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Old 21st March 2013, 02:15 PM   #11
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Originally Posted by battradio View Post
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Here is a schematic , and one with some mod done to it
What's the value of R3? Leave the original 10k or change to 20k?
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Old 21st March 2013, 07:03 PM   #12
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I'm not sure what happened to my amp but since I did the balance elimination I'm having bad crosstalk and I think phase cancellation. I took photos before and after and I'm positive I got it right.

What's happening is when the inputs to both channels are plugged in (stereo), the vocals are coming from the right speaker and the music from the left speaker seems out of phase. If I plug in only the left channel it plays (mostly) from the left. If I plug in the right channel it plays from both speakers equally.

I only had 330ohm resistors but I figure that would only reduce the amount of feedback.

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Old 21st March 2013, 09:23 PM   #13
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-.-" Never mind. I had the speakers connected wrong because I forgot common was on the far side not the center.
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Old 23rd March 2013, 09:03 AM   #14
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I found these yesterday and picked them up tonight for $25 with the Zenith Allegro console but the console was solid state so it got scrapped but I kept the drivers. Two Zenith 10" paper woofers, two small Philips dome horn tweeters, and two crossovers.

These remote speakers sound amazing with the Magnavox amp driving them. The bass shakes things in the room.


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Old 23rd March 2013, 12:49 PM   #15
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If your not using the tuner use 20- 22 k to keep the font end voltage the same
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Old 23rd March 2013, 12:52 PM   #16
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Quote:
Originally Posted by lazzer408 View Post
I'm not sure what happened to my amp but since I did the balance elimination I'm having bad crosstalk and I think phase cancellation. I took photos before and after and I'm positive I got it right.

What's happening is when the inputs to both channels are plugged in (stereo), the vocals are coming from the right speaker and the music from the left speaker seems out of phase. If I plug in only the left channel it plays (mostly) from the left. If I plug in the right channel it plays from both speakers equally.

I only had 330ohm resistors but I figure that would only reduce the amount of feedback.

Here's a pic.

Click the image to open in full size.
You have it wired wrong , something is not grounded correctly .
Click the image to open in full size.
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Last edited by battradio; 23rd March 2013 at 12:56 PM.
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Old 24th March 2013, 06:25 AM   #17
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Originally Posted by battradio View Post
You have it wired wrong , something is not grounded correctly .
It was right. I just goofed the spade speaker connections. I have since added binding posts. That was all it that was wrong.

Quote:
Originally Posted by battradio View Post
If your not using the tuner use 20- 22 k to keep the font end voltage the same
I swapped the 10k for a 22k. B+ to the opt is now sitting at 335v. 6EU7s are getting 292v. I separated the left and right output tube cathodes each pair with 220ohm+2.2kohm (200ohm total) with a 160uf cap in parallel. That was the only handy way to make 200ohms. My cathodes are at 13v though and I believe they should be closer to 10v. I need to find out why.

Any damage at 13v? Is that correct to say my output tubes are under biased?
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Old 24th March 2013, 03:33 PM   #18
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nice looking older speaker cabs, no one makes art like that anymore
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Old 24th March 2013, 05:34 PM   #19
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There's something almost "dungeonesque" about them, if that's even a word. Maybe they remind me of my creepy aunt's house that was full of 60s-70s era wooden/iron furniture and chain-hung lighting that looked like small torture cages. Had I known then what I do now, I would have called dibs on the tubed Scott equipment that my uncle had built into the bookcase. The whole house was wired for sound. Speakers everywhere. I remember family reunions with "California Dreaming" playing on vinyl.

I found an ad for the speakers. "Tuned port"? More like a 3.5" hole in the back. No tube but it's amazing how deep the sound is. They play down in the 30s easily.

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Old 24th March 2013, 06:37 PM   #20
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I hope I can explain this correctly...

On the input of this amplifier (9302-00) it has 47k from input to grid and 470k from input to ground. This essentially makes a voltage divider for the input (to provide 470k input impedance and to reduce gain?) and 517k total resistance for the grid.

Could I simply use a .1uf cap from the input straight to the grid? This would leave the 517k grid resistance intact and capacitor couple my input. This should increase the sensitivity about 10% correct?

Last edited by lazzer408; 24th March 2013 at 06:40 PM.
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