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
Opened up on my workbench I can easily see things that are the same as the 5503 type and a bunch of things that are different.Obviously, the motor is different (DC instead of AC). The service manual for the 5514-5515 has a nice write up on the electrical differences between the 550x and 551x types (you can download the service manual from Beoworld with a Silver membership or higher).Another couple quick differences are with the platter. The 5503 has a small sub-platter that holds a heavy top platter. The 5503 belt goes around the heavy top platter. The 5523 has a large sub-platter that the belt goes around. The 5503 top platter just slides on top of the sub-platter. The position dial for the tonearm is also different between the 5503 and the 5523. The markings on the dial look different.
Here is another inside look at the 5523.
The 5523 has connectors for the wire harness wiring to the main board. The harness wires on my 5503 are soldered to the main board.
Here is the component side of the 5523 main board. It is pretty much the same size of the 5503 board but of course a totally different layout as the circuitry is different.I haven't decided if I will do any rework on this board yet. I'll probably see if I can adjust/calibrate the rotation speed. If I have problems with that adjustment, then I'll work on the board. Otherwise, I think I'll let the turntable continue with its service until the next check up.
The phono cable on this 5523 deck is causing a very low hum. Either the ground wire is not doing a good job or I need a better cable. This 5523 turntable didn't come with a DIN type connector. As this picture shows, it has two RCA phono plugs and a ground wire. Remember how the 5503 had double shielded phono cable? The 5503 turntable is dead quiet connected to my preamp. I think I will replace that whole cable with a new one. I'll have to decide if I want to attach a DIN plug or RCA plugs again.
Another great thread with good pictures
However, to avoid confusion in the future I have one correction (couldn't quote the pic, but it's on the first page):
sonavor: The type 5503 has a CD-4 board that is between the incoming external, phono cable and the Beogram phono signal assembly.In this picture you can see the phono cable on the left, the CD-4 board and the plug to the tonearm assembly phono wiring (on the right).
The type 5503 has a CD-4 board that is between the incoming external, phono cable and the Beogram phono signal assembly.In this picture you can see the phono cable on the left, the CD-4 board and the plug to the tonearm assembly phono wiring (on the right).
That isn't really a CD-4 board; it is a regular 2-channel muting relay board with a delay circuit. Your unit seems prepared for the option though, as it has the four-channel output cable.
Incidentally, I just bought an early BG6000 type 5502 and will begin a thread on that once I find the time. It will be interesting to compare these.
--mika
Interesting: i wonder if the 5523 version always came with that RCA cable. Perhaps it was an option for the North American version ?
I have the 5513 version. It looks identical. However, mine has the DIN cable. Also, all five pins of the cable leads to a connection on the board, so I think there was still the option of adding the CD4 demodulator. Does your has this option as well ? Do all pins leading to the black square connector seems usable ?
My 5513 deck is actually disconnected and in transport mode. If you need any photos of any part for comparison, I'll be happy to post them. However, from what I see, the interior looks identical.
Out of curiosity, can you confirm that the thickness of the ribs on the platter of the 5503 version and 5523 are different ?
thanks for sharing..
Guillaume
tournedos: Another great thread with good pictures However, to avoid confusion in the future I have one correction (couldn't quote the pic, but it's on the first page): sonavor: The type 5503 has a CD-4 board that is between the incoming external, phono cable and the Beogram phono signal assembly.In this picture you can see the phono cable on the left, the CD-4 board and the plug to the tonearm assembly phono wiring (on the right). That isn't really a CD-4 board; it is a regular 2-channel muting relay board with a delay circuit. Your unit seems prepared for the option though, as it has the four-channel output cable. Incidentally, I just bought an early BG6000 type 5502 and will begin a thread on that once I find the time. It will be interesting to compare these.
Yes, good catch. I also realized that when I opened up my 5523 turntable and saw the same board. It is a little confusing because the 5503 has a 2 channel/4 channel switch on the side of the chassis. The 5523 does not. I'll show a picture of the two boards side-by-side. In Menahem's PDF file on the 4002 he shows the full 4-channel board with RIAA amp from a Beogram 6000.
