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J 595 RV pics [message #15433]

Sun, 20 March 2011 13:23

Marc
Messages: 7
Registered: March 2011
Location: NC

Junior Member

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 #15434 is a reply to message #15433]

Sun, 20 March 2011 14:42

Kustom_Bart
Messages: 601
Registered: October 2010
Location: Greenville, MichiGUN

Senior Member

You can forward them to me @ btketner@charter.net and I will put them up for you.

Bart

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Re: J 595 RV pics [message #15435 is a reply to message #15433]

Sun, 20 March 2011 15:50

Kustom_Bart
Messages: 601
Registered: October 2010
Location: Greenville, MichiGUN

Senior Member

Pics, thank you Marc Smile

http://i27.photobucket.com/albums/c176/bketner/k1.jpg

http://i27.photobucket.com/albums/c176/bketner/k2.jpg

http://i27.photobucket.com/albums/c176/bketner/k4.jpg

http://i27.photobucket.com/albums/c176/bketner/k3.jpg

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Re: J 595 RV pics [message #15436 is a reply to message #15435]

Sun, 20 March 2011 15:52

Marc
Messages: 7
Registered: March 2011
Location: NC

Junior Member

cool! they turned out better than I thought they would!
Thanks!

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Re: J 595 RV pics [message #15438 is a reply to message #15436]

Sun, 20 March 2011 17:35

conductortom
Messages: 96
Registered: July 2010
Location: Okla

Member

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 #15439 is a reply to message #15438]

Sun, 20 March 2011 17:58

Marc
Messages: 7
Registered: March 2011
Location: NC

Junior Member

Both are guitar heads, I think. The have two channels; effects and no effects.
the owner only brought the chassis so I'm assuming they are both heads....

Marc

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Re: J 595 RV pics [message #15478 is a reply to message #15439]

Thu, 31 March 2011 22:27

Marc
Messages: 7
Registered: March 2011
Location: NC

Junior Member

Well, I replaced all the electrolytics on the effects board and found them to be 25% and up out of tolerance and a couple were dead or my fluke just couldn't read them. That replacement shotgun got the reverb working again.

The tremolo as shown in the pics was missing the lamp. the LDR seems to work as it varies with light. I got a #48 lamp and shrink wrapped them all cozy and re-installed the bug. No go on the tremolo. The light end seems to have a varying voltage but there is no action on the ldr end. I tried a known working bug from another kustom and it didn't work either.

I have got over the solder joints touched up a few that looked maybe suspect. I next to nothing about transistor circuit trouble shooting but it seems like all the legs of the transistors have voltages that are roughly close to the schematic.
The schematic I have is very close to the board although the voltages are exact they are pretty close.

Any common fixes that anyone can share?
Thanks,
Marc

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Re: J 595 RV pics [message #15479 is a reply to message #15433]

Fri, 01 April 2011 12:07

chicagobill
Messages: 2006
Registered: April 2003

Senior Member

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 #15484 is a reply to message #15433]

Sat, 02 April 2011 11:42

stevem
Messages: 4775
Registered: June 2004
Location: NY

Senior Member

Hi.
In that first picture you posted that big black cased 1966 dated cap on top center has its + lead going to ground and that should not be the case.

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Re: J 595 RV pics [message #15489 is a reply to message #15433]

Mon, 04 April 2011 12:56

chicagobill
Messages: 2006
Registered: April 2003

Senior Member

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 #15492 is a reply to message #15489]

Mon, 04 April 2011 17:45

Marc
Messages: 7
Registered: March 2011
Location: NC

Junior Member

thanks guys, I haven't had a chance to get these amps back on my bench...I'll update as soon as I do....

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Re: J 595 RV pics [message #15496 is a reply to message #15433]

Tue, 05 April 2011 18:57

stevem
Messages: 4775
Registered: June 2004
Location: NY

Senior Member

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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