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May 25, 2019, 04:13:59 am

Author Topic: Paramour 1 with various upgrades - zero voltage on 12AT7 [resolved]  (Read 717 times)

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Offline patrickamory

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Re: Paramour 1 with various upgrades - zero voltage on 12AT7
« Reply #30 on: October 19, 2018, 08:04:59 am »
Hi guys,

I just had another thought. I have a little DPST switch in there just before the binding posts, to switch between transformer windings (4 ohm and 8 ohm).

I just measured continuity across the switch terminals and the binding posts and I'm seeing continuity between both poles and the center terminal, and the binding posts, in either switch position. Surely one set of windings should be closed off depending on switch position?

Does this imply that the switch might be fried? If so, should I try bypassing it? And if so (million dollar question), how do I figure out which OPT wires represent which speaker impedance? My speakers are 16-ohm Valencias.

Thanks for the continuing help and advice.

Offline patrickamory

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Re: Paramour 1 with various upgrades - zero voltage on 12AT7
« Reply #31 on: October 19, 2018, 09:33:19 am »
Amazingly, I was able to dig up my spec sheet for the upgraded OPT (attached).

I'm going to take the switch out of service and connect directly to the 16-ohm (yellow) secondary.

Offline Paul Birkeland

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Re: Paramour 1 with various upgrades - zero voltage on 12AT7
« Reply #32 on: October 19, 2018, 10:48:50 am »
The 0-4-8-16 ohm winding is a continuous piece of wire with very low DCR.  Regardless of the switch position (unless it has a center "OFF" position), you're going to read lots of shorts between everything.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline patrickamory

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Re: Paramour 1 with various upgrades - zero voltage on 12AT7
« Reply #33 on: October 19, 2018, 11:04:09 am »
PROBLEM SOLVED.

With the switch out of the system and the binding post connected to the 8-ohm wire, I read 6 VAC across the speaker terminals.

Hooked the amp up, and music.

Thanks for your help, everyone.

Offline patrickamory

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Re: Paramour 1 with various upgrades - zero voltage on 12AT7 [resolved]
« Reply #34 on: October 19, 2018, 06:04:16 pm »
Btw... they sound absolutely killer. Garrard 301, Shindo Masseto, Valencia drivers in custom cabinets with original crossovers.

My Cortese is headed back to Japan for service. The Paramours aren't as quiet, but otherwise are completely holding their own in the system.