Beogram 2400 – a generic question

[Wojciech Herchel]

Hello,

 

I have recently acquired a Beogram 2400, which happens to be working beautifully – one thing that is weird is that the turntable body moves up and down (together with the tonearm) in the chassis – or it bounces, if you will… is this intentional, or is there a screw missing somewhere fixing the actual turntable to the chassis such that it does not move?

[Mark-sf]

Nope, the bounce is intentional to prevent acoustic feedback. Enjoy your new purchase!

[Wojciech Herchel]

Thank you.

Second question I have that the stylus has a tendency to drag over the record a bit – particularly on the new/modern record – when it returns to home after finishing the record or pressing Stop – is it an easy adjustment? The stylus force is set at 1.5gr, it is a MMC20E. anything else that needs adjusting?

[Mark-sf]

If you remove the counterweight you will see a screw that adjusts the tonearm height when it is cued up. This should be 5mm above the record surface.

[Wojciech Herchel]

Hi – where is the screw though? on the outside part of the counterweight, where the slider is or on the inside – see the picture – there is a screw on the inside part of the counterweight, where I marked in white – as it is dark and was not visible on the picture.

[Mark-sf]

Lift the silver counterweight out of the arm and you will see it.

[Wojciech Herchel]

How exactly do I lift the silver counterweight? Does it slide off or something? Maybe a daft question, however I am a new to this, so wouldn’t want to break something by mistake…

[Mark-sf]

Grab the edge to the silver plate on the rear of the tone arm and lift it out. It fits using friction.

[Wojciech Herchel]

Got it, managed to take it out. The manual says the adjustment should be made with a counterbalance weight inserted though…? So I adjust, put it back in and measure and readjust if need be? stating the obvious, I can’t access the screw if the counterbalance is in…

 

Attachments:

You must be logged in to view attached files.

[Mark-sf]

The issue they are trying to address, is that when the weight is removed, the suspension will be higher on that side and the tonearm will show a great distance from the surface. Simply adjust and place it in but not fully seated so that you can check the height.

[Gabe]

Hi, I just did this on a B&O I got off eBay and fixed up a couple days ago.

Play a not critical record and have the tone arm run in the middle.

While playing, push nothing on the Control Panel and Pull The Plug to cut power.

While holding the tone arm, slide the clear plastic force indicator to 1.0 grams.

Set the B&O Gram Balance (Kit came with my MMC4000 cartridge in 1976) on the center of the record and place the stylus in the groove at 1.0 grams. (Saw a MMC4000 cartridge kit box on eBay about $90, no cartridge of course.)

Look to see if the balance teeters level. If not, use a small screwdriver to move the Lead Weight in the Tone Arm in and out. There is a small hole in the back of the tone arm to reach the slotted set screw in the weight. I think there is a small hole in the dust cover too, to reach through and access the set screw. While holding the tone arm protecting the cartridge, you can wiggle the weight loose by grabbing the edges of the small rectangular aluminum plate. Look at the set screw and see how it works. You can adjust it and press the weight back into the tone arm as well.

When your Tone Arm indicator is set to 1.0, and the Balance teeters at 1.0, you are golden.

Now set the sliding Tone Arm Scale to around 1.2 or whatever your cartridge and records need.

Remove everything placed on the record surface or elsewhere, and plug your B&O back into the power outlet.

Gabe

Attachments:

You must be logged in to view attached files.

[Gabe]

The Floating Suspension:

Remove the Platter and you will see 3 big slotted head screws. A quarter fits well.

Turn and raise the 3 screws fully counterclockwise to lock the turntable for shipping or moving with no bounce.

Turn the 3 screws fully clockwise to release the turntable to rest on its 3 leaf spring suspension.

Gently place you hand on the wheel and push down slightly, and you can feel the soft suspension.

Now place the Platter on the wheel, and the turntable should be “sprung” to just float. This is excellent.

I have an odd situation I cannot figure out. My 2400 that I bought in 1976 floats perfectly. But my eBay 2400 I just got and restored, requires that I place TWO platters on it to get it to “float”. The 2400’s are exactly the same, but the eBay one seems to have “stiffer” springs. Any ideas to fix this? Adjust or soften?  Thanks,

Gabe

[Mark-sf]

About an inch from each transit screw, there is a covered hole that accesses a screw that governs the height of each of the leaf springs. Make sure the motor runs smoothly with 2 records on the platter and the suspension is level and has equal top and bottom spacing when the records are removed.

