power supply resistor values?

[Tdale]

On the nice power supply layout that was posted a while ago, the resistor between B2 and B3 is a 2.2 K 5W resistor. Is it critical that it is a 5W resistor?

Also, the resistor values are: Choke - 2.2K - 10K - 12K - 1K

Are those correct?

[Normster]

On the nice power supply layout that was posted a while ago, the resistor between B2 and B3 is a 2.2 K 5W resistor. Is it critical that it is a 5W resistor?

Also, the resistor values are: Choke - 2.2K - 10K - 12K - 1K

Are those correct?

I typically use 3 watt metal oxide resistors. The 5 watt in that layout was just because I had one on hand. The dropping string is just a guess. The "normal" Dumble string is 2k2, 22k, 1k but I was trying to provide seperate filtering for the reverb tube, hence the additional filter cap and resistor. I'd be prepared to buy a few additional resistor values to cover your bases. It may work out better using 2k2, 18k, 4k, 1k (or close equivalents).

[dogears]

If you do the math, you may find that 1w is fine. I also like to raise the last resistor from 1k to 2.2k

Best to shoot for the 200v bogey. Don't worry what Dumble did. Every PT is different.

On the nice power supply layout that was posted a while ago, the resistor between B2 and B3 is a 2.2 K 5W resistor. Is it critical that it is a 5W resistor?

Also, the resistor values are: Choke - 2.2K - 10K - 12K - 1K

Are those correct?

I typically use 3 watt metal oxide resistors. The 5 watt in that layout was just because I had one on hand. The dropping string is just a guess. The "normal" Dumble string is 2k2, 22k, 1k but I was trying to provide seperate filtering for the reverb tube, hence the additional filter cap and resistor. I'd be prepared to buy a few additional resistor values to cover your bases. It may work out better using 2k2, 18k, 4k, 1k (or close equivalents).

[Tdale]

I probably won't be using B6, but I thought I'd add it, in case I want to build a reverb, or something like that later.

Will the last resistor and filter caps (B6), do any harm if they are there, but doesn't have a plate to feed?

Tommy

[Normster]

I probably won't be using B6, but I thought I'd add it, in case I want to build a reverb, or something like that later.

Will the last resistor and filter caps (B6), do any harm if they are there, but doesn't have a plate to feed?

Tommy

Probably not, but you will want to change the dropping string. You could just leave the resistor off of B+6 until you're ready to use it. (IOW, it won't be connected to anything.) In that case, I'd definately start with 2k2, 22k, 1k and adjust as needed. (Or try dogears suggestion and use 1k, 22k, 2k2.)

[Tdale]

Is 1K - 22K - 2k2 for B5 - B4 - B3 in that order? Or B3-B4-B5?

Tommy

[Normster]

Is 1K - 22K - 2k2 for B5 - B4 - B3 in that order? Or B3-B4-B5?

Tommy

B+3 = 1k, B+4 = 22k, B+5 = 2k2 (per dogears). The Dumble schematics show it the other way around but give it a try and see what your voltages look like.

[Tdale]

Stupid question, but just to make sure: The B+5 resistor is the one between the B+4 and B+5 outlet, right?

Tommy

[Normster]

Stupid question, but just to make sure: The B+5 resistor is the one between the B+4 and B+5 outlet, right?

Tommy

Yes

[Tdale]

I got some 3W resistors for the power supply, but I only have 1K, 10K and 12K.. I guess I could put some of them in series to get those values..but I'd rather use single resistors.

1W should be ok I suppose.. or I might go for the 2,2K - 12K - 1K to start with, and check my voltages once I finish the amp..

Tommy