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PostPosted: 27 Jul 2016, 10:40 

Joined: 14 Apr 2016, 16:02
Posts: 53
Location: Argentina
Hi everyone! I Have a vintage Grundig R400 Amplifer that only works at 4 Ohms output (STK461) My speakers are 6 Ohms and output power is not an issue for me, but the protection fuses always blown up... The only way is to put 4 Ohms speakers? I know that the only issue in solid state amps is to not go under amp impedance but higher only decreases the output power and elevate distortion... that is true? or exist amps that only works in only one kind of impedance?


PostPosted: 27 Jul 2016, 12:44 
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Joined: 08 Aug 2009, 03:11
Posts: 2229
Location: Chilliwack, BC
You have a problem, then.

6 ohm speakers draw less current, not more. Fuses shouldn't blow.

Try a different set of speakers (6 or 8)... your 6 ohm ones may have pooched X-overs or a voice coil short.

....vintage Grundig....

That was common for EU amps to demand one, low impedance (Siemens, Telefunken, Philips, B&O all did it at one point or another). Was a cheap way of getting more power by spending less deutchmarks on a power supply ;)


-= Gregg =-
* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
Work: Classic Valve Design

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