can any stereo receiver be turned to mono?

Some stereo amps allow you to bridge for mono operation, I don't believe yours is one of them. 

thanks!

What audio source are you playing? If it is an external component such as a CD player, you can convert the input signal to mono using a pair of Y cable connectors.

If what you want is a stereo/mono switch to summing the stereo signal to mono, insert this circuit to tape-monitor loop, the tape-monitor button will become a stereo/mono switch.
https://www.vinylengine.com/turntable_forum/download/file.php?id=11690&t=1

Or use a stereo to mono converter box.
https://www.amazon.com/OSD-Audio-SMC21-Converter-Isolator/dp/B07FFBJ8KR/ref=pd_lpo_328_img_1/136-081...

Even easier, connect the + from both channels into one. +L and +R both go to chassis ground, so connecting L+R positive sums them yielding mono. This is what happens inside the Y connector. Either that, or the amp goes up in smoke. Which this being a receiver and knowing how I feel about receivers just may be my ulterior motive.

Only one way to find out for sure. 😂🤣

millercarbon - please do NOT give engineering advice that looks serious.   I understand that you might think this is a joke, but somebody may take your advice and potentially fry their receiver/amp.  You never want to connect two outputs of anything into a single target, especially if they are speaker outputs from an amp/receiver. 

Also, this is NOT the same thing as a Y connector.  It is perfectly fine to use a Y-splitter to send a single output to multiple inputs.  However, a special circuit is required if you want to "sum" multiple signals.

Just wanted to add, that for me mono means ONE loudspeaker playing a mono source, not summed stereo with two loudspeakers. OP, are you just trying to get mono to play on both channels? If that is the case, you can feed a mono source to one channel and connect both loudspeakers to that channel. You'll loose 3db of power but it will work.   

One more time. How DO you feel about receivers?

On the record I don't care for mono.  Both ears still work.  Kinda.

Simple answer is NO. That receivers amplifiers cannot be bridged for mono use. Do not follow MC's advice. What others are saying will yield 2 mono channels from either 2 different speakers or 1 speaker if that's all you connect. 

i'm an older guy who remembers that all recievers from the 70's had a mono/ stereo switch!!

Relax, it's a receiver. A $30-60 receiver, at that. Well worth trying for entertainment value alone. Or think of it as a mercy killing, like the way they do the injured horse. Only in this case afterwards while you air out the room you go on CraigsList and find half a dozen better ones listed under Free Stuff. After a quick search you go pick up the closest one, it will be sitting there on the curb, and maybe stop by get another one while you're out driving around. Then back home compare and use the least bad sounding. Just be careful not to pick up an AVR by mistake. 

Older vintage receivers had stereo/mono switches, this one does not. A stereo/mono switch does exactly the same thing as the Y-connectors others suggested. Still the amps cannot be bridged in that receiver. 

@fiesta75 

I have a Sansui 4000 (my living room stereo) that does have a mono switch. I really wish this one had a switch. 

THanks for the help everyone!