Review: Woo Audio WA6 vs. WA6SE (stock units) - Page 6

I have found that the drive/power tubes do have a nice infuence on the sound. The 6de7's have more attack and synergize better with the detailed Bendix tubes in my DAC. The 6ew7's have more decay and a wider, deeper soundstage, and they seem to compliment the WE396A in the Paradisea which exhibits these same traits. In both cases, this is with the Sophia rectifier. (I don't see any reason to roll something else into the rectifier socket - it's that good!)

This is almost like having two different systems to synergize with headphone choices or music genres. I find I prefer the 6ew7 sound and I would choose it if I was forced to pick one combination for all situations. Fortunately, I am not restricted and I can roll these various tubes for the variety.

I suspect that one could find rectifiers to support these two different signatures if a Sophia 274B was out of the price range. I know that the 5R4GYB works very well with the 6ew7's for a wide soundstage and smooth sound. I think that the 5U4G or 5AR4 might be the best match for the 6de7's, but I haven't gotten to experimenting with those yet.

I have played with several different tube combinations over the past couple of weeks. I think the choice of power tubes makes a little more difference than I originally thought.

I start with the Sophia Princess in the rectifier slot. This provides a lot of detail and soundstage for either choice of power tube.

If I roll in the 6de7's, the sound is almost solid-state in presentation. The emphahsis is on dynamics, impact, good solid bass, and less air around the notes. With 6ew7's, the amp becomes more tube-oriented. The seductive warmth is there, along with better imaging and more decay, but a bit less impact. I am using Sylvania NOS power tubes in both of these cases.

It almost like having two amps in one. These differences are less apparent to me with other rectifier tubes. Perhaps that is because the rectifier tube choice is impacting the sound in ways that I am not accustomed to and can't describe properly yet.

As I comment about these things, I must say that I am not covering new ground here. These impressions are no different from what jamato8, takezo, and HeadphoneAddict (among others) have said before about these tubes, but it is new and interesting for me to travel down this same path.

However, the different thing is the realization that the Sophia 274B combined with the Sylvania 6de7's provide a sound that is very similar to what I remember from hearing a quality solid-state amp like the GS-1. Perhaps I am imagining this similarity, but there is no doubt that the amp has more impact and less warmth with this tube combination.

I have a pair of the RCA's from Jack that I put away early after moving to the 6EW7's. I am going to try those again tonight. It's been a while since I listened to them, and the amp & Sophia are both over 100 hours now. Things have probably changed with my setup. Lots of stuff is burning in at the same time.

Jam says to get older ones, but I can't figure out how to tell the dates. There doesn't appear to be a date code on the RCA's.

Sorry for your wallet, but I know you will enjoy this amp when you get it. It will be a great match for your phones. If you are not going to buy the Sophia Princess, you should at least get a few NOS tubes to roll in place of the stock tubes. Discovering the various sound changes from tube rolling is a lot of fun, and multiple tube choices for each slot will give you some options to synergize with your two different phones.




@Larry: Well, the Sylvania 6DE7's absolutely trounced the RCA's. Actually, the RCA's did not sound very good at all, so I am convinced that my RCA's must be bad. I ordered another pair of NOS RCA's last night, and I will try this again when they arrive.

These RCA's have 50+ hours on them, so they should have softened up by now. They sound harsh and muddy.