Beogram 4002 (5513): Installation of Upgrades - Universal Power Supply, SyncDrive and Internal RIAA Pre-Amplifier

I just sold a Beogram 4002 (Type 5513) to a customer in the UK. The restoration of this unit is discussed in this post. The new owner wanted to be able plugging it in in the UK without using a 110-to-220V transformer (Type 5513 Beogram 4002 have a supply preset for 110V). This issue can be addressed by installing a modern 'universal' power supply that can work with any grid voltage between 100V and 240V (read more in detail about this approach here). In addition to this new power supply he also wanted the Beolover SyncDrive and internal RIAA pre-amplifier installed.

I started the work by removing the hood and aluminum panels:

This unit had already received the Beolover Commander remote control before I put it up for sale.

First I focused on upgrading the power supply. This shows the original 'classic' transformer setup in place. The encapsulated transformer sits right next to the cable feedthrough and behind the fuse box. In other 4002 Types the voltage selector sits beneath the fuse box. In the 5513 type the voltage selector is replaced with a dummy plate and the transformer is directly wired for 110V only.

This shows the modern replacement, a Meanwell RS25-24 power supply which can operate on any grid voltage: 

It can supply 25W and has a tunable 24V±~4V output voltage range. 25W is more than enough since all the DC platter motor Beograms are rated 15W. This picture also shows the 3D printed adapter plate that I had to design for bolting it into its proper location, while using the original transformer mounting holes in the enclosure.

This shows the supply with bolted on adapter plate:

I removed the four screws that hold transformer and fuse box in place:

It seems best to cut the secondary wires of the transformer at about 40 mm. This results in long enough leads for connecting the new supply:

I soldered 3mm lugs to the cut off blue secondary wires and to new wires for connecting the new supply to the fuse box:

Then it was time to connect the new input wiring for the MEanwell supply to the fuse box. For this I unsoldered the wires going to the transformer (upper connections in the picture): 

and then I soldered in the new red/black wires. Here you can see them emerging from the fuse compartment:

Then I bolted the fuse box back into place:

The next step was bolting the new wiring to the screw terminals of the supply:

Note that the polarity of either connection is not important: The input wires are AC and the blue output wires connect to the rectifier on the main board that previously turned the secondary AC of the transformer into DC for the electronic circuitry.

At this point I also adjusted the output voltage of the supply to the maximum 28V that are possible with the RS25-24. This is done with the white trimmer on the right of the terminals as far clockwise as it goes. 

After adjusting the length of the input cable a bit at the cable gland in the enclosure feedthrough I was able to bolt the adapter plate to the enclosure bottom while smoothly routing the wiring through the 'channel' that I designed for this purpose into the adapter plate. This shows everything in place together with the sub-platter (there is a ~9 mm gap between supply and platter, enough for comfortable belt mounting:

Next came the installation of the Beolover SyncDrive. The SyncDrive is a synchronous motor driven by a dedicated digital control system. This gives it exceptional log-term RPM stability, similar to the later Beogram 8000/8002. This shows the original DC motor still in place:

The SyncDrive is a 'bolt-in and play' replacement for the original motor, i.e. there is no need for soldering. This shows it in place:

The red wiring harness connects to the RPM-panel jack on the main PCB. For this a small adapter breaks out the necessary connections to the red SyncDrive harness, while the original plug is also plugged into the adapter:

The final task was the installation of the internal Beolover RIAA pre-amplifier. The Beolover RIAA directly replaces the original output PCB of the Beogram, shown here still installed:

The Beolover RIAA is also a plug and play upgrade, i.e. all that needs to be done is unplugging the original board and then plugging in the RIAA board:

Then the keypad can be installed again.

This concluded my upgrade work on this Beogram 4002. I will now play it for a couple days to make sure there are no intermittent issues, and then it will be time to send it to its new owner in the UK!

