More Sonic Goodness from Woo Audio - 300B Monoblocks!

I know, I know. Woo Audio has been getting a lot of coverage here on Head-Fi lately. But to me that is a good thing. I think most people like to share the pleasure that their love of music brings to them...more than they like to complain about things. Though there is certainly enough of the latter going on around here! I am including pics but be advised, I was only using a Canon Powershot A520 (not a DSLR) and the photographer isn't all that great.

In the Spring of this year I developed an interest in high quality audio through headphone listening. That is what lead me to Head-Fi. I started out with a Darkvoice 332 tube amp and a pair of AKG K701s, using a Denon DVD 3910 as a source. That was in late April. I recycled a Lovan rack that I bought several years ago and here is what I had:



I absolutely loved the sound of this simple setup. The Darkvoice amp effortlessly drove the K701s and after a little bit of tube rolling I was very happy with the sound. But in a few short weeks I was thinking about expanding my setup and decided that I did not want a source switchbox to connect multiple sources to the Darkvoice.

Enter Woo Audio and the WA2. Jack was terrific to work with and helped me to make an informed decision. Within two weeks the Darkvoice 332 was replaced with the WA2.



Now I had the basis for a system that I could build on. I took the Tung-Sol 5998 power tube upgrade and replaced the remaining stock tubes with NOS Tung-Sol 6X4 and Amperex 6DJ8 Orange Globe drive tubes. This was a considerable step up in sound quality from the Darkvoice 332 ,which I still believe is a fine headphone amp. The build quality of the WA2, with its tank-like construction, is second to none as far I am concerned.

At the time I was wrestling with the decision to buy the WA2 I kicked around the thought of just cutting to the chase and buying a WA5. I have to admit that I was very much seduced by the thought. But in the end I had a plan and wanted to stick to it. At that time I expected to get a pair of monoblock tube amps to drive my speaker rig. I was thinking of buying amps from China as a cost-saving exercise. But as time passed I became a little worried at the prospect, especially where after-the-sale support is concerned. In the meantime, I contacted Jack at Woo Audio and told him how thrilled I was with the performance of my WA2. I also suggested that it would really be great if I could persuade him to custom build a pair of monoblock amps for me based on the 300B.

The following morning I received a reply from Jack informing me that he can custom-build a pair of amps for me. So I gave him some information he needed and waited to hear back on the basic design and the price. Within a few days I recevied the following note:

Jack even offered to send the WA5 demo unit to me for evaluation. I already knew what I was going to do so I didn't need to demo the WA5, but I appreciated the offer. The cost of the monoblocks was about the same as the WA5, which was fine with me. We worked out the payment terms and I sent Jack an initial deposit of $1,000 to get the project started. Within a week Jack sent the designs to me for review and approval. The only change I requested was that he put the power switch on the front panel for convenience. Once the designs were approved the waiting began. It was a little over a two month wait, which was really fine. Jack was very up-front about the amount of time that would be needed to build and test the amps and then get them delivered to me. During the time my build was underway I know that Jack was tinkering with Blackgate and V-Caps because other customers were asking him about them. He offered the V-Cap coupling capacitor upgrade to me but made no mention of the Blackgates, so I asked him about them. He said that to install Blackgates he would have to rebuild the power section in both amps, while the V-Caps were relatively simple installs. I'm very certain that if I were to press on the Blackgates that Jack would have offered to do it for me. But I decided that I did not want to endure a lengthy delivery delay. I was already waiting two months and was anxious to get my hands and ears on these amps. So I asked Jack to do the V-Cap upgrade and told him that I would forego the Blackgates. A few days ago two wooden crates arrived:



These puppies were well packed and quite secure. I went to the basement to get my cordless drill so I could remove the covers, and inside each crate was a bundle of audio goodness:



Once this project was started, I knew I needed to do something about my audio rack, and bought a Salamander Designs Archetype 5.0. I had a few concerns about its rigidity, but after I completed the assembly it became clear that my concerns were not well founded.

I installed the tubes and then placed the amps in my rack and cabled them up. The power cords are Green Dragons courtesy of Moon Audio. I have some NOS 6SN7 on hand, a variety of Sylvania and RCA tubes. And I fully intend to replace the stock Chinese made 300B tubes with new stock Western Electric 300Bs after I put a few hundred hours or so on the amps with the stock tubes.



Here is a picture of the entire rack, with my Rega P7 turntable and Denon DVD-3910 universal player.



For speakers I am using a five year old pair of Klipsch Reference 5 floor standing speakers. They are high efficiency (94db @ 1w/m if I recall). They sound very good, but I have plans to replace them, probably with Omega Super or Max Hemp single drivers; I am still looking into speakers. My new monoblocks can drive the Klipsches to ear bleeding levels and the sound never breaks up or distorts. All of that out of a pair of 10 watt amps. The sound coming from my rig is damned good. I was listening to Bjork - Debut a few moments ago and the presentation had punch and presence. Channel seperation is superb and the soundstage is wide and enveloping. Earlier this morning I was listening to Cannonball Adderly - Somethin' Else, and was struck by the rich mids and nuanced, well articulated highs. Right now I am listening to Jeff Beck - Wired, and it sounds so good I am having trouble concentrating on this post. In fact, I'll be back in a few moments.....Jeff Beck is calling and I can't resist. Yes, after that experience I think I can be happy with the Klipsches until I can settle the question on what to replace them with. Later today I will spend time taking in some classical music on this setup.

This is also something of a "Head-Fi appreciation" thread as well. This is truly a terrific community of people who are passionate about audio. We may have spirited debates from time to time on equipment and approaches to this hobby, but I think that most people here understand that it's all about the music and there is room here for everyone -- regardless of setup or budget. Becoming a contributing Head-Fi member was one of the easiest decisions I ever made.

Some specific thanks are in order: Jack Wu (naturally) who not only builds visually and sonically stunning amps and stands firmly behind them, but has also become a trusted friend and advisor. I would also like to thank Jamato8, who was always more than happy to advise me about tubes -- even when I really didn't want to discuss them. All kidding aside, his insights into tubes were very instructional and helped to narrow the field as I tried to select tubes from what seemed to be an endless array of options. And finally I would like to thank the numerous people who posted about their experiences with the WA5, most notably Stax-i-nox and Tyrion. Your glowing remarks and praise of the WA5 greatly influenced my decision to move forward.

Note to the MODS: Feel free to move this post to another area. I wasn't sure quite were to put it, but felt it would probably be of the greatest interest to people who hang out on the amp forum.

--Jerome

It's great sounding, too.

--Jerome

I think the choice will depend on your goals. Mike wanted a high quality amp that could drive his K1000s and Sennheisers equally well, and function as a great speaker amp too. As he said, the WA5 seemed tailor made to his needs.

After getting the Darkvoice 332 and then deciding to move on to a better system, I knew that I wanted a seperate preamp that drove a pair of monoblocks. Having monoblock amps has been a long-time desire of mine but I never seemed to get around to planning and more importantly budgeting for it. But this time I was really determined to get it done. I'm pushing 50 and decided that there was no time like the present.

Just keep in mind that if you go with monoblocks that you are going to need a good quality preamp if you don't already have one. My WA2 is really terrific, but it added an additional $1,300 to the tab when you take into account all of the tube rolling I did (and I'm not done with that yet on the WA2, as I am thinking about a pair of Siemens or even Telefunken CCa drive tubes ($$$). But not until I buy new speakers and a pair of WE 300Bs.

Still, if I had a WA5 instead of my WA2 and WA-MB300Bs I am absolutely positive that I would be just as happy and I don't need to hear the WA5 to know that. To me it comes down to the trust and confidence that I have in the product's creator that tells me most of the important things that I need to know.

--Jerome

Dang!

--Jerome

Here's something important that I learned today about 300B tubes. They throw off a LOT of heat. After listening to the amps for a few hours I wanted to double check the shelf spacing to make sure there was ample ventilation. The tops of the tubes were not hot, but the bottom of the shelf above the amps was hot enough to fry a hamburger on.

The 5998's in my WA2, by comparison are also large tubes but do not generate very much excess heat. The shelf bottom above my WA2 was not even warm to the touch. So I adjusted the shelves in the rack to leave about 2" of space between the top of the 5998's in my WA2 and the bottom of the shelf above it, and then raised the shelf above the monoblocks by about 3". This doubled the space above the 300B tubes. After more listening, that shelf is much cooler now.

--Jerome