Hi I just got a Technics SU V2 amp and can't get sound from the speakers. What size speakers would suit this amp? What is the correct method to connect the speaker leads to the back of this amp, I've not seen terminals like them before. Cheers.

That sounds suspiciously like an issue with speaker connections rather than amp output!

There are manuals and specs here including a Service Manual

https://www.google.com/search?q=technics+su-x840+user+manual

..

Check inside power supply fuse, it may be just that but if you put a new fuse and blows you may have a power output devices failure, let me know your results.

If you went so far as looking at the wires on the tweeters you could have taken an ohmmeter to them to see if they're blown.

Is there a back story to this? What preceded the investigation?

See there is a problem with the volume conroller as it is 18 years old the controller has worn out replace the volume controller with a new one and you will be able to enjoy great sound again

Usually this is a defect in the output amp IC. If you have no experience with repairs of these types of units, have it checked by a service shop. If the output AMP IChas failed, it will cost about $75 for a replacement. This unit uses an RSN3306P IC .

Dan

usually meens it is protecting itself from destruction
check your wires and speakers for problems

hello. we cant help if we dont know what music source you are using.

An amp will cut out if the output protection circuit kicks in. This circuit compares output power against the preset level. Each channel has it's own, independent protector. There are calculations that can be done, but for a novice the rule of thumb is to "never use a speaker with a power rating less than the amp AND a lower impedance than stated". Typically using a 4 ohm load on a 8 ohm system is inviting disaster. Even if the system does not become a smoke generator, you might notice that though "louder", the sound quality is deteriorated. Many "audiophiles" often hook up some combinations of speakers to have "surround" without really understanding that the collective impedance actually changes (generally lowers).

Did you ever find the solution to the left channel issue? I have the same problem with mine.