Beogram 4004 Type 5526 - Restoration Project - SyncDrive and Remote Commander Installation

Continuing on from this project's previous post, I needed to install a Beolover SyncDrive platter motor and a Beo4 Remote Commander.

However, there were still some other follow-up tasks like checking the 21V supply voltage (to make sure it doesn't have any noise), adjusting the TR3 collector voltage with the new R26 trimmer, installing a Beolover platter detector lamp replacement, installing Beolover RPM indicator LEDs and running the platter speed calibration.

Here is the 21V measurement check.  The inset oscilloscope screenshot is zoomed in on the 21 V line so I could check the ripple. The measurement looks very good.

Next, I installed a Beolover platter detector lamp module so I could check (and adjust) the platter detection signal with the 1TR6 trimmer I installed (in an earlier post).
Once the 1TR6 trimmer was properly set, I moved it over to the component side of PCB1.

I changed the speed indicator lamps in the Beogram 4004 RPM indicator panel to Beolover LED modules.

Now I could install the SyncDrive platter motor, run its speed calibration and test the platter detection functionality of this Beogram 4004.

SyncDrive speed calibration...

At this point I was able to calibrate the Beogram 4004 record tracking.

I removed the platter belt for this calibration procedure so I could rotate the platter by hand and check the Beogram 4004 servo motor performance when advancing the tonearm.

While this procedure is usually a repetitive adjustment and measure series of steps, I was pleasantly surprised that I was able to lock in the correct setting only using the coarse screw adjustment shown in the picture above.

Usually I get the setting close using the coarse adjustment, then dial in the final setting with the Beogram 4004 eccentric screw adjustment and/or the Beolover tracking lamp trimmer.

Now for a quick check of the platter detection signal and the position sensor run-out groove detection.

The empty platter detector signal looks good.

Previously I had adjusted the position sensor to output 5V when the clear part of the position scale was in front of the detector.  Note that when the blacked out part of the scale is blocking the sensor, the voltage is around 10 V.  Those can be checked and adjusted (using PCB1 trimmer 1R88) without the platter motor if desired.

The last section of the position scale has a series of narrow black bars.  This is so the position sensor will generate a series of pulses that the detection circuit on PCB1 can interpret as the run-out groove of a record. Each run-out pulse adds to the voltage level that capacitor 1C33 charges up to in the detection circuit until the detection threshold is reached. At that point, the run-out detection circuit initiates a stop and return to end the record play.

This picture shows the position scale bars entering the position sensor area. The inset oscilloscope screenshot shows what the run-out sensor signal looks like when the tonearm is moving through the run-out groove.  In this case the run-out detection circuit triggered on the third pulse.
Note: My measurement point here was at the node for 1D41, 1D42, 1C33 and 1R82 on PCB1.

Last, but not least, was to install the Remote Commander...but first, I still had to clean the old oxidation off the Beogram 4004 control panel button contacts.  I applied some Deoxit fluid on the cleaned contacts.

While checking the button panel I discovered that one of the buttons was badly damaged and would not work.  I replaced the plastic button with a spare.

With the button panel restored and tested, I install the Beolover Remote Commander.
This version of the Remote Commander is designed to operate using a Bang & Olufsen Beo4 remote control.

Also...note that the Remote Commander installation is using the Beogram 4004 options.

Using the Beolover Remote Commander with a Bang & Olufsen Beo4 remote control can be a little bit tricky.  That is because the Beo4 remote control is configurable and may not be ready to work with controlling a Beogram right out of the box.

This was the case I ran into with this Beo4.  It did not have the Phono option in its list of supported components.  Adding that to the Beo4 menu list is not difficult but it wasn't intuitively obvious.
Beolover describes the setup in this video.

This Beo4 had one additional wrinkle however.  It did not have a Phono named function in its memory to add to the list of components.  It did have "N. Radio" which, it turns out, is another function name that works as a phono selection.

My next step will be to reassemble the rest of this Beogram 4004 and do some record play testing.

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 4002 (5513): New Wood Plinth, Dust Cover, Keypad and Installation of a Commander Remote Control System

I recently functionally restored a Beogram 4002 (Type 5513) for a customer in Virginia. He decided to also get its cosmetics upgraded with a new walnut 4000c style wood plinth, hood and keypad, and also get a Beolover Commander remote control system installed.

This shows the final condition of the unit:

Beolovely! Almost like new!

My first project was replacing the cracked wood plinth:

Its left front corner had taken a hit at some point:

I put the frame into the oven at 250F. After baking it for 30 min I took it out and with a carpet knife cut the wood panels from the metal fixtures. The glue gets weakened by the heat treatment and the metal parts are easily liberated when hot. The more difficult task is the removal of the hardened old glue remnants. I usually soak the parts in Goo Gone for 24 hrs. I spray the product on and then wrap the parts in plastic foil to prevent drying out:

After 24 hrs the glue can be rubbed off with a bit of effort. This shows the cleaned parts after washing them with dish detergent:

I use 3M 300LSE double sided tape for glueing the parts into the new frame. This shows the tape backed parts together with the new 4000c style walnut frame:

I use two small Beogram 400x aluminum cover plates as alignment help for gluing the metal frame pieces at the right height into the wood frame:

I also use a strip of parchment paper on one side of the metal parts for keeping it from sticking while pushing it into the corner on the other end. The aluminum plates have a thickness that matches the machined recess in the wood frame perfectly, which makes it easy to glue the metal parts at the proper level. This shows the nice alignment achieved with this method:

Her a shot of a corner:

Beolovely! On to the keypad.

This shows the original keypad with finger smudges (on the right) together with the restored keypad that I installed:

The first step was replacing the cracked original plastic brackets that hold the RPM panel in place. They often crack when people pry out the RPM panel in an off angle:

Luckily there are perfectly reproduced replacements available at the DKsoundparts store in Denmark. This shows the two new replacements together with the extracted original parts:

All one needs to do is transferring the metal springs to the new parts:

This pictures shows them installed:

And here bolted into the new keypad:

The new brackets need to be adjusted that the RPM panel is flush with the left keypad side:

Before I put in the new keypad I installed the Beolover Commander remote control receiver board:

It plugs directly into the keypad jack of the main PCB. This shows the keypad installed with the Commander auto-repeat indicator LED bolted in under the keypad screw:

My customer also wanted a new Beolover Carriage Motor for Beogram 4000, 4002, and 4004 installed. This upgrade makes the carriage run more quietly while drawing less current, which protects the H-bridge transistors. This shows the original motor still in place:

I unsoldered the leads and took it out. This shows the original motor still in the enclosure together with the new replacement:

The new replacement fits perfectly into the space with the two provided rubber rings for damping its vibrations:

This shows it bolted in with the leads soldered back on:

The final upgrade was a new hood. This shows the new hood together with a new aluminum trim strip:

The first step of the transfer is unbolting the old hood from the metal hinge. The screws are easily accessed after prying off the aluminum trim on the sides of the hood. This reveals the mounting screws:

The centered alignment of the new strip is a snap when using the Beolover alignment aides (orange):

I usually use a blue tape strip for making a pencil alignment mark:

Once the alignment has been marked, the hinge can be bolted into the new hood and the trim can be installed:

A crucial moment is the bending of the side parts. The Beolover bending block that is included with our trims helps getting a precise corner fold:

This shows one of the corners:

Beolovely! And here a picture of the completed hood assembly:

This Beogram was now not only perfectly restored on the inside, but also in perfect cosmetic condition on the outside! Here a few pictures showing off its lovely looks: