There are Vids to look into to set gains with min tools ,like a dmm and a volt clamp meter even. I tune by ear.. Old school way.. Its not perfect, but it has worked for me for more than 20 yearsare there any voltage and wattage meters similar to the smd meters, that dont cost an arm and a leg .he cant be the only one putting them out. he may have his own shop but there has to be someone else that has made some. if thats the case, then i need to learn to make some and get in on the market.