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Old 21st May 2009, 12:11 AM   #201
tinitus is offline tinitus  Europe
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Hi
I really need to build this sweet amp

Considered lots of other options
ElCheapo, Darling, sex-amp, Decware, LadyDay, Seth/Horus etc
Even the new AudioNote Interstage 2A3/300B

Well, I still like the whole idea of SimpleSE, overall design, choise of tubes, build options, and not least the building instructions and support, it all seems to fit together very nicely

But when will I get started
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Old 30th May 2009, 08:40 PM   #202
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Can anyone tell me the idea B+ for EL34's???



I have just switched resistors. With the 560ohm resistor. I was getting 490 on the B+

I just installed a 680ohm resistor and I am now getting 409 on the B+


If it needs to be lower I have a 750ohm resistor on hand.




TIA



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Old 30th May 2009, 09:04 PM   #203
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Nikolas - where are you measuring B+ ?

B+ shouldn't change by changing the cathode bias.

George (Tubelab) has a chart that shows B+, OPT load & cathode bias resistor value.

http://www.tubelab.com/AssemblyManua...ormers_SSE.htm

First I would verify your B+ voltage.
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Old 30th May 2009, 09:14 PM   #204
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Hmmm.


I guess I didn't know what I was measuring.


The 2 yellow wires coming off the board measure 506v

The two red wires beside them are what measured 409v and 490v with other resistors?







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Old 30th May 2009, 09:25 PM   #205
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I'm not exactly sure what you are measuring either. Those are the wires coming from the transformer?

You don't want to measure B+ there. I'd measure it at the big choke where it connects to the motor run cap (if you have one).
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Old 30th May 2009, 09:34 PM   #206
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Seems like I forgot everything I learned since putting the amp together.




The amp is in the rig now.


I'll do some reading and relearn what I forgot and do some more measurments later...







Nick
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Old 30th November 2009, 10:59 PM   #207
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I JUST LOST EVERYTHING I WROTE!!!


So I'll make it short and sweet.


I just got my amp running again after parting it out.


THE PROBLEM.

When I go to flip the switch from Triode to UL. The amp sends a LOUD buzz to the speakers.


Anybody have any ideas?


Please let me know if you know.



Nik
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Old 1st December 2009, 12:06 AM   #208
rknize is offline rknize  United States
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It makes this sound during the transition or it always buzzes in UL mode? Expect it to make a loud pop or scratch or other noise during the transition. Ideally, you shouldn't throw this switch while the amp is on (though admittedly I also do it from time to time). Your tweeters will thank you if you avoid it.
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Old 1st December 2009, 12:12 AM   #209
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Quote:
Originally Posted by rknize View Post
It makes this sound during the transition or it always buzzes in UL mode? Expect it to make a loud pop or scratch or other noise during the transition. Ideally, you shouldn't throw this switch while the amp is on (though admittedly I also do it from time to time). Your tweeters will thank you if you avoid it.

It always made a pop or a scratch noise in transition before. But now its constant and its loud enough that I think it would damage my speakers if left on long enough.

I figure I must have something wired backwards???

Or could the UL taps be bad? The Opts are Transcedars and there Brand new...



Nik
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Old 1st December 2009, 12:38 AM   #210
rknize is offline rknize  United States
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So if you power up in UL mode, you get a buzz? My guess is that you wired the switch wrong and maybe leave the screens floating in UL mode? The screens should be on the common switch connection with the UL taps and the plate (via resistor) on either side.
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