RCA RP-218 changer

[hermitcrab]

been playing the 1963 RCA hutch lately because the sound is so clean... yesterday I picked up a few used albums and played them on the RCA... Something didn't sound right , so I tried the RPM app on my phone... the changer is playing about 35 rpm.. this is new to me , never noticed it before . what would cause the changer to speed up?... the platter is clean , no excessive build up anywhere, it is playing a couple rpm too fast on all speeds ... do I need to shave the idler? I am hesitant to do such a drastic move, as how do I know if the line voltage was higher then usual? I have about 6 different meters , digital and analogue and none of them read the mains voltage the same...always a volt or two difference

[stbasil]

Maybe the idler is hitting the motor spindle between speeds? Just a thought....

[Motorola minion]

I have a 1963 as well, but haven't gotten around to it. The flat-pack cartridge with "airplane" stylus is likely not good.
This speed question plainly gives me an excuse to pull my changer at last
The mat is stiff, so I need to get my snap ring pliers to pull the platter and see what is what
Ill get a power cord to power just the phono, check speed if its not locked up.
Stay tuned.

[electra225]

Motor mounts sagged, causing suggestion #1?

[hermitcrab]

Motor mounts sagged, causing suggestion #1?

I wish, those got changed out with new ones last year when I went through the changer

[hermitcrab]

I have a 1963 as well, but haven't gotten around to it. The flat-pack cartridge with "airplane" stylus is likely not good.
This speed question plainly gives me an excuse to pull my changer at last
The mat is stiff, so I need to get my snap ring pliers to pull the platter and see what is what
Ill get a power cord to power just the phono, check speed if its not locked up.
Stay tuned.

Not sure what cart mine has , but it has the dual needle setup where you push it one way for 33 and the other for 78... and it is failing , sometimes one channel will not play , I think due to the saddle being old.

[Motorola minion]

RP-215/216 have pulley height adjustable by a threaded shaft with 3/8" nut but I don't see one on mine

Maybe what you see below is the same and, if so, it may be adjustable only by adding thin spacer washers under the pulley.

Ill pull it out later to check but I think motor mount grommets are gone, there is a lot of play and no cushion holding up motor to mitigate vibration transmission onto motor board.
SO...motor shaft has dropped a bit as pulley rides too high on 33 step. Ill attempt to run and see if speed is even close

[TC Chris]

it is playing a couple rpm too fast on all speeds ... do I need to shave the idler? I am hesitant to do such a drastic move,

Just a quick note on the idler-diameter thing. The diameter of the idler wheel has no effect at all on speed. The diameter of the motor' turret, yes. The diameter of the platter, yes. But no on the idler. It just translates whatever motion it gets from the motor to the platter. It's a little bit counterintuitive.

Shaving an idler can correct LOW speed if it's caused by a glazed surface and slippage, but generally you'll hear low of speed variation--"wow." And it's not related to diameter, just to surface friction or lack of it.

Chris Campbell

[Conelrad]

The buildup of idler detritus on the motor shaft can increase speed, as it will change the ratio. Give it good cleaning and see what happens.

Some broadcast TT's had a slightly larger motor shaft on the 45RPM setting, to get just a bit more music between ads.

That drove some listeners with perfect pitch crazy.

DG

[Doug]

Only thought I have if the the motor mounts are bad
With the platter on the idler may ride up or down or even tilt.
Which motor mounts are mention above.

[Hi-Fi-Mogul]

The buildup of idler detritus on the motor shaft can increase speed, as it will change the ratio. Give it good cleaning and see what happens.
DG

I vote for this also. I have been amazed sometimes at
how much rubber was annealed onto the stepped
speed rotor.

[Motorola minion]

Looks as if I need to take that suggestion, second from top is the 33.3 rpm turret, which looks pretty crusty.