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Woo Audio WA5 LE



Standard Build Woo Audio 5 LE Headphone Amplifier


In this day of mass produced equipment it is nice to find a small boutique headphone and headphone amplifier company who are sincerely into it. So how does the selection process work? The big question is which amplifier to have these guys make for you, and why?


 I have had tube equipment forever. My first mono amplifier was a gift from my Grandmother, something pulled out of an old early 1960s console unit. In the early 1970s solid state equipment was just starting to be put into use and almost everything had tubes. Everyone wanted the solid state equipment and no one wanted tubes. As children we would collect huge grocery bags of tubes and throw them into the street for the popping sound they made. For the last twenty years there has been a small but ever growing resurgence of interest in tubes because of the warm buttery sound they affect on music.


 The romance of tubes is just that, a simple romance. In the early days you had to turn them on and wait for a while until you heard this faint hum, a turn on the volume knob gave you some little crackles then the music started to flow. To some the view of tubes glowing at night is mesmerizing and adds to the experience of enjoying music. Woo Audio has taken the tube technology into the 21 century and made it reliable, high quality and beautiful. The hum and crackles are gone, what we get is just pure romance, and a signature sound which is the essence of pure music. For some Woo Audio equipment may seem unpolished from a design aspect, for others that clean industrial look minus the gold knobs and chrome is right where they want to be. To me the equipment feels really well made and the simple look fits my style.


 If you do a little research you may find Woo Audio has a nice customer base here at Head-Fi. How did that happen? It occurred the old fashioned way. A small company is careful and builds a hand full of products, offers great customer support and builds a reputation. This may sound cliche but I figure they really did it with one handmade amplifier at a time. This kind of stuff makes you feel right about making an investment in audio equipment. How many companies do you know of offhand where you get a return phone call or e-mail by the next day at the latest, from the owner? I am no expert in this world of headphones but I have an average amount of common sense. Buying one of these amps is a little like buying a car, you have to look at the wiring. Flip a Woo Audio over and remove the bottom plate cover and take a look. Some amps look like they were made by 5 year olds in finger painting class. A Woo Audio amp looks like a piece of hand crafted art. The design is orderly and all the workmanship is first rate. None of this would matter if the design didn’t come from a master too.


So let us guess at why anyone would even want a Woo 5LE in the first place. What does this thing do? What does this thing not do? First off if you have any dream of moving into full range Fostex single driver full size stereo speakers you will want the Woo Audio 5. The LE model does not have speaker binding posts and will not let you plug in electrostatic headphones. If you want to use electrostatic headphones you will want the Woo Audio 5. Single driver full range speakers allow the use of up to 10 watts of power output to drive a highly efficient single driver full range speaker. These have no crossovers and will sometimes use a horn type of enclosure to amplify the bass frequencies. I am into rock and closed back headphones so the LE was the model I chose. I did give Jack at Woo Audio a call and had them custom build a preamp output in case I wanted to use the headphone amplifier as a preamp.


So why would someone get the Woo Audio 5LE and not another companies headphone amplifier? What are the benefits of Woo Audios’ other amps? I had always dreamed of a 300b amp. The 300b tube was in use in one of the first amplifiers ever built. The Western Electric 300b tube is so reliable that they were placed under the Atlantic in the first intercontinental transatlantic telephone system. I had read for years about this magic mid range. Every article kept reiterating about this indefinable 300b X-factor! I had never even heard a 300b amplifier before but these audio reviewers were almost in tears. I had to get a taste of the action. Pure music they said.


My first amplifier built by Woo Audio was a Woo 3. You PayPal them the money, they e-mail you the confirmation and you wait until you get a Fed-X tracking number. The build time is different for each amplifier and they have been exact on the build time twice so far with me. I loved my Woo Audio 3 but wanted more. So what did I get?


