That's because a MIL-spec 1/4 watt resistor is a derated 1/2 watt industrial resistor.
Should I avoid these under rated resistors for size reasons? I was obliviously picking these, disregarding size. Time to start over? lol
I was hooked on the more for less 🙂
I forget the lead spacing on the boards. If the resistor body length is around 2 mm less than the hole spacing they will sit flush. If the resistor is longer you can always put them in at a slight angle or up above the board It wouldn't look as pretty if that matters
EDIT: Disregard. They are electrolytic Alum.
Also, I have a mixed pile of Rubycon caps...
Would the Polarized caps which are 250V - 2.2uF. (rated to 85 C and/ 105 C) be suitable for C20 ?
The rest of the ones I have stockpiled are 1uF (%V, 350V, 250V), and a variety of 240uF of various voltages. All of which wont be useful here 🙂
Also, I have a mixed pile of Rubycon caps...
Would the Polarized caps which are 250V - 2.2uF. (rated to 85 C and/ 105 C) be suitable for C20 ?
The rest of the ones I have stockpiled are 1uF (%V, 350V, 250V), and a variety of 240uF of various voltages. All of which wont be useful here 🙂
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If the resistor is longer you can always put them in at a slight angle or up above the board It wouldn't look as pretty if that matters
I'm a little bit OCD with stuff like that, but my wife would tell me that this is a good opportunity to work on it, LOL.
Okay,
Have all the Transistors, diodes, & capacitors picked out. Haven't decided on resistors yet, will sort out later today hopefully. All of the "misc" items are dealt with except:
1) I never thought to order the mica insulators with my DIY Audio order :S . I can find TO-220 on mouser, digikey etc, but can't find any for the TO-3P. Any suggestions?
2) is the enameled wire something I would find at the hardware store?
Have all the Transistors, diodes, & capacitors picked out. Haven't decided on resistors yet, will sort out later today hopefully. All of the "misc" items are dealt with except:
1) I never thought to order the mica insulators with my DIY Audio order :S . I can find TO-220 on mouser, digikey etc, but can't find any for the TO-3P. Any suggestions?
2) is the enameled wire something I would find at the hardware store?
1) I never thought to order the mica insulators with my DIY Audio order :S . I can find TO-220 on mouser, digikey etc, but can't find any for the TO-3P. Any suggestions?
Mouser:
P/N: 43-77-20G
This seems like it could work for both?
Mouser:
P/N: 43-77-20G
This seems like it could work for both?
Those will work good for TO3P, but they're a little large for TO-220.
The enameled wire can be tough to find. An automotive alternator shop or a motor rewind shop will usually have some around.
Those will work good for TO3P, but they're a little large for TO-220.
The enameled wire can be tough to find. An automotive alternator shop or a motor rewind shop will usually have some around.
Thanks. Good tip for the wire, I`ll make some calls!
I just realized that the Digi-key BOM is already done up...I never seen that column on my tablet, but I can see it on my desktop computer. That would have made life easier... Oh well!
So new plan: gonna use the digi-key suggests with the following upgrades:
1) Q 10 will use MJE350
2) Q 11,12,13 will use MJE340
3) Q16,17,18 will use MJL4281AG
4) Q19,20,21 will use MJL4302AG
5) Using 1N194BCT-ND for D1/D2 (is this a good alternate?)
6) Omitting R18 (Zener reference)
7) Have not found alternate source for Noble resistors(no longer available)
8) C3,10,12,14,16 substituted with 338-3259-ND (Is this OK?)
9) Omitted LC Cap
10) Which transistors need the mica insulators? I'm assuming Q 16-21, and the guide mentions Q 10-12. is that all of them?
Sorry for the big post. 🙂
So new plan: gonna use the digi-key suggests with the following upgrades:
1) Q 10 will use MJE350
2) Q 11,12,13 will use MJE340
3) Q16,17,18 will use MJL4281AG
4) Q19,20,21 will use MJL4302AG
5) Using 1N194BCT-ND for D1/D2 (is this a good alternate?)
6) Omitting R18 (Zener reference)
7) Have not found alternate source for Noble resistors(no longer available)
8) C3,10,12,14,16 substituted with 338-3259-ND (Is this OK?)
9) Omitted LC Cap
10) Which transistors need the mica insulators? I'm assuming Q 16-21, and the guide mentions Q 10-12. is that all of them?
Sorry for the big post. 🙂
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I just realized that the Digi-key BOM is already done up...I never seen that column on my tablet, but I can see it on my desktop computer. That would have made life easier... Oh well!
So new plan: gonna use the digi-key suggests with the following upgrades:
1) Q 10 will use MJE350
2) Q 11,12,13 will use MJE340
3) Q16,17,18 will use MJL4281AG
4) Q19,20,21 will use MJL4302AG
5) Using 1N194BCT-ND for D1/D2 (is this a good alternate?)
6) Omitting R18 (Zener reference)
7) Have not found alternate source for Noble resistors(no longer available)
8) C3,10,12,14,16 substituted with 338-3259-ND (Is this OK?)
9) Omitted LC Cap
10) Which transistors need the mica insulators? I'm assuming Q 16-21, and the guide mentions Q 10-12. is that all of them?
Sorry for the big post. 🙂
You can use these 0.22 5W resistors:
Power Resistors 0 22 Ohm 5W Metal Plate Non Inductive x4 USA Genuine | eBay
or if you trust Chinese vendors:
10pcs 0 22R 220MR 5W 10 Non Inductive Resistor | eBay
BPR56 is low inductance series.
MJE are not so good for Q10 to Q12. Use recommended transistors or similar. Good