PrimaLuna Dialogue Preamp = emotionless?


After years of running a PS Audio Direcstream dac directly into ATC active floorstanders, I decided to take everyone’s advice and add a preamp into the mix. I picked up a used PrimaLuna Dialogue with highly regarded Mullard CV4003’s and Phillips 5R4GYS’s, the tubes purchased by the original owner five years ago from Upscale Audio, a terrific source. My correspondents were correct about adding a good preamp: it transforms everything in a very big way. That’s the good news -- and bad. The latter is the reason for posting.

Before the preamp, this was a modestly warm system, for which the Directstream is known. It was one in which it was not hard to find myself drawn into the music and performance. Since adding the PrimaLuna however, I find myself watching -- or listening to -- emotion but not feeling a thing. That is, beyond marveling at the other characteristics of the presentation. After that, I’m left perfectly cold - 100%. This is not at all what I expected -- or desire.

So what to do... Is there anything I should look at with the preamp? What about other preamps, preferably tube ones? The skinny these days is that tube gear developers are trying to imitate the "neutrality" of solid state, the so-called modern tube sound some call it. With the PrimaLuna, I was expecting to find a point in between the classic tube sound and the common solid state one, but what I’m hearing is more than a little distant from that.

(Other than adding the PrimaLuna and not having Ultimate beeswax fuses in the DS and PL currently for other reasons, nothing else in my system has changed: modified Oppo 203 w/ digital output only, PS Audio P15 Regenerator and AC-12 power cords, and MG Audio Design AG2 ICs,)
highstream

Showing 5 responses by lowrider57

I think your first move should be to roll in some new tubes. The current tube selection may not be to your taste or they need to be replaced; they are five years old with unknown history.

I don’t know the different tube stages of your amp, but you don’t need to use the same tubes in all positions.
I love the CV4003’s, but they are laid-back and you may need to add more dynamic and engaging tubes. NOS Amperex, Telefunken, Sylvania all have more detail, are very open, yet still retain the timbre of tubes. NOS tubes have more realistic sonics than new production and are worth the extra money. There are so many NOS you can try that are less expensive than those mentioned.

A good source of information..
http://www.audiotubes.com/12au7.htm

The rectifier tubes may also need replacing. And it's possible that a different brand may be more engaging, although Philips makes  excellent tubes.

After reading the @paulcreed comments, trying different rectification may help influence the speed and impact of the PL.

I love the Brimar CV4003's, I'm using them in one of my amps.
I previously used Mullard longplate square getters. The Brimar has a more extended top-end than Mullard with more transparency, yet keeps a nice amount of warmth. I always use Brimar in one of the stages of my amps.
There still may be the possibility that using a neutral tube in one of the stages may present more engaging sonics, but I'm interested in your findings.

The preamp output impedance of 256 ohms is a good match in your situation and shouldn't present any issues with SS or tube amps.


I’m not a PL owner but have owned many tube preamps. I highly recommend NOS Tung Sol rectifiers for a deep bottom end.

For a dynamic, lively presentation 1950s Amperex Holland Bugle Boys are an affordable alternative to the 7316 tube.


My take on "emotionless" is different than johnss. 
being emotionless, am assuming you want more of that CJ warmth from the earlier CJ gear.

If you are looking for warmth, then keep the Mullards and use rectifiers that are more lively and provide more clarity. A change in coupling caps could also help.
I assumed you needed a more engaging experience; more dynamic, more transparent and 3 dimensional. It's easy to have these characteristics and maintain some warmth.
 I still maintain it's a mistake to use the same style of tube throughout all the stages. 

Can you provide a more precise description of the sonics you seek from your system?