Beogram 8000 (5613): A New Arrival from Virginia - First Impressions

I recently received a Beogram 8000 (Type 5613) from a customer in Virginia for a full restoration. The unit arrived safely packaged in a Beolover shipping container. No shipping damage occurred. I removed the unit from its packaging and put it on my bench:

The unit looks pretty good cosmetically. But the dust cover has the usual damages:

This could be fixed with a new cover from the DKsoundparts store in Denmark. The aluminum surfaces of this unit are all pretty good. The platter is almost flawless:

Of course the aluminum panels had come loose due to the usual deteriorated double sided tape:

The shield under the black plate that sits beneath the arms also fell off:

I put the unit into service position:

Then I removed all functional components and set them up on my rotating Lazy Susan work platform:

I removed the sub-platter and had a look at the platter speed encoder ("tacho") disc. Many Beogram 8000 still carry their original plastic disc, which are often delaminating causing severe fluctuations of the platter speed. This unit already had its plastic disc exchanged with a laser cut stainless steel replacement (also available at the DKsoundparts store):

After this visual inspection I plugged the unit in. The LED dot in the display became visible indicating standby. Usually a good sign, but in this case pressing start only elicited a brief movement of the carriage, followed by a total power blackout. After a couple seconds power came back and the carriage returned to its home position.

My guess is that this phenomenon has to do with the power supply of the deck, which probably has out of spec reservoir capacitors. This may explain why the power went out after moving the carriage for a few mm. We will see what happens when I am done with rebuilding the PCB. Stay tuned!

 

Beogram 8002: Full Restoration and Installation of a Beolover Commander Remote Control System

This post describes the work done during the restoration of the Beogram 8002 that I had recently received from a customer in Missouri. My initial assessment of this unit is posted here.

This shows the unit in the 'ultimate service position' with all the vital parts completely removed from the enclosure and set up on my Lazy Susan:

I really started liking working on a rotary platform since it allows access from all sides without having to bend the wiring etc...

As usual with the 8002 I started with restoring the PCBs. This shows it unplugged from the chassis and the keypad:

I removed the microprocessor shield can giving me full access to all the electrolytic capacitors that needed replacing:

This is a detail shot of the reservoir capacitors that stabilize the power rails:

I replaced all the electrolytic capacitors:

This shows the restored reservoir capacitors. The one with the red bottom is a custom designed Beolover part that replaces the vintage 4-legged 2200uF unit that is normally found on this board:

Here a comparison between the Beolover part and the original one:

The next step was replacing the decoupling capacitor in the microcontroller enclosure. While a bit tedious to replace, it is an important one that should not be omitted. It makes sure that the processor functions properly if there is noise on the 5V power rail. Systems with motors are notorious for such noises due to the EMF generated in the motors. The capacitor (gold) sits right below the microcontroller IC:

Here a view from below:

And a detail shot of the capacitor solder points:

They can be a bit difficult to access due to the added shielded cable. It is a good idea unsoldering the cable before going to town on the capacitor. One item to consider is that the lead next to the enclosure wall also serves as a board via, which means this pin needs to be soldered on both sides of the board! Gotta love 1980s circuit board technology!...;-). I usually unsolder the lead away from the enclosure wall

and then rotate the capacitor until the other lead breaks off:

Then I use my desolder gun to remove the pin fragment. The next step is soldering the negative leg of the new capacitor that goes next to the wall on both sides of the board while the cap is upright:

Then I use the desolder gun to reheat the solder point, which liquefies the solder on both sides of the board, allowing to push the capacitor lead a bit further in. Then the cap can be bent into position while feeding its positive leg into the other solder pad:

Then it can be soldered in on the bottom side, followed by reattaching the shielded cable (take a nice high-res picture before removing this cable so you know where it goes after the new cap is in). Vintage audio is fun!...;-). I reassembled the microcontroller can and reinstalled it on the board:

