I bought a Vox Cambridge 30R for 5 bucks at a yard sale last weekend. Took it home and noticed low output, brownout symptoms.
The same old story with these amps. After doing a test by jumping the optocoupler. I realized what the problem was.

The real problem is, I cant find these online anywhere. So my question is, what's a suitable replacement ? or can I make on out of a led and photocell ?

This is the original part VTL5C2:
https://www.alliedelec.com/excelitas-technologies-sensors-vtl5c2/70219696/

Im wondering if perhaps this one will work:
https://tubedepot.com/products/opto...K5scvTyqaLJlsa0D_czH2PNLrFW_FaCBoCAiYQAvD_BwE

Thank you very much for the help.