Here is a picture of the two input output boards for the Beogram types. The board looks very similar. The 5503 has a connection underneath to the 2-CH/4-CH switch on the side of the chassis. My Beogram 4002 type 5523 does not have the switch but the board is very similar. I'll bet the board is the same for the Beogram 4004 which has the switch. Correction Note: The pictures should say Output instead of Input board
This picture shows the difference of the platters. The 5523 pads for the vinyl are a little wider.
One more picture of the two platters
hamacbleu: Interesting: i wonder if the 5523 version always came with that RCA cable. Perhaps it was an option for the North American version ?
My 5523 patch cord looks identical, down to the goofy looking spade for the ground (which is not a perfect fit to a BM4000, by the way).
sonavor: Here is a picture of the two input boards for the Beogram types. The board looks very similar. The 5503 has a connection underneath to the 2-CH/4-CH switch on the side of the chassis. My Beogram 4002 type 5523 does not have the switch but the board is very similar. I'll bet the board is the same for the Beogram 4004 which has the switch.
Here is a picture of the two input boards for the Beogram types. The board looks very similar. The 5503 has a connection underneath to the 2-CH/4-CH switch on the side of the chassis. My Beogram 4002 type 5523 does not have the switch but the board is very similar. I'll bet the board is the same for the Beogram 4004 which has the switch.
Looking at the schematics for the output board of the two types, I can see that the board is just the output muting relay. What I believe I have with my two 5503 types are Beogram 4002, US model turntables that had an option to install a CD-4 board (as Mika mentioned earlier). Those two turntables have the 2-CH/4-CH switch but I think the board is just the standard 2-channel output board. That matches up with my 5523 type which does not have any 4-CH option.
Thanks for the confirmation regarding the turntable platter: that means that the 5503 version has always been aesthetically similar to the Beogram 4000, apart from the control panel. It also means that the 5503 version might be a slightly better turntable due to it's heavier platter and AC motor. (Well, maybe it's relative: the 5513 version and up, might be less complicated, thus stable, turntables).
If Rich turntable also have a RCA cords, maybe it's safe to say that the 5523 version were only constructed this way.
I was procrastinating my project of changing both speed pots on my 4002, type 5513. This thread motivated me on my project ! I took the opportunity to take some photos. I think that the comparisons between the US versions of the same model are quite interesting...
Heres the output boards on mine: It does look similar to your 5523 board. However, if you look carefully it owes more to the 5503 versions. Note the additional wires for the optional CD4 decoder:
If we look at the display through a source of light, we can see that an indicator for the 4ch exists. Does the 5523 has it too?
On the right side of the deck, we can even see the presence of a hole, covered with a black tape. So the 5513 version definitely has the option to be converted to a 4 ch deck:
Yes, the panel on the 5523 also has the 4 CH indicator marking. It makes sense that B&O would make that part common.
Does your 5513 phono cable have an additional outer sleeve and shield coming out of the turntable (Additional sleeve over the cable you show in the picture)?
Personally I don't think the AC motor version of the 4002 is any better than the DC motor versions. Both are great turntables and obviously last a long time. I have had my 5523 since 1977. I plan to keep both the 5503 and 5523...plus add a Beogram 4000 soon. One thing I am interested in the Beogram 4000 is the position indicator of the tonearm. I think that was a cool feature that I wish B&O had kept.
I checked my 5523 chassis and it doesn't have any cutout available to add a 4-CH switch later. I was curious about that though so I checked one of my Beogram 4004 decks and they don't have a 4-CH switch. I just assumed they would. The 5526 output board looks like this -
sonavor: I was curious about that though so I checked one of my Beogram 4004 decks and they don't have a 4-CH switch. I just assumed they would. The 5526 output board looks like this -
I was curious about that though so I checked one of my Beogram 4004 decks and they don't have a 4-CH switch. I just assumed they would.
