Beogram 1700 adjusments – wow and flutter parallelism speed

[GessWurker]

Hi – I recently acquired a Beogram 1700 and have noted audible (though subtle) speed variation. With an app, I was able to confirm excellent speed accuracy (33.33 in a measurement taken today) but w/f is problematic, coming in at .37. The belt that came with the table was somewhat stretched and slipping from time to time so I replaced it some weeks ago with a belt (talc applied).  Any advice on how or whether it’s even possible to improve (i.e., decrease) the wow and flutter? According to B&O’s official Beogram 1700 specs…

Wow and flutter DIN < +/- 0.09 %     (Really?! I’m not even close.)

I’ve used the app I mentioned earlier, called RPM, on three separate turntables. Results: My Beogram TX2 comes in at .26; my Fluance RT85 comes in at a very nice .15; my Beogram 1700 (as I said) comes in at .37.

Any and all help much appreciated.

[Mark-sf]

First you should note that your phone is heavy relative to a record and this will negatively impact the WF test on most beograms due to their lightweight construction, floating suspension and low torque. To use that app you need to readjust the suspension so it’s free and level when the phone is centered over the spindle and that the belt is centered on the pulley and platter. You should also also make sure the motor pulley and platter edge are clean. Finally, unless you got the belt from a legitimate B&O parts site, I would suspect it.

[GessWurker]

Yes, I’ve found that the TX2 is especially sensitive to weight, but anecdotally, not so much the 1700. In fact, the 1700 seemed to hum along quite nicely even when I put a substantial 370g record weight on it, just as a test, mind you. The TX2 screams bloody murder with such a weight.  Anyway, just now I cleaned the motor pully and platter edges on the 1700 and gave it another go with the app. Dang. Now the app measures w/f at .44.   Doh!  🙂

Guess I can try a different belt. If you’ve got a recommended vendor, please let me know.

Oh… true story… I used the app to test a direct drive vintage sony (ps-lx2) I bought for $25 for non-playback purposes. Just needed something that would spin. Anyway, the sony tank won the w/f competition easily with a score of .12!!

[GessWurker]

So… three things I’ve done:

1. Ordered a replacement belt from Beoparts.
2. Downloaded WFGUI and experimented with it a bit. (Lots of 3150hz test tones out there, by the way.)
3. Ordered the Stereo Review Test Record (vintage 1979) from Discogs.

Let’s see what we learn!

 

[Mark-sf]

If putting such a weight on it is not disrupting its suspension and belt running location, then its suspension height is not correctly adjusted.  Such a weight requires readjustment to compensate. Non-suspended turntables such as direct drives do not have this requirement.  The WFGUI with a test record and the DIN filter should better reflect the true performance. If you get a good belt and everything is adjusted properly and still seeing W/F>.2 then I would suspect the motor bearings may need a new oill suffusion or replacment.

[marcham]

Funny enough, I found your forum post as I was having serious wow and flutter issues with a Beogram 1700 that I just picked up. After recapping the board and adding a new belt, I was lost. My rpm app would get readings of up to 3% w&f. After nearly tearing my hair out, I found the solution. For me, it was the motor. Removed the pulley and put a good drop of machine oil on it, running it using the TURN button. After reassembling, the table now runs like a beauty. Good luck with your issue!

[GessWurker]

Interesting! Can you post your w/f measurement after lubrication? I just popped off the pully and applied some oil. Let’s see what happens! (Will measure later.)

[GessWurker]

I added a drop of oil to the motor, but found w/f slightly increased (as measured with my heavy phone running the RPM app). Stay tuned.

[GessWurker]

Logged results from today’s WFGUI test w/Stereo Review test record. Note: Have not yet received new belt from beoparts. Will post new results with new belt in future.

Hz        RMS    W/F
3157.6 0.1527 0.2552
3146.0 0.1040 0.2552
3156.9 0.1176 0.2552
3147.6 0.1221 0.2552
3154.1 0.1278 0.2935
3150.5 0.1248 0.2935
3150.0 0.1445 0.3161
3154.0 0.1216 0.3161
3148.0 0.1251 0.3161
3154.2 0.1273 0.3161
3148.1 0.1078 0.3161
3153.4 0.1385 0.3161
3149.6 0.1110 0.3161
3151.9 0.1129 0.3161
3152.9 0.1315 0.3161
3148.6 0.1187 0.3161
3155.4 0.1211 0.2604
3146.5 0.1267 0.2726
3155.6 0.1162 0.2726
3147.1 0.1307 0.2964
3154.5 0.1362 0.3145
3149.4 0.1180 0.3145
3152.1 0.1069 0.3145
3152.3 0.1134 0.3145
3148.4 0.1208 0.3145
3155.2 0.1457 0.3145
3145.9 0.1110 0.3145
3155.8 0.1348 0.3145
3146.4 0.1095 0.3145
3155.1 0.1119 0.3145
3148.3 0.1111 0.2886
3153.0 0.1314 0.2886
3151.5 0.0945 0.2886
3149.3 0.1126 0.2886
3153.9 0.1216 0.2886
3147.4 0.0891 0.2820
3154.6 0.1334 0.2502
3148.2 0.1164 0.2502
3153.1 0.1099 0.2502
3150.1 0.1390 0.2963
3150.5 0.1268 0.2963
3153.0 0.1353 0.2963
3146.7 0.1170 0.2963
3155.9 0.1252 0.2963
3145.3 0.1047 0.2963
3156.9 0.1448 0.2963
3145.7 0.0982 0.2963
3155.6 0.1474 0.2963
3147.8 0.1049 0.2963
3153.2 0.1137 0.2912
3150.7 0.1241 0.2912
3149.9 0.1205 0.2675
3153.2 0.1136 0.2675
3148.4 0.1201 0.2675
3153.4 0.1088 0.2675
3148.7 0.1153 0.2675

[Mark-sf]

You need to adjust your speed as well.

