[jamato8]

I think with more time the bass will get better. The Black Gates add even more speed (this is really less smearing though there is little with the 3) and the bass has more impact. I would let the 3 break-in for 150 or 200 hours and see how you like it at that time.

Paralleling the 6DJ8 takes out the preamp function of the amp so it is just a headphone amp now and is not used as a preamp at all.

On the schematic I will have to look everything over. I have the flu right now so I do not have the drive to get to that.

John

 

[HiGHFLYiN9]

I've felt the same way that the bass is a little on the weak side with the woo, however it seems to be getting more punchy as I go. Bypassing the input caps seemed to help.

 

[jamato8]

Since this is an OTL amp the output caps, as with anything in the signal path, are very important. There needs to be enough capacitance to get the curve down in the good bass region. Too little capacitance and the frequency response is all messed up. At 440uF there should be enough. After the BG's the bass tightened up and seems to go deeper and on heavy bass recordings with my HD650's, you really get some impact; enough that I do not miss my speakers. I also added the Solen Fast Caps with bypass (.1 or .01. if this is not done the Solen can add a splashy white underlying sound) to the B+ of the 6080/5998 and the B+ of the 6DJ8, which adds up to a very "tuneful" bass. Sometimes bass can seem deeper on certain amps but that is often due to distortion and lack of the lower bass control. Tighten up the bass and at first it doesn't seem as deep and then as you listen you realize that the notes can be distinguished.

John

 

[spiritman]

And then mod it! How can I get the drawings/parts list? I can make one but not buy/mod one. HELP!!!! JOHN!!!!

 

[HiGHFLYiN9]

Oh that's an easy one spiritman, just buy the Woo and when money permits pick up the upgrades a little later down the road.

 

[jamato8]

I put in a 7236 and for those who wanted more bass, this is the way to go. The amp goes deeper and the bass is taught and solid. I am also using some 6BZ7 tubes for the drivers. The combination is very detailed and I can feel the bass in my shoulders.

John

 

[spiritman]

How can I get the drawings/parts list?

 

[jamato8]

I don't think the manufacturer of the Woo 3 would give you a list as they sell the whole unit. I would have to go through and make up a list and do a schematic of the thing. I don't have the time right now. I wouldn't want it in anything but the case it comes in. It would be hard to duplicate such a nice package but then diy can have interesting outcomes.

All it really is, is a driver with a cathode follower, which is pretty common and I know there are schematics on line.

John

 

[spiritman]

Yes the case!! It rock's! I was into your mods on the orig. design. All you did, ie caps,wire,etc. If you ever get the time. And want your little one to have little ones. Let me know! OK?

 

[jamato8]

I have not touched the 3 now for a couple of weeks while working on my portable dac and general portable setup. This gives the time needed for the amp to settle in and the caps to really form (Black Gates in the signal path).

I have to say the beautiful musical landscape has only gotten better. There is an effortless presentation to the sound. Bass is dynamic and tight yet natural as is the rest of the frequency spectrum. I really enjoy my speaker system but I feel little loss when using the Woo 3 and the HD650's with my silver cable.

The tubes I have settled on for now are a Tungsol 7236 power tube and 6BZ7 General Electric driver tubes. I installed some Vampire OFC flash gold plated RCA's a while back and all high purity silver signal wire with teflon tubing. For me, the amp really captures the essense of the music and is a joy to listen to.

John

 

[sacd lover]

jamoto8, what are some other good sounding 6bz7's besides the GE's? Have you tried the tung sol or sylvanias? I have a lot of GE's but only a few tung sol or sylvania. I found some amperex but they are probably rebrands.

By the way, you finally got to me... I ordered a Woo 3 this weekend. I am actually more interested in using the Woo as a preamp. But I am sure the Woo will see plenty of time with my senns.

 

[jamato8]

I have some RCA 6BZ7's which are nice. I don't find a lot of difference between the 6BZ7's except for two almost clear top RCA's that are very special but I have no idea why as they look the same as the others except for the lack of good flashing/getter.

I hope it works good as a preamp I never tried as that and now that I have paralleled the halves for more current and lower impedence I can not use it as a preamp. I would ask that the caps on the input be left out as they are not needed unless you have DC on the signal, which you should not. It is just one more cap in the signal path.

There are also some Raytheon that I tried but the GE work fine. I can compare more and let you know what I hear but you have excellent ears and it looks like a few different ones to choose from. Oh I have found some nice ones with copper support rods and some RCA's made in Canada.

John

 

[sacd lover]

Quote:

Originally Posted by jamato8 I have some RCA 6BZ7's which are nice. I don't find a lot of difference between the 6BZ7's except for two almost clear top RCA's that are very special but I have no idea why as they look the same as the others except for the lack of good flashing/getter. I hope it works good as a preamp I never tried as that and now that I have paralleled the halves for more current and lower impedence I can not use it as a preamp. I would ask that the caps on the input be left out as they are not needed unless you have DC on the signal, which you should not. It is just one more cap in the signal path. John

Thanks for the info.

I will think about skipping the input caps as I doubt I have any DC on the signal either.

 

[sacd lover]

I hope it works good as a preamp I never tried as that and now that I have paralleled the halves for more current and lower impedence I can not use it as a preamp. I would ask that the caps on the input be left out as they are not needed unless you have DC on the signal, which you should not. It is just one more cap in the signal path.

John[/QUOTE]

I emailed Mr. Woo about leaving the DC blocking caps out. He apparently was hesitant to do so originally. However, they have revised the amp and he stated no DC blocking caps were used in the construction of my amp.

 

[jamato8]

I know but another purchaser also had them omitted and Mr Wu stated that the unit sounded good after doing so. There is no reason to have them there with the modern equipment most use. It is too bad he does not offer upgraded caps etc.

John