question about some parts

[JimiB]

I used the BOM and there are a couple parts on there- I'm not sure what there for

AVX Metal Oxide Varistors?

and the higher wattage resistors- I understand all the ones listed on the Kelly '90 schem but there are others-
Everything I'm ordering is 1 watt carbon film - is this ok? Do I need to use some 1/2 watt?

Do the 9.1K's need to be 3W?

2 - 1.5K 2W
2 - 100K 2W what are these for?

Thanks!

[UR12]

I used the BOM and there are a couple parts on there- I'm not sure what there for

AVX Metal Oxide Varistors?

and the higher wattage resistors- I understand all the ones listed on the Kelly '90 schem but there are others-
Everything I'm ordering is 1 watt carbon film - is this ok? Do I need to use some 1/2 watt?

Do the 9.1K's need to be 3W?

2 - 1.5K 2W
2 - 100K 2W what are these for?

Thanks!

Hey Jimb

The varistor goes on the power switch in parallel with the 110 wires coming in. It provides a little spike protection on your power line.

Yes the 9.1k need to be 3 watt. Mouser was out of 2 watt last time I ordered (last week) and you'll probably have to go with the 3 watt anyway. The 1.5k don't need to be 2 watt, 1 watt will do fine and I usualy just use a 1/2 wat for these and it works fine.

The 2 100k need to be 2 watt. They are bleeder resistors used to drain the power supply caps when the amp is turned off.

Hope this helps!

[JimiB]

The 2 100k need to be 2 watt. They are bleeder resistors used to drain the power supply caps when the amp is turned off.

I was going to use a 3W 470K for this like the schm. shows, are the 2 100K's better?

Thanks for the help!

[UR12]

The 2 100k need to be 2 watt. They are bleeder resistors used to drain the power supply caps when the amp is turned off.

I was going to use a 3W 470K for this like the schm. shows, are the 2 100K's better?

Thanks for the help!

The schematic is wrong. The Liverpool uses a 470k and the Express (Franchesca anyway) uses 2 100k in series. Either will work just fine it just depends on how exact you want to be.

[JimiB]

cool thanks!

[gearhead]

The component layout in the files section does have the 2x100k 2w resistors. All the schematics don't.

Also, pay close attention to where the bias voltage is connected: -before- the 47k res and -not- directly to the bias pot. Thank UR12 (and whoever did the layout) for that one too.

[JimiB]

are you refering to the Kelly '90 layouts?

[gearhead]

Yep, and all but the A6.