This is a tube preamp (2XECC83/12AX7) format 19 "reduced size (48 x 26 x 4.4 cm). It is a bit heavy (4 kg) but it's still okay.
There are 2 channels: clean and lead each of which can be boosted to be almost 4 channels into practice:
- The clean passes only through the first floor lamp in V1,
- The crunch passes through the two floors of the lamp in V1,
- Lead the software goes through two levels of the V1 and V2 of one floor,
- Lead the heavy through the two floors of the two lamps.

It was for the Clean / Crunch:
- Gain
- A switch "bright"
- A 3-band EQ
- Volume
For Soft / Heavy Lead:
- Gain
- A 4-band EQ
- A switch "contour"
- Volume
And the global:
- A switch "Gain Lo / Hi"
- A switch "clean / lead"
- A switch "preamp defeat"

The connection is fairly complete
Front:
- An input priority
- With a headphone amplifier and frequency correction 1.5 W
Rear panel:
- A secondary input
- Send a single
- Two send (loop stereo)
- Two return (stereo loop)
- An output volume knob
- Two line-level output
- Two output with frequency correction and 1.5 W amplifier
- A jack for stereo switch "Gain Lo / Hi" and switch "clean / lead"
- A jack for stereo switch "outline" and switch "preamp defeat"

The only thing that I blame him is not to be MIDI. Finally, for the price ...

UTILIZATION

Configuration is very simple even if the channel clean / crunch sounds much louder than the lead channel.
The manual is short, in English or German, but quite clear.
We obtain easily a big sound, whatever the settings, everything is a matter of taste.
The connections are simple and straightforward.
However, the trick is painful changes channels: two pedals to change channels Z4 type are necessary if we want to make the best of the beast. This defect is corrected fairly easily with a built-in that manages the channel changes as the G-Major.

SOUNDS

I have adopted in the following configurations:
ESP Eclipse II, Ibanez RG7321 -> E530 -> TC Electronics G-Major -> VHT Black Beauty 2562 -> OUR 4X12 V30
ESP Eclipse II, Ibanez RG7321 -> E530 -> Sound Card M-Audio Delta 44 (G-Major in loop)

The basic sound was very nice but a bit too bright for my taste. So change lamps for two ECC83 JJ Tesla.
And it is sending the heavy in heavy!
In clean, beautiful clear sound and balanced. It is not particularly hot but very punchy.
It is a bit cramped on the Ibanez but very large on the PSE, which proves that the violin is respected.
The crunch is as I love it that is clear and cold, just a little crispy. The huge class but it will not appeal to most people. Again the dynamics is the rendezvous.
The low lead is enormous rock. Very dynamic, rich sound and well balanced, very typical lamp and not a speck of metal, rather British in mind.
The heavy lead is a complete massacre. VHT on direct bury it everything I've tried before. Extra large, fully pierces the mix, very accurate and a lot of gain for the metal I do not exceed 2 / 3. The grain is tight but keeps the character. Ibanez on it is very dry and serious. ESP hard on it all.
Everything sounds direct, brief ecstasy with each stroke of the pick.

I play metal so it suits me perfectly preamp.

Only "defect", it sounds very special and it is very difficult to change without distorting everything that makes its qualities. Try before you buy.

For my part I put 10 because I can not turn 11.

OVERALL OPINION

I use it for a few months and I do not regret a thing: not to have bought before.
I tried quite a few heads before:
- Mesa Dual Rectifier (good) and Roadking (very good)
- ENGL Powerball (good)
- Peavey 5150 (bof)
- Line6 Spider Valve (medium)
- Laboga Mr Hector (good)
- Marshall JVM410H (very good), JCM900 (bof), JCM800 (good)

and I initially fell for the duo E570 E840/50 and a friend who is really great.

But there is really splayfooted complete. To test urgently but changing the original lamps.

Value for money unbeatable opportunity. I would do this choice two hundred times if necessary.