Turntable is playing slow, can we adjust speed?

TRY stretching the belt a bit.

Try looking underneath the turntable. There might be two speed presets one for 45 and one for 33. They could be covered up by stickers.

Presumably you mean correcting the speed to play 45 and 33 correctly?
Some turntables have the speed control(s) as a preset(s) built into the base on the underside of the unit. Often covered with a sticker. You simply remove the sticker and stick a small screwdriver in the thing and turn it.
Others have the preset inside on a circuit board, got to by removing the bottom of the turntable. Others have it built into the motor itself.
You should replace the belt first if the speed is slow on both 45 and 33, before adjusting the motor speed.

You may be experiencing Acoustic Feedback, although it doesn't really make any sense the way you describe it. Make sure the tonearm is balanced and the proper weight is dialed in on same. Does it make any difference if the volume or bass are turned down, which my point to the Acoustic Feedback.

Found this post trying to troubleshoot my Aiwa PX-E860U-after replacing the belt and lubricating bearings, the speed was off. 33 setting was playing slow. Here's the fix:
1. unplug and flip upside down
2. Locate the two holes marked 33 & 45 where black dots are visible underneath
3. Using a very small flat screwdriver(I used one from an eyeglass repair kit), adjust the speed clockwise for faster, counterclockwise for slower

this is a DIY solution, so not perfect, but it works. I played the tracks along to a Spotify recording to get a good match. Hope this helps someone else!

Hello Rosie,

Some turntables have a pitch adjustment feature which allows you to speed up or slow down your records. The adjustment controller is usually a slider or a wheel somewhere on the turntable and is usually labelled "Pitch" "Adjust / Adj" or "Pitch Adj".

Please check for this feature on your turntable then get back to me if you are unable to find it. Please include the brand and model number of your turntable.

Hope this helps.

Regards,
BElectric

the belt will not adjust the speed unless it is slipping, therefore will slow down not speed up.
there should be a speed playing dial. for lp or 45's.
or have you had it repaired. if someone replaced the pullies on the drive or driven end this could have change the ratio and speed.

Sometimes on the base of the turntable (under side) there are two presets one for the 45 speed and one for the 33. They might be hidden under a label or something. You might even have to go inside to find them. Anyway a small flat head screwdriver inserted in it should adjust the speed. You might have to work out which controls 33 speed. And of course if it is below you will have to figure out how to adjust it with a record playing. "Get out and get under!!!!" as they said about cars!

My older Thomas Pacconi turntable was also turning too slowly. Rather than replacing the belt or needle, I tried using an eye glass repair screwdriver to alter the trimmers inside the motor. But the changes didn't take. Then I tried trimming the power to the motor using the larger trimpot next to the motor with the motor itself set to the 78 rpm setting. But the adjustments to the trimmer didn't get the platter to spin slow enough - it wouldn't play an LP. To get the speed down further I replaced the 1K trimmer with a 10K trimmer I picked up for a buck at Radio Shack and successfully adjusted the turntable down to down to 33 1/3 rpm usage. All that was needed was a soldering iron and a 10K trimpot to get the job done.

Most older models had a rubber belt that will deteriorate over the years and if you cannot find one search in "O" rings at hardware store for correct size.