I discovered an amazing coincidence in my speaker cabinet:
[Preface]
Since owning an SVT-CL (with H810) the treble knob has stayed at zero (for me, treble on the amp and/or tone on the instrument must be cut severely, and after experimenting with these two I decided to leave the treble knob at zero).
Love the above, even its trademark thickness, but wanting an alternative with clearer lows - I mean severely, perfectly clear - I bought a current model Class D amp and cab with a 15" (and one or more smaller drivers). Oh, it performs perfectly as designed.
But predictably, even with the treble turned down with the available controls it retains a sharpness that I needed to work on. First thought was an outboard EQ unit (a James stack (plus a gain recovery stage) in the effects loop would probably be enough), but first decided to try disconnecting the cab's smaller drivers.
It isn't safe for the amp, depending on the type, to just disconnect those, so I prepared to replace one or more of them with non-inductive power resistors. Upon investigating their impedences, and the crossover (Googling as I went because I'm not an expert), I discovered the following very convenient coincindence:
[END Preface]
With a first-order speaker crossover at 800Hz, the location and slope of the treble cut in the signal going to the low end is very close to that of the James (SVT-CL) treble control set to zero! (This is according to the Duncan Tone Stack Simulator of the James stack with the circuit values set to be the same as in the SVT-CL. It's 6dB/octave and down about 16dB at 4kHz.)
View attachment 4164707
The result is a rig whose sound is *exactly* what I had asked for. I'm very relieved that the money wasn't wasted. Very lucky.
***
There are more consequences for me:
-I'm confident that the decision to reduce the number of drivers (to reduce the complexity of their interactions) was correct for me (with the 810 a distinctive alternate).
-I'm sure that I prefer a smooth rolloff of the highs (just as the enclosure shapes a smooth rolloff of the lows) instead of the (ragged) natural rolloff of the driver (which adds a voice that I don't need for bass).
-So I think that most of the pressure is removed from the selection of the *exact* 15" driver with the perfect voice in that sense; all of the popular ones will have
enough highs, which will probably be smoothly rolled off anyway.
- As I'm never ("Never say never"? Wrong this time.), NEVER going into a Class D amp to try to mould it as I would a tube amp, I am resting comfortably with this new amp as a pure "black box".
-I have another all-tube amp, currently in pieces and needing a rebuild (to convert it from circuit boards and too-small components to old-fashioned construction that I can work with), which (according to my knowledge and according to how it sounded) should have much tighter speaker damping than an SVT, but it can go on a back burner now. No pressure to get it back together, as this new amp is performing this function. I took it apart to improve hum and noise (which I know I can do), but I'm kinda sick of that scene. Life is short, etc.
It's a lot off of my mind!
All of this is for the sake of my Embassy Pro (among others), which is a member in good standing of the THUNDERBIRD family.
It had new tubes installed about 3 yrs ago and a grid resistor just before I got it from a TBer. It was always more quite than my trusty V-4BH (same 100w head), which was not a problem since I just had this as a back up and for home use. The store that had my trusted amp tech closed and I have no idea where he's at. Going to have to find someone when this gift from another region is under control. Why can't I live in SoCal or better Chucky live in Ky?
