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If bypassing the RIAA to use the BC9500’s PHONO input, you will also need to move the Beogram’s datalink connection from DIN pin 7 to DIN pin 6.ย ย Non-RIAA-equipped Beograms use pin 6 for datalink, whereas RIAA-equipped use pin 7 (the same as Tape).ย The Tape 2 input socket on BC9500 expects datalink on pin 7, and the PHONO input socket expects datalink on pin 6..
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Do you know the way how to bypass the preamp of the Beogram 4500, please?
As a Silver Member you are able to download the Service Manual here:ย ย https://beoworld.org/?a=download&key=cae6a88b27cd8dd84ce21c7a01e06b95
As you can see, many Beograms of that era (both with and without RIAA) share the same service manual because they are similar internally.ย Basically, you want to disconnect/bypass PCB4 totally, and reconnect with the ‘non-RIAA’ muting circuitry as shown on page 2-1 in the little dotted area labelled ‘in versions without RIAA’.ย The circuit diagram also shows that the datalink connection should beย moved from pin 7 to pin 6 as I mentioned earlier.ย I haven’t attempted this myself, but if you are confident with hifi electronics it should be no problem.
EDIT:ย There’s a photo attached to McGruse post here that shows a BG4500 with RIAA removed – it may be some help!ย https://archivedforum2.beoworld.org/forums/p/26480/211502.aspx#211502
Location: Warwickshire, UKMy B&O Icons:
I can’t vouch for the audio quality (I suspect it would be poor), but if you don’t wantย to modify the BG4500 you could always feed it’s output through something like this and then in to the PHONO input:ย https://www.ebay.co.uk/itm/154567034473
But you would have to convert DIN to Phono plugs (and reverse) and feed the datalink connect from DIN pin 7 of the input to DIN pin 6 of the output.
Location: Warwickshire, UKMy B&O Icons:
Seriously, just connect the pins 6 and 7 on the DIN plug and you will get remote control through the Aux channel. You can of course open up the Beogram and remove the RIAA but this will be far more complicated. Beograms with the built in RIAA are probably worth more than the non RIAA fitted decks as they can be used with all sorts of modern equipment. What you need is a Beogram 9500 (rare) or more reasonably a Beogram 5005 0r 5500 which don’t have a RIAA fitted and will work with the 9500 ( Good choice of system – in my view the best designed system B&O made – just bought another myself!) You can probably sell the 4500 for more than it would cost to get a 5500.
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The alternative would be a Beogram 8000 which is a definite step up from a 4500 or 5500.
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Seriously, just connect the pins 6 and 7 on the DIN plug and you will get remote control through the Aux channel.
I don’t think this will work, because being an RIAA equipped deck the datalink will already be on pin 7 and he already tried Tape 2.ย I think that when plugged into Tape 2 his Beogram 4500 will be controlled only after selecting PHONO on the remote, but of course the audio is not then connected.
EDIT:ย Peter, you must be experiencing a little ‘deja vu’ ๐ – seeย https://archivedforum.beoworld.org/forums/t/32271.aspx
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Of interest, when I bought my first BC9500, which I bought new, the dealer also sold me a BG4500 as he had not realised it had a RIAA. Of course it produced a dreadful sound through the phono input and he rather shamefacedly replaced it with a 9500. I cannot remember what I did with the deck – I suspect it might be with the BC9500 which I lent to a friend many years ago! I will probably use a 4004 with my new 9500 if I need a record player.
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