The 5526 output board looks like this -
All the "extra" circuitry on that board (visibly separately on the left) belongs to the rudimentary Datalink control of the 4004. There wouldn't have been space for the rather complex CD-4 decoder anywhere on top of that, and I believe quad audio was already dead in the water by the time the 4004 game out, so B&O had time to rationalize the other mechanical parts to ignore the option as well.
sonavor: Does your 5513 phono cable have an additional outer sleeve and shield coming out of the turntable (Additional sleeve over the cable you show in the picture)?
Yes, with a silver braiding wrapped around the inner wire. Mine is not original since it was converted to RCA long ago. I've re-reconverted to din though... that silver braiding is for the chassis ground and I connected it to the metal casing of the din connector.
I, also, don't think that there's a big difference between these version. In fact, I also own a Beogram 4000 and I must admit that I don't see any difference in sound between it and my 4002. Maybe it's just that i'm untrained. I must admit though that the execution of thing on the 4000 is much more elegant. The panel with the indicator is beautiful in the dark (however useless: it's just an extension of the chariot) The strobe is also an elegant feature. (But also might be useless for some who prefer to rely on sound pitch to tune their turntable) The fastwforward and rewinding function are also much more convenient to use.
But I think the simplicity of the 4002 and 4004 makes them great turntables too
...But, my favorite one is still the 8000 !
(By the way, I scanned the Technical product information for the 8000. It since has been uploaded on the site if some are interested)
tournedos: sonavor: I was curious about that though so I checked one of my Beogram 4004 decks and they don't have a 4-CH switch. I just assumed they would. The 5526 output board looks like this - All the "extra" circuitry on that board (visibly separately on the left) belongs to the rudimentary Datalink control of the 4004. There wouldn't have been space for the rather complex CD-4 decoder anywhere on top of that, and I believe quad audio was already dead in the water by the time the 4004 game out, so B&O had time to rationalize the other mechanical parts to ignore the option as well.
Thanks for the info Mika. I should have read the information about the 4004 more carefully. It does mention that it is the same as the 4002 except with remote control functionality with the Beomaster 2400. What confused me though was the mention that it could be linked with the Beosystem 6000 as part of a quadrophonic system. I thought that the 4004 added some 4-CH capability but it doesn't.
Here is the schematic for the Beogram 4004, Type 5526 output board
I am looking at replacing the phono cable on my 5523 now. I have a question about the wiring of the cable. Currently, the stock cable on my turntable is as shown in the picture here. The tonearm supplies a Right Channel High (RH), Right Channel Low (RL), Left Channel High (LH) and Left Channel Low (LL). On the Muting Relay board, the RL and LL are joined together. The LH routes through the muting relay and out connector P9-1. The RH routes to connector P9-3 and the RL/LL routes to P9-5. On the RCA phono plugs, the Left shield shows it is connected to the P9-5 low signal but the Right RCA plug shield is not connected to anything. I can see that the cable shields for both signal wires do tie together at P9-5 so I am thinking the right RCA plug shield might be the source of the problem. I might replace just the RCA plug first and see if that corrects the problem.
On the DIN plug, both ground of each channels (outer shield on your RCA cable) share the same pin/wire. So I would have guess that both outer shields of your RCA wire leads to the same point on the board (the copper naked wire)
I verified that the right channel RCA plug has a loose wire for the shield. If I measure continuity between the RCA plug shield and P9-5, I can get connection if I wiggle the wire. So I'll go ahead and replace the RCA plugs on the cable.
I kept the original cable and just replaced the RCA phono connectors.
Here is the completed cable.
