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January 27, 2020, 09:13:24 PM

Author Topic: Stereomour and 16 ohm Altec Valencias  (Read 1131 times)

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Offline kevin flynn

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Stereomour and 16 ohm Altec Valencias
« on: March 27, 2016, 04:32:27 PM »

Hi, 

I have Altec 806As, which I understand are 16 ohm speakers, at about 97 db efficiency.  I will be building a Stereomour amp, my first SET, and am wondering about the output impedance setting, which I gather can be adjusted to the speakers.  I also have other high efficiency speakers which are 8 ohm, which would be nice to be able to use as well. 

Question is, whether the potential gains of wiring the amp at 16 ohms for the Altecs are substantial enough to outweigh the flexibility of being able to also hook up the 8 ohm units.  I guess I can try it out and see, but re-wiring can be a pain....

Maybe I should just wire the amp at 8 ohms, and call it good, -or will I be missing the boat with the Altecs? :-\
Perhaps someone has had experience along these lines?

Your input appreciated.

Thanks,

Kevin

(Any plans for impedance switching option, ala SE Experimenter?)

Offline fullheadofnothing

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Re: Stereomour and 16 ohm Altec Valencias
« Reply #1 on: March 27, 2016, 04:57:26 PM »
You can drive 16Ω speakers from the 8Ω tap. You give up a tiny bit of power, but with that level of efficiency, you would never really miss it. Driving 8Ω speakers on tbe 16Ω tap has definite sonic penalties a and should be avoided, however.
Joshua Harris

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Offline Natural Sound

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Re: Stereomour and 16 ohm Altec Valencias
« Reply #2 on: March 27, 2016, 06:28:05 PM »
Kevin, The impedance switch kit works with the Stereomour as well. Both kits use the same transformers.

http://bottlehead.com/?product=output-impedance-switch-kit-for-s-e-x-2-1-and-stereomour

Offline fullheadofnothing

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Re: Stereomour and 16 ohm Altec Valencias
« Reply #3 on: March 28, 2016, 05:28:41 AM »
The instructions do not cover installation in a StereomourII. Working without instructions is NOT recommended for first time builders.
Joshua Harris

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Offline kevin flynn

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Instructions
« Reply #4 on: March 28, 2016, 07:24:37 AM »

Thanks Mr.s Natural and Headfull for the replies, both informative and helpful.

As it happens, I've built several Bottle-kits, including the SE Experimenter.  That doesn't mean I'd want to tackle adding the switches without guidance. 

Just for the record, does such guidance (installing impedance switching for Stereomour II) exist somewhere that's accessible to forum members?. 

If not, that's cool, I'd probably just build it with the 8 ohm connections 8).

Thanks,
Kevin

Offline Paul Birkeland

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Re: Stereomour and 16 ohm Altec Valencias
« Reply #5 on: March 28, 2016, 09:09:31 AM »
The Impedance Switch kit can be installed on the Stereomour II, but we haven't revised the instructions for it.  Looking over the manual, your biggest hurdle would likely be adjusting some of the wire lengths along the way, and that the red and black posts on each channel are switched from SMR1 to SMR2.  Other than that, with your experience, I don't think you'd run into any issues.

-PB
Paul "PB" Birkeland

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Offline kevin flynn

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Re: Stereomour and 16 ohm Altec Valencias
« Reply #6 on: March 29, 2016, 06:09:44 AM »

Thank you for the attention to this question and your response. 
It appears there will be plenty options with this amp.

Kevin