Re-capping TTs?

[thebes]

Picked up a Bang and Olsefson 2402 Beogram TT last weekend at a garage sale for $25. Cart's ok, but worn.

It had a stuck lifter so while I freeing that up I noticed that there's

at leat one cap in there. The other thing that looks like a cap

is some sort of glass thingy.

Now I know re-capping is highly recommended for speakers and amps

etc.,sose I'm wondering if it also makes sense for turntables.

Noticed some of my other turntables have caps alos.

So, what's the skinny?

[3dzapper]

They are motor start/run caps that shift the phase going into the motor andrarely go bad. That said, I thought the motor on my VPI was bad as it was "cogging" and running slow. Turned out to be the .68uF motor cap that was bad.

If you want to change them for S&Gs, watch the voltage. 125/.707= 176V peak to peak without any surges. Stay with 400VDC or better caps for safety.

Rick

[pauln]

Thebes, nice to see others have B&O tables around here. If you have trouble finding a replacement cartrige, let me know. I have some spares; MMC 20 S, and a few MMC4000.

The MMC 20 S is virtually unused (less than 10 hours) because it only has a simple spherical diamond and I have better units, but it is in pristine shape.

The MMC4000's are a far superior unit using an eliptical diamond. I have three and could part with one.

I do my serious listening with my MMC6000 which is the top of the series for this design.

http://www.sound-smith.com/cartridges/indexBeo.html#classic

http://www.beoworld.co.uk/mmcpickups_1.htm

Paul

[Cal Blacksmith]

Photo taken from B&O site.

I have a B&O 1900 TT as my backup table. I bought it new in 1977 and it has served me well since then. I don't remember what cart is on it, I need to check, I might be interested in the 4000.

LInk to my TT specs

[pauln]

Cal, mine is the same - 1900 bought new in 77, in constant use since then, the MMC4000 is made for it. Since the cartridges are no longer made by B&O the originals are scarce, but they show up on ebay. Might have to buy one connected to an old table in some cases, but deals can be found. There are some companys that make replacements in this series but they are very expensive. If you can find a good MMC6000 you won't be sorry - I keep an eye on ebay for them.

Let's see if Thebes wants to take my offer on the 20 S or the 4000, if the 4000 is still up I'd be glad to offer it to you.

[Cal Blacksmith]

Since you have one also, mabey you would know where to get a new(er) dust cover? The plastic tabs on mine broke and the spring came off. I guess Epay might be the best here also as a second cart for it would be nice, two with one stroke so to speak[]

[J.4knee]

YA know Wane, old Thebes there might be able to make you one. If I rember correctly he has built a dust cover or two.

[pmsummer]

Cal,

I picked up a spare Beogram 1700 WITHOUT cart for $20 on ePay. I grabbed it for spare parts for my 1700. The dust cover was MUCH nicer than mine, so I swapped it out.

Picked up a used MMC 6000 last week whose nose guard had come off for $28. The stylus and sapphire cantilever were in great shape, so I glued the nose back on and it's an IMPRESSIVE cart... sounds better than my MMC 20CL (which was top of the line).

I love my Beogram, and it's been a good and faithful servant for 23 years. Now I've two of the beauties. Danish DJ?

[pmsummer]

If you can find a good MMC6000 you won't be sorry - I keep an eye on ebay for them.

The MMC6000 I bought a couple weeks ago was advertised as an MMC4000. It came in an MMC4000 box, complete with brush, scales, little B&O screwdriver, and spec sheet (and two little noses...and the plastic cover). When I inspected it, lo and behold it was the 6000. The 4000 case obviously came from a replacement.

I've got a pretty good MMC 20S as well. Not sure why.

[thebes]

So capping is not a problem. Good. One less thing to blow up/catch fire when I'm working on it. Thanks Rick.

That's my TT Cal, thanks for posting that.

Paulin, I might be interested in one of the carts but I'm not sure

about compatability. I probably have the original needle, it's a

MMC 20e. She's a bit worn looking under my Rat Shack pocket

microscope. With no rest arm for this tt it's really easy to bang

up the needle.

Isn' the 4000 designed for tangental TT's? Is the 20S a lesser cart

than the 20e? I know some of this is rebadging models but I

figured you guys that own them will know a lot more than me.

Finally, price. Have I mentioned that I'm a certifiable

cheapskate?[] but I am a fellow forum member, generous with my time

and talents and the Twins took all my money. (in rereading this I am

sorry to say my whining is not quite up to snuff today)

Played the turntable for several hours last night. Once I

increased the tracking weight from 1.2 to 1.5 grams it seemed to do a

better job. A little bass shy, with a shallow but wide

soundstage and very good detail.

Any tweaks, setup advice to suggest?

[pauln]

The MMC4000 is perfectly compatible. The needle and cartridge are an integrated unit (in fact the whole chain of needle, cartridge, tone arm, and table comprise an engineered integrated unit) so don't try to remove the needle as with others.The MMC20e is eliptical and a better diamond than the MMC20S.

I have found that the best sound comes from tracking a little above the recommended 1 gram level as well. Compared to regular systems, the B&O may sound a little bass shy at first, but this is only because they are flat out beyond where you can hear. Other systems tend to use a heavier tip mass and resonate (sibilance and cymbols) up around the 17-19KHz range and you lose some the the real high end clarity from masking of the higher sounds by the lower sparkly resonance- so the bass sounds more pronounced. You may come to find the B&O sound is very nice and pure.

For setup, you will have noticed by now that the table is very low in height and quite heavy. If you bang on the top surface there will be no sound transmittedt to the platter - the platter and arm are suspended (be sure to lift the platter and release the three big screws), and the motor/pully/belt assembly is further sub-suspended within the first platter/arm suspension. This means the table is virtually impervious to vibration and feedback.

As far as the dust cover, well I've replaced mine three times in the last 30 years and now I go topless. There are three screws on the back that will release the dust cover and the hinge mount. The result is a clean table even more resistant to vibration and feedback.

There are lots of beater tables on ebay that can be had cheap for parts and cartridges.

[pauln]

<?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Thebes,

On reflection, I am thinking that your question about the B&O setup needs more input.

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Tracking Force

You will have noticed by now that the B&O table has no adjustments except for the tracking force. There is a screw behind the counter weight that is accessed by a hole. A little flat blade screwdriver may be used to move the weight forwards and backwards so that when the tracking force slider is set to 0gm the arm will hover in a neutral position. That is all you have to do to calibrate the slider so it is accurate.

Vertical Tracking Angle built in.

Cartridge physical position relative to the arm, platter, etc., - built in.

Various angles of alignment built in.

Basically, all of the usual adjustments that need to be made to setup a cartridge on a tone arm and table dont exist on a B&O because all these where taken into account in the design, that is they knew everything about the physical attributes of the cartridge and designed the tone arm and table characteristics with all these things optimized for highest performance.

Anti-skating not only built in, but really interesting! Really!

The anti-skating adjustment on most other tables is a lateral force at the back of the tome arm to compensate for the skating force that tends to push the stylus to the center to the record. In the B&O, this force is accomplished with a series of little ball bearings that reside under the angled planes of a gear-like assembly within the vertical spindle housing of the tone arm. The amazing thing is that actual skating force varies across the record, and the differential torque of the tone arm caused by the skating force is constantly variably matched by the reverse torque impelled by the planar surfaces trying to climb over the balls. So antiskating is proportionally and constantly adjusted to what is required across the whole record always correct.

Maintenance

Just a few things need to be done every once in a while. I lift the platter and remove the belt for washing with mild soap. I use a Q-tip saturated in record cleaning solution (I make my own) and clean the path around the spinner assembly above the bearing where the belt goes around to rotate the platter, then clean the contact point where the rubber perimeter of the belt drive wheel is impelled by the motor spindle.

Every so often I give the RCA output jacks a scrub to shine them up (they are silver).

Every so often I break out the microscope and examine and clean my styli collection.

The brief history of B&O

You have probably noticed that B&O stuff looks sort of funny (low, modern, cool, beautiful). Here is the real story. Back in the great war both B and O were involved in the resistance in Denmark. They were clever fellows and made a radio transceiver disguised as a toaster. If you recall Hogans Heroes coffee pot used to listen in on Col.Clink you get the idea. They made a lot of these kinds of things during the war always meeting the engineering challenge to make it look like something else. After the war, friends requested they make some audio gear for them and their response was, What would you want it to look like? The rest is history. They made the first stereo cartridge in Europe and some of the best turntables ever engineered. The company went on to made receivers, radios, speakers and other things, many of which are pretty good, but their forte was always super advanced cartridges and turntables through and through.

