@alightronics found them on Amazon, very competitive pricing. Are data sheets available?
One of my amps runs the 300b very hot, 550v on the plate,100mA fixed bias with 55w dissipation to output 20wpc. The amp was designed for KR 300B XLS super 300b tube. Only other substitute I’ve found is Emission Labs 320B XLS that can handle the heat. Both KR and EL are $1,000+ pair. The KR is a fantastic tube in the amp, as it should be for the price!
Looking for cheaper substitute/backup. Is the Horizon designed like typical WE 300b with max ratings of 400v, 100mA and 36w dissipation? Or can it handle the heat of my Cary LX-20? I have another amp with 300b drivers to 845 power output tubes. It runs the 300b well within the WE specs.
thanks