Can someone here tell me how to change de emphasis on a Dyna FM3? Oddly, or not, I'm now not sure, the de emphasis on my Tandberg 3001A sounds like it would in the EU when set to 75uS. It's definitely overly bright so I switch it to 50uS. It now sounds great. OTOH, the Dyna FM3, which functions as it should, sounds like it needs higher de emphasis. Does anyone know what it actually is?
TIA
TIA
Definitely the FM-3 uses 75uS, which is provided by the PEC 555004 module.
Remove the module and replace it with new parts, changing the 510pF capacitor to 340pF for 50uS.
http://www.tubes4hifi.com/Dynaco FM-3 manual.pdf
Remove the module and replace it with new parts, changing the 510pF capacitor to 340pF for 50uS.
http://www.tubes4hifi.com/Dynaco FM-3 manual.pdf
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So my confusion remains. Higher de emphasis results in brighter over all character, correct? If so, why does 50uS on my Tandberg sound correct here in Canada when in the EU, it also sounds as it should as per their protocol? 75uS on my Tandberg here in Canada sounds as it would in the EU, too bright lacking in bottom end. Now enter the FM3; it sounds here like 25uS on my Tandberg. Weird.
I should mention the sound as I switch from 75uS - 50uS - 25uS on the Tandberg is progressively attenuated as it should be.
I should mention the sound as I switch from 75uS - 50uS - 25uS on the Tandberg is progressively attenuated as it should be.
Far as I know, Canada uses 75uS for FM de-emphasis, same as the USA.
Of course changing the de-emphasis setting does not affect the bass, and
any apparent effect in the bass range is psychoacoustical and not measurable.
Many FM stations do broadcast less than high fidelity sound, though.
Of course changing the de-emphasis setting does not affect the bass, and
any apparent effect in the bass range is psychoacoustical and not measurable.
Many FM stations do broadcast less than high fidelity sound, though.
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The higher the de-emphasis time constant, the duller the sound. If it sounds too bright, either the de-emphasis time constant is too small or there is something else wrong that causes a bright sound. The processing of the radio station, for example.