PrimaLuna Dialogue Three Preamp Review

[BDWoody]

I'd love to see someone with the (balls) courage and $ to send in a Macintosh tube amp for testing.

The fear would be in the shipping and handling, not that it wouldn't at least meet its stated specs.

I would have no problem with a big glowing McIntosh in my system if I were in the market for a tube amp.

 

[Blumlein 88]

I'd love to see someone with the (balls) courage and $ to send in a Macintosh tube amp for testing.

Stereophile has measured the modern version of the old MC275. Pretty nifty performance. Better than this preamp in fact. Meaning if you padded down the output of the power amp it would be cleaner than this Primaluna.

McIntosh MC275 power amplifier Measurements

Sidebar 3: Measurements

www.stereophile.com

Here are the specs for one of the McIntosh preamps currently offered. They have a history of exceeding claimed specs when tested. The cost is higher, but it shows the Prima Luna is not SOTA or even close for tube preamps.

 

[C. Cook]

Funny how some people embrace older inferior technology as superior. At some point I am sure someone will claim Edison cylinder records are the way to go. Probably a "warmer" sound.

I dunno. In some respects it's simply nostalgia and the "steampunk" ethos (even if not articulated as such). Tube amps look "cool" and for a lot of people who use them, specs aren't all that important if they sound good enough. I do think there are some scenarios and recordings where I might prefer the "tube sound" but I wouldn't be lying to myself about the distortion. Sometimes a little distortion can cover up bad recordings or mask "harsh" elements of a recording that might be too readily revealed by low distortion efficient speakers?

 

[C. Cook]

By tube standards though, it seems OK.

That's pretty much the rub. It is fine for a tube amp, and I don't think many people willing to spend that kind of money for this level of performance are kidding themselves about how it really stands up to "modern" class D and AB in terms of T&M (or "sonic purity").

 

[amirm]

I had the specs for a different model. Review updated. The darn thing weighs 53 pounds! No wonder it killed my back moving it. Why in the heck does a pre-amp need such massive transformers????

 

[MaxBuck]

Performance is mediocre at best, but it sure is pretty.

 

[Guerilla]

Shouldnt a used tubeamp be serviced before measurements? I wonder if only the case is designed in Europe.
Cheers!

 

[Talisman]

Actually the fastest consumer cars and even Formula One cars no longer have clutches. A manual transmission even in the "hands of someone know knows how to use it" cannot keep up with a car with paddles shifters etc. Manual transmissions have been obsolete for decades. BTW Ferrari started using them in 1989...

I have explained well what I mean, and why I consider the manual transmission to be the emblem of the sports car. If this is not understood, it is because there is a lack of a sports car culture base

 

[Peternz]

I guess it is ok for the price, $259 for some fun experimenting with tube stuff. Not something I would have in my system permanently though.

 

[Jimster480]

I am not even sure what the purpose of such a device is

 

[DMill]

I guess it is ok for the price, $259 for some fun experimenting with tube stuff. Not something I would have in my system permanently though.

I think you misread the price. Multiply 10x.

 

[nerdstrike]

My first instinct was "what a fancy toaster! With handy pre-amp feature"
Ultimately ruined by the power specification 50W won't toast much of anything.

 

[Prana Ferox]

From the measurement point of view, the tube preamplifier is abysmal. But, I have a basic question: Can't a preamplifier be realized with a multiple switch and a potentiometer? Why do you need the intermediate amplification? (Please no jokes, this is a technical question)

The other minimum job of a preamp is impedance matching, i.e. a unity gain amplifier should have appx zero infinite input impedance (what your sources see) and infinite zero output impedance (what your power amp sees.) If you don't have that, current draw in your downstream equipment can affect the frequency response upstream - similar to what we see with cheap chip amps where different speaker impedance can give you varying response in the amp treble output. (For speakers you may see this called damping factor, which is just speaker input impedance divided by amp output impedance.)

