Looks like things are getting lost in the 6sn7 on the channel two side.
Good side 1.3V and the suspect bad side the voltage is not stable jumping between 650mV to 800mV
Good side 1.3V and the suspect bad side the voltage is not stable jumping between 650mV to 800mV
Did you clean that socket, tube pins, and the tone control pots?
Do that and try again.
That's a bit off, but the tone controls probably are not set to be flat.
The signal is not missing yet, so go on after cleaning the parts.
The scope is preferable to use, rather than the DVM, for signal tracing.
You are looking for presence or absence, rather than the exact magnitude of signals.
Please use the scope and not the DVM for the signal tracing.
Do that and try again.
That's a bit off, but the tone controls probably are not set to be flat.
The signal is not missing yet, so go on after cleaning the parts.
The scope is preferable to use, rather than the DVM, for signal tracing.
You are looking for presence or absence, rather than the exact magnitude of signals.
Please use the scope and not the DVM for the signal tracing.
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Yea I mean total dummy, I have this scope sitting there in front of me and I choose to use the DMM, lol. Okay I have to take a quick break I have not eaten all day but will get back to this asap!
Thank you!
Thank you!
Remember, there's no point in doing all of this until after you have cleaned
all the tube sockets, tube pins, pots, and switches.
all the tube sockets, tube pins, pots, and switches.
Okay agreed, I did what someone, maybe you told me, take the tubes out, wipe with deoxit and lintless towel, put back in and out a few times.
I just found a resistor that is not wired correctly, not sure if it would make a difference but it is on one of the output taps. Let me fix that.
Probably a bad ground connection on the probe.
Always use x10 probes on tube equipment.
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Yea i am using a cheap Chinese probe, I am in the process of a move and packed away my good probes! 🙁
So okay, that resistor I put it in the right place but it didn't make a difference, long shot anyway.
So, I am looking at the output blocks on this amp and it is very weird, how they work. The c2 output is connected to a block that isnt actually connected to the outputs of the transformer. The C1 is however connected directly to them. Looks like the c2 outputs go from the block (which has the speaker terminals, back to the phase revers switch and balance check switches on the front panel and then back? but I am not seeing anything except a couple wires on the block that has the putputs, very odd! I have to look in the schematic to figure it out.
So okay, that resistor I put it in the right place but it didn't make a difference, long shot anyway.
So, I am looking at the output blocks on this amp and it is very weird, how they work. The c2 output is connected to a block that isnt actually connected to the outputs of the transformer. The C1 is however connected directly to them. Looks like the c2 outputs go from the block (which has the speaker terminals, back to the phase revers switch and balance check switches on the front panel and then back? but I am not seeing anything except a couple wires on the block that has the putputs, very odd! I have to look in the schematic to figure it out.
There we go, traced it back to the Reverse normal switch, if I select the reverse, then the signal shows up at the output!
Let me like you said, do a proper clean on the switches, look closer at the schematic on the wiring of this rev norm switch and then I think we will be able to put this to rest!!! unreal 😵
Let me like you said, do a proper clean on the switches, look closer at the schematic on the wiring of this rev norm switch and then I think we will be able to put this to rest!!! unreal 😵
But that does not mean it's the switch.
That reverses the channels.
So actually that means the switch is ok.
But clean it anyway.
But still clean everything that has not yet been cleaned.
Otherwise it's a waste of time to look for problems, since we already know everything is dirty.
That reverses the channels.
So actually that means the switch is ok.
But clean it anyway.
But still clean everything that has not yet been cleaned.
Otherwise it's a waste of time to look for problems, since we already know everything is dirty.
Which cleaner for switches and which for wiper pots do you recommend again please? Deoxit but which ones? Thank you.
okay but if I have the switch in Norm, there is a channel 1 and no channel 2 signal, if I put the switch in Rev there are both channel 1 and channel 2.
Could be broken/bad wiring, bad solder joints, etc.
Could be dirt in the switch, or worn contacts in the switch.
yep, i am going to study the schematic and then look at what is there, from what I think I know, these Eico's could be bought as a kit so who knows, maybe the OG owner didn't wire it correctly? Also, clean in the meantime like you said!
yep, and also, i noticed that when i put the loudness to on, the signal amplitude will drop as well, something else to look into! 🙂