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Hello, first I will apologize for my bad English and grammar skills, its not my native language.
My peavey xxx has a problem, i think The amp is on the ultra channel by default, when i switch to crunch only the crunch LED comes on alongside the ultra LED, no relay clicks. also when on the Ultra/crunch channel the controls for the channels are mixed up.
The only way i can make it switch normally is by removing the preamp tubes V1 or V3, that way the amp switching works fast and the way it was intended. I also checked the continuity between the relay (K2, K3) pins to make sure everything was switching with the preamp tubes removed, and every thing seems to be operational.
with preamp tubes on i was getting around 12-13v supply to the relays, with the tubes out, i was getting around 17-19v.
so im guessing there is a short in the heater circuit? if i understand the schematic correctly the voltage supply for the relays is the same for the heaters.
SCHEMATIC :
https://www.thetubestore.com/lib/the...-Schematic.pdf
I checked the heaters at pin 4-5, if thats helps,
V1 with tube pin 4 = 5v, pin 5 = 4.5v
without tube pin 4 = 0v, pin 5 = 0v
V2 with tube pin 4 = 14.9v, pin 5 = 5v
without tube pin 4 = 24v, pin 5 = 0v
V3 with tube pin 4 = 13.5v, pin 5 = 4.6v
without tube pin 4 = 21v, pin 5 = 0v
There is a 4.7k resistor (R77), its after the rectifier connected to the AC heater supply, I get 22v on one side and 22v on the other, no voltage drop, the resister measures 4.7k with my meter, i hope this might help too.
if anyone can guide me in the right direction i would be thankful. Im no tech or an electrician but i can solder and have a meter and i already took the whole amp apart so im aware of some safety issues, and i believe the capacitors self drain when the amp is of, i do check them with the meter just to be sure.
This is my last try to fix this thing, after that i think im done with it.
THANK YOU ALL
P.S
Things i've done in the past attempts to fix it:
I replaced the k3 relay with a 12 volt relay ( different type I couldn't find the same relay in my country ) I replaced Q7 Q8 Q10 Q11 transistors.
I also dissembled the toggle switch and cleaned the inside contacts, I removed the ribbon cables and soldered regular wires because the ribbon cables were loose.
My peavey xxx has a problem, i think The amp is on the ultra channel by default, when i switch to crunch only the crunch LED comes on alongside the ultra LED, no relay clicks. also when on the Ultra/crunch channel the controls for the channels are mixed up.
The only way i can make it switch normally is by removing the preamp tubes V1 or V3, that way the amp switching works fast and the way it was intended. I also checked the continuity between the relay (K2, K3) pins to make sure everything was switching with the preamp tubes removed, and every thing seems to be operational.
with preamp tubes on i was getting around 12-13v supply to the relays, with the tubes out, i was getting around 17-19v.
so im guessing there is a short in the heater circuit? if i understand the schematic correctly the voltage supply for the relays is the same for the heaters.
SCHEMATIC :
https://www.thetubestore.com/lib/the...-Schematic.pdf
I checked the heaters at pin 4-5, if thats helps,
V1 with tube pin 4 = 5v, pin 5 = 4.5v
without tube pin 4 = 0v, pin 5 = 0v
V2 with tube pin 4 = 14.9v, pin 5 = 5v
without tube pin 4 = 24v, pin 5 = 0v
V3 with tube pin 4 = 13.5v, pin 5 = 4.6v
without tube pin 4 = 21v, pin 5 = 0v
There is a 4.7k resistor (R77), its after the rectifier connected to the AC heater supply, I get 22v on one side and 22v on the other, no voltage drop, the resister measures 4.7k with my meter, i hope this might help too.
if anyone can guide me in the right direction i would be thankful. Im no tech or an electrician but i can solder and have a meter and i already took the whole amp apart so im aware of some safety issues, and i believe the capacitors self drain when the amp is of, i do check them with the meter just to be sure.
This is my last try to fix this thing, after that i think im done with it.
THANK YOU ALL
P.S
Things i've done in the past attempts to fix it:
I replaced the k3 relay with a 12 volt relay ( different type I couldn't find the same relay in my country ) I replaced Q7 Q8 Q10 Q11 transistors.
I also dissembled the toggle switch and cleaned the inside contacts, I removed the ribbon cables and soldered regular wires because the ribbon cables were loose.