Disadvantage of no FET input circuit?

[mmmoser]

If one chooses to skip the FET input option on a Dumble circuit is there any change in the amp? The way it sounds, etc? I am thinking it could be totally skipped with no ill effects...correct or false? Any adjustments need to me made?

[ToneMerc]

Any adjustments need to me made?

If the FET is omitted you need to hang a 150K bleeder off of B+5. This is seen on the D'Lite which is sans the FET circuit.

TM

[greekie]

I skipped it, and didn't use the 150K bleeder, and it sounded fine!

[ToneMerc]

I skipped it, and didn't use the 150K bleeder, and it sounded fine!

The bleeder just loads down the PS rail to simulate the FET circuit being connected so that you can use the as built rail string resistor values. If you don't, then you will have to make adjustments the string values because your preamp voltages will be too high.

TM

[amplifiednation]

How many watts would that 150k resistor need to be rated for? 3W? Right to ground?

Can you just change the B5 dropping resistor? Or would that cause the other nodes to be too high??

I've been thinking about pulling the FET out of my 102

[ToneMerc]

How many watts would that 150k resistor need to be rated for? 3W? Right to ground?

Can you just change the B5 dropping resistor? Or would that cause the other nodes to be too high??

I've been thinking about pulling the FET out of my 102

Just a 2W is fine and yes could just tweak the string when you disco the FET circuit.

TM

[mmmoser]

Great advice. I did look and see that resistor on the old d'lite files I have. They use either a 150k or a 220k. Looks like a 150k for the 50 watt versions and a 220k for the 100 watt versions.