Yup, if you don't know how to use a voltmeter, it's time to take it to someone else for some electron tracking. If David is up for it, that's be good because he's close (I think). (Don't you love it when someone volunteers you?!)
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| Author: | Guy [ September 17th, 2013, 12:43 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
Yup, if you don't know how to use a voltmeter, it's time to take it to someone else for some electron tracking. If David is up for it, that's be good because he's close (I think). (Don't you love it when someone volunteers you?!)
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| Author: | craigh [ September 17th, 2013, 12:56 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
David did look at it. I did as he suggested & I replaced surge voltage capacitor, rectifier tube & fuse. All tubes properly glow but no sound. Craig |
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| Author: | randy warren [ September 17th, 2013, 1:48 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
did David get it working at his house? When was the last time it made sound? And by sound, do you mean NOTHING? No hum, noise, anything? |
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| Author: | craigh [ September 17th, 2013, 2:02 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
David figured out there was a short. We never hook it up for music due to that. It worked till it shorted out roughly six years ago. Today no sound, no noise & no hum. Just the beauty of the light tubes. |
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| Author: | Guy [ September 17th, 2013, 2:30 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
It looks like there is more than one problem, so it would be good if David can take another look at it. It may seem frustrating, but I bet there's not much more wrong with it. The short may have taken something else with it, or something is just a bit too old. I'm sure it will work again! 
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| Author: | Roscoe Primrose [ September 17th, 2013, 2:51 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
Guy wrote: just a bit too old. I'm sure it will work again! Guy uses that line a lot 
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| Author: | craigh [ September 17th, 2013, 4:59 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
I'm just a bit too old. LOL |
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| Author: | dberning [ September 17th, 2013, 6:42 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
Yes, we had it working here with the 5U4. The filter capacitor was bad in addition to the shorted rectifier tube which blew the fuse. We had it working, but there was very high ripple in the power supply, but the amp put out good power in both channels. I suspect that you are missing a B+ connection when you installed the filter capacitor. There are a lot of chances to do this as it is a multi-section capacitor. A multi-meter would help track down the problem, and I would be happy to take another look to see what's wrong. David |
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| Author: | craigh [ September 17th, 2013, 8:49 pm ] |
| Post subject: | Re: My dead Dynaco ST-70 |
I would appreciate that. When is good for you? Craig |
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| Author: | craigh [ September 20th, 2013, 11:24 am ] |
| Post subject: | Re: My dead Dynaco ST-70 |
The ST-70 is up & running. Doesn't have the "slam" of the SS amp I was using but it's so much better. Thank you for everything David. Craig |
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