[Gabe]

Mark-sf,  Thanks, your instructions were spot on. I would have responded sooner but I was waiting for new drive belts and a 2400 Service Manual to arrive from eBay, so I could drive the Platter properly, and possibly see a diagram of what you described. The 3 Hight Adjustment Screws go to Cleats that deform the 3 Leaf Springs, and have a prevailing torque so they will remain where set. I turned all 3 counterclockwise a half turn and tested, and then did an additional half turn each. Platter now floats perfectly, just as my original 2400.  (I will bubble level it once the turntable is in its final position.)

The (thin) Service Manual is kind of funny. Written by B&O’rs for B&O’rs, if you do not already know the turntable well, there is a lot of assumed information simply not discussed. For example, setting the Stylus-Force in the section called Pickup Arm Balance. There is no way to teeter-tot the Tone Arm about -0- with the Stylus and Weight installed while the Tone Arm Lift mechanism is in the raised position. It is best to do this adjustment (with a scale if you have one) with the Lift descended, and that is by playing a record, and unplugging the power. Now you have total free control of the Tone Arm, and can play with balancing it, either at -0- force (a level teeter-tot) or against a Gram Scale equal to what is set on the Tone Arm Scale.

Of course there is a lot of priceless information too. For example setting pots R4 & R5 for 33-1/3 & 45 rpm is accessible from the top after lifting the thin black plastic disk. Now I just need a Stroboscope Disk and Lamp. My plan WAS to use a piece of white tape on a record and count revolutions against a stop watch.

Wish List after reading the Beogram 2400 Service Manual:

Stroboscope Disk & Lamp

<b>Test Record 3621004</b>  & 2 Chanel Oscilloscope (To test and adjust the Anti-Skating.)

Instruction Diagram  3535056  (This might just be the Owners Guide pamphlet.)

Anyone ever seen “Test Record 3621004” and where to buy one? 

Test question: Why wouldn’t a copy on tape or CD work?  🤣

Thanks Mark-sf, and anyone else that might have a lead on my wish list.

Cheers, Gabe

[Mark-sf]

I would simply get a simple strobe disc for speed adjustment and not worry about the anti-skate setting. Counting rotations WON’T work. Investing in a scope and test records is only warranted if you want to get into the refurbishment business.

[Gabe]

Hi Mark,  Primarily, I’d like to make sure my original Beogram 2400 & MMC4000 are in the best shape possible, and the Elliptical Stylus at 1.0 to 1.2 grams set to best preserve my vinyl. In the past couple weeks I’ve now restored three 2400’s; mine and the 2 eBay units I bought for parts, but was able to get all 3 reliably fully functional. (Well, the 3rd has a stubborn to engage Pause and Stop that may be due to a missing or stuck Dog Catch under the Cog Wheel. Pardon my Danish, I mean Release, Switch Arm, Hammer, Cam, Release. Anyway, I’ve really had a lot of fun!  And hearing my soft-sleeve-stored vinyl for the first time in 35 years brought tears to my eyes. (35 years? Yea, graduated – work – marriage – kids – now retired.) But 35 years!!!? Well our home came with two built in theater surround systems (no phono just CD/DVD), and I was lazy. Now also breaking out my Bob Carver Cinema Grand and Yamaha NS-1000M Speakers, that I may do a Crossover CapBank re-build.

So, I love the elegance, simplicity, AND performance of the 2400. I may keep looking for re-build projects AND cartridges. MMC’s that do not meet snuff will go to the experts with tiny fingers for re-build. And so, I think I would like to invest in a Strobe, Test Record, and Scope. I found:

Strobe & Light $30.29

Stylus Force Gauge $12.95

Sharp Track-ability Test Record $19.23  (B&O Test Record 3621004 anyone?)

RCA to BNC Adaptors $6.99

Handheld 2 Chanel Oscilloscope $89.99, Or BenchTop 2 Chanel Storage O-Scope $154.

So, $159.45 to $223.46 for all the new equipment I think I’ll need. About the same as an eBay re-build project.

Here are the photos of what i’ve found…  Cheers, Gabe

Attachments:

You must be logged in to view attached files.

[Mark-sf]

You only need the strobe disc and an incandescent/neon bulb. I would also not consider any scope that didn’t have a 5mv per division sensitivity for phono work. That one is 100mv. Best of luck with your projects.

[Author]

Posts