When it comes to Boutique Pedals, nothing beats the Matchless Hot Box. Its a Preamp/Overdrive pedal. Everything about it spells boutique. The chassis is some kind of hard stainless gauge steel. All the components are point to point. Resistors ( not a single carbon film resistor in use) and Caps are top notch, some caps are even customized for Matchless. There two 12ax7 tubes mounted in phenolic sockets with a built in 220 volts power supply. Controls are lit internally like all matchless stuff. It costs around US$400 if you can find one. It beats that so-called modded TC Electronic SCF on the other thread. By the way, I like my SCF just as is without any tubes and stiff middle finger. That finger has serious confidence/ego issues.
But does it sound US$400? It depends and it did not WOW me. I tried and forced myself to like it but it was such a disappointment -- it was only after I changed one of the tubes to a NOS GE 12at7 that the Hot Box really come into being. I replaced some SOVTEK 12ax7 and boy what an improvement a genuine GE or Brimar made in the overdrive sound. It now sounds close to my Vox AC30 though not exact. Suddenly the fuzzy gain of the pedal turned into a smooth and sweet overdrive thru a strat. It just made my strat fat without any loss of definition. Upon further research I can still mix and match other tubes and actually dictate the level of drive on the Hot Box. Furthermore, the circuit is so sensitive to type and construction of the tube that you can change tonalities by changing tubes. NOS seems to be the best choice for this critter. This was not so with my Mesa Vtwin which was not at all sensitive to the type of tube, it just sounded fuzzy. What I like about the Hot Box is that it has now become flexible in terms of sound. No need for mods or switching ICs, all you have to do is switch tubes and it takes a different property.
However there are cons to it -- it cannot be powered by a 9 volt, the pedal has a large footprint, it ain't true bypass. But even without true bypass, the clean signal sounds great and rich.
For me, this is the top of the heap when it comes to boutique -- even beating the Klon Centaur. It however is really dependent on how much extra you are willing to shell out for NOS preamp tubes and thus mileage varies. So, I have to say it is an acquired taste and you have to be very specific with regards to its application. After all, not everyone likes the sound of a vox. But one thing is for sure, when it comes to construction, workmanship and what it does in totality, no stompbox in anybody's arsenal can match.