Exceptional for correcting the FX Loop of an amp that has a simple break between the pre and power, with enough signal to drive the send and return efficiently. Has a voltage doubler which gives 31V from the 9V supplied. Bias is at 22V for the J201 Fets. More details after the pics below:
Mini Klein-ulator Buffered FX Loop – The Rig Doctor Inc. (therigdr.com)
Nik from Ceriatone:
''In early spring of 2007, I decided I wanted to build a certain rare, expensive, and Californian amplifier, and I began to go through the previous years of research I had done. Pictures, schematics, even conversations I had read became fair game. Keep in mind, this was before I discovered some of the great internet forums dedicated to building these types of amplifiers. In any case, I came across a design for tube-driven effects loop interface. It was designed for use with the passive serial effects loops in these incredible amplifiers. I quickly decided that I too needed to build one of these tube effects loop buffers. Unfortunately, design parameters plagued the process. I couldn’t find a transformer of the same size and mounting, and the unit’s power supply was still a mystery. About a month after I decided I HAD to have one, the project was temporarily shelved. A few weeks later, I realized that I might be able to come up with a solid-state version that performed similarly, but was much easier and inexpensive to build. After some brain-storming, I posted a schematic and layout of a working Klein-ulator in the public domain. While the freeware unit works great, I knew I could make it better. I redesigned and tested new ideas over the next year, and even had the opportunity to compare it to a Dumbleator-based tube effects loop buffer I built (thanks to various individuals who helped me procure parts). Once I was able to compare it to an “actual” unit, I was able to change a few things to improve the design further. Upon careful testing, it became clear that the two 3 designs (one tube and one solid-state) performed shockingly similarly. Both units smoothed the tone in a very pleasing manner, and added a perceived “3D” effect to single note lines. Both could be used to overdrive an amplifier’s phase inverter for lush and very complex tones. I was also able craft the solid-state unit’s frequency response to the same as the tube unit. Most importantly, both units allowed the successful use of effects in an amplifier’s passive effects loop. While the Klein-ulator is not meant as a “replacement” for the tube-driven units, I think you’ll find it performs quite well. I hope you enjoy it''