The final step was stabilizing the tab on other end of the shielded cable. It often breaks off, and it did so in this case:

I added a bit of shrink tubing to stabilize this connection after soldering the wire back on:

There are two more capacitors that should be replaced. they stabilize the 5 and 15V supplies and are soldered directly to the voltage regulating transistors that are bolted to the metal bottom of the enclosure for heat sinking:

This shows them replaced:

Next came the output relay. It is under the clamped shield inside the DIN7 output jack assembly:

The shield can simply be pulled off revealing the original omron relay:

I replaced it with a new encapsulated type:

It has a similar form factor and so the shield can be put back on as it was before:

I usually add a switch (red) to this assembly that allows connecting the signal and system grounds:

With the new output relay in place it was time to focus on the <</>> button assembly under the keypad. This shows the back of the keypad:

The black box contains a light bulb and two photoresistors, which control the amount of power the carriage motor gets depending on how vigorously one presses the << or >> buttons. The cover of the black housing can be pulled off after releasing the plastic tabs with a suitable screwdriver. The bulb is in the center and the resistors are on the sides:

The photoresistors are often out of spec preventing proper adjustment of the <</>> voltages. I replaced them with new ones. They are easily removed. The glue can sometimes be a bit tedious but often a razor blade allows breaking it off from the board surface:

This shows one of the new ones installed. They are a bit smaller than the original ones. It seems putting them flush with the black box top results in a working setup:

This shows them installed:

I also replaced the bulb with a white LED and a suitable current limiting resistor mounted on the solder side under the box:

Note that it should be positioned like this to prevent interference when the board is inserted back into the keypad assembly.

I plugged everything back together and turned the deck on. Then I adjusted the <</>> voltages to be 620mV by adjusting the two screws in the black housing lid:

There was one more thing to do on the electronics end: Replacing the platter motor phase shift capacitor. It generates a phase shifted sine wave relative to the main motor drive signal. This capacitor is housed in the black transformer box. I pried the lid off (careful to not break off the plastic tabs!). This revealed the grey capacitor can. This picture shows it still installed together with the Beolover Motor Capacitor for Beogram 8000 and 8002:

The capacitor can be pulled out for easier access to its solder pads:

After unsoldering the two black leads I installed the new capacitor assembly:

The polarity of the leads does not play a role since it is an AC voltage that is applied to this capacitor. The Beolover part is setup to both accommodate 50Hz (EU) and 60Hz (US) Beograms. Simply connect one of the leads to the COM pad and the other to the 39uF pad for 50Hz or the 27uF pad for 60Hz grids like in this case.

After this it was time to focus on the carriage. I liberated it and removed the spindle. It is a good idea to take a detail photo of the small adapter into which the spindle nut is inserted. So one can put it back together properly after cleaning everything. For the record:

This shows the old lubricant encrusted parts after extraction:

While they were cleaning in my ultrasonic cleaner, it was the perfect moment for adjusting the vertical arm parallelism. This is done with a screw on the bottom of the carriage assembly, i.e. it can only be accessed when the carriage is 'up':

A look from the side after my adjustment:

With the carriage up it is possible to replace the tracking sensor light bulb with an LED assembly. The bulbs break occasionally, and so it is a good idea to install a Beolover Tracking Sensor LED Light Source for Beogram 8000 and 8002. This shows the tracking sensor housing with its cover on:

I slid the cover out, which revealed the small circuit board that carries the photo resistor and the bulb:

Getting the board out is a bit tricky due to the filigrane nature of the setup. The first step is liberating the wire harness. It is held in place with a couple of small rubber rings stuck to plastic posts. This picture only shows one of them since one had gone missing in the enclosure and I only found it later when I put things back together (see below for how it looks with both in place):

I removed the rubber ring:

And then pulled out the four wires (be careful to not disturb the very thin signal wires that go into the center of the lateral arm bearing):

