Above all, I note that I am the manufacturer, but also the first user of my products, so here I give an opinion as objective as possible, I do not talk about price ... and put an average rating of each party , not to distort the future review, but these notes do not bring reveal what I think of the products.

Technology: Electro Harmonix 12AT7 Prampli lamp Gold and output transformers of Lundahl.
Connectivity:
Symmetrical XLR microphone input, line level asymmetrical Jack High Impedance
Output line-level XLR or Jack symmetric with floating ground.


UTILIZATION

In terms of the checks:
- Low-cut filter with 2 frquences cut choice
- Switch with 48V phantom power rgule
- Switch phase inversion
- Potentiomtres gain and volume

It's very simple, one branch is chosen if we cut the bass or not, and we look for the combination gain / volume is going well.

L o is a gte: the prampli, her colleagues as "vintage" and "clean-V" does not cons raction, so the saturation comes quickly. If you do your type of rglage a small press "rec" and surf the Internet when the musician is recording, you may be surprised.
If ever the level rises sharply, it will play the gain to ensure that the signal does not saturate. I t aa specific on that choice to design a prampli like a, I wanted to have this little light saturation (it speaks well of a prampli lamp?)

SOUND QUALITY

Those with whom I will test this hardware I hopes to confirm this: the sound source is Fidler (when not saturated obviously)
Coloration is playing with the gain and trying to reach the saturation limit of the lamp.
The gain of this is enough lev prampli see too much, making it ideally suited to having a microphone output level too lev.
I did not test with a ribbon microphone, but it could very well behaved.
No audible breath.

OVERALL OPINION

Rcemment I lou an Avalon 737SP and a Universal Audio 6176. Raliss tests are online on the official site.
I can give here my opinion on this comparison:

At a normal recording (0dB VU), 3 pramplis offer sounds intressant. I confess I do not like the rendering of Avalon (I do not want to start a DEBATE, this is just opinion), which, with rglages gain and volume DIFFERENT gives substantially the same sound all the time that I can not find the Universal Audio or Audio Jymm.

In terms of the differences that do not necessarly agree, I note the level of output:
The Jymm Audio Universal Audio has a similar output level, the Avalon can go far del (which does not necessarly used).
Always at the difference: this saturation, achieved very easily with Jymm Audio, much less readily with Universal Audio, and almost inaccessible with the Avalon, despite a gain thrust.

The opinions collected during the comparative t have the most faithful Jymm Audio reproduced the sound of the guitar or voice ...