The amp is a Line 6 Spider Valve Mk II 112 Tube Combo and the converter I'm looking at purchasing is this
if you want to get it working without modifying th psu you could get a step down converter.
I have about 35 Yeelights and am pretty happy with them. You can get them from GearBest for about 21CAD right now. Have you tried them before? One thing to note is that while they run fine in 110V after they're actually set up, setting them up is an enormous pain without a voltage converter. I have this one and it works great: https://www.amazon.ca/gp/product/B004MPR3X6/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
Your best bet is it to buy a dual voltage hair straightener. They draw a lot of wattage and therefore need a pretty beefy transformer. The same goes for hair dryers.
You'd need a beefier 200 or 300 watt transformer, which is too large for travel: https://www.amazon.com/Simran-AC-200-Voltage-Converter-Transformer/dp/B004MPR3X6/ref=sr_1_6?ie=UTF8&qid=1502385522&sr=8-6&keywords=transformer%2B200%2Bwatts&th=1
This is the one I got: https://www.amazon.com/Simran-AC-200-Voltage-Converter-Transformer/dp/B004MPR3X6/ref=cm_cr_arp_d_product_top?ie=UTF8&th=1
The converter doesn't have any utility to me outside of setting up the bulbs, but I just plugged a lamp with the bulb in it into this converter, and then I was able to put the bulb on my wifi. After that, I can put the bulb in a regular 110V fixture and it works fine.
For 120W as small transformer is possible.
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