EZ81 Subs any other choices?
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Truth is, it depends if you notice!nyazzip wrote:
by the way, is it dramatic when a rectifier goes, or a gradual decline...?
Rectifiers hardly ever fail - but when they do, they often take the PT with them, and then the silence is deafening (usually with smoke). They don't stop rectifying, they just draw more juice to do it!
A friend of mine noticed brown stuff oozing from the PT of his AC30, and that it was running a trifle hot just in time! He was inside the box to change an indicator lamp.
The easiest precaution is to put one of those external temperature indicators on the PT if you're using the amp hard, and log the working temp. If the working temp goes up 5 deg in a week, you got a failing rectifier.
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dotfret wrote:A friend of mine noticed brown stuff oozing from the PT of his AC30.
That can't be good! Makes me think of the Kids in the Hall: http://www.youtube.com/watch?v=vzHhC2-DL-A
You could always put a couple UF diodes in line before the tube rectifier as insurance. You'll lose a volt or so across the diodes, but it should sound the same.
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i bought an antique power transformer for a couple bucks at a seconds shop a few years ago in hopes that i might be able to make sense of it/use it. anyway after i removed the end bells, i found all the leads were encased ("potted"?) in a tarry-glassy black resin that smelled like creosote. nasty stuff, i think sniffing it took a couple years off my life. anywho, maybe that's the stuff that was leaking out of the aforementioned hot Vox
but as an aside, how do you keep a rectifier tube from destroying a PT? in other words, does anyone have any specific fuse advice, ie values/locations/voltages? the standard slo-blo line fuse wouldn't protect the PT in a rectifier blow up would it?
but as an aside, how do you keep a rectifier tube from destroying a PT? in other words, does anyone have any specific fuse advice, ie values/locations/voltages? the standard slo-blo line fuse wouldn't protect the PT in a rectifier blow up would it?
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Re: EZ81 Subs any other choices?
lots of posts here about using sag resistors. I do love the feel of a really saggy amp when playing clean and on the edge. However, I also love the tight drive that these amps are so good for. was thinking of a switch with different levels of sag. How saggy can this amp get? where do sag resistors go? and what values are people using to achieve this.
P.S. I'm new here
any help would be very well received.
Thanks
P.S. I'm new here
any help would be very well received.
Thanks
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Re: EZ81 Subs any other choices?
Welcome to the site!livetoride3000 wrote: ↑Tue 03/30/21 6:00 amlots of posts here about using sag resistors. I do love the feel of a really saggy amp when playing clean and on the edge. However, I also love the tight drive that these amps are so good for. was thinking of a switch with different levels of sag. How saggy can this amp get? where do sag resistors go? and what values are people using to achieve this.
P.S. I'm new here
any help would be very well received.
Thanks
There's lots of sag from the PT, so I often skip the sag resistor. But, if you want to add switchable sag resistors, you can. They would go between the rectifier and the first filter cap. If you review the "Superlite TMB" schematic in the downloads section, you will see the sag resistor in the circuit.
100Ω is typical, but you could go higher. Maybe make a rotary switch with 0Ω, 100Ω, 150Ω, 220Ω.
Thanks,
Josh
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