[ooheadsoo]

You can see the outside of the amp here: http://mysite.verizon.net/jack_zhiwu/customized1.html

I'm listening to it now. As a preamp, it's got lots of gain for my tastes, no quibbles at all in that department. In fact, per my tastes, the lowest volume setting is too high. As a headphone amp, my max listening position so far for a very loud listening session is around 12 oclock with classical music which is usually mixed at a lower overall gain than is pop music. Other people may need to turn it up higher, depending on their tastes.

First thing I noticed? Where was the bass with my passive preamp?? I had to readjust my subwoofer's settings to get it to mesh well with my speakers again. From what I remember, my main complaint with my passive preamp was a cold midrange. Well, I don't feel that any more. I don't think the midrange is overly warm, either. Tube roll off? Haven't noticed any yet. Highs seem as extended as ever. No problems with violin solos so far, and I'm listening to some Cyrus Chestnut right now to see what I can make of his right hand tinkling.

The little bubble wrap thing is a tube I forgot to take out before taking the pictures, and I have an Alps stepped attenuator installed instead of the normal pot.

 

[agile_one]

Very pretty amplifier, ooheadsoo, congrats, and compliments to Mr Woo.

A few questions, if you don't mind ...

- what tubes does it use? if 12ax7 in pre section, you could tone down the gain by rolling in a 12au7

- ball park price?

- how was Woo audio to deal with?

Thanks, and great picture and comments - very helpful for all.

 

[ooheadsoo]

I don't know much about tubes, but the small one is a Sovtec 6922 and the big one is a GE JAN 6AS7GA tube.

Edit (whoops, forgot to answer your other questions)

The case was purchased by myself and shipped directly to him, so no extraneous costs there. Preamp output comes standard, so no extra charge there either. In general, he charges in the VERY ROUGH ballpark figure of $10-20 per extra pair of rca jacks, so you can work it out from there. I've got 4 inputs, 2 outputs, and a tape out.

How was it dealing with Woo? Suffice to say we communicated practically daily about the amp and traded at least 40 emails. He never took longer than a day to answer.

 

[Edwood]

Woah. Is the tranformer in a tin can?

-Ed

 

[usc goose]

i dig the alien retro look.

 

[ooheadsoo]

Power transformer, yes, tin can

Actually stainless steel can

It's an OTL design.

 

[some1x]

Nice chassis! Makes me jealous that I didn't get a custom aluminum one for mine (can't wait for it to arrive next week)

How do they sound with your HD600s?

 

[ooheadsoo]

Only listened to it for a little while on my 600's because I'm listening to speakers more these days. The one thing I have to say about it is that before, with my meta42, my speakers were more transparent sounding than my headphones. The only advantages that the headphones had were a more phase coherent presentation and tighter bass. Now, I think the headphones are more transparent than my speakers in most ways. I'll have to listen more to be certain.

What's for sure though, is that headphone soundstage doesn't compare very well to speaker sound stage

There are times where when listening to headphones I'll think, "Wow, that came out of left field!," and be impressed with the soundstage of headphones, but the out of head experience of speakers...I haven't experienced them with headphones yet, not even AKG K-1000's

 

[ooheadsoo]

Well, I think that this preamp has done what I hoped it would do to my system. Most noticeably, I don't remember which track on my only Cyrus Chestnut cd it was, but with my passive preamp, there was a part where the high notes just fell flat and the harmonics were missing. After listening to the whole Cyrus Chestnut cd now, I didn't hear any of that in any track. It sounded great. I'm having a hard time saying that the midrange is warm. My speakers have a very cold midrange and it was a major beef of mine with these speakers. However, I can say that I no longer feel that the midrange is objectionably cold. My speakers are also very detailed. I don't feel that any detail has been taken away by this tube preamp. If anything, there are a few things that I didn't notice in recordings previously with my passive preamp and I'd like to go back and confirm that I wasn't imagining things. Some things in the background sounded like it was synced differently than I was used to it sounding.

My one remaining problem is a hum coming from (I think) my power amp. Time to try a cheater plug, I guess...I can hear the hum coming from my right speaker when it's quiet.

 

[HiGHFLYiN9]

Sweet! If anyone was holding back because of the looks of the Woo Audio, these should be the pics to change their minds. Too bad the holes look a little big for the torroid and the smaller tube otherwise it would have been perfection.

 

[whatIsInside]

So much thanks!

This is going to be an exciting topic.
Woo

 

[Hajime]

I really liked the sound of this amplifier when I had it in my system. I think it is a great bargain for what Mr. Woo charges.

 

[ooheadsoo]

The tubes and tin for the transformer actually extend from the bottom of the amp, so there should some breathing room for them. It was done this way to prevent screws and bolts in the top of the amp. The top of the case is what you remove to access the innards. The only true cosmetic problem with the amp is that the marks for the source selector switch are not in a perfect semi circle. He must have slipped when milling the little dimple out. No going back once the drill's begun...

Also, the source selector switch uses a shaft that extends to the back of the amp so that there don't need to be wires running from the inputs to the switch (thanks Woo) and the shaft's connection to the switch is a bit loose. I'll see what I can do to tighten it up, if it's not too much of a hassle...that is if I can stop listening to music.

 

[Sean H]

Very nice! Congrats! Looking forward to hearing more about this amp too.

 

[gsferrari]

Now I cant wait for the amp to arrive !!!

Mr. Woo is sending me one the amp that was used at the recent Chicago meet...should be a blast if what Hajime has been saying is even half true