Pauln

[thebes]

Thanks for taking the time to provide me with the general setup info,

maintenance regime and background on the start of B&O. Both

interesting and sueful. Not a combination you get every day.

It is a sweet sounding turntable and a little "burn-in" (it's had

probably not been playe in quite a while) seems to have helped a

lot. This also has a speed control and thanks to MikeBSe I have a

really nice test record that has built in speed indicators so I can

dial that in also.

So the 4000 sounds like the way to go. So what's the (shudder) price?

A PM or email is fine.

[pauln]

Thebes, since you are a fine forum member, and since you didn't make fun of me for taking the unequal wire length thread into an extended OT excursion about the molecular mechanism of photoreception; just provide a mailing address and I will send it on. Box, slipcover, instructions/specs, stylus guard, brush/screwdriver/tracking force scale,,, the whole kit. My welcome to the B&O brotherhood.

Pauln

[thebes]

Thebes, since you are a

fine forum member, and since you didn't make fun of me for taking

the unequal wire length thread into an extended OT excursion about the

molecular mechanism of photoreception; just provide a mailing address

and I will send it on. Box, slipcover, instructions/specs, stylus

guard, brush/screwdriver/tracking force scale,,, the whole kit. My

welcome to the B&O brotherhood.

Pauln

Whining works! Who knew![]

Paul that's is an extremely generous thing you have just done. I

mean that with complete sincerity (something you have figured out by

now is not what I'm prone to do).

I reluctantly take you up on your offer, because again, that is very, very generous.

I have numerous bits and pieces, parts and whole gizmo's lying around

here. Anything you happen to be looking for? How about some music?

I'll email you with the details.

Rats, I completly forgot and missed out on your reply to the unequal

wire thread. Very interesting. I'll respond after I've had

some time to digest it. It's funny, I'm an avid science fiction

fan, but often the concepts and hard-science behind the better stuff is

hard for me to get my hands around, partially due to limited math and

hard-science background.

It's even funnier in another sense because I was the "science" guy for

my congressman when I worked on Capitol Hill. Some of the

conversations with scientists were somewhat tortured (to say the least)

as I tried to comprehend what they were telling me.

By the way, the Beogram will be running with my Thebes-O-Bogen monos,

CJ pre and Heresys. Your new to me cart will be keeping good

company.

[pauln]

Sent priority mail this morning. Looking forward to seeing what you think.

[thebes]

I received your very kind gift on Saturday. Installed it and

followed your advice on clenaing the belt and rollers and with the

essentially new stylus (examined it under my handy-dandy pocket

microscope).

Big difference in sound, bass imrpoved and the soundstage deepened. This TT sounds wonderful.

Can't thank you enough Paul.

Take note fellow Klipschers, yet another oustanding example of why this place is unique.

[pauln]

I'm very pleased that you are enjoying the MMC4000. It is a very superior design classic. Have you noticed that it uses four coils instead of two? (has nothing to do with its Quadraphonic capability).

One more thing to add...

I use a rubber washer a little more than an inch in diameter and about a quarter inch thick as a record clamp. I've never had a record slip without it, but it's utility is actually something else. When I start a record, I first grab the washer clamp and spin the platter a little past normal angular speed, then press the start button. This relieves the motor from the initial stress of torquing the platter to playing velocity. I have to believe that in the long run this results in an extended life for the motor. I've loved my B&O for 30 years and want it to last forever.

Pauln

[lwhaples]

I received your very kind gift on Saturday. Installed it and

followed your advice on clenaing the belt and rollers and with the

essentially new stylus (examined it under my handy-dandy pocket

microscope).

Big difference in sound, bass imrpoved and the soundstage deepened. This TT sounds wonderful.

Can't thank you enough Paul.

Take note fellow Klipschers, yet another oustanding example of why this place is unique.

Members helping members,That's one reason I enjoy this Forum as much as I do.

Larry

[Cal Blacksmith]

I am glad everything worked out so well. Paul that was very generious for sure! Thebes, you have a good sounding unit there, ENJOY!

I made a half hearted bid on a few new carts but passed when the price went over $100 for the "top of the line" cart. Perhaps they are worth it but it is not a high priority right now.