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This is the first Archived Forum which was active between 17th April 2007 and 1st March February 2012

 

Latest post 09-30-2009 3:24 PM by Dillen. 4 replies.
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  • 09-22-2009 8:04 AM

    Repaired Beomaster 1700 Tuner/amp, sounds awful.

    I think I posted in the wrong forum to start, so I'll repost here!

    Hi, first post, so please excuse any toe treading.

    I recently rescued from my late father in-laws basement a Beomaster 1700 tuner/amp which had been down in the damp for over15 years.

    It looks like he had a nasty accident/short and literally burnt several resistors on the left channel side of the output amp. I'm not an electronics expert so I took the belt and braces approach and replaced all the burnt components, all the transistors and all the capacitors (except the pair of big 5000uF ones) on that side of the amp.

    By some miracle the thing works, (and after a clean and a respray of the base, looks fab) but the sound it produces is sort of "empty". It's playing though a pair of good condition RL60's, QED speaker cable and the source is a new, resonable quality CD player (which works very well on my Jap stuff). It's not lacking volume, just sounds like it's playing through 6" of foam. Both channels sound this way, not just the one I've rebuilt.

    So, if anybody has some idea/suggestions of what I should do/how to sort this fine piece of kit, please, I'd be happy to receive them.

    I'm considering changing the 50000uF caps and replacing the components of the tone control board as I'm sure the years of damp haven't helped. Also, do I need to source any particular type, manufacturer or quality components??

    Cheers, Mark.

  • 09-22-2009 9:14 AM In reply to

    • Dillen
    • Top 10 Contributor
    • Joined on 02-14-2007
    • Copenhagen / Denmark
    • Posts 5,008
    • Founder

    Re: Repaired Beomaster 1700 Tuner/amp, sounds awful.

    Mark, Welcome to Beoworld !  Yes -  thumbs up

    The Beomaster 1700 was never one of the better amplifiers but it should still provide a pleasant
    voluminous sound and not sound "empty".
    Capacitors can cause the strangest faults and I suggest you replace the lot.
    If you still have doubts regarding the amplifiers performance, connect a signal generator and an
    oscilloscope and do a frequency sweep to check out its response. That will tell you exactly if
    something is amiss somewhere.

    Martin

  • 09-22-2009 9:52 AM In reply to

    Re: Repaired Beomaster 1700 Tuner/amp, sounds awful.

    Thankyou for that, I'll start digging out the diags and start ordering!

  • 09-30-2009 2:52 PM In reply to

    Re: Repaired Beomaster 1700 Tuner/amp, sounds awful.

    Hi again,

    All caps swapped out, went mad and replaced all the caps on the output amp and tone control board.

    It sounds a lot better, but a long way into the bright side, I'm having to push the bass way up and the treble down into the minus.

    All the caps were the same value uF's but higher voltage values, and where possible "audio" type caps used.

    Is this the mysterious "breaking in period" I hear and wonder about as the all the transistors got changed as well... It was a nasty burn it had.

    Would a re-cap of the RL60.2's crossovers help, I don't think they have been done.

    Sorry lot's of questions there, any opinions would be welcome, I've only just started playing the HiFi game!

  • 09-30-2009 3:24 PM In reply to

    • Dillen
    • Top 10 Contributor
    • Joined on 02-14-2007
    • Copenhagen / Denmark
    • Posts 5,008
    • Founder

    Re: Repaired Beomaster 1700 Tuner/amp, sounds awful.

    Sounds most of all as if you are using the phono (turntable) input for a line level source (tape/CD...) which should
    have been connected to the tape input.

    Caps in speaker crossovers usually age with a muddy and mumbled sound as the result (read: less treble).

    Martin

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