beolover: Beogram 4002 (5513): Full Restoration and Upgrade with SyncDrive, Commander Remote Control and Internal RIAA Pre-Amplifier

This post discusses the restoration of a Beogram 4002 (Type 5513 with DC platter motor) that I received from a customer in Louisiana. He commissioned a full restoration and upgrade with the Beolover SyncDrive, Commander remote control and internal RIAA pre-amplifier.

This shows the final result of my efforts:

Let's see what it took to get there!

This shows the unit as received with the aluminum panels and platter removed on my bench:

I started out with restoring the arm lowering and carriage translation mechanisms. This shows the original condition:

I removed all the components for ultrasonic cleaning and re-lubricating:

This shows the liberated carriage:

I usually put it on a soft pad to protect the fragile wiring on the underside. I also removed the solenoid

They often have magnetized plungers from years of actuating the arm lowering mechanism. I removed the plunger for demagnetization:

This one showed evidence of magnetization: It was able to attract a ferrous setscrew:

I worked on it with my tape head demagnetizer until it did not attract the screw anymore at close distance:

This is an important step of any Beogram restoration. A magnetized plunger is often the root cause for delayed arm lifting during the auto return at the end of a record. Not a happy moment when the new $800 cartridge drags across the record for a few inches until it finally gets lifted up!

While the parts were in the ultrasonic cleaner I started working on the restoration of the PCBs. The main PCB has two power Darlingtons installed on the solder side. This shows 1IC1, which regulates the 21V power rail. It is usually a TIP120:

I replaced it with a TIP102, its stronger cousin:

I also installed a 100nF capacitor (yellow) between its emitter and a conveniently located GND pad. This capacitor is necessary to quench high-frequent oscillations that can occur with modern TIP transistors in this circuit configuration. After replacing the other solder-side-mounted 1IC4 with a TIP107, I removed the board to work on its component side. This shows the original board with its colorful 1970s capacitors (which may be considered the bell bottoms of electronics...;-):

Here a detail shot of the RPM section consisting of a Siemens relay and the two trimmers to its left for setting the platter speed:

I replaced all electrolytic capacitors, power transistors, RPM relay and the record sensor transistor with new parts. The RPM trimmers were replaced with modern 25-turn encapsulated trimmers. This shows the rebuilt board:

Here a detail shot of the rebuilt RPM section:

Next, I removed the keypad cluster and extracted the output PCB, which is located beneath the keypad.

This board features the output relay and its delay circuit:

I replaced the relay and its electrolytic capacitor, and I also installed a (red) switch that allows connecting signal and system grounds in case there is a hum in the audio signal when connecting the Beogram to an amplifier:

With the keypad out it was a good moment to replace the incandescent bulbs in the RPM trimmer panel above the keypad. This shows the extracted panel flipped over:

Removing the covers revealed the bulbs:

The little green PCBs in front of the panel are the Beolover RPM Panel LED Backlights for Beogram 4002 and 4004 (Types 551x/552x).

One of the light bulbs had been replaced with a non-spec lower voltage type that obviously needed voltage dividing resistors to operate on the 21V rail of the Beogram:

I removed the bulbs and installed the LED boards:

They directly solder to the pads used for the bulbs and act as an extension of the original PCB:

The bulb covers still fit on wth the LED boards installed:

It was time for re-assembling the carriage again: This shows the shiny cleaned mechanical parts back from the ultrasonic cleaner:

I always install a new damper gasket:

Replacing this gasket is an important item since the arm lowering speed depends on it. The original gaskets are usually hardened and/or deformed and that can cause episodes of undamped arm lowering. Not a happy moment when that newly rebuilt cartridge crashes on the platter!

