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TEST setting on R.105 II level indicator control

 
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T.O. Chef
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PostPosted: Sat Sep 26, 2009 3:17 am    Post subject: TEST setting on R.105 II level indicator control Reply with quote

Can anyone shed some light on just what the TEST setting on the 105 II actually does?
Does it bypass any or all of the protection circuitry on the head unit PCB?
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ColinR
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PostPosted: Sat Sep 26, 2009 10:45 am    Post subject: Reply with quote

Quote:
what the TEST setting on the 105 II actually does



It's for testing (by qualified technicians) the protection circuitry on the head unit PCB.


Quote:
Does it bypass any or all of the protection circuitry on the head unit PCB


No.
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speakerguru
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PostPosted: Sat Sep 26, 2009 6:03 pm    Post subject: Reply with quote

I think it was a quick way to check everything in the LED and protection circuits was working. I seem to remember the circuit was set to its most sensitive so that the LED would light and the relay would trip without deafening the tester.
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T.O. Chef
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PostPosted: Sat Sep 26, 2009 9:45 pm    Post subject: Reply with quote

Ah. Seems to make sense. I've yet to trip anything ever, and even getting the LED's to illuminate at all gets output up to discomforting levels.

The set up instructions warn against using the setting in regular listening mode but I've mistakenly done so for a days long period once with no audible or damaging affect. Thanks Speakerguru.
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geoffwood
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PostPosted: Wed Nov 04, 2009 9:57 pm    Post subject: Reply with quote

Best thing is to remove it completely. What's the point of optimising all sorts of stuff in one's system then hanging a signal-sucking network like that across every thing !!!

I ran mine for 15 years with it removed, and with an adquate size (ie not too SMALL) amplifier and sensible use, had no problems whatsoever. Fortunately the 105.2 is inherently protected against amps going DC by the series input capacitor (which incidentally may benefit from bypassing with an additional largish - several uF - polypropylene film cap).

geoff
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T.O. Chef
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PostPosted: Fri Nov 06, 2009 2:39 am    Post subject: Reply with quote

Interesting. Have you done this bypassing of the large value cap's on the input?
My version has 4 x 120uF cap's C1-C4. I assume this involves a bypass cap on each of them?

I'm currently working on a second set of crossovers for my 105's (leaving the originals completely intact). Since the bits are on hand already I will try using Solen's, but with electrolytic Bennic's C1-C4.
Going to be a tight fit. Large values mounted on the board backs. Spacers to clear the box rear panel, and likely some small alterations to the damping foam. Wish I could find some of that same density. I really don't want to trim any of the original. Anyone any thoughts on what I could use?

Anyone here ever compared a Solen capped 105 II crossover to an original and care to share their findings?

Did you find any benefit to system sensitivity by disabling the protection circuitry?
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geoffwood
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PostPosted: Fri Nov 06, 2009 2:50 am    Post subject: Reply with quote

Just one needs bypassing, as the are all in parallel. Just gives the higher frequencies something nicer to go thru 'unimpeded'.

Removing the S-Stop didn't improve sensitivity noticably, but I at least imagined cleaner highs - more 'air' as some would have it.

geoff
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