help me to understand the gain

Your DNA1 has an input sensitivity of 1.2 volts .. which means a 1.2 volt signal will drive the amp to it's rated output (150 WTs)

The PL3's output voltage is 5 volts as measured in a Stereophile review and way to much output for the DNA1's input stage

The PL3 is over powering the DNA1 input stage and you can't use all the volume control available in the PL3 as it only takes 1.2 volts to drive the amp to max output

You can put a 10db attenuator at the amp's input or just remove the PL3 and drive the DNA1 from the Dac ... which has Tube output and a volume control

The Dac's 2 volt output is much more compatible with the DNA1's 1.2 volt input sensitivity

Unless you need the PL3 to switch other sources ... take it out as you already have Tube flavor in the Dac

Wouldn't hurt or cost anything to give it a try ... Ditch the PL3 to and give it a listen

Nothing to add to the gain comments, I agree you simply have waaaaaaay too much.

Your speakers are begging for a low power SET amp like a 300B. Keep an idea on the classifieds and you can find a very nice 300B amp in the $1,000 range. A passive pre and an SET is my recommendation.

.

04-29-11: Davehrab
The PL3's output voltage is 5 volts as measured in a Stereophile review and way to much output for the DNA1's input stage.

With due respect for your well intended comments, I believe you are misinterpreting that spec. That number represents the output voltage at which the onset of clipping occurs, as indicated by a significant rise in distortion. The higher that number the better, everything else being equal. The actual output voltage at any instant of time will equal the input voltage multiplied by the gain that is provided by the preamp at the volume control setting being used (12db being the gain corresponding to the maximum setting of the volume control).

You can put a 10db attenuator at the amp's input or just remove the PL3 and drive the DNA1 from the Dac ... which has Tube output and a volume control.

If the PL3 is used, putting a 10db attenuator at the amp's input won't work well. Bass rolloff will result, as I indicated in my previous post. It also won't be a sufficient amount of attenuation.

Good point about the volume control on the DAC, though. Assuming it is the D1 model, I note that it also includes source switching, for both digital and analog sources. I don't know what its output impedance is, but if it is low enough to work well with an in-line attenuator, perhaps ditching the preamp AND putting a 10db attenuator at the amp inputs would do the trick. The OP might want to ask the DAC manufacturer what its worst case (maximum) output impedance is, across the audible frequency range.

If it were me, though, I would seriously consider Herman's suggestion of a 300B SET amp, or other low powered tube amp.

Regards,
-- Al

I completely agree with Almarg and Herman.

I would suggest selling the amp and replacing it with something that is less powerful and has lower gain.

An SET amp would be my preference.

Wow, thank you very much for all the inputs. It seems all the parameters affects the gain, and it sounds like really my system is lacking synergy. And there is alot of technical stuff that I don't really understand, please excuse me if I ask something stupid.

It seems the gain of the amp is not a published specification. I can only see it inside the Stereophile review under measurement section. How stupid ...

Almarg, thanks for your insight about bass roll off with attenuator. I don't have the engineering background to understand the correlations between impedance and all those stuff, but I will take your words.

I really want to keep the PrimaLuan preamp. I don't have anything technical to back me up, but in my experience, the preamp has a bigger impact to the sound then the amp. And I like how PrimaLuna sound, so, I likely will keep it.

I will try to connect the DAC directly to the amp, but I will missed the PrimaLuna sound.

About the option to lower the gain of McCormack, I think I won't go that path also. It seems I will need to send the amp to Steve, it is kind of a hassle. Also, my new Zu speaker won't need such high current, so, if it is not compatible, I may sell it out and get something else.

As people can see, my Maverick DAC has a volume control as well. So, I can lower my DAC input so I can make the volume know of the preamp within a usable range. This is similar to if I lower the volume in iTunes. My question is, how would this affect the sound? Will I run into the bass roll off problem like using attenuator?

Another option is to get another amp. I would like to try the SET amp. If I want to keep the PrimaLuna, what parameters should I pay attention to? I know most of them are pretty low power, but as said, power is not the real problem. I don't think they publish the gain info. Also, does the requirement to have input impedance > 100k Ohm still applies? Maybe more straight forward, what is your recommendation?