Retubing the Audio Note M8 phono preamplifier

I was going to call this “Tubey Tubey Do” or “Tu be or not Tu be” but then I remembered how irritating all those cutsey chapter titles can be in those “So You’re an Idiot” books – so I refrained. No thanks are necessary.

Audio Note M8 Phono
The Audio Note M8 Phono preamplifier.

The location of the two output tubes in the M8
The location of the two output tubes in the M8. You can also see them both in the above picture on the left, side, glowing hot orange.

We have heard three different sets of output tubes (a matched pair is required, one for each channel) in the M8 here lately. The current system is the following:

Showroom 4
Marten Coltrane loduspekaers, Audio Note Kegon amps, Audio Note M8 preamplifier, Audio Aero Capitole CD player all on Acoustic Dreams rack and stands with Nordost Tyr speaker cable and Valhalla interconnect, lots of Shunyata power cables.

The tubes had a larger than expected impact on the sound of the M8. Much larger than our experience swapping out the various tubes on the Audio Note Kegon amps:

Audio Note Kegon
The Audio Note Kegon 300B tube-based high-gain 20 watt SET amplifier

The Phillips EGG 5687 tube
The Phillips EGG 5687 tube

In The First Corner

Phillips ECG – very laid back, a little syrupy, lots of harmonic content, some details are missing from the mix.
For me, personally, the Phillips was a little too laid back and there was too much information missing with respect to details in the music.

In The Second Corner :

A perfectly matched pair of GE “five star” 5687’s. [Thanks so much, Mark!] – cleaner sounding than the Phillips , more transparent, more dynamic. Quite romantic.
The GE tubes were quite nice, well-balanced, rich harmonics and I liked the pre when it was in this configuration.

The Tung-sol 5687's
The two Tungsol 5687’s Glowing in Action.

In The Third Corner:

Tungsols 5687 – Amazingly transparent. Images SNAP into focus. Lots more rhythm. Lots more detailed than the other two sets of tubes. MUCH more engaging.
I told Neli “Now the M8 sounds as good as the M10!” She gave me that old sour “Are you NUTS?” look – and I WAS exaggerating in that way that men do around women they like to annoy – but seriously, it was kick ass transparent, by which we mean not just good imaging but excellent convincability.

BAMM! Musicians were … musicianing… in the room.

There was oodles of suspense and anticipation as the music started building to major and minor climaxes.

There was good continuousness, by which is meant in this instance that the notes all seemed to come from the same stage and same instruments – and were not just appearing out there alone, in space, willynilly, strangers to each other.

Very engaging -by which we mean we were drawn to listen to the system at the expense of things we really ought to be doing instead.

A little less romantic and harmonic color than the other two tubes – so the Tung-sol may not be right for everyone. But WE liked it….

But what would be really optimal would be if we could swap tubes in and out, depending on if we are in a deeply romantic mood, flirtatious mood, or sight-seeing mood. Oh. Wait. We can. 🙂

Except that…

… Unfortunately the M8 has to leave us for awhile … sucks.

A special thanks to Peter and Mark for setting it up so we got to hear what we heard. What can be better fun than this on a snowy Sunday? I mean besides THAT.