hi guys,
sorry if this seems like a dumb one, but here goes. I'm working on my first project which is a blackface-style champ. I finished the work today and of course despite my great care, it's not working.....lots of hum and my lightbulb's burning brightly. I'm retracing my steps (i'm using Tino Zottola's book Volume 1)carefully, double checking all my moves, but It's been nagging at me that some of the resistors I used got pretty hot while soldering. Maybe very hot would be more honest. Did I burn these up? I'm not getting Ohm readings off some of them and am wondering if that could be at least part of my problem. I tend to overdo it a little making sure my soldering connections are good. I also probably have my soldering station set too hot (650F). I'd appreciate some tips and would like to know about the whole heat/resistor thing. I appreciate your time.
regards,
blueman61
resistor question froma 1st timer
Moderators: pompeiisneaks, Colossal
Re: resistor question froma 1st timer
Blueman61,
I guess it possible but I doubt it. I set my iron at 650 all the time. It's not the temp but the technique that matters. It may be something entirely different like a wire you forgot to ground or something else simple. Why don't you start out by giving us some photos and some symptoms. Does it make any sound? Have you checked your voltages at the tube socket pins?
I guess it possible but I doubt it. I set my iron at 650 all the time. It's not the temp but the technique that matters. It may be something entirely different like a wire you forgot to ground or something else simple. Why don't you start out by giving us some photos and some symptoms. Does it make any sound? Have you checked your voltages at the tube socket pins?
Great things happen in a vacuum
Re: resistor question froma 1st timer
Blue,
Temperature of the iron is not the only issue - it's also a matter of how long you leave the iron on the component. Leave it long enough and maybe you could cook a few resistors. Since you are experimenting, locate a few of the resistors that are not reading anything and remove them from the circuit. Now see if they read what they are spec'd.
"Overdoing" a solder joint can be a bad thing. This may be a good time to refine your technique.
Temperature of the iron is not the only issue - it's also a matter of how long you leave the iron on the component. Leave it long enough and maybe you could cook a few resistors. Since you are experimenting, locate a few of the resistors that are not reading anything and remove them from the circuit. Now see if they read what they are spec'd.
"Overdoing" a solder joint can be a bad thing. This may be a good time to refine your technique.
Re: resistor question froma 1st timer
There is no need to pull the resistors out of the circuit to check their value unless they are paralleled with a capacitor. Just put your meter leads on the resistor leads and take a reading.
Great things happen in a vacuum
Thanks
I'll attatch a couple photos as soon as I can. Thanks for all the input. I knew about a few of these things, but will follow advice and see if I have success. I'm not leaving the iron on the joint for more than a second or two but in my( perhaps overzealous) efforts to make wires and component leads as short as possible, some of the resistors are mighty close to the solder joint and heat up fast. FYI, this amp has trminal strips not a board. I'm headed out to the shop right now and will hopefully meet with success, if not I'll get back on here kicking and screaming I'm sure. Thanks again. I truly appreciate the feedback and support. BTW, bnwitt, you're not the guy from Brown Note are you?
Regards,
blueman61
Regards,
blueman61
Success then.....
Hi guys,
I had some luck with my champ. I found several mistakes and corrected them. I then had about 10 minutes of satisfaction playing my guitar through the low input jack during which time the amp buzzed once or twice for about a nanosecond and then functioned very nicely. Feeling very succesful and a little full of myself, I then pugged into the High output jack and the amp buzzed "like a cheap TV" (thanks for the metaphor Bill Kirchen). After this, I plugged back into the low input and the buzzing continued with no more guitar sound other than a faint garbled distorted mess when I played (much quieter than the overwhelming buzz). I tested all the voltages and they are on the low side. For example: Pin 2 of the 5Y3 should have 5v AC wrt pin #8 and 325 DC. I'm getting 3.8 volts AC/ 286 DC. I know so little that I don't even know if this is within the parameters of acceptabilty. Other voltages are similarly low. The good news is that nothing has blown up and my lightbuld is down to a dull glow after the intial switching on. I can't help feeling that something is touching something else it shouldn't and that I'm very close to success if I could just find it. I'd like to post some photos for reference, but can't seem to figure that out either. I'm having a major case of feeling like a moron, so any help with posting photos (make it very basic step by step please) or any ideas would be most appreciated. FWIW, my PT is a Hammond 272x and my OT is a Hammond 125CSE. Hope you guys can help.
regards,
blueman61
I had some luck with my champ. I found several mistakes and corrected them. I then had about 10 minutes of satisfaction playing my guitar through the low input jack during which time the amp buzzed once or twice for about a nanosecond and then functioned very nicely. Feeling very succesful and a little full of myself, I then pugged into the High output jack and the amp buzzed "like a cheap TV" (thanks for the metaphor Bill Kirchen). After this, I plugged back into the low input and the buzzing continued with no more guitar sound other than a faint garbled distorted mess when I played (much quieter than the overwhelming buzz). I tested all the voltages and they are on the low side. For example: Pin 2 of the 5Y3 should have 5v AC wrt pin #8 and 325 DC. I'm getting 3.8 volts AC/ 286 DC. I know so little that I don't even know if this is within the parameters of acceptabilty. Other voltages are similarly low. The good news is that nothing has blown up and my lightbuld is down to a dull glow after the intial switching on. I can't help feeling that something is touching something else it shouldn't and that I'm very close to success if I could just find it. I'd like to post some photos for reference, but can't seem to figure that out either. I'm having a major case of feeling like a moron, so any help with posting photos (make it very basic step by step please) or any ideas would be most appreciated. FWIW, my PT is a Hammond 272x and my OT is a Hammond 125CSE. Hope you guys can help.
regards,
blueman61
almost forgot!
I have replaced both input jacks with brand new switchcraft models and this has produced no changes. I also have the jacks sinsulated from the chassis with insulating washers.
Blueman61
Blueman61