Can I use my own otel-collector (contrib) with SigNoz or does it need to be a specific otel-collector from SigNoz?

It depends what you are going to use the collector for. With the main signoz deployment that runs everything it must be signoz-otel-collector.

I currently have my own otel-collector but I would like to play with signoz traces (to start with) , or do you mean something else with “depends” ?