I am happy to report there is no longer any hum with this turntable and it sounds great.As I started to work on the phono cable repair I decided that I didn't want to reopen this turntable later so while I had it on the bench I reworked the circuit boards and ran through the service manual adjustments.To start with I recapped the main board and changed out the adjustment pots with new ones. There were only three electrolytic capacitors but several tantalum capacitors. It may not have been necessary to replace the tantalums but I decided to anyway since I had replacement WIMA polyesters on hand and I am happy with the way my 5503 turned out.Here is the recapped board - component side
One 0.1uF replacement capacitor had to fit on the trace side
I also replaced the 100uF electrolytic capacitor on the output board. I didn't have any 1 Mohm pots so I left the original one in place.
When I pulled the output board to work on it I discovered it is the same board as the BG 4004, type 5526...it just doesn't have the components installed.
Those are the only electrical replacements I made. I left the one, large 4000uF capacitor on the chassis alone. I measured it and it measured 4400uF.The next step is to do some of the electrical service manual checks.I started with the Slow Slide Transport Adjustment. That is the Forward and Reverse buttons on the Beogram. The adjustment is in section 4-1 of the service manual. It is a simple adjustment : Measure across the tonearm assembly motor and adjust the voltage there while operating the Forward (>) and Reverse (<) control buttons. Pot R56 is for Forward. Pot R57 is for Reverse. The expected voltage is +-3 VDC depending on where you put your leads. I connected to the main board connector P5 pins 2 and 4.This picture shows the voltage measured when the Beogram slow Forward button is being pressed.
Here is a better picture of the adjustment pots for the Slow Slide Transport adjustment
In section 4-2 of the service manual there is an adjustment for the Photo Darlington of the tonearm transport position. On this check the DVM is placed across the collector of 4IC1 to ground. When the tonearm position marker is on a clear (transparent) part of the position dial, the voltage should measure +5 VDC. The adjustment for the voltage is the R88 pot.
The final electrical adjustment I did was the turntable speed (33 and 45 RPM). I did that last because I didn't need the platter on the turntable for the previous adjustments. For the speed adjustments I just put on the sub-platter and my test record with the reflector stickers. The digital tachometer will read the speed while the adjustments are made with pots R15 (33 RPM) and R14 (45 RPM).
Here is what the test record looks like spinning on the platter
The first mechanical adjustment I made was for the tonearm tracking force. The adjustment is the same procedure as I did on the 5503.I placed a cartridge on the tonearm, set the tracking force to 1 gram, then adjusted the rear calibration screw until I measured 1 gram on my scale.Even after calibrating the tracking force I always use the external scale whenever I change the tracking force I am using. The reason is the little dial on the side of the tonearm isn't accurate. Even after calibrating it to 1 gram for 1 gram on the dial, when I changed the dial to 1.5 gram, the actual reading was 1.7 gram on the scale.
The most time consuming adjustments can be the mechanical adjustments in section 3-1. I performed the same adjustments on the 5503 so I knew what I was in for. First, you have to adjust the platter height and make sure it is level. That is done with a platter height adjustment bolt, a locking nut and three leveling bolts in the center of the chassis.The locking bolt should just be hand tightened. The height being adjusted is the distance from the tonearm/detector arm top to the platter deck. With the locking bolt loosened, the large brass bolt in the center can be turned to go up or down. That sets the height of the platter.This can take time because to check the setting you have to put the platters back on, measure the distance, then do it all over again if it is off.You also have to make the adjustment with the transport locks tightened down and then again loose.The leveling bolts are to make adjustments if the 23 mm isn't even from the edge of the platter to the center (you have to measure the distance with the tonearm at both locations during the adjustment).
Here are my two height measurements when I was done.
The turntable platter adjustments don't end there though. Once the platter height to the tonearm is set, the suspension has to be checked so the platter is level with the turntable deck. That adjustment is with the bolt and nut on each of the three suspension springs. This also took a long time as the platter and deck get removed and reinstalled numerous times as adjustments to the suspension are made. You have to take care to make sure the deck gets securely in place each time.
It took me a little over two hours to get through the platter and suspension adjustment on this Beogram. I was glad when it was done but it is something that needs to be correct.
Tonight I have the 5523 back in one of my systems playing perfectly again. No hum from the cable any longer and the restoration should last me for a very long time.