Full OGY… with Class AB amplifiers

[naka]

My initial intention was to have a low power tube amplifier and high sensitivity speakers, and my search was mainly around the usual suspects EL84 or EL34 integrated amps and 3-way speakers with a large paper cone bass driver and mid and high compression driver / horns. My aim was having a big sound to enjoy my Jazz and Blues CD collection, with perhaps less detail and tridimensionality but more realism and presence… anyway, something different from my usual high power / high current amps with low sensitivity monitor speakers.

Unexpectedly, I “bump” into the Full OGYs at one of my usual dealers and fall in love with them. Aesthetically, mind is always open because my main desire is to have the performance, but I must admit that they were very different that I was looking for.
There is nothing in the market like the Full OGYs in every sense. Its design and technical characteristics made an impression that they could only work with tube amps, so I thought!

After the long set-up period (see my thread about it on the section about the OGYs) I have started to do some tests, mixing and matching all the pre, power and integrated amplifiers that I have in my system and to my absolute surprise the Full OGYs are a good to excellent matched with the majority. Notice that all are high current type - because my other speakers were always low sensitivity (from 82 to 84 dB!).

The wonderful Copland CSA70 integrated amp (Class AB) is a great match. Super smooth, very transparent with a large and deep soundstage, making the OGYs less “beamy”, more relaxed but still with great imaging. The bass delivery is everything I ever dreamed of and the highs totally non-fatiguing but with a good amount of air and detail. Wow!
The volume control (Alps potentiometer) is very progressive, allowing tiny adjustments, a surprise with the 92-93dB Full OGYs.

One of my regular combinations with some speakers is the Rogue RP-1 tube preamp and the NAD 275BEE power amp. This combo is very well matched, and the pre introduces a bit of warm / color to the wide sounding power amp. In fact, the NAD seems to be has good as the preamp allows.
With this combo, the first thing of notice is the extra range and tightness of the bass registers, a tiny bit more meat-on-the-bones on the mids also, but again a bit less open in the highs.. still a great match! Very fun to listen to.
The volume on the RP-1 is a digital controlled stepped attenuator (1 dB steps) and has a lovely sense of progression.

The Naim NAC122X / Flatcap 2X / NAP150X pre-power (with the dedicated power supply for the preamp) is one of my all time favorites. It has all the known qualities of the Naim sound, but with a more organic side, almost tube-like. This rated 50w / 8 Ohm has a sense of grip and almost unlimited sense of power, that makes the music breathe with ease. With the Full OGYs that effortless character is very much present.
The volume control implementation on the NAC122X is the closest that I know from perfection! It is based on Alps potentiometer (blue series) but using the remote control, the progressiveness of the steps is almost liquid, millimeter-by-millimeter! Amazing
It is what I am currently using.
Still, I have to try the (stiff-as-hell) Naim NAC A5 speakers cables, that the brand hugely recommends when using their amps.

The Kinki Studio EX-P7 pre amp and EX-M7 power amp (that usually are used with the Magnepan LRS+) didn’t work well with the Full OGYs, being too dry and sterile! A complete miss match.

More soon

Notes:
- the speaker cables used were the Klotz LY225
- the source was mainly: Norma HS-DA1 dac, Synthesis Roma 69DC dac, Auralic Aries Femto, Shanling ET-3 CD transport

[naka]

More about the synergy with the Naim pre-power combination - Nac122x / Flatcap 2x / Nap150x:
The result is almost perfect… this amp combo has super control over the speakers, but perhaps only lacking the absolute refinement on the treble, some more air… but a minor thing really.

Besides all the extra care on the power supply aspect of the design, the Naim power amps are one of the few that don’t use a Zobel network in the circuit (also Exposure don’t use it) and from my understanding that can lead to a more direct and pure sound.
Perhaps that combined with speaker with a wide band crossover-less design leads to what I am listening: a very palpaple, engaging, much smoother sound, still with super fast transients.
The feeling is there more to it, some spice to the sound presentation.

More important than anything the system have that “need to listen more and more” feeling

Today I have replaced the Klotz speaker cables for the Naim Nac A5, and although this is the only cable that Naim recommends, the result was not as positive as I have anticipated. The sound got to much dense, a bit more fat and a tiny bit stress. Simply the previous perfect balance was gone. Still listenable but the volume knob range was diminished with that extra energy.

Tomorrow I will definitely go back to the Klotz… also I am thinking of getting the 4mm version.

[jacek]

4 mm version will sound different. That is for sure. From my experience 4mm has even more body, but as always the whole set up is important for the end result. With transistors it can be good choice. At the end your ear will tell you

[naka]

That is good to know Jacek, I will get the 4mm version and do some experiments