This gave the small board enough slack that I was able to pull it out from its cradle. This enabled access to the solder pads allowing me to unsolder the bulb and pull it out:

This shows it together with the Beolover replacement part:

The LED assembly fits into the orifice for the bulb bottom

This shows it from the side, inserted all the way:

I soldered one leg and then adjusted the orientation of the little board. Then I tacked on the second lead:

This shows the installed LED board from the top:

Then I pushed the board back into its proper position:

Finally, the wire harness can be put back and the little rubber rings pushed on their posts to hold the wiring in place:

In the meantime the carriage parts came back nice and clean from the ultrasonic:

I coated the rods with Tactikel NST to make them as slippery as possible. Then I reassembled the carriage mechanism. This shows the spindle nut in place together with the small black adapter:

It is a bit tricky to get everything into the proper place at the same time. Three hands would be perfect for this. Oh well...we can only hope for advances in genetic engineering to optimize future generations of Beolovers!...;-). A good approach seems to be putting the spindle/nut in place under the carriage and insert the longer rod in the back:

Then push the rod into its receptacles:

And then stick the spindle end onto its plastic nipple followed by pushing the other end of the spindle into its bearing next to the motor. While this is done the carriage needs to be tilted forward accordingly:

This shows the spindle pushed back into its bearing at the pulley

The final step is putting the shorter front rod back into place:

Now the belt can be installed 

followed by the rotary encoder assembly:

Once everything was back in place I adjusted the arm parallelism with my new tool:

It fits on the front rod of the carriage to be properly aligned. Its arm is perfectly orthogonal to the rods. This makes it a snap adjusting the sensor arm orientation:

Once the sensor arm was perfectly orthogonal I adjusted the tonearm to be parallel with the sensor arm.

Then it was time to adjust the tracking sensor feedback. This shows the LED lit up, still with the cover off:

After pushing the cover back into place:

The adjustment is done with a small screwdriver by turning the screw on the side of the tracking sensor assembly:

The goal is to adjust it in a way that the platter turns 2-3 times after the needle is down before the carriage starts moving.

At this point the deck was functionally operational and I gave it a test spin. I put on a recent acquisition, an earlier Earl Klugh record called "Heart String" that came out in 1979 on United Artists Records (UA-LA942-H). The deck performed nicely. Here is an impression:

My customer decided he wanted the new Beolover Commander Remote Control for Beogram 8000 and 8002. This upgrade allows controlling a Beogram 8000 or 8002 with an Apple remote control. This shows the components:

The circuit board headers 

directly solder into the P8 and P5 positions on the keypad PCB. Originally, they are occupied by an angled header that connects the keypad buttons to the microcontroller, and a grey ribbon cable that supplies power and also connects the << and >> button signals to the carriage motor control circuitry. This shows the header and cable still in place:

And here after transferring them to the Commander board:

And here an impression of the Commander board installed on the keypad PCB:

The infrared receiver is fed out between top and bottom parts of the enclosure:

After a function test of the Commander system, it was time to work on the cosmetic issues this deck had. First I removed the double sided tape remnants under the aluminum plate around the platter. These residues can be removed with isopropyl alcohol. For this process it is a good idea to protect the metal bottom part of the enclosure with a plastic bag. The paint on the metal surfaces dissolves in alcohol. After the residues were removed sufficiently, I epoxied the plate into place. I usually put some 4-40 washers near the spots where the tape was and add dabs of epoxy under and on top of the washers:

Then I put the plate on and clamp it in place:

The metal shield that fell off the black cover under the arms is best glued on with some modern double sided tape:

I installed the new hood and put everything back together. And then it was time to enjoy this lovely restored Beogram 8002 with a nice record! I selected one of my favorites, Miles Davis' "Filles De Kilimanjaro" (Columbia CS9750) that was issued in 1969:

The deck performed Beolovely! I will play it a bit more and if nothing else comes up it will soon be time to send it back to its owner!