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Rockola Grand Salon 468
Posted: Thu Apr 16, 2009 9:56 pm
by DoghouseRiley
I've recently bought one of these in excellent condition.
It is currently fitted with a 1970s Shure M75ED cartridge. This isn't the original, but gives excellent reproduction apart from one thing. The tracking noise from the stylus seems quite loud on the run in to records. It doesn't seem to be too bad when records are playing, few people seem to notice it. Could it be that this cartridge is too sensitive for the amplifier?
Any ideas? The orginal cartridge I read was the now discontinued Shure N44C
Re: Rockola Grand Salon 468
Posted: Wed Apr 22, 2009 4:51 am
by Ron Rich
I dono for sure--but since there are no other answers, I'll take a couple of guesses--Is the AVC functioning --is it working correctly? Is the needle set down adjusted too far "out" ? Ron Rich
Re: Rockola Grand Salon 468
Posted: Wed Apr 22, 2009 7:41 pm
by DoghouseRiley
Thanks for that, but perhaps I haven't explained it well enough.
The mechanics are working fine, I've checked it with the manual. I just think the cartridge might be too sensitive for the amplifier. I've asked the question of a jukebox repair engineer and he is of the same opinion. I'll change the cartridge and it'll probably cure the problem.
Re: Rockola Grand Salon 468
Posted: Thu Apr 30, 2009 7:16 pm
by DoghouseRiley
I've now got an original cartridge installed, (I bought a S/H pick-up arm unit as it gave me a spare complete pick up cable, in case I ever need one all for the price of a cartridge). The bass response has improved, but this noise of the needle on the record is still there.
Very noticeable as soon as the needle touches the record and until the music starts, but to be fair it isn't so noticeable with the volume at a louder but acceptable level, particularly from several feet away.
Re: Rockola Grand Salon 468
Posted: Thu Apr 30, 2009 11:10 pm
by Ron Rich
Once again--is the AVC working correctly (or at all)--and is the needle set down adjusted to specs.? Either one or both can cause that problem--also "worn" records are a factor--Ron Rich
Re: Rockola Grand Salon 468
Posted: Thu Apr 30, 2009 11:24 pm
by DoghouseRiley
Hi Ron thanks for your reply.
The "set down" for the needle seems to be OK, as it neither slips off any record or starts playing too early.
I might have made the needle clearance slightly more than the 1/8th it says so in the manual as it has to clear the selector arm on "B" sides, am I being too cautious?
Sorry, but to be honest I've no idea about the AVC either what it is or how to check it.
Yes there is a difference in the quality between many records due to their different ages, but even on a "new" record, i still get that noise.
Re: Rockola Grand Salon 468
Posted: Fri May 01, 2009 1:52 am
by Ron Rich
AVC is "Automatic volume control", also sometimes called AGC. (Gain). A quick check for it is to play a record with the VC about 1/2 way up, lift the needle for about 3-5 seconds and place it back on the record--audio should be louder, and quickly soften to the original level.
Raising the arm should have no affect--that I can see-- Ron Rich
Re: Rockola Grand Salon 468
Posted: Fri May 01, 2009 3:40 pm
by DoghouseRiley
I've done as you've suggested Ron, but it seems that raising and lower the arm makes no difference, the volume remains the same.
There seems to be plenty of gain in the amp, I've the control on a lead for volume and reject and on Nos. 2 or 3 it's plenty loud enough.
Could it be that it is now too sensitive to low frequencies?
Re: Rockola Grand Salon 468
Posted: Sat May 02, 2009 7:24 pm
by Ron Rich
If lifting the tone arm off the record for a few seconds does not result in a louder sound when you put it back onto the record, your AVC is not functioning. Some amps have a switch to turn it on/off--I don't remember on that amp--
As for the "control lead--on #2 or 3--" I have no idea what you are attempting to say ? Ron Rich
Re: Rockola Grand Salon 468
Posted: Sat May 02, 2009 7:46 pm
by DoghouseRiley
Hi Ron, thanks for the reply.
It's the same amplifier as this one for sale on ebay
http://cgi.ebay.co.uk/ROCKOLA-JUKEBOX-5 ... otohosting
The control lead I mentioned is the remote control (not really "remote" as it's on a lead conected to the back of the box) with two slider controls for the volume of each channel, graded 1 to 10 and it also has a button to eject the record being played at that moment.
Re: Rockola Grand Salon 468
Posted: Wed May 13, 2009 11:35 am
by DoghouseRiley
I recently bought a complete second hand arm for this as it was cheaper than a replacement cartridge. I was able to remove the complete wiring that goes from the cartridge to the amplifier, in case I ever needed to replace the original. It had an original cartridge which I exchanged for the old Shure M75 ED which I was using as the original cartridge "lost a channel."
I made this video (it's only made on a little Lumex digital camera) to show a friend the workings of the box and particularly that of the wheel arrangement that mechanically records the plays received by each disc. How ingenious was that system?
Anyway, to the point. You can hear what I think is excessive needle noise before the record starts to play and at the end before the arm lifts. It disappears completely if I lift the arm whilst the record is playing. It is less when the amp is switched from stereo to mono.
Am I obsessing about this?
Re: Rockola Grand Salon 468
Posted: Wed May 27, 2009 8:02 pm
by DoghouseRiley
I've managed to find someone to look at my jukebox and he has resolved this problem, despite the fact that he only usually works on NSM jukeboxes. it appears that the noise on the records is caused by almost silent vibration from the turntable motor being picked up by the cartridge. This he demonstrated by telling me to put my finger on the gripper arm as the record played. He is going to replace the grommets which he says will cure the problem. So I'm well pleased.
Re: Rockola Grand Salon 468
Posted: Tue Jun 02, 2009 3:29 pm
by DoghouseRiley
Success!
Changing the grommets completely cured the problem.
To the inexperienced eye, (like mine) the originals looked in good condition, weren't cracked or split, but in actual fact over time had become hardened though still pliable.
The new ones seemed very soft by comparison.
What I thought was excess needle noise, was actually the vibration of the motor being picked up by the cartridge. Now you can hardly hear the needle track in.
Re: Rockola Grand Salon 468
Posted: Fri Jun 12, 2009 12:25 am
by DoghouseRiley
Now that my machine is working well (touch wood) I decided to give some of the records a clean with meths. A few came with the machine and were quite dirty.
I noticed under the "Scan/stop/play" control there are three brown flat capacitors/resistors? about two inches long by about a quarter of an inch. I accidently touched one and then found that all three were quite warm, the machine having been on for about an hour.
Is this normal?
For anyone interested, a parts supplier in London I've bought a few bits from, is kindly going to e-mail me a Rock-Ola lubrication chart, when he has some time.
As this will probably be common to many models, when it arrives I'll put it on "Image Shack" start a new topic on here and provide a link.
Re: Rockola Grand Salon 468
Posted: Fri Jun 12, 2009 3:16 am
by Ron Rich
Is there any markings on the "brown/flat" things ? Ron Rich