ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello fellow Beogram users. Happy to find this forum available.
I'm the second owner of a B&O Beogram RX2 turntable with an original MMC3 cart.
The first owner is a friend of mine and kept this platter in mint condition.
I've owned it now for a few years and it serves me well and still sounds amazing.
It has always had one little annoying problem, that is the Left RCA jack is starting to go bad.
If it's seated well on the female, usually there is no problem. If not the left channel signal seems weak.
If I touch the male ever so slightly, it buzzes out. The Right male does not do this.
Therefore, I'm considering replacing the signal cables.
The plan currently is to convert the fixed cable ends to a pair of quality chassis mount RCA sockets.
Utilizing the existing cable to make the connections from the PCB to the sockets.
Also add a solid copper Grounding Post.
This would fix the problem, and provide better flexability in cable choices and lengths.
I have many questions going into this project.
The first being...Has anybody done this conversion before?
Appreciate any advice regarding the topic.
First, not sure how important this is to you, but "converted" B&O almost always lose value considerably. Original is generally preferred.Next - the original signal cable is of a decent quality, but the inner cores tend to break apprx 1-2cm upstream from the RCA plugs because themolded plugs are rubbish.Cut the plugs off (+ 5cm of the cable) and fit new good quality RCA plugs.
Martin
I agree with Martin.
And don’t forget that the cable’s capacitance is carefully calculated to charge the cartridge optimally.
Your project may therefore alter the sound and lead to disappointment!
Jacques
Yes, I have considered adding new males, which would be the easy quick fix. And I agree cable capacitance needs attention. I knew full well some folks would recommend replacing the connectors and/or replacing the original cable with a higher quality cable at the PCB.
I still like the option to add sockets using the existing cable internally. I know shorter cables are better, but not always possible. This is where cable length (and capacity) comes into play. I have read about people doing this conversion on Technics tables with great success.
Regarding Capacitance: Can anyone confirm the MMC3 specs are 150pF. I'm a little confused by the Total Load needing to be > 400pF?? seems a little high. Shouldn't my target load be about 120pF?
Looking at the Service Manual, shows the Load Capacity as <400pF. That makes more sense.
Someone got their Pac-Man eating the wrong way :-)
Do the RX2's connect the tonearm wires to the Signal cables with a 6-Pin? or are they sodered to a PCB?
I have yet to crack the case open. Looking at some pics on the Internet, not always reliable.
Found some good info on Capacitance on another Forum.
On average, a MM Cart would have a total load of 400pF.
100pF (Phono Input) + 80pF (Signal Cable) + 20pF (Tonearm Wire) + 200pF (Cartridge) = 400pF.
If the MMC3 is rated at 150pF, then we would want 150pF matching load. Ideally.
Leaving a cable target Capacitance = 30pF. That's really low, but I guess we have +/- 50pF to work with.
I saw a new pic on ebay of the RX2 Plinth, I'm not sure there is space to add RCA's to the back panel, so I may simply replace them as advised. Keep you posted.
After removing the top plate, I quickly realized there is absolutely no space to add RCA females. So I ordered some Furutech connectors for everything. New RCA Males, Ground Spade and AC Plug. Aside from the one bad RCA jack, my power cord had damage from a previous rabbit roommate. Bunnies love to chew on cords. I lost 18" off the power cord. I sleeved the signal and ground cables to provide better cable management. The ends of the sleeving are kept nicely in place by some simple silicone vacuum hose. The whole thing turned out great and no more buzzing from the jacks. The Furutech connectors I got at a great price off eBay. I just had to wait 3 weeks. These connectors are over the top superfluous and the whole project could have costed much less. But I'm happy with the end result.
Thanks for keeping us posted!
In my opinion expensive connectors are a bit of con especially power plugs/cables
How did you get inside the rx2 to the solder points for the rca cables?