In order to make sure I wasn't fooling myself due to the newness-excitement factor I have intentionally delayed this little review of the Emission Labs 5U4G mesh rectifier for a while, making room for more listening sessions to confirm my impressions.
This mini-review of the Emission Labs 5U4G mesh plate is done by comparing it mainly to a metal base gz34 phillips miniwatt. I wanted also to do a systematic comparison with the High Wycombe gz 37 as well, but found that it became too much to too keep the sound signature of three tubes in mind while rolling them. I could of course have compared the gz34 and the EML first and then done the EML and gz37, but I think a systematic comparison between the EML and the gz37 will have to wait for some other time. The comments on the rectifiers are based on the 6H30DR's as drivers. This is significant because the strengths of one rectifier over another only reflects how good the match is with a particular set of driver tubes.
What creates the tube sound? My, maybe somewhat controversial claim is that one important ingredient is a slight smudging (in lack of a better word) of tones. Measurements does in general reveal higher levels of harmonic distortion in tube gear than in solid state. If this smudging effect is due to the specific second order harmonic distortion created by tubes or something else I don't know, but the effect is definitely there. In some tubes this smudging affects the whole frequency specter. In other tubes this smudging seems to affect only lower frequencies. Some tubes seem to display very little of this smudging which makes the sound of the tube closer to what one typically could expect from solid state gear. Other tubes have a much more pronounced smudging effect, creating a very sweet and warm "tubey" sound. The tube is then often less dynamic and details are a bit muffled. So one could say that tubes can be placed on a a scale from the very dry, ss-like, to the sweet end with tubes producing a strong "tubey" sound. The EML tube is leaning more to the neutral end of the scale than the mb gz34, but it does this without losing the tube "magic".
So why do I prefer to listen to tube gear when solid state can reproduce music with less distortion than my tube gear? What is the tube "magic"? To me the tubesound is more natural. It produces a sense of acoustic space that I have yet to hear from SS. It produces a more full-bodied musical presentation and it produces less listening fatigue than SS.
Because tube characteristics vary to a large degree, combining tubes is not straight forward. As several here has commented doubling up of a good driver tube in e.g both preamp and transporter may not be a immediate success. For example both the RCA cleartops and the 6H30DR's leans toward the sweet end of the scale, though with much bottom-end energy. Doubling up of them in both preamp and transporter may result in a sound that floats out and loses its focus, especially in the bottom end where these tubes individually are strong. The sound becomes "overcooked".
The same applies for combining rectifiers with drivers as well. In combination with the 6H30DR's I felt that the sound of the mb gz34 on certain recordings became "overcooked". This has not been a problem with the EML rectifier. It is a tube with better transparency in general than both the mb gz34 and HW gz37. This may be partly because it doesn't have the mid-bass hump of the mb gz34 (or the slightly recessed upper-bass of the gz37), but in addition to this it sounds to be in more control. The definition is in general a little better. The details comes through better. While it is maybe not quite as punchy as the gz34, it still a a very dynamic tube. But because the dynamics is not especially pronounced in any one frequency area it comes across as more relaxed than the gz34.
As for sound-staging it is in this department the EML most clearly outperforms the mb gz34. The huge EML sports a XXL soundstage with better height, width and depth than the mb gz34. Partly this may be due to its transparency revealing more spatial cues, but I don't think this is the whole explanation to the magnificent soundstage of this tube.
Congratulations to those of you thay already have Dan's new mod in place in the transporter! I see that the mod has led to new rounds of tube-rolling for some of you. Maybe the EML with it's control and clarity is what you are looking for. At least in my rig, and in combination with the 6H30DR's the EML produces the best sound thus far.
For me the EML has turned out to be a very good investment and is now the permanent stable mate with the 6H30DR's. Other driver tubes may, however, demand something else from their stable mate.
