EZ81 Subs any other choices?

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nyazzip
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Post by nyazzip »

hey they blocked the word "Matsus*ita".....ridiculous....
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joe6v6
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Post by joe6v6 »

Given the choice I always opt for an octal recto socket, by using diffrent tubes it allows you to play with the secondary voltage to a pretty wide degree. This can change the tone & feel of the amp pretty significantly. Ive had more than one 18 that, to my ears, sounded much better with a 5y3 vs a GZ34. Careful though, some rectifiers draw more curent than others. .. Joe
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pvg_320
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Post by pvg_320 »

I personally prefer a matched pair of EZ81's...for those times when single-ended rectification just won't do. :)

http://cgi.ebay.com/EZ81-TESLA-NOS-STRO ... 51932686f8
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Post by zaphod_phil »

Now that's got to be one of the silliest things I ever heard of! :lol:
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lildog
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ez81

Post by lildog »

Yeah, go for it....why not 3?? makes more sens in a way...or..?
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colossal
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Post by colossal »

EZ81s seem to be quite readily available and inexpensive, even as NOS. Any recommendations for new production as well as NOS?

Thanks.
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krx
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Post by krx »

colossal wrote:EZ81s seem to be quite readily available and inexpensive, even as NOS. Any recommendations for new production as well as NOS?

Thanks.
As long as they're within spec, they all sound and function essentially the same.
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dotfret
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Post by dotfret »

nyazzip wrote:
by the way, is it dramatic when a rectifier goes, or a gradual decline...?
Truth is, it depends if you notice!

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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krx
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Post by krx »

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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krx
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Post by krx »

I guess the quote function stopped working with the reboot

:?:
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nyazzip
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Post by nyazzip »

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?
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Post by zaphod_phil »

FYI [quote] works, but [quote=<username>] doesn't work in new posts for some reason. This is under investigation.
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livetoride3000
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Re: EZ81 Subs any other choices?

Post by livetoride3000 »

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
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Re: EZ81 Subs any other choices?

Post by JMPGuitars »

livetoride3000 wrote:
Tue 03/30/21 6:00 am
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
Welcome to the site!

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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zaphod_phil
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Re:

Post by zaphod_phil »

nyazzip wrote:
Sat 05/29/10 1:30 am
hey they blocked the word "Matsus*ita".........
:lol: :lol: :lol:
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