The switch acts as a bare wire but a potentiometer (i.e. variable resistor) is obviously neither ideal or constant impedance in either direction without buffer amps.

(Edited because I had my input/output impedances swapped)

 

[Peternz]

I think you misread the price. Multiply 10x.

Oh wow, thanks. Well, that makes the thing completely ridiculous.

 

[radix]

Stereophile has measured the modern version of the old MC275. Pretty nifty performance. Better than this preamp in fact. Meaning if you padded down the output of the power amp it would be cleaner than this Primaluna.

McIntosh MC275 power amplifier Measurements

Sidebar 3: Measurements

www.stereophile.com

Here are the specs for one of the McIntosh preamps currently offered. They have a history of exceeding claimed specs when tested. The cost is higher, but it shows the Prima Luna is not SOTA or even close for tube preamps.
View attachment 309426

There's also things like the CJ PV series, which can be had for about $1k used (e.g. a PV10 or so).

Specifications​

• Gain: Phono Stage 35 dB (phono overload 500 mV at 1kHz)
• Line Stage 28 dB
• Distortion: less than .05% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 70 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
• Phase: Phono Stage is phase correct, Line Stage is phase correct
• Mechanical: 14 x 4 3/4″ x 11 1/4″

Or their current lineup, which seems to have a higher THD but lower noise floor, but is pricy.

Conrad-Johnson PV10 preamplifier Measurements

Sidebar 2: Measurements The output impedance of the PV10A at its line output measured about 690 ohms, give or take less than 10 ohms depending on the channel, the setting of the level control, and whether the balance control was in or out of the circuit. The line-level input impedance varied...

www.stereophile.com

 

[usersky]

I am not even sure what the purpose of such a device is

This got my vote for the comment of the month!

 

[LTig]

The other minimum job of a preamp is impedance matching, i.e. a unity gain amplifier should have appx zero input impedance (what your sources see) and infinite output impedance (what your power amp sees.)

You've got this reversed ...

 

[CleanSound]

I am not even sure what the purpose of such a device is

Personally, I wouldn't buy tube at all. Unless I am just really rich and I can buy, buy, buy, then I'll buy a tube just for fun, to try and to experience this tube thing and probably be bored after few weeks.

But there are people out there who are drawn in by it. Even those who knows it's old tech and inferior but are still drawn to it and willing to spend money on it, that is their prerogative, albeit everyone else should be free to express their opinion on how stupid they think it is.

But here is the problem, there are those who from the bottom of their heart believes that tubes sound better than solid state because there is some tube magic. That set of people, are a lost cause. . .let them be, besides ignorance is bliss.

 

[Michael Fidler]

I had the specs for a different model. Review updated. The darn thing weighs 53 pounds! No wonder it killed my back moving it. Why in the heck does a pre-amp need such massive transformers????

Considering you need 19 watts out of those transformers just to heat the rectifiers before any DC power can get through to the preamplifier valves, let alone power their heaters, might be a clue! Also the design seems to use a separate power supply for each channel, indeed two separate rectifiers when traditionally you'd only use the one.

Also using heavy overrated transformers in a beefy power supply is a great way to buy the impression of quality in the view of the consumer. Similar cost per unit weight as CNC aluminium/stamped metalwork. I think PS Audio do the same as per their YouTube channel, quite a nifty marketing trick when so many cheap and nasty things are relatively flimsy and lightweight. If you're feeling the weight of the thing while you set it up it's probably going to have a strong psychological effect that will play a big part in changing your perception when you start listening...

 

[DMill]

PrimaLuna was getting a lot of attention in audio circles I ran in 20 years ago. Favorable reviews, good looks, and a high price tag made them very desirable to audiophiles. I’m glad to see they measure ok-ish for what they are. As someone who still has a functioning tube amp in one of my 3 systems, I tend to root for tube amps. That said, I’d really have a hard time recommending tube gear to anyone. I suppose if I bought tube gear today it would be McIntosh. At least I’d be able to sell it for the high price they command. They probably are worth the investment if you really want tubes.