Hello everyone on the forum!
I am a new member and I write from Sardinia.
In my city there are few technicians and therefore I decided to "specialize" in repairs, even if I'm just starting out!
I find myself with this hiwatt t40 combo with numerous problems.
listing I don't have the negative voltage of the bias in pin 2 of the el84, so when I mounted a new set of el84 tubes I immediately noticed red plate.
furthermore this amplifier has a diode bridge on the filaments which tends to get hot.
I honestly don't understand how it was designed or at least this is very ambiguous.
Since the wiring diagram is not available and they never reply on the hiwatt.uk site, I ask you for a huge help.
I find myself in the position of not being able to repair this amplifier.
I tried to follow the diagram to have a logic, but I don't know why there is no negative voltage of the bias and because the graetz point heats up so much.
thanks if you can.
Sorry for my english.
Caesar
I am a new member and I write from Sardinia.
In my city there are few technicians and therefore I decided to "specialize" in repairs, even if I'm just starting out!
I find myself with this hiwatt t40 combo with numerous problems.
listing I don't have the negative voltage of the bias in pin 2 of the el84, so when I mounted a new set of el84 tubes I immediately noticed red plate.
furthermore this amplifier has a diode bridge on the filaments which tends to get hot.
I honestly don't understand how it was designed or at least this is very ambiguous.
Since the wiring diagram is not available and they never reply on the hiwatt.uk site, I ask you for a huge help.
I find myself in the position of not being able to repair this amplifier.
I tried to follow the diagram to have a logic, but I don't know why there is no negative voltage of the bias and because the graetz point heats up so much.
thanks if you can.
Sorry for my english.
Caesar
Because they don't care, their entry-level devices have become disposable.
Start by removing all the tubes and tracing the bias circuit from the power transformer.
then see if your diode bridge still heats up
if yes, find out why
if not, see if you have consistent values (by rule of thumb +/- 8 to 14v).
one last thing, if you're working on someone's device and knowing that you're not sure of yourself, don't charge for your services, it's the cost of your learning.
Thank you very much for replying, but I would like to clarify that it is true that I try to repair amplifiers but in this case it is my guitarist's amplifier, in the band of which I am the bassist!
I would never have asked for compensation!
in my city (Sassari) it is very difficult to find good technicians.
In any case, I'm the one who expressed myself badly.
I can't but thank you, but I find it really unjustified that no wiring diagram can be found for this amplifier, also because it has double tracks and it's really complicated for me as I'm a beginner.
In any case I will try to do the checks suggested by you!
I sincerely thank you.
I would never have asked for compensation!
in my city (Sassari) it is very difficult to find good technicians.
In any case, I'm the one who expressed myself badly.
I can't but thank you, but I find it really unjustified that no wiring diagram can be found for this amplifier, also because it has double tracks and it's really complicated for me as I'm a beginner.
In any case I will try to do the checks suggested by you!
I sincerely thank you.