A month went by and I read an e-mail that Fed-X had my amplifier at the Fed-X hub. I was able to arrive at work late that morning and showed up to retrieve my two amplifier cases. Woo Audio has now modified their shipping system around special molded foam inserts and uses cardboard boxes. My order was placed at the end of 2008 and they still used wooden crates. Both systems work great. The wood weights more though. Each crate weighed about 40 pounds and had big handles attached to the sides. I threw them in the trunk and off to work I went. On lunch I went home and tried everything out. Upon opening the cases you find all your tubes, one power supply unit, one amplifier unit.


* Two 300B power tubes
* Two 6SN7 driver tubes
* Two 5U4G rectifier tubes


Also a power supply connection cable, and a set of instructions. You will need to supply your own power cord. I ended up using my computer cord for a long time then made some changes. The amp needs time to burn in about 300 hours before sounding the best. Many here are in disbelief of this phenomenon at Head-Fi. The company who builds the product states it as a reality and I feel I could hear a difference. You can only run the amplifier for 8 hour stretches and the amp should not be left alone. My suggestion is just turn it on and enjoy the ride of your life! I have recently re tube the amplifier and feel stuff should just be left to break-in naturally.


Upon my first listening experiences I found the Woo Audio 5 LE to have all the power I could ever use. My reference set of headphones are the 11 year old Sony MDR-CD-870 closed back headphones. I also rotated in my other favorite headphones the AKG-k701 open back headphones. My personal favorite headphones in use with the amplifier are the Flagship Denon AH-D 7000 closed back headphones. A great synergy with the AH-D 7000s seemed to allow me to reach an apex in sound never before obtainable with the Woo Audio 5 LE.


So you are reading this entire page and your question is………..How Does It Sound?


 It generates an alternate place. A place with grand authority. A place you can visit and stay if you want. There is no ear fatigue even after long 4-5 hour listening runs. Just a big place where the sound stage goes off into infinity. A place where all your old CDs and records become something new. Take something as simple as a bell sound. We hear bell sounds all the time. Now the bells have a shape and a size, a texture along with an inner and outer texture and a decay reverberation quality. Sometimes the sounds seem to actually contain a color and contrast. How could that be? Things sound real when they are recorded real sounds. When they are processed sounds that is when stuff gets crazy. Big warm sublime worlds of perfect tone. A place where drums sound like wood and you can almost touch the snare surface. Another sound cliche here, this thing is causing chills down my spine? A source as simple as a woman singing with a guitar sounds natural as you would think it would sound in real life, nothing more nothing less. It is the simple uncolored tone that we need sometimes in music reproduction. How close do things sound? An easy way for me to put it is that the Woo Audio 5 LE makes things sound very close. Got it? Did I use the audiophile word sound stage yet? No? It is beyond that descriptor.


I have no answers for you, I am just this guy with headphones on. I will have to conclude that I really know very little on the subject of headphones. But I do know what sound I like.


 The great thing was the immersion factor. That is the only dam thing we are looking for here. All this talk of musical honesty, of truth. It really does not matter at the end of the day if you were swept away in the tide of somebody’s musical recording. There was some trouble in paradise; I now heard my recordings for what they were and what they were not. Some stuff was thin and some stuff was thick as a mountain. After all these years I never thought one piece of machinery could whittle my record and CD collection down to a small pile. Yes, be careful what you wish for as reality is a double edged sword. The rose colored glasses of audio color are ripped, actually slapped off your head and you hear your collection for what it is, beauty marks and warts in all.


I have always accepted that no matter what we do a set of little headphone speakers cannot match the visceral gut massage of a great set of audio speakers. I still feel that way but there is again the X-factor, the funny little illusion that is created just next to our reality, that place along with the sense of wonderment that keeps me coming back for more.


