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OK here's the scoop (kind of long)

Posted by Burnt Fingers (A) on August 23, 2005 at 21:21:41

In Reply to: Sure, tell us where you ended up....... posted by Chuck Y on August 23, 2005 at 18:04:13:

OK here goes...

I have to start by describing the listening room. I have my system in an extra bedroom that we've turned into a nice listening room. The house was built in 1940. The room has an oak floor and old plaster walls. So yes it is a "live" room (btw, I just ordered a set of RoomTunes tuning pack). On top of that, the Gallo Reference 3 loudspeakers are slightly weighted toward the upper end. Don't get me wrong, the speakers are amazing. The slight emphasis to the upper end produces midrange and highs that are like honey. They have enormous soundstage and detail. They present air between the instruments and vocals beautifully. But they tend to emphasize the upper end in my listening room just a little more than I was comfortable with. So my room and the speakers pushed me to persist in finding the right tubes. The effort paid off :-)

I started by replacing just the power tubes without switching the pre-amp tubes. I first got a set of Electro Harmonix KT88's and installed them. They were much smoother than the brighter stock tubes that the PrimaLuna came with. I was almost happy with the sound. But the more I listened, I realized it was now missing some of the sweetness on the upper end. Cymbals didn't ring like they did with the stock tubes. True, they weren't as harsh sounding as the stock tubes, but they were still just a little bit dull sounding in my system.

Next I got a quad of Tung-Sol 6550's. They kind of went all over the place. The sound just didn't seem connected. They were brighter than the EHKT88's that I was starting to get accustomed to. But they wouldn't lock in and sounded kind of disjointed. I pulled them out and stuck the EHKT88's back in.

I also got a set of Electro Harmonix 12AX7's and 12AU7's at this point in time. I paired them with the Tung-Sol 6550's and wasn't impressed. I also paired them with the EHKT88's and still not blown away at all. The stock PrimaLuna pre-amp tubes performed better in this system.

Well by now I was starting to get a little frustrated. I talked to TubeWorld and they told me I was going sideways instead of moving forward. I had to agree 100%. He recommended some NOS pre-amp tubes. He suggested a set of CV4004=12AX7 Mullard tubes (1981) and a set of 5814A RCA black plates (1973). I decided to go ahead and splurge and get the 4 tubes for $230.

While I was waiting for the pre-amp tubes to arrive I called Kevin at Upscale again. While I was upgrading pre-amp tubes, I decided to upgrade the tube in the Ah! CD Player too. They recommended Amperex 7308 tubes for the CD player. The 7308 tube arrived a day before the pre-amp tubes arrived so I got a chance to audition the Amperex tube by itself without any other tube changes.

The Amperex 7308 made the most dramatic change to the system. I now got bass notes. The Gallo speakers are not bass monsters. Simply changing to the Amperex 7308's brought me delicious bass. It also brought more detail to everything I listened to. The Amperex tubes are FANTASTIC. I was seriously impressed with this tube upgrade. The stock Sylvania tubes that come in the CD player are just no comparison at all.

Next the pre-amp tubes arrived. The CV4004=12AX7 Mullard tubes (1981) and the set of 5814A RCA black plates (1973) brought the system up to the a whole new playing field. The sound was now warm. In fact it was gorgeous. The music was more inviting. It sounded tremendously more lifelike.

I put the Tung-Sol 6550's in with the new pre-amp tubes (remember the ones that were weird before with the PrimaLuna pre-amp tubes) and now they sounded great. The 6550's snapped into place.

I was happy with where I had brought the system to but I still wasn't 100% satisfied. I wanted it to be better than I deserved for the price I paid for this modest system and I knew I was just about there. I still felt there was just a few more drops of juice that I could squeeze out of this system. So I ordered two more sets of power tubes from Upscale. I know, I know, I'm at the point of obsession now, but it was really driving me nuts. I figure, hey I can always unload my least favored tubes on E-Bay so, I won't be out all that much.

The final touch. I ordered a set of EI KT90's and a set of SED KT88's from Upscale. Glory at last!

I had high hopes for the KT90's. Let me start by saying that the KT90's are reasonably accurate. And if I had never heard any better tubes I would have likely been impressed. But I have heard better tubes and the KT90's were a disappointment. They sounded just like they looked - long and thin. They are a little louder than the KT88's. They'd probably be good for hard core rockers. But they just couldn't cut the mustard in my system.

Before I comment on the SED's let me tell you how the other tubes sounded with the upgraded pre-amp & CD tubes...

EHKT88's still sounded kind of dull. I was underwhelmed with their performance. Nothing spectacular going on with these tubes.

The Tung-Sol 6550's actually sounded pretty darn good with the upgraded tubes. Like I said above I could almost leave them in and be happy. They became my second favorite tubes with the right pre-amp tubes in front of them.

The clear winner in this line up was the SED KT88's with set up I've put together. The SED's are dynamic as can be, plenty of punch where needed. The sound is rounder than the second best tube (Tung-Sol). The sound is fatter and far more detailed than the EI KT90's. The sound is more present and alive than the EHKT88's and the top end is fuller. The SED's brought out more bass than the other tubes too.

I had a tube gear audiophile friend stop by last night. He's got great ears. He had heard the original system and liked it. He heard it when I first upgraded the power tubes to EHKT88's and he could hear an improvement. When he heard it last night he was blown away. I had lined up 10 disks for an audition. We went from Eva Cassidy, to Lyle's Large Band, to Norah, to Natalie Merchant, to Cowboy Junkies, to Gillian Welch, to Elvis's Costello's North, to Aaron Copland, to Miles - and then we went back to Eva Cassidy to finish on. He had Eva Cassidy's Blues Alley disk so he was very familiar with it. He has also listened to the disk at a local tube gear store that carries a lot of Cary and Conrad Johnson stuff. He said that cut 13 (Oh, had I a golden thread) was the best he had ever heard it anywhere. And he meant it. Yikes what a compliment! When he said goodbye to my wife as he was leaving she asked him what he thought and he told her he had heard the angels singing.

Well I've gotta say that all the effort to match the right tubes to this system paid off. This system has genuine heart and soul with these tubes. It is sweet. It is powerful. It is dynamic. It has a soundstage to die for with instruments placed perfectly on stage. I've had friends come over and insist that I'm hiding a center speaker somewhere because the vocals are so locked in dead center between the two speakers; the speakers just just about completely disappear. Heck it even mimics surround sound to a degree because the sound wraps around so far to the right and left.

Here's the complete system:
PrimaLuna Prologue Two - SED KT88's, Mullard 12AX7 1981, RCA 5814A
Ah! SuperTjoeb 4000 (w/upsampler) - Amperex 7308
Gallo Reference 3 speakers
DH Labs Power Plus power cord
DH Labs Silver Sonic Q-10 speaker cables
Harmonic Technology TruthLink interconnect

In closing I'll say that my findings are simply my opinions. I listened long and hard with a very critical ear. What I came up with in the end is a home run IMHO. Of course my home rum might just strike out for somebody else in a different situation. Everything is relative. But I can honestly say I sure am satisfied with the range of tubes I ended up with.

Thanks for reading :-)

Rick Gelinas

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