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Post by elvis8burgers on Sept 16, 2010 17:22:11 GMT -7
big time....like I don't think a 20/40 should. On the 20w setting, there is a noticeable, loud intrusive hum, which gets louder as the gain knob is increased to max. On the 40w setting, it's louder still.
The head was built 13 months ago. I'm putting the amp through an O/B cab fitted with 2 x Cel Golds and wired for 16ohm load.
Anyone got any suggestions before I whip it in to my amp man and ask him to put his slide-rule across it?
Otherwise, my first Z and I'm liking it lots.
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Post by JasonM on Sept 17, 2010 16:06:34 GMT -7
Does it hum with the reverb off? Any of the tubes look/glow weird?
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Deleted
Deleted Member
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Post by Deleted on Sept 18, 2010 16:40:48 GMT -7
Does it hum with the reverb off? Any of the tubes look/glow weird? Process of elimanation Is it humming with no guitar plugged in. If your plugged in it could easily be your pickups. I use mostly single coils. They hum..Just the Nature of the Beast.
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Post by elvis8burgers on Oct 17, 2010 15:10:42 GMT -7
Does it hum with the reverb off? Any of the tubes look/glow weird? Process of elimanation Is it humming with no guitar plugged in. If your plugged in it could easily be your pickups. I use mostly single coils. They hum..Just the Nature of the Beast. Turns out V1 and V2 had both gone west and need replacing. New valves on order. Together with a minor board mod that Z have recommended (1 resistor value change) and the new valves on board, I should be rockin' again soon. Also had the reverb tank and leads out as thought they might not earthing properly, but all checked out AOK. Brent & Jim at Z have been extremely helpful during my diagnostic Q & A stages - so big thanks to them both. As always, it's the simple things that can be overlooked - as Edwin Starr said "Tubes! Ha! what are they good for?" or was it something else.......?
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Post by argytar on Oct 18, 2010 15:23:33 GMT -7
hi! I got occasional hum problems too mostly associated with the reverb. Which resistor did the doc recommend changing and with what type/value? Thanks!!
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Post by elvis8burgers on Oct 21, 2010 9:57:53 GMT -7
There is just one resistor changed from 2.2Mohms to 1.2Mohms. I have board plans pre- and post change that identifies which one. If you message me your email addy I can copy you. I don't have any way of posting publically.
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Post by pmpgator on Oct 29, 2010 17:53:26 GMT -7
Is that resistor change recommended for everyone? How do we find out if it is something we should do? What is the effect of the change?
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