[GessWurker]

Yes. Fortunately, speed is easily adjusted.

Below are the w/f results logged after belt replacement. I can live with (more of less) .2 w/f.

3151.8 0.0778 0.1964
3144.6 0.0807 0.1964
3154.6 0.0900 0.1964
3143.2 0.0892 0.1964
3154.0 0.0756 0.1939
3144.8 0.0867 0.1939
3151.3 0.0916 0.1939
3147.4 0.0536 0.1939
3148.6 0.0894 0.1939
3150.6 0.0744 0.1806
3145.5 0.0745 0.1794
3153.0 0.0949 0.2078
3144.4 0.0751 0.2078
3152.4 0.0763 0.2078
3146.1 0.0881 0.2078
3149.5 0.0940 0.2078
3149.2 0.0986 0.2078
3146.6 0.1020 0.2078
3152.1 0.0776 0.2078
3143.7 0.0950 0.2211
3154.8 0.0821 0.2211
3142.3 0.0874 0.2211
3154.3 0.0866 0.2211
3144.1 0.0921 0.2211
3151.5 0.0708 0.2211
3147.1 0.1084 0.2211
3148.4 0.0633 0.2211
3150.3 0.0677 0.2211
3145.6 0.0896 0.2211
3152.6 0.0663 0.1921
3144.3 0.0804 0.1921
3152.0 0.0825 0.1921
3146.1 0.0695 0.1921
3149.0 0.0769 0.1860
3149.1 0.0931 0.1860
3146.3 0.0766 0.1810
3152.5 0.0903 0.1810
3143.2 0.0972 0.1829
3154.6 0.0676 0.1829
3141.9 0.1019 0.1930
3154.3 0.0645 0.1930
3143.8 0.0889 0.1930
3151.5 0.0884 0.1930
3146.7 0.0944 0.1930
3148.5 0.0740 0.1930
3150.4 0.0975 0.1930
3145.6 0.0671 0.1930

[GessWurker]

And next up, I’d like to adjust tonearm parallelism. I’ve got the manual but haven’t figured out where the adjustment screws are. Can somebody tell me?

Ah. A repairman clued me in. All good. Need to loosen the circled bit. Then you can gently (and very carefully) adjust the tonearm as necessary.

[marcham]

Glad you got to a spot where you are happy! I haven’t had a chance to check the table with the RPM app again, but I believe it was around .2 W&F when I checked last. That is perfectly fine for me as I can’t hear that in the slightest. Remember not to get too caught up in the numbers (the RPM app also isn’t exactly perfect). Enjoy that Beogram!

[Mark-sf]

That adjustment is your azimuth and really cannot be done visually. A static measurement assumes the diamond and cantilever is perfectly orthogonal to the record surface which is seldom true. Unless you have a measurement capability to check for optimum channel separation using a test record, you should not try to fine-tune this adjustment.

[GessWurker]

I have a test record.

[GessWurker]

I’ve also got an Azimuth grid.

[Mark-sf]

Am azimuth grid assumes a perfect cartridge and won’t yield the result you are seeking. Correct azimuth alignment is when both channels are at their maximum balanced separation which requires both a test record that has single-modulated channel tracks and an RMS meter or a Fozimeter for the measurement.

[GessWurker]

Right. And I’m about to throw in the towel trying to get the volume of the leakage and reference tones to match exactly. Using a tiny bubble level so I could see what I was doing, I would go ever-so-slightly too far in one direction or the other adjusting the tonearm, hoping to hear a different result in the separation test. No dice. So far, the high-end rebuilt cart I got from AO hasn’t worked out how I hoped. Maybe it’s not a good match for my 1700; maybe the table has other issues; maybe I’ve done something not quite right; I’m really not sure. I’ve adjusted anti skate more than I care to admit. All that being said, true statement: I got better results across the board with the old MMC20EN that came with the table. But… I have no idea what kind of wear the stylus has or what state the suspension is in. That said, yesterday I sent the MMC20EN that came with the table to SoundSmith for evaluation and potential rebuild. Crossing fingers I’ll make it to the promised land.

 

Ah… found an interesting germane comment from Peter Ledermann, at least with regard to his cartridges:

‘…if one channel is always much better in terms of less crosstalk than the other; tune the azimuth by using the worse of the two channels. Again, the best way to tune the “worst” channel is to find the point where the crosstalk “just” becomes minimized and go no farther. Verify that the other channel is still better in that it has less crosstalk. If you NOW FIND that you have NOT gone more than a tiny bit off the neutral position to do this, you have probably hit the best azimuth.

If you find you are way off neutral, that is wrong, and you must start over.’

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