Like so many this Beogram had a cracked spindle nut holder. This picture shows the original white part together with the Beolover replacement part:

This shows it installed using the original screw:

I added all the other components back in. This shows the re-assembled carriage setup:

I also installed a new Beolover Aluminum Carriage Pulley for Beogram 4002 and 4004 and a new belt:

The next step was replacing the incandescent light bulb in the tracking sensor housing. This shows the original black bulb housing still installed:

Removal of the housing revealed the tracking aperture:

This shows the new Beolover Tracking Sensor LED Light Source for Beogram 4002 and 4004 (red) next to the original bulb setup:

The LED is approximately in the location of the bulb filament. This shows the LED assembly installed:

The final task on the arm lowering system was cleaning and re-lubricating the pivot point of the damper to arm linkage. It is located in between the tone- and sensor arms. You can see it stick out from the v-cut in the small plate that is bolted to the counterweight in the picture below:

I removed the two screws that hold the sensor arm down. Then I removed the linkage:

In this case the lubricants on the rod the linkage pivots on were hard enough to pull out the rod when I pried the linkage out:

A visit to my arbor press in the garage liberated the rod. You can see the crusty lubricants on it:

I glued the cleaned rod back into its socket with a dab of epoxy and then put the linkage back on it with a bit of synthetic grease. The rest of the mixed up epoxy I used for reattaching the little copper plate that helps the arm move laterally when it is in its up position:

Next I replaced the fourth and last incandescent bulb, the one in the sensor arm. This shows the little black sensor compartment pulled out:

To the left of it the Beolover Sensor Arm LED Light Source (Beogram 4002, 4004 and 4000) with its alignment aid waits for installation. This shows it installed:

This concluded my work on the carriage. It was time to empty out the enclosure for vacuuming out all the transport lock bushing fragments. They need to be removed since they can impede the free movement of the floating chassis. This shows one of the transport locks after removing the top part of the assembly:

A beautiful case of degraded bushings! This shows the emptied out enclosure:

After vacuuming it clean it was time to install a set of new Beolover Transport Lock Bushing Set for Beogram 4000, 4002, and 4004:

The three bushings come in two halves each. This makes installation very easy. Simply insert one of the halves from below

and the other from the top:

Note that some Beograms have slightly larger orifices for the bushings. It is a good idea to use a bead of superglue gel on the vertical parts of the bushing halves to lock them in place.

After re-assembling the transport locks I installed a Beolover Main Reservoir Capacitor for Beogram 4002 and 4004 (Types 551x/552x):

This Beogram 4002 has a 'dual capacitance' setup, i.e. it had the green and additional orange wire that use the on-board rectifier of the Beolover board. The orange wire was as usual long enough for a wrap around one of the capacitors for a neat setup.

This unit had a damaged mains transformer that blew the fuses. Therefore I removed the transformer and installed the Beolover Transformer Replacement Kit for Beogram 4002 and 4004 (Types 551x/552x):

I wrote a separate post describing the installation procedure in more detail. Please, see here.

Now that this Beogram was on a solid power footing it was time for adjusting the bias of the sensor transistor 1TR3 with the 25-turn 5MOhm trimmer that I use to replace the original fixed bias resistor 1R26. This procedure requires installation of the trimmer on the solder side first so it can be adjusted, while the deck is powered on. I set the trimmer to get the prescribed 4V at the collector:

Then I moved the trimmer to the component side where it fits neatly behind the new 1TR3 transistor (it is a good idea to replace these since they often lost some of their gain making the record detection unreliable)

After repairs or changes to the record detection system it is a good idea to measure the sensor response. This shows the signal on the 1TR3 collector with a spinning empty platter under the sensor:

Each dip in the trace corresponds to a black platter rib passing under the sensor. More than 6V peak to peak is a very nice result. This sensor is ready for duty!

This Beogram was nearing completion, and it was the moment for doing all the mechanical adjustments to align the platter and arms and get the floating chassis situated properly. The first step towards this goal is making sure the aluminum plates settle properly on their alignment pins and that their locking mechanism via the wood frame works properly. The wood frame can only do its locking job if it is straight in the back. If the panels are warped, it can be difficult to get the locking pins of the aluminum panels to catch the matching openings in the metal fittings glued to the wood frame. This Beogram had a still nice original rosewood frame, but it was warped outward towards the back of the frame, i.e. the openings in the fittings were too far out, making it difficult to get the aluminum plates settled. I used some suitable scrap wood pieces and carpenter clamps to straighten them out:

I usually let the clamps do their job for 24 to 48 hours. Usually, this straightens the frame sides out fairly well as a check with a metal ruler shows:

Here the other side:

Before I installed the straightened out frame I adjusted the sensor arm base and the arms to be orthogonal to the carriage rods using my new Beolover Arm Alignment Tool for Beogram 4000, 4002 and 4004:

It makes it a snap to do this alignment properly. Then I installed the frame and a newly restored keypad to replace the old smudgy one. Here you can see them in comparison:

Beolovely! All that needed to be done for swapping the keypads was transferring the plastic pieces that hold the RPM panel down to the new keypad. In this case the original (brownish) pieces were cracked and so I installed replica parts (clear) obtained from the DKsoundparts store in Denmark:

They require transfer of the original springs from the old pieces:

Not too difficult to do:

This shows the rebuilt keypad with the new pieces installed:

See here if you are interested in fixing or getting your keypad fixed. A new keypad is a great way to increase the cosmetic appeal of a Beogram significantly!

