J 595 RV pics [message #15433] |
Sun, 20 March 2011 13:23 ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
Marc
Messages: 7 Registered: March 2011 Location: NC
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Junior Member |
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I have pics of the preamp and effects boards from a J595 RV available for upload.
I'd like to add images to this post but I don't have a pic sharing site. How do I go about uploading pics?
I'd be happy to forward them to someone who could upload them....
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Re: J 595 RV pics [message #15438 is a reply to message #15436] |
Sun, 20 March 2011 17:35 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
conductortom
Messages: 96 Registered: July 2010 Location: Okla
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Member |
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Pictures look good, but my affects board is different then that one. Is that head a pa head or a guitar head? Was that the right schematics? Thanks Marc and Bart
Tom
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Re: J 595 RV pics [message #15479 is a reply to message #15433] |
Fri, 01 April 2011 12:07 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
chicagobill
Messages: 2005 Registered: April 2003
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Senior Member |
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The first thing to determine is to see if the lamp is flashing at all. As I recall, the lamp doesn't light up really bright at all, but you should be able to see the light get dimmer and brighter.
If the light doesn't flash, then you need to see if the vibrato LFO (low frequency oscillator) is working. And then see if the driver circuit is getting the fluctuating voltage to the lamp.
Check the dc voltage at the collector of Q310. The schematic shows that it swings from 9-12 volts. You should be able to read the voltage here and see it rise and fall at different rates depending upon where the speed control is set.
If you do have a working LFO, then follow the varying voltage from the collector of Q310 to the top of the intensity control. Then from the wiper of the intensity pot through C315 and R330 to the base of Q309 and on to Q308, etc.
Have you tested the three transistors Q308-Q309-Q310?
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Re: J 595 RV pics [message #15489 is a reply to message #15433] |
Mon, 04 April 2011 12:56 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
chicagobill
Messages: 2005 Registered: April 2003
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Senior Member |
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It just looks that way, if you look at the back of the board in the next photo, you'll see that the trace is not grounded at that point.
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Re: J 595 RV pics [message #15496 is a reply to message #15433] |
Tue, 05 April 2011 18:57 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) |
stevem
Messages: 4758 Registered: June 2004 Location: NY
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Senior Member |
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Yup, I took a quick galnce at it and was going by what I could see of the shadow of the trace thru the board.
Sorry!
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