Eden Wt 800. Preamp circuit maintenance

[KonnorA]

I'm running In to issues with the output resistors on the preamp circuit getting hot. when using the amp bridged mono.

the stock resistors are
3w 390ohm.
And 5w 390 ohm

I first just raised the resistors off the board a little bit but they're still getting way to hot
Any thoughts.
theese are the ceramic cement axial resistors. maybe there's a better component
Or maybe I can get a higher wattage ?

[Dave H]

Eden WT800 sch.pdf

[nosaj]

I'm running In to issues with the output resistors on the preamp circuit getting hot. when using the amp bridged mono.

the stock resistors are
3w 390ohm.
And 5w 390 ohm

I first just raised the resistors off the board a little bit but they're still getting way to hot
Any thoughts.
theese are the ceramic cement axial resistors. maybe there's a better component
Or maybe I can get a higher wattage ?

What problems are you having with the amp or are you hunting for an issue to fix? No disrespect meant but you opened the amp for some reason.

nosaj

[nevetslab]

Those are the HV supply dropping resistors, standing vertically, joined in series, ahead of the 15V Zener diodes (1N4744A). That's always been a weak link in this earlier version of the WT800. You might want to change those vertically-mounted PCB resistors to a pair of 20W Axial parts, mount them onto the floor with terminal strips, though space is tight in there. Those are ALWAYS running hot, as the load is constant. They finally added a LV CT winding to make use of a pair of 3-terminal IC regulators, which solved that problem, while introducing a new problem of the leads not quite reaching the PCB reliably.



Putting a pair of 20W axial lead resistors of appropriate value (750 to 820 ohm) leaves you having to deal with the other 5W resistors already glued to the floor.

Are you losing either of the LV Bipolar supplies from heat damage on the preamp board?