continuity

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FE911
Posts: 44
Joined: Mon Apr 16, 2007 6:01 pm
Location: Denver

continuity

Post by FE911 »

Stupid question probably, but here goes.
I've pulled apart my wreck(again). It's cobbled together, pretty much straight forward except for the dual bias tap test points. I've had problems with the prescence pot hiss, and was tackling that at the time. Thought, I'd re-run the heater wires. Used 14 guage, wanted the purple,what a pain! Found a couple of really stupid mistakes. Put her back togther. Lead dress could be a little better, but it was getting late. Fired it up, tried to bias a new set of el-34's and was not getting any readings that were right, or anywhere near. Looked at it for a long time, trying to find something wrong. Tested continuity on all wires. Broke one, I give up on solid core wire!
But I noticed I have continuity between the positive and negative on the output jacks ? That's just not right! I keep staring at the thing and can't find anything wrong. Maybe one of you guys can tell me there's a micro relay in the OT that combines them for load dissipation when it's off or something. I wasn't even drinking last night!!
FE911
Posts: 44
Joined: Mon Apr 16, 2007 6:01 pm
Location: Denver

further

Post by FE911 »

I disconnected the load selector switch. The 4,8,16ohm leads out of the OT all have continuity with ground.
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gearhead
Posts: 928
Joined: Sun Mar 19, 2006 2:54 am
Location: Virginia (Fairfax)

Re: continuity

Post by gearhead »

I just went thru this drill myself. They're actually not continuous to ground, but close enough to set off any continuity checker.

If you have a good enough meter, you will find a -minute- difference between ground and each of the taps. I got 1.1, 1.2, and 1.3 for the 4,8, and 16 ohms; but that was just my meter. The 4, 8, and 16 is acuallty an AC impedence load vs DC resistance.

https://tubeamparchive.com/viewtopic.php?t=4744&start=0

Posting your voltages would be great!
FE911
Posts: 44
Joined: Mon Apr 16, 2007 6:01 pm
Location: Denver

wrecked

Post by FE911 »

Quick check again, trying to clean it up a little. Broke a power tube socket pin. Just need to take a break for a little while. Thanks for the help, Gearhead. Probably sniffing too much solder.
FE911
Posts: 44
Joined: Mon Apr 16, 2007 6:01 pm
Location: Denver

tubes

Post by FE911 »

Put it all back together. Hooked up test leads to bias. Got 30 and 34. Not as tight as when I used my 6v6's. Still a little hum on prescence, but much better. Hooked up my Chinese Les Paul Custom(got ripped off, they really know how to make 'em look like the real thing now) with a set of real 60's t-tops-mean as a snake. Went through a few rounds of La Grange. Feel much better, cheers!!!
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drhulsey
Posts: 986
Joined: Sun Mar 18, 2007 3:19 am

Re: tubes

Post by drhulsey »

FE911 wrote:... Went through a few rounds of La Grange. Feel much better...
Nothin' like the Rev. Gibbons to make an axeman feel better :D
Tim

In case the NSA is listening, KMA!
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