down under my bed for my Mac laptop and check my emails real quick. It turned out that EveAnna, the wonderful EveAnnna Manley, owner of the multi-million dollar Manley Labs would like to come to My place, listening to MY system and trouble-shoot my buzz problem with the newly acquired 300B preamp !!!! Well would you feel IF Michael Fremer offered to come to YOUR place to help you setting up your turntable?? I felt just like that: deeply appreciated, special and well taken cared of..just as Kevin Deal from Upscale Audio promised.

Quickly checking my schedule, I found out that i had reheasal later that day, so I called EveAnna up (She left me her private cell number in the email), hoping she would be kind enough to reschedule it for me...and she gladly agreed!!!! How nice of her!

The day after, she came as promised, on New Year day, to help me!!!

In person, EveAnna looked really young ..much younger than in the pictures i saw at CES, or Manley website..with a warm, easy going, friendly personality that made me appreciated her much more than just because of what she was trying to help me with.

After a quick check on my system grounding and cables, she decided that there might be a defect with my 300B pre and said that she might have to take it with her back to the factory to perform more tests on it. But before she did that, EveAnna wanted to take a look inside the 300B pre to see if there was something obviously wrong that she could quick-fix for me since she did not want to leave me "with no tunes during New Year Day".

Upon popping off the preamp's bottom and did a few measurements, EveAnna suspected a "designing flaw" that might have been escaping everyone else' s eyes and ears, including Manley Labs' engineers and alike. A quick call to one of her guys' and a minute later, we had a schematic of the 300B pre sent to my email address and then printed out. After looking at the schematic and a quick chat with that person ( I did not have the privilege to learn his name), EveAnna found the problem and with her tools she bought with her, it was reversed in a matter of few minutes.

Putting everything back and reinstalling the preamp in my system...and when we turned the switch on... voila`..!!! the buzz was GONE !!!

I was so impressed with EveAnna 's skill, given that now she mainly deals with other aspects of the company rather than technical issues...but this clearly shows that she does get involves deeply with the whole company in every levels !!!

The problem was at the switch that selected between "HEADPHONE" and "LINE OUTPUT" modes: In "HEADPHONE" mode, instead of muting the OUTPUT by disconnecting it from the OUTPUT STAGE and then shorting both legs of the RCA female jack to Ground (Pretty much like shorting the input of your preamp to prevent any interference), the "old design" left this OUTPUT RCA jack open, hence, it was vulnerable to any noise and will transmit this noise to the power amps. In my case...this noise is a different systems, this noise could be different types or, if you are lucky, no noise at all (this might be the reason why other users and/or reviewers never reported any issue).

Still, no matter what your experience with this preamp is, I still think it is a good idea to check with Manley Labs on this modification.

Now..the preamp and my whole system is very quiet, both in HEADPHONE and LINE OUTPUT modes, and it sounds even better without all the noise and stuff.

One more thing that is still lingering in my thoughts, which i really want to hear from other users out there (OR if you ever read this, EveAnna, I'd greatly appreciate if you could explain to me WHY): Are there really ANY differences in the sound of the LINE OUTPUT in DIRECT or TRANSFORMER modes, because i heard NONE!!!

One of the reviewers (Jason Victor Serinus from Home Theatre High Fidelity - 2004) claimed that the sonic difference in LINE OUTPUT between DIRECT and TRANSFORMER modes was of "major differences".

I CANNOT hear any differences at all. Is this just me? How about any other users out there? Are you able to hear any difference at all?

Given that the Direct mode should be use with amps and speakers, and Transformer Mode should be used with headphones, but i cant refrain myself from trying both of these to see if there's any differences sonically in different modes.

It is very easy to tell the differences in Headphone mode when switching back and forth between Hi Z and Low Z for headphones impedances, but for me, I cannot tell the difference between Direct and Transformer mode through LINE OUTPUT. In Transformer mode, the sound should be difference versus Direct Mode due to the coloration of the transformers used, but my ears detect none. Using my rusty schematic reading skill on the Manley 300B pre 's schematic that EveAnna left for me, I traced the signal through different modes and here is what i found out:

1. In HEADPHONE mode, the transformers must be used (obviously), and upon switching between Hi Z and Low Z , these transformer output windings are connected to each other in either Series or Parallel pattern. Hence, the difference in sound results.

2. In LINE OUTPUT: Here, we have an option to use or NOT to use the transformers (hence: DIRECT or TRANSFORMER modes)

2a. With Direct Mode (NO transformers): The output is coming straight from the 300B it supposed to be purest, uncolored.

2b. With Transformers: In this mode, the transformer output windings are connected to each other in Parallel pattern in LOW Z position. On the other hand, in HI Z position (300-4000 Ohms), one of these two windings is switched out !!! (vs. in Series if in Headphone mode)

Is this the reason why the sonic difference is too small that I cannot hear vs the much more audible difference in HEADPHONE mode?

Is it because of the two transformer output windings in parallel pattern does not color the sound that much, so there is NO audible effect in Transformer Mode compared to Direct Mode?

Why, in HEADPHONE mode, both of the transformer output windings are used (either in series or parallel) in HI Z and LOW Z, BUT in LINE OUTPUT with Transformers, these windings are only used in either Parallel (LOW Z) or one of them is switched out Series (HI Z) ????

If anyone can explain this for me and the benefit of this design, I'd greatly appreciate it.

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Great review, and very nice to hear of such good and quality service. That together with their products explain their longevity. One minor point. Lieutenant Kije is by Prokofiev.
I have the good fortune to own a pair of Custom Manley Monoblocks(over 200 watts in triode) and have dealt with the fine people at the Chino facility and can report similar attention and support. Manley Rules!
Nice review Jaytea...thanks for the info. It's always great to hear about great service and support these days...hats off to Manley Labs.

You have a very nice system!

Uru975: Thanks for the correction... :)
1967: Glad that you had great experience with them to. Those manufacturers deserve loyal supports.
Dave: Thanx for the kind words. I just got a pair of Sophia 300B princess mesh plate to try out..out of the box, they sounded more extended in frequency extremes and quieter compared to the stock tubes...unfortunately, one channel is louder than the other one...swapped the tubes and the sound changed. I called Sophia Electric and they are overnight-ing me a replacement pair tomorrow (Good people too !) Hopefully the new pair will work fine..i kinda like the sound of Sophia Electric Princess already!