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BRONZE Member
I was not referring to to the solenoid screw adjustments you referenced. The correct one to address the OP’s issue is the adjacent damper cylinder screw that regulates the air flow as its piston prevents the arm from dropping with a thump.
BRONZE MemberWhile there is no muting delay adjustment as on the later models, you should be able to eliminate the thump by adjusting the damper cylinder set screw. The are should lower in between 1 and 1.5secs.
BRONZE MemberI would focus on the components around the 1TR14 portion of the electronic switch and I would also reflow solder connections in that area.
BRONZE Member1D16 is a Zener diode that is supposed to set the base voltage of 1TR5 which turns on the lamp in the detector arm. If it shorts it not only will not keep the lamp off but will pull down the 22V rail that will impact other circuits such as the solenoid driver. Glad you got it working again.
BRONZE MemberFirst, if you are only getting 18v then there is still a power supply problem. I would work backwards to see where the voltage drop is occurring. You could still have a bad cap or transistor. As to 1R36, you may have a bad Zener diode, 1D17.
BRONZE MemberYou may have an issue with the 22v DC supply that feeds both circuits. Lowering the arm with the cuing control does not need the lamp working. Check that you have 22.8V on the high side of 1R42 and 12v on the collector of 1TR11 when the table is on and the arm is stopped before the record. If this table has not had a capacitor replacement, it is long overdue and where I would start. You can get a service kit for your model here.
BRONZE MemberFor your system, going to the SMMC2 would be well along the diminishing curve with the rest of your system. The SMMC3 is the sweet spot.
BRONZE MemberI cannot recommend turntable needles.com as I have no experience with them. Any of the MMC cartridges will work with your table; however, if it was me, I’d go with the SMMC3 from Soundsmith. B&O used them for the release of the Beogram 4000C using an SMMC20CL. This gets you the nude hyper-elliptical diamond where the 4 is a bonded diamond.
BRONZE MemberI really doubt it and actually am quite appalled. Here they are offering a limited edition $30K system and only supplying an MMC4 cartridge! As an alternative to Soundsmith (which I have used) there is turntableneedles.com that advertises new MMC cartridges.
BRONZE MemberThe 4002 employs both static (weight) and dynamic (spring) tracking force adjustments. With the dial at 0 you need to adjust the rear counterweight using its screw so the arm floats with 0 tracking force. Then the knob should apply the specified force by adjusting it to your cartridge’s requirement.
29 May 2025 at 02:45 in reply to: Recommended Load Capacitance for MMC-20EN, MMC-20E, SP-12, SP-10? #65892BRONZE MemberB&O cartridges are not very sensitive to capacitive loading. Simply adjust your setting by ear but remember that the cables are already going to contribute to the value.
BRONZE MemberThose controls are actually photoresistive and depend on a lamp on the board to operate. It likely burned out, or there is a bad solder connection.
BRONZE MemberALF, those jumpers most definitely need to be removed as they are shorting the inputs to the outputs which will cause oscillation. Glad to see you got it working, Enjoy!
BRONZE MemberIt’s not really a mystery as a short will not take out your cartridge coils since they are not conducting current. If you are reading 6V DC on each of the + and – inputs then the passive components are likely fine, and your issue is the ICs. You should use hot air and flux to replace the ICs. There are plenty of YT videos showing how.
BRONZE MemberActually, pins 2 and 6 are the feedback loop inputs and not the signal inputs. Pins 3 and 5 are the inputs and 1 and 7 the outputs. I don’t know what you mean by “checking the inputs” because putting a probe on an input of a high-gain stage will produce an audible side effect. Given how inexpensive these opamps are, unless you find a burned part, it is easier simply to replace them as long as all the voltages check out.
BRONZE MemberThere are 2 voltages going to the board – 22v and 12v. First, I would unplug the board and check that the power supply is outputting the correct voltages. Then after removing the power cord, I would reinsert the RIAA card and check the voltages on it per the service manual. Make sure you check for 12v on each IC. Since each IC is amplifying both channels, a bad one can impact both. If you have an oscilloscope, you can check the nature of the noise and the point in the curcuit that it is originating from.
BRONZE MemberAssuming it does not have a phono preamp board, it depends on what input you are connecting to. If you are going to a DIN Phone input, you need a 5-pin DIN cable. If you are connecting to an RCA phono L/R jacks, you need a shielded pair plus a separate chassis ground wire.
BRONZE MemberIn the US there were no finish choices. The base was a dark gray matte plastic.
BRONZE MemberIf you do not have continuity between the cartridge body clip, board ground, chassis ground and external ground wire you will get hum.
BRONZE MemberAcross the many 40xx turntables I have serviced, I have never replaced the pulley of a working motor. You’ll be fine with the proper belt and shaft pulley.
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