PrimaLuna Dialogue Preamp = emotionless?

Of course, maybe it's the Philips rectifiers that have seen their day. They should be warm too. I had a similar problem with the stock rectifier that came with my Lampi Atlantic TRP dac (currently being repaired). After trying a few others, I found an Osram U50 that gave the dac more warmth and a whole lot more. 

@helomech - I don't understand your suggestion. As indicated in the OP, I ran from the Directstream to the speakers directly before adding the preamp. Hence the comment on how much of an improvement the latter was in all ways but one.

I got a reply from PL NA today that says the Mullards should be warm, and suggested changing the input tubes and, failing improvement there, take a photo of the bottom insides to see if any modification had been made.

The first pair of Brimar CV4003's, inserted in the center slots (6 in total, 3 each side), are having the same effects I've seen many times with a new cable. That is, the sound is warmer but lacks clarity and dynamics and is a bit recessed spatially. Have to see what develops with burn in. 

Thanks for the replies. The preamp is non-demanding on tubes, so five years should be well within their range, although admittedly I don't know how the previous owner handled it (tubes were not why the previous owner sold it). In describing the Mullards, I found that many people use some version of warm, sweet, lush, liquid, smooth to, so that’s what I was expecting. I haven’t found this set of tubes laid back or lacking in dynamics. In anticipation of the PrimaLuna, I’ve started watching for good deals on Brimar CV4003’s and have just now rolled in an NOS pair. There’s also a pair of Brimar 13D5’s (CV4003) on the way. These four will cover the most important spots on the front end. The Brimars seem to be considered a bit warmer and more extended on top and bottom than the Mullards, but as you all say it’s in the mix (and taste).

Output impedance of the PL preamp is 256 ohms. Input impedance of the ATC SCM19As is 10K. I hadn’t considered that, although in a discussion with Don Sachs, he mentioned his preamp would need a 3uF cap to handle impedance that low (don’t know the output impedance of his).

P.S. Not sure why "follow" isn’t alerting me for this thread.

Thanks for the suggestions. Twenty-five hours in, the Brimar CV4003’s have improved a lot but like the Brimar rectifier I mentioned, have turned the preamp into sounding pleasant, which is not a recommendation. Maybe a matter of placement? Have to play around and wait awhile as they burn in. The Amperex 7316s don’t come cheap. From what I’ve been able to find, the aura around D-Getters has more to do with that characteristic happening to be in tubes people have liked, rather than the type of getter having something specifically to do with it. The Brimar rectifier sell for a lot less, so will give it a try. The PL tech suggested the PL 5AR4, which I have, or what some customers have liked, the JJ GZ-34.

I’m going to re-verify that 10K ATC amp impedance, as a few people have commented about it seeming unusually low.

@ aolmrd124   I'm afraid you missed the jist of the OP and discussion. I didn't say the PL is emotionless, but that contrary to expectations the one I'm listening to is and wondered if I was missing something, along with asking about alternatives (in case this one doesn't work out). Thanks for the suggestions about tubes. I have listened to the NOS Brimar 5Z4G rectifier, a different tube, in a Lampi Atlantic TRP dac. I found it euphonic and very good all around, but had this sense that it was sedating rather than enchanting me. It turned out I wasn't alone in that thought. Certainly not all Brimar tubes sound the same, to wit the CV4003 I've added, although warmth seems to be part of Brimar's makeup, if user and dealer comments are to be believed. Any thoughts about how the 5RGY would be different than the 5Z4G?

@teo  I don't know what to say except that if you read what my OP to say that I found the PL addition worse, you missed it by a long shot. I said that it was a great addition, really a fantastic addition, in all respects but one, and I posted here to get help figuring out about that one. Speaking generally, of the roughly 10-15 preamp developers, same-dac users and others that have offered advice about adding a preamp, only two, including yourself, have argued against it. Even Paul McGowen of PS Audio, after decades of believing that a direct dac to amp connection is best -- it's even in the Directstream manual! -- has in the past week or two admitted on his blog that he's been wrong all this time, after finally doing some comparison testing with one good preamp or another. So yes, I know it's counterintuitive, contrary to a belief I had been operating on for several years out of keeping it simple and logic, but then so is a lot in audio.

Actually, on second look, the Brimar recti doesn’t sell for a lot less. I’ve seen a pair for as much as $699, although most are in the $130 each range + shipping from the UK.

Toss out a problem like this and get a myriad of ideas! Thanks.

I've now done are couple of things. First, I got ahold of a two of pairs of Brimar CV4003 tubes, one pair being the highly regarded 13D5 version, and placed them in the four key 12AU7 locations. That's done wonders in terms of cutting the cool edge and enhancing the quality of sound all around.  

The second thing I did was consider getting another, somewhat better preamp in a similar price range to the used PL. It's something I would have done from the beginning had I been aware of the options. Specifically, I looked most closely at the well-regarded Don Sachs 6SN7 and the Supratek Chardonnay (Australia), which is designed around the same tube. After asking for advice at What's Best forum, doing a lot of reading, exchanging PM's and asking questions of the developers -- both are one man operations -- I decided on the Supratek. Among the reasons that most favored it for me is that it is explicitly advertised as naturally warm, and that it has true balanced outputs, which should solve the noise problem with the Lampi dac (when it comes back). I don't think the Sachs' unbalanced pre would have done that, and he seemed inclined to agree. I should be seeing it in two to three months. In the meantime, the PL has taken a very nice turn. 

@Dsper  The Oppo's analog board was removed, so it's no longer a dac, if that's what you are referring to. Ric improved the digital circuitry, which is almost identical to the 205's, replaced the power supply, better stabilized the disc player and got rid of the optical port, which he said undermined the unit's sound. In addition, between Oppo and dac are a PAD Neptune spdif cable and an iFi spdif iPurifier, the latter powered by a Paul Hynes SR4 LPS with a Zenwave Audio copper (5V) power line. The Oppo also has the advantage of allowing very good audio and video in one unit, which these days is an exception.

I haven’t found the home version of the ATCs, in my case the SCM19A, to be surgical (a TAS reviewer didn’t either). Plus, I’ve got AM Ultimate fuses in there, which are on the warm, liquid side, along with using PS Audio power cords and MG Audio ICs, neither of which are cool. But the Lampi TRP dac did definitely cool things off relative to the Direcstream, but it seems that was by design. Trying to make tube sound like solid state is common these days. In any case, I improved its tubes. While I await its return from repair, the Brimar CV4003s, primarily the 13D5 type, in the PL have done a wonderful job with the DS. And for the long haul I decided to go with a Supratek Chardonnay preamp, which is supposedly on the involving side and has true balanced inputs/outputs. It should be here in a couple of months.

The MZ2 would be functionally inadequate for my purposes. Rather, I considered the MZ3 seriously, asking on a thread in another forum site where it stands on the cool-warm spectrum, my preference being for a bit of the latter. The unanimous response was to warn me off. As I noted in my last post, "Trying to make tubes sound like solid state is common these days." No, thank you. In addition, it’s now clear that the chance of some hum/buzz in going from an unbalanced preamp to the balanced ATCs is high. That leaves the balanced version of the Microzotl, which tone/timbre aside, is over twice the cost of the Supratek, other factors aside.