Forum upgraded to SMF 2.1.2!
Started by Gustaf, May 06, 2016, 03:31:52 PM
Quote from: phatt on October 13, 2018, 08:49:58 AMI don't have that Amp but a read of the schematic tells me it will matter little as 12 volts is still within the 16 Volt cap ratings.I doubt you would hear any difference in the sonic result.Though V1 will last longer if heater is running 12Volts :tu:Phil.
Quote from: phatt on October 16, 2018, 08:31:37 AMNo way to really know without an A/B test circuit. But I'm guessing that with the Valve preamp section running wide open and then gain at 1C3A you are bound to have some hiss.You can always reduce R4 and 5 too a more sane 100k that will reduce some excess hiss but be aware that U3A is active even when the TS part is switched out.As far as the Valve section goes it's a Marshall/Bassman type circuit but volume is after tone stack which means the preamp is full on all the time so hiss will be evident even at lower setting of volume.R17 could be made as a pot for preamp gain, that might have worked better.Sorry I can't think of anything else,Phil.
Quote from: phatt on January 28, 2019, 01:10:32 AMSorry but Unless you tell us Where Exactly in the circuit have you inserted the new input,,it's all meaningless?could be VR9? or at R33?Forget the presence idea,, bad for the PI stage. xPPhil.