Hi all,

I have just finished restoring my new (old) BG6000 CD4 with MMC20EN.

I bought it off Ebay about a month ago, cosmetics were pretty near perfect, but it was butchered inside: The cable to amp had been replaced by a home job with 2 RCA plugs (wired directly to the original 9-pin plug on the CD4 Demodulator board; Non-original screws and bolts; Dirty unprofessional soldering, etc, etc.

I have rebuilt it according to the manual, replacing all electrolytic capacitors, and resistors and diodes as necessary. As the Quad cable to amp is not available, I rewired it using CAT5 network cable (4 x Twisted pairs).

It works perfectly except for one thing:

When a CD4 LP is played with the CD4 switch OFF, the sound is just fine, as expected. By that I understand that the MMC20EN is serviceable.

But as soon as I switch the CD4 switch to CD4, and the red 4ch light illuminates, there is very scratchy distortion.

Is this a limitation of the MMC20EN, or could there be another reason?

Regards

M Yachad

Hello Yackadm,

The CD4 demodulator contains a pre-pre-amplifier and can provide 4x300mV when on.

If you connect your Beogram 6000 to a classic RIAA phono input which accepts only a few mV, you will completely saturate it.

When CD4 on, try to connect the BG6000 to an AUX input to verify if this is O.K.

To what amplifier do you connect your BG 6000?

Congratulations to give back life to this beautiful machine.

Enjoy your Beogram 6000!

Marc

The cable itself is CAT5E, but the Connector is an original Hirschmann 5-pin DIN.

The turntable is connected to the BM3400 Phono-4 channel input, as it should be. This input is, in effect, a line-input.

It is a beautiful unit, and much enjoyment was had in restoring it.

Is there anyone out there who has an MMC20EN with a BG6000 or BG3400, with a real CD4 Quad LP, who can tell me if the same thing happens, when switching CD4 to ON?