Hi there,

I have been lurking this forum for a while now...
About 2 months ago, a friend lent me an old SE 84C he is not using any more (he is into WAVAC stuff now...).

I could not believe what I heard with my Prame 100 db horn speakers.  
Soon after that my Manley Lab Stingray 2x50 watt stereo push pull of 8 EL 84 was collecting dust (I have sold it since: too bad, it looked really great in the dark).

I could not believe the dynamics I heard from such a feeble amp: much more dynamics than with the 2x50 watts Manley using the same tubes (I am talking microdynamics here).  Compared to the SE84C, the Manley sounded almost constipated, unliberated.

BUT the SE84C was clipping at times, especially on bass heavy content (Prame speakers have twin 30 cm woofers), such as hammond organ or electric piano (any time the bass  lasted more than a brief time). I had to turn it down constantly to prevent clipping.
To alleviate the problem, I bought the CSP (with the SE 84C still on loan from my friend).  

I found that the clipping was now less of a problem and the CSP brought more finesse (with the right driver: an RCA 5U4B), but less "punch" and "weight" or "impact" to the sound.

You see I am a dynamics nut: there is nothing more dynamic that live music, and this is why you get so involved in a live concert: you are not going to listen while reading or watching TV or working if you are in front of a live band.

You CANNOT reach THE concert level dynamic range, EVER: you can only approach it .  Just listen to a live drum solo ! The cymbal crash, the bass drum kick hits you in the chest and YET, it is not fatiguing (unless through a bad PA sound system).

Dynamic range is best when it is all the way up !
Just think of the "contrast" knob on your PC monitor or TV set: Everybody turns it all the way up, because the constrast is never as good as what you see in reality.  So if there was a "dynamic range level" knob on your amplifier , what would you do ? Turn it all the way up, of course !  That's when the music begins to grab you ,  when you have got to leave everything and do nothing but  LISTEN !   That is why I got into high efficiency horns in the first place, then into SET after that: once you have heard SET amps  on high efficiency speakers , you cannot go back to push pull.

I turns out that two months later (in fact, just today) I found (by accident) the solution to the CSP "finesse" vs "weight" dilemma: turn both volume pots all the way up, and turn the Ah Tjoeb volume output all the way down, then adjust volume with the Ah Tjoeb. This also works with the Taboo.
Last thursday, I got the Taboo. That first day I thought the 84SEC was better and that I was going to turn back the Taboo.
I took more than 10 hours for the dynamics, bass and medium to come out. After a week it is still improving. I had to roll tubes to make a fair comparison with the  SE 84C: RCA 5U4B, Valvo EL 84 (the CSP has all Siemens tubes, and RCA 5U4G rectifier for better dynamics).
Well, what is the verdict ?
After a week of listening, I turned back the SE 84C to my friend with many thanks for the long term loan ! No more clipping, my friend, more punch, more bass, and no trade off: just as much finesse, but more dynamics ! Remember that "dynamic range" knob, the aural equivalent of your "contrast" knob ?  Well, only one amp has it in the world: the Decware  Taboo. I am talking about the two little knobs in front of the driver tube: they make a lot of difference to me : as you turn them up , the dynamic range increases, and the music is more "upfront" and involving. Of course, since I am a dynamics nut, I always turn them all the way  up !

What about the "lucid" switch ? I hear less of a change with this switch than with the "dynamic constrast" knobs.  But I do prefer the "lucid" position, for three  reasons:
1) Even more dynamic range, and this time, macro dynamic range (from low to high sound level) => you get more involved, music grabs your hears even  more. Voices seem to be  more "there" with the "lucid" switch on.
2) More space: the soundstage seems to expand in all directions, including towards you: you feel more immersed in it, rather than in front of it.
3) More finesse and harmonic texture: at first it feels you have turned on the "reverb" switch on a guitar amplifier. Except that too much reverb is fatiguing , because it adds something that was not there in the first place. Here it's different: you seem to hear more of the natural reverberant sounds that you did not hear before. You hear this best on a good piano recording: you hear more of the resonance inside the piano, all the piano strings that were not hit but resonate because they are close to the string  that was played.

Also you hear more of the reverberant sound in the room, and this is heard especially on good "live" recorded concerts. this gives you a more "3D" sound. Turning back the switch to normal the aural scene appears more "flat", like a curved screen in front of you, rather than a bubble including you.
To conclude :  
The taboo is definitely better than the already excellent SE84 C : you get more power, bass with more muscle, more punch, no clipping, a more "alive" sound, and, with the lucid switch, you get more 3D magic, more space, and more  harmonic texture, in a world, you get lost into music...

- Bernard




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