AC or DC on pins ?
Moderator: VelvetGeorge
- Stretchy
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AC or DC on pins ?
Noob question... Just finished my build (100 watt), powered it on, nothing blew (that's good), got conclusive readings on pin 2 and 7 of v4-7 and pin 4- and 9 of v1-3. That measurement was in AC.
Then, following the guide, I checked pin 5 of V4-7 and got ok readings (in the range the guide says it should be), that measurement was done in DC.
Then, I know I should check the voltages against the chart voltage. My problem is that I know that pins 2 and 7 of power tubes should be in AC and pin 5 in DC, but for the rest, like pin 4, should I be AC or DC ? Was it somewhere in the guide but I'm too tired too see ?
Also, I wanted to drain the caps as per the guide, but wanted to make sure I had current in the caps before trying to drain them, and when I checked on the caps itself, using DC on a 600V range,I never saw any readings... how could this be ? Afterwards I did the draining procedure jsut in case. Could someone have readings like I had(pin 2 and 7 of power tubes and bias readings and so on) with such a major problem as having no power in the filter caps ? Is my multimeter good for the dump ?
Then, following the guide, I checked pin 5 of V4-7 and got ok readings (in the range the guide says it should be), that measurement was done in DC.
Then, I know I should check the voltages against the chart voltage. My problem is that I know that pins 2 and 7 of power tubes should be in AC and pin 5 in DC, but for the rest, like pin 4, should I be AC or DC ? Was it somewhere in the guide but I'm too tired too see ?
Also, I wanted to drain the caps as per the guide, but wanted to make sure I had current in the caps before trying to drain them, and when I checked on the caps itself, using DC on a 600V range,I never saw any readings... how could this be ? Afterwards I did the draining procedure jsut in case. Could someone have readings like I had(pin 2 and 7 of power tubes and bias readings and so on) with such a major problem as having no power in the filter caps ? Is my multimeter good for the dump ?
- Stretchy
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Re: AC or DC on pins ?
Was reading the master volume guide to look at the clearer picture in them to help me spot a problem on my 100W and it seems that in the testing sequence, after testing what I tested (bias and heather wires) I shound throw the standby switch (which seems pretty darn logical), but since I followed the guide so precisely I haven't done this (reread it and never saw any mention of throwing the standby switch in the testing sequence).
I'm preparing to work now, but could this explain the problems I got ?
Also, in this master volume guide, I checked the chart and it indicates where AC should be read!
I'll test it this evening... the day will be long.
Let me know if you think I got it wrong...
I'm preparing to work now, but could this explain the problems I got ?
Also, in this master volume guide, I checked the chart and it indicates where AC should be read!
I'll test it this evening... the day will be long.
Let me know if you think I got it wrong...
- Stretchy
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Re: AC or DC on pins ?
Hmmm... no one ?
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Re: AC or DC on pins ?
Yes, flip the standby switch when reading the voltages on the pins. Otherwise, there's no high-voltage running through the amp.
- Stretchy
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Re: AC or DC on pins ?
Thanks!
That's what I decided to do after reading the other guide. The amp is alive, sound INCREDIBLE and with less bacground noise that my Marshall 1987 RI... Nice glassy sound. Gonna crank it a bit tomorrow!
Thanks for the help. Is it me or the part when we should flick the standby switch is not in the guide ?
That's what I decided to do after reading the other guide. The amp is alive, sound INCREDIBLE and with less bacground noise that my Marshall 1987 RI... Nice glassy sound. Gonna crank it a bit tomorrow!
Thanks for the help. Is it me or the part when we should flick the standby switch is not in the guide ?
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Re: AC or DC on pins ?
Yeah, the instructions leave a few things out.
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Re: AC or DC on pins ?
Do you need to have speakers hooked up when you throw the standby switch?
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Re: AC or DC on pins ?
yes you must have speakers connected when you turn the amp off from standby into high voltage mode. YOu can destroy your amp like that. I made a mistake of pulling the wire out and even one sec is too long.
- toner
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Re: AC or DC on pins ?
Only if the power tubes are installed.Invocator wrote:Do you need to have speakers hooked up when you throw the standby switch?