With frame and keypad in place I started the process of aligning arms, platter and floating chassis to get the platter parallel to the arms across their travel, and the platter flush with the surrounding aluminum panels. This can be an iterative process that takes a few passes to yield proper alignment.

Once this is completed the arm adjustments can be done. I usually replace the flimsy locking washer that holds the counterweight screw in place

with a square M3 nut and a washer:

This allows locking my tracking weight calibration in place so it can survive the shipping process. Before I did the weight calibration I adjusted the arm lowering limit:

The tip should stop about 1 mm above the lower parts of the platter ribs as shown above. Then I used a digital weight gauge to adjust the arm counterweight to get 1.2g weight at the 1.2g mark of the adjustment wheel:

The adjustment wheel is not very precise and it can be a good idea to check the tracking weight occasionally with a gauge to make sure the weight is still correct.

Then I adjusted the tracking feedback:

Before giving this restored deck its first test spin I installed the requested upgrades. First came the Beolover Internal RIAA Pre-Amplifier for Beogram 4002 and 4004:

It is a direct no-solder plug and play installation. Simply take out the original output board and plug in the RIAA. Then I installed the Beolover Commander Remote Control for Beogram 4002 and 4004:

I also installed a Beolover SyncDrive assembly:

The SyncDrive puts DC motor Beograms on par with the older AC motor models in terms of RPM stability and wow and flutter, while giving them the absolute RPM accuracy of the later 8000/8002 models.

At this point I was very close to trying this deck out the first time. All it still needed was the replacement of the original grimy DIN5 plug

with a lovely new all-metal plug with gold plated contact terminals:

Beolovely! Time to give this restored Beogram a first spin! I selected one of my favorite latin jazz albums: Ramsey Lewis' "Goin' Latin" which he released in 1967 (Cadet LP790). A great compilation of very smooth latin jazz. Perfect for setting the mood for long afternoons of fixing Beograms!..;-). I also love the cover art! From a time when plane travel was still an exciting pleasure instead of today's cattle herding approach!

Here an impression of this album together with the Beogram:

It performed perfectly!

I set out to replace the badly scratched plexiglass hood with a new replica cover. The first step was removing the old hood. I used a razor blade for prying off the side parts of the aluminum trim. This reveals the mounting screws:

This shows the new hood, new aluminum strip, and the liberated metal hinge assembly:

There is a little flaw in the design of these new hoods: They have a recess in the plexiglass just where the aluminum trim bends down on the sides. That makes it difficult to get a precise bend of the trim since there is a void right at the edge. I alleviate this issue by gluing 3D-printed plastic bits into the upper end of the recess, filling the void.

Once the epoxy is hardened, I trim the bits with a razor blade to get them flush with the plexi edge.

The next step of my hood installation process is testing if there is any interference between the metal hinge assembly and the hood while opening and closing the hood. In this case, the hood actually touched the 'stabilizer bar' designed into the plastic shape to keep it from sagging:

Such interference should not be ignored. It causes stress in the plastic every time the hood is opened or closed, and eventually it will lead to cracking of the plastic. Since this Beogram had a later hinge assembly with pressed-in dowel pins, it is not possible to remove the metal hinge parts for bending them a bit for more clearance. The solution in such cases is Dremeling the hood at the interference location to increase the clearance:

Not too pretty a solution, but necessary. The good news is that the small Dremeled area is practically invisible when the hood assembly is installed.

After these corrections, it was time to install the hood! I removed the hinge assembly and set up my alignment tools for the aluminum trim:

I used a strip of blue tape for making an alignment mark:

Then I bolted the hood in again. This time I put some white glue into the threads to prevent the bolts from coming loose. They cannot be tightened very much since it is easy to crack the plastic when the bolts are too tight: