BIC 980: new owner with crazy questions !!

[duncan_england]

Hi everybody
Most regulars here probably know I just imported an old BIC 980 from USA to England. Now reassembled after shipping and cleaned up, all connections on, belt seems fine and no rust or gunged up. I am now awaiting the step down transformer. Whilst waiting, I have got some curious questions that I have no idea on. Perhaps someone out there could give me some answers. (Doug, hint hint!!)

I will be using this belt drive for CD-4 vinyl.

1) What is the Anti Skating Dial and when do I need to use it and how?

2) What on earth is a Stylus Force, and how do I use this?

3) How do I set the correct speed? Do I use the pitch control or do I need a 50/60hz platter strobe disc? I'm getting a bit confused on this question.

4) On the stylus lever do I use circle for normal stereo stylus and elliptical for shibata?

Any advice and info most gratefully received.
Thanks
Duncan The Brit

 

[Doug G.]

Hi Duncan,

OK, let's get down to it. \:^)

1. All pivoted tonearms with an offset headshell (angled) have a tendency to be drawn toward the center of the record while playing a record. This is due to various forces acting on the stylus/arm. It is called skating. The anti-skate control adjusts a spring tension to put an opposing (outward) force on the arm to counteract the skating force. This way, there is equal force put on each groove wall (right and left) to keep stylus and record wear equal on both sides. On the 980, the anti-skate lever is the rear one on the gimbal ring at the rear of the tonearm. I'll explain how to adjust it in a minute.

2. Stylus force is simply the vertical force necessary to keep the stylus in contact with both groove walls. This is critical because if the stylus bounces around in the groove, the record will be damaged. I'll explain this in a minute too.

3. Does your 980 have four rows of dots on the strobe disc that's visible in the little window at the left front by the little knob? I remember that yours seemed to be a later 980 so it should. So, it already has a 50/60 Hz. disc. For 33 1/3 RPM records you want to adjust the knob so that the second row of dots in from the knob appears to be standing still while the platter is turning. For 45 RPM records, use the row of dots farthest away from the knob and do the same thing with the knob. Get the dots to stand still. In each case, the platter is then set to the correct respective speed.

4. The "stylus" lever is used in conjunction with anti-skate but, since anti-skate is kind of inexact, it's not really critical where it is set. This is especially true with CD-4 records. There is a little experimentation involved. Normally, you just set the lever to the type of stylus you are using. I'll tell you how I set it below.

To set the adjustments for CD-4, here is what I do:

I have the "Stylus" lever set to elliptical.

With the cartridge mounted in the headshell and the shell installed on the arm, set both levers at the rear of the tonearm to zero. Now turn the counterweight (the big, round silver thing on the rear of the tonearm) until the tonearm is floating parallel to the platter. This indicates that it is balanced and ready to have the stylus force applied. This is done with the front of the two levers on the gimbal ring. The numbered markings are in grams and each small mark in between is a quarter gram.

I set the force to 2 grams for an AT12Sa. I usually set the anti-skate lever to about a half gram less than the stylus force and get good results with CD-4. So the front lever is set to "2" on the gimbal ring and the rear lever is set to about "1 1/2".

These settings should get you good performance with CD-4 but it may take a little messing around to get it dialed in.

Doug

 

[duncan_england]

Good evening Doug,
Wow...such precious information. Thank you so much... and for keeping it in simple terminology! I understand all this.
Yes mine has the window/mirror with the 50/60Hz disc. Now it's all starting to make sense. I think what I'll do first is set up when the transformer arrives and try normal stereo first with the newish Phanstiehl stylus supplied. If it sounds ok, then switch cartridges and do a proper set up following your recommendations with the AT12sa cartridge. I would hate to damage the Shibata diamond on its first set up.(although I've heard they take a few hours play to "bed in")

It's quite strange. Every record player in the past I've purchased has been literally plug and play, motorised with pre set speeds and all simple to use. Going back in time is a completely different kettle of fish. How on earth did we cope in the 1970s with audio hardware? I remember my family just had a square grey Bush record player which was automatic and played great Top 20 singles.Mono, and valve but a lovely smooth sound. Then my Dad got a Bang and Olufsen set up which took me years to understand..... 31 YEARS ON AND I'M STILL AT IT !!!!

I will let you know how I get on in this thread.
Thanks again Doug, You're a Star.
Have a good weekend
Duncan

 

[duncan_england]

Dear "Doctor" Doug,
I have the transformer. No problems with power or starting up. Turntable actually runs smoothly and Phanstiehl stylus working very well for a STEREO test using your settings. The problem is speed.

My Symptoms:
1) The strobe disc will not slow down or stop when you adjust it's controller. The 4 rows of dots just keep whizzing round at a constant speed. (Strobe reader is lit up when t/table is running.)
2) The speed of the t/table now is slightly slower than 33 1/3rd.
3) When you switch from 33 to 45rpm the platter stays rotating at 33rpm speed but I can see the red plastic speed guide has worked as the belt has moved into the 45 rpm lower slot of the red guide.

I presume a new belt would help as well.

Thanks Doc, I await your diagnosis with interest.

Duncan:banana:

 

[mtgc]

Duncan,

While you await the word from Doctor Doug, I think you are on the right track with questioning the belt. I have found when I get a used turntable from almost any source I just swap out the belt, of course if the turntable is a belt drive of course, just for insurance before I do anything else to the turntable.

Good luck and keep us informed as to your progress.

MTGC
Michael

 

[mtgc]

ADMIN: Should we use Doug's post above as a sticky? It pretty much sums up turntable specifics.

MTGC

 

[duncan_england]

Thanks Michael,
Yep changing the belt makes sense. If the motor is pushing out the right speed, but the belt is worn or stretched it's not likely to make the t/table go faster, but it would slow it down. I wonder if a worn belt would affect the strobe settings as well. Don't know... watch this space!! ooops...thread...... for the next lesson in 1970s sound education.
Doug's info has been absolutely brilliant. I wouldn't have got this far without his advice. He should get a medal for services rendered!

Duncan
(does this mean I could be the only Brit on QQ with a BIC980)!!

 

[Doug G.]

Hi guys,

Sorry for the tardy reply. I was out all day yesterday.

Anyway, the belt shouldn't be a real issue as long as it isn't really stretched out and drives the platter. When a BIC is new, it takes about 1/2 - 2/3 revolution for it to get to speed. As the belt ages, it will take longer but it should still be OK.

If you do decide to get a new one, I suggest buying one from Turntable Experts in New York. Adam has the original orange belts.

Duncan, look through the clear plastic lower cover at the front while the turntable is running. A little right of center, there is a little light bulb that is part of the oscillator circuit to control the platter speed. This light should glow orangey and kind of dimly and steadily. Is yours?

When you turn the pitch control knob, is there any change in the appearance of the strobe markings at all? If so, this means the speed control is basically working but is just out of range.

This is adjusted by setting the top knob in the center of its travel. Then gain access to the speed control board at the front underneath. I do this by lifting the base up at the front with the wing nuts removed. There are three adjustment contols on this board. Two are along the long side of the front of the board and one is on the right side of the board. The lone constrol on the side is the coarse adjustment for speed. Turn this control until the strobe markings for the speed you are adjusting stand still (in this case, for 33 1/3 @ 50Hz, the second row in from the knob).

Of course, if the light from the little bulb is pulsating, it means a different adjustment which I will explain if that is the case.

Don't worry, there are no dangerous voltages present in that area. Or even shock producing, for that matter. The motor in the 980 runs on 24 vts.

Doug

 

[duncan_england]

Hi Doug,
Thanks for your last posting. Here's the latest news:

1)The pitch control knob seems to make no difference at all. The strobe disc just keeps going, none of the lines of dots stop.
2)The oscillator board bulb glows steadily and is not pulsating.
3)I tried adjusting the blue coarse wheel, from one extreme to the other. The 33rpm line of dots only slowed a very slight fraction then sped up again. (My wife stood there watching it).

So no luck yet. It plays records really well but is well under the speed of 331/3 rpm.

I remember the ebay vendor said " the rpm adjuster is pegged at one end of the adjustment, but is so close to right on that I never, in 40 years bothered about it. No one could ever tell."
I could tell straight away she's running slow, - miles out !! -and notice now I've actually given it a gender!!

I really hope this isn't bad news. Any other fixes Doug?
Duncan

 

[Doug G.]

The next thing to try is, with the turntable switched off, unplug and replug all the connectors going to the control board in case there is some kind of bad connection.

If that doen't work, it kind of points to a problem with the board.

I have some spare boards that are untested but I could send one to you to try if you would want to swap it out. It's pretty easy since all the connectors are plugs.

Doug

 

[duncan_england]

OK, have just tried that Doug. All 3 white connectors prized off, wiped and reconnected. Man, those terminals are at least 2 cm long!! Quite tight getting them on/off. Still no difference. The oscillator bulb still glows constant dim and strobes still not stopping when adjusting the coarse adjustment. Here I went back to finding that fractionally slowed point and then tried the pitch control in case of any improvement. - Negative still no stopping that darned strobe pattern!!!:howl

The drive belt was skew wiff as it goes around the pulley, so I have removed and refitted it untwisted. One thing I noticed is when selecting 33 speed, the red plastic guide rubs against the belt. Move the rpm slider selector lever forward about 1cm from where it says 33 and it is free from friction. (not very reliable but I won't be playing 45s) So I think this has been tinkered with before.

The belt I've got is black. I don't know how old it is.
The thing is Doug, the speed is close to 33. Perhaps a new orange belt might just peek it up to the right speed. I got a quote from Adam at Turntable Experts today as well for 2 belts. $10.95 each, $5 for shipping 2 belts. As you say it could be the board that's playing up.
Frustrating eh Doug? I am SO close to achieving an ambition!
Duncan

 

[Doug G.]

Great work, Duncan!

Always best to eliminate everything mechanical before jumping to blaming a PCB like I was in the process of doing \:^)

Anyway, the top of the motor pulley which drives the belt should be even with the top of the red plastic belt guide. If it's not, that is why it will rub on the belt when the control is in the correct position. There is a set screw on the pulley you can loosen and move the pulley up or down as necessary.

So yeah, I would say get the new belt, readjust the motor pulley, and we can go from there. Of course, you can adjust the pulley anytime.

Doug

 

[duncan_england]

Cheers Doug,
I have ordered 2 new belts so I will wait for them to be mailed before I do anything else. This thread is getting long as well. Doug, I'll start another thread when I resume - ok.
Thanks mate
Duncan