VAC owners, sound off

Happy for you ! Amperexes in the 12au7 spot will bring you back some extension in the highs, decay maybe or maybe not. In my preamp, it did but it is a more subtle difference than changing the 12AX7 tubes. Remember to wait at least 50 hrs of running the new tubes in order to hear the best of them.

You say the preamp has a little less decay than with the original tubes. This means it is there somewhere but hidden since you heard it before. You have more bass and weight, obviously your hearing is rebalancing itself. You might just hear your decay back once you are accustomed to it.

Have trials with your speakers positionning and have a look at your acoustics. Don't forget to check your electronics isolation to vibration. Better quality electronics are more sensible to the surroundings. Doesn't cost anything and most of the time does a lot.

Have fun !

Glad you got the RCA Cleartops, they are excellent overall, and do remain a comparative bargain. I agree that Andy at VTS is beyond reproach, and I have also had good luck with Brent Jesse Recordings for NOS.

So I figure I'll just tack onto this thread rather then start a new one. After listening to the pre for about 2 weeks I think I've adjusted to the sound. My impression is that it's, in a word, unremarkable? I find the mids and bass light and lacking. Vocals -- which I think any good pre should do well, are also light and even sound a little boxy and compressed. Presentation is also bit flat. Basically the sound lacks dimensionality and fullness.

Reason I bring these observations up is they seem to fly in the face of the overwhelming kudos to the VAC sound. I'm not hearing it, or at least what I'm hearing isn't what I believe so many people would be raving about.

I do have the unit on brass cones into brass feet, underneath of which are iso-node pods. I do this primarily because the shelves on my custom rack are natural wood and not 100% flat, and the cones are height-adjustable. While the cones also help tighten focus, I do notice that they lighten the mids and bass to a degree (the iso-nodes help counteract that). But I tried the unit on its own feet, with only a slight improvement.

Maybe I'm looking for the wrong things? I listen to hard and classic rock, electronica, some solo acoustic. Maybe this pre sounds better with different music styles. Maybe there's a system dis-synergy. Don't know. At this point I'm ready to put it back up for sale, but thought I'd try here beforehand to see if anyone has any thoughts or troubleshooting ideas.

I surmised the same thing. Outside of impedance matching, is there any other specs to check between pre and amp for compatibility before rolling the dice?