What do you do to set this thing up? For some it must look like a Dr. Frankenstein tool used for evil. Well, you take it out of the box. The tube sockets are marked on the amp where the tubes go. There are six tubes. I would use a white sport sock around your hands so as to not get oil on the tubes. Variations of glass tube wall temperature due to hand oil pollution diminish tube life. You hook up your turntable RIAA preamp or CD player to the gold platted RCA inputs on the back. The build quality feels equal to the front bumper of a 57 Chevy. Make sure that your headphones are plugged in and the volume knob is all the way left. Make sure the on/off knob is to the left too. Plug it in and you’re off. At night with the lights off there is really something of a show. We are not at the level of the Alaska Aurora Borealis here but considering it is something you are turning on in your living room or bedroom, it’s a show. The 300b tubes {there are two} light up and emit a bright blue glow for ¼ second as everything powers up. There are other types of tube glowing too with the support tubes. The main 300b glow is orange with a faint blue glow going on constantly. There is a slight mechanical feel and sound when the on switch goes on with the power supply unit. Latterly the on and off knob actually has a slight mechanical shake when you turn on the amp! That is just juice flowing though this sucker. It is kind of cool because it reminds you that you are dealing with electrical power here. Electric power has a strange mechanical aspect to it at times.


I had read that the Woo Audio 5LE was primarily excelling in reproduction of the middle range of the audio spectrum. It was unarguably a magic middle range enticing me back every night for a personal meet up. I was very happy with what I had. I could have even lived the remainder of my days just the way things were. But……………………………………But there was more. Somehow the Gods Of Head-Fi had more on their agenda for me. More was to be revealed at a time when I least expected it. In come improvements. The second phase in my learning curve was the use of cables. A huge matter of controversy and rightly so as some times results are noted and sometimes it is a wash. In the business of HI/FI you have two groups. The first group are the down to earthies who just will not believe something that cannot be tested and proved in numbers. The second, lighter group are looking between the numbers to a place in the hinterlands where numbers don’t exist. This group gets high on placebo and would soak their amps in water if they thought it would improve the sound. I found myself in the middle of sorts. I tried some pure silver cables my first day with the Woo and found the sound too treble. I had always looked forward to testing power cords, racks, vibrating and counter vibrating rocks and the other grocery bag of fuzzy logic. Really? How could any of the other “little” stuff make a huge difference in my system? All I can say was I was wrong! I was wrong about the Woo 5LE being middle range in reproduction. With the addition of cords and cables the Woo became a bass monster. Not any average monster, but Frankenstein’s bass monster. Skyscrapers of bass. Not everywhere but a blend into the sound stage right where it was to be in nature. I felt bad for what I had previously thought, I did not know truth!


So what else do you want? Huh? Well, Woo could get creative and put some new finagled USB in the rear end of the thing. They could start to convolute things and make it one of those 24/96 mono/hybrid desk top coffee makers with a milk foamer for the in crowd. They could make it have more than three knobs. Why? It is what it is. Simple. Powerful. Sleek. Sexy. May I remind you this thing has only three knobs.


1} Volume.

2} On/Off.

3} Source.


It performs with anything you throw at it. It will show you if your phonostage is thin. It will show you if the grid going to your house is dirty. At the same time it will allow you to live a musical life. What emotion there is in the experience of the human hearing music. Is there any better headphone amp out there? From what I have heard there seems to be small differences. This is really how I feel. Other amplifiers out there are going to have small differences. In this price range somehow stuff starts to get closer together and not farther apart as you may first think. The difference is like the subtle space between notes or the space and decay between the rhythm, but there is something else that is there, maybe it’s the 300bs, a smoothness, a velvety feeling like touching cloth, a softness that I have come to like and be addicted to. Yes, If I had a chance to do it over again I would.  


So if you get a chance try one out at the next Head-Fi meet near you. Or if you have a gut instinct just place your order like I did.




Equipment Used In This Review

Sony MDR-CD-870 Headphones
AKG k701 Headphones
Denon AH-D 7000 Headphones

VPI Scout Turntable
Clearaudio Aurum Classic Phonograph Cartridge
PS•1 Phono Preamplifier and HC•1b Dual Mono Power Supply by Monolithic
Rega Planet Compact Disk Player
Virtual Dynamics Master Series RCA interconnects
Electra Glide Audio Reference Glide-Reference Standard "Fatboy" Power Cord
Electra Glide Audio Epiphany X2 Power Cord



Pros: Very dynamic, vast soundstage, improvement in mostly all aspects over a WA6

Cons: HD800 can still be picky with certain tubes. But this is not this amp's fault!

    My WA5-LE is by far the most expensive component in my system, but I can see why. The moment I un-packaged this very heavy piece of kit, I could tell I was in for a ride. By size alone it literally screamed quality. Then there is build. Without an industrial bender there is no way any part of the chassis bending at all. I have dealt with flimsy mass market chassis' before. I accidentally sat on my Ah! Njoe Tjoeb 4000 chassis, and had to bend it back in shape in order to screw it back together.

    The amp with stock tubes, is awesome in it's self. I was immediately treated to a sound that was superior my WA6/6GL7 in every way. The sound stage encompassing, the bass more heft, the treble sweeter, perhaps a little too sweet -- we'll get into that later. Also significant was the airy quality that was represented. Anything in the upper midrange was given a little boost, and I am nothing but happy because of this. The HD800s I use have a slightly recessed upper midrange. The boost compliments this unattractive trait nicely. The tubes I used to begin with were your Shuguang-98 300Bs, Shuguang 274B recitifiers, and your 7N7 -> 6SN7 adapters with the early GT style plate 7N7's.

    Now for the not so good news. Out of greed, I figured I could just not do without more sound quality. After twiddling my thumbs for a few days, I decided I needed, more like wanted, some Sophia Princess 300B mesh plates. I put a few more hours on the stock tubes waiting for the Princesses to arrive. Upon delivery, I went back to bed. It was 9:00 in the morning and I was tired!!! After that I got over being groggy, and then plugged the Sophia's in for my first listen. Then came the bad news. I did not really appreciate these new tubes. Compared to the Shuguangs before, the Sophia's seemed hollow in the upper midrange. Maybe you could call them more neutral, but this is the very reason I liked the Shuguangs, and at this point preferred them more.

    Strongly considering to send them back, I had an idea. I had other 7N7's, the newer GTB style, so why not give them a shot. It was a good thing I did, otherwise I would have sent back an awesome pair of tubes! That's right, with the newer GTB plate 7N7's the sound was, well, awesome. Instrument separation was the biggest improvement. What was slightly convoluted on the Shuguangs, was more detailed because the inner detail had increased. Bass was slightly more controlled, and while almost everything else bettered the Shuguangs, I noticed the upper midrange was slightly more recessed than the Shuguangs, but only slightly so. And as mentioned above, the Shuguangs were sweeter and had, slightly more treble detail, which I prefer. This sweetness however was sibilant at times, so I could do without it.

Bendix 6106:

    I never figured different rectifier tubes offered any change is sound quality up until now. In my WA6, I started with the default NOS Russian. Then I tried the Valve Art 274B, no difference. I kept this one in a while, considering it was a 274B and dirt cheap if I ever needed more. The problem I had was the tube arcing, looked just like a lightning bolt. This could not have been a good thing, so I snagged a NOS Mullard 5AR4 off of ebay. I enjoyed this for a while, but mistakenly became neurotic, and bought a Bendix 6106. I figured, "designed for missiles," this tube will never break or arc. And so, it remained in my WA6 until I bought this WA5-LE. I just had a brief foray into this amp with Bendix 6106 though. These came at about at about 9:00AM too, and you guessed it: ANOTHER NAP! After this, I plopped the new rectifiers in and found a slight increase in treble and, bass. I wasn't too fond of the bass after about two hours as it was somewhat flabby. Nevertheless I was somewhat pleased for the rest of the day.

    As I awoke, and did my daily routines, I went in for a another listening session. The WA5-LE was turned on, I let it sit for 5 minutes, and then I played a few tunes. What I did not expect was how displeasing this combo sounded this day. A reviewer on another site, mentioned he thought these tubes sounded "too hot." I would not say, hot, but I felt it sounded like the soundstage was struggling to come out, and that bass was even flabbier. It also sounded very grainy. Not to mention even though there was more treble, it sounded very hollow.

    Disappointed, I did a swap back to the stock Shuguang 274B. Everything was alright again. After another double swap, I concluded these tubes weren't for me. I boxed these guys up, and sent them back. A shame really... I believe shipsupt asked if the B+ voltages are the reason. I don't know. They could be. All I know is there was an undeniable difference, although sometimes subtle, between the 2.

    It goes to show. Don't dismiss unknowns as placebo unless you've actually given them a try. From now on, I intend to stick to my Shuguangs, until I can afford a relatively cheap matched pair of rectifiers. I intend on waiting a while though, I just bought a new WA5-LE!

Full Music 6SN7:

    I just received a pair of Full Music 6SN7. My first impressions are: More treble, yay! It's a fair bit drier though, does not seem as lush and meaty as the 7N7's. It is however a bit more detailed with the slightly more treble. This kind of like taking a step back into using the Shuguang 300B-98. I will keep these in for a day, and then switch back to the 7N7's to compare.

    Listening further today, songs with electronic high hats have more of a tizz to them. In fact most tracks have more sizzle to them. Songs with natural echo are more preserved. I also hear things never heard before, but that was the case with both the other 7N7's. Things are starting to feel a bit edgy, bright and spitty now, however, so I'm still going to wait a day, but I expect the 7N7's to come back on top.

    Okay, I've waited a day. After listening to the Fullmusic for an hour this morning to burn their sound signature into my brain, I have now gone back to my 7N7's. It is confirmed. I like the 7N7's better. I tried explaining this before, but if I had to describe the 7N7 tubes in comparsion, in a few words, I'd say,"Crunchy, meaty, and extended." In fact almost everything seems better except for slightly less treble, which I know I've gotta get over!
    Another thing I will say is, these tubes make the WA5-LE dead silent on both the HIGH Impedance and LOW Impedance jacks. With my previous 7N7's the LOW jack was dead silent upon arrival, but the HIGH impedance jack had a fair bit of hiss, and hum. Mike from Woo said there is no need to use the HIGH jack unless you need more volume. The HIGH Jack should be used for headphones with low sensitivity like the Abyss planars. Therefore up until about a week ago, I had been using the LOW setting since a few days after receiving the amp, but decided to try out the HIGH impedance jack just for kicks. Now I know this is very likely placebo, Mike already said there is no need, but I kinda think the HIGH output gives a beefier sound! Granted there is still a very mild, almost indistinguishable buzz and hiss from the 7N7's, most of the hum and buzz has gone away, but during any music it is inaudible. Apparently amp or tube break-in may not be placebo either.


    I just received a Tripplite IS250 Isolation Transformer in hopes that the left over noise from my 7N7's would go away. I cannot say that I notice any difference between the before and after. I also bought it special order from a store and can't return it. I'm considering opening it up and removing the output ground to neutral to see if there is any difference.

Woo Audio WA5 LE

Technical Specifications: * Two 300B [PDF] power tubes * Two 6SN7 driver tubes * Two 5U4G rectifier tubes * Voltage: AC 110/220V, 50/60 Hz * External dimension (each): 8½(H), 9"(W), 17"(D) * Weight: Amp Unit: 35 lbs, Power Supply Unit: 40 lbs Headphone Amplifier Specifications: * Headphones impedance : 8-800 Ohms * Frequency response: 10 Hz—60 KHz, -2dB * Power output >= 1.5 watt * Signal/Noise: >= 95 dB * THD: <= 0.08%, 1Khz * Standard Features: Independent headphone * High-end output transformer design * Point-to-Point wiring * One 1/4" headphone jack for high impedance output, and * One 1/4" for low impedance * Four pairs of gold-plate RCA inputs * Selectable input switch

Model Name/TypeMPNEAN/UPC

Related Media/Links:


WA5-LE Upgrade Announced (Sep. 3, 2015)



Pre-release Pics:




Pre-release Specs:




Hull, Scot. "Review: Woo Audio WA5LE v2 vacuum tube headphone amplifier." Part-Time Audiophile. September 27, 2015 Web.


    28 Sep. 2015. <http://parttimeaudiophile.com/2015/09/27/review-woo-audio-wa5le-v2-vacuum-tube-headphone-amplifier/>


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