I am almost positive I had a short on the tone board (my fault...), power amp section seems to work fine if I press 'tone direct' but no sound through preamp.
I pulled all the transistors on the tone board and tested them using the diode function on a MM. Initially I thought the 2SK170s were bad but I may have been testing them wrong. Regardless, bought 4 new LSK170s from Linear Systems. Also replaced the 2SC1845s with KSC1845s since I had them lying around. All the other transistors tested good, which concerns me as I expected to find something toasted.
Paranoid about frying the LSK170s as they are expensive. I have a DBT and a cheap variac I just bought, anything I should watch out for when I power it up? I also have the preamp section disconnected from the power amp for now.
Was planning to just use the DBT and give it a go but thought I would do quick post to see if there was anything else I should be thinking about.
I pulled all the transistors on the tone board and tested them using the diode function on a MM. Initially I thought the 2SK170s were bad but I may have been testing them wrong. Regardless, bought 4 new LSK170s from Linear Systems. Also replaced the 2SC1845s with KSC1845s since I had them lying around. All the other transistors tested good, which concerns me as I expected to find something toasted.
Paranoid about frying the LSK170s as they are expensive. I have a DBT and a cheap variac I just bought, anything I should watch out for when I power it up? I also have the preamp section disconnected from the power amp for now.
Was planning to just use the DBT and give it a go but thought I would do quick post to see if there was anything else I should be thinking about.
Hmm 🙂
A variac or bulb would not provide any protection at all for small signal circuitry... but the good news is that the impedances around any FET in a preamp will be so high that damage is pretty much impossible.
I think whatever your 'no sound' problem is with the tone circuit in circuit will be found through simple basic fault-finding.
A variac or bulb would not provide any protection at all for small signal circuitry... but the good news is that the impedances around any FET in a preamp will be so high that damage is pretty much impossible.
I think whatever your 'no sound' problem is with the tone circuit in circuit will be found through simple basic fault-finding.
First thing you should do is download schematic or service manual from elektrotanya and upload it here.