A Black Box to Solve Everything

@bdp24 Yes a preamp and a reasonably easy kit to build. Nelson is brilliant with solid state devices and while Ralph and Roger are/were known for their brilliance with tubes, Ralph has now demonstrated he can manufacture a solid state amp with similar distortion characteristics as tubes. Somewhat of a little known fact, Roger's first amp to be manufactured was the one he designed for the Beveridge 2SW speaker. It was a solid state amp designed specifically for the woofer section. This required him to develop the RM-3 active crossover to act as a frequency dividing network as the 2SW required biamping. The RM-3 also used sold state devices.

Getting back to the B1, Nelson's choice of the Korg Nutube is interesting and I'm sure was selected to support his circuit requirement to allow for the adjustable harmonics. However, it's probably the worst tube I have ever dealt with. Many examples of this tube are extremely microphonic. I went through 3 of them building that kit and none of them were quiet enough. So I never could really test out the adjustable distortion feature.

@knotscott 

Tubes for guitar and tubes for hi fi have very different objectives. Audible distortion for a guitar amp is a desirable feature, not so for a hi fi amp.

FYI, distortion ("overdrive") is not the sole goal or attribute of guitar amps/pedals that attempt to mimic tubes!  "Clean" tube tones are as prized as "dirty" tube tones as is the ability of some of them to mimic a variety of amps that are associated with different types of tubes. Some examples include but are not limited to: 6L6/6V6 for Fender, EL34 for Marshall, EL84 for Vox, etc. This seems quite in line with what the OP states:

My thinking is that of a black box with switches and knobs to adjust harmonic distortion to mimic different tube types. 

 

 

@koestner 

I have a BSG QOL Signal Completion processor in my system and I use it most of the time. It is not adjustable and I would not describe it as adding any sort of tube distortion. It affects the phase information in the signal and adds depth and focuses the imaging. I suppose one could describe these effects as tube virtues but I've never heard any piece of tube gear that has such a dramatic impact on the signal. I also have a Yaqin tube buffer which produces a very subtle difference - nothing close to what the QOL provides.

BTW, I've experimented with several signal processors and the QOL is the only one I use. It adds a very nice effect.

Isn’t this whole conversation a bit ironic? Trying to create a high tech solid state device to mimic the natural, 3 dimensional sound of a simple tube based circuit?  I always thought that the primary reasons why good quality tube amps can sound so good is the relative simplicity of their design w/far less components on the signal path & the high voltages they can swing? Not sure if an additional “ black box” would help this ?

Indeed, @jonwolfpell. I wince when I see someone describe an amp as adding "tube warmth" to the sound. That’s not what good tube amps do; what they do is not create the "cold, hard, dry" sound of bad solid state. I always loved the term J. Gordon Holt used to characterize the sound of the best tube amps: liquidly transparent.

I vividly recall the first time I heard "grain" in the sound of electronics. I was already aware of the term and concept from photography, and to then hear tiny little "clumps of sound" in the sonic "picture" a hi-fi was creating (one with solid state pre and power amps), in contrast to the grain-free liquidity of the sound the ARC system (pure tube, not hybrid) I was comparing it with was creating, was clearly audible.

The appeal of tubes to me has always been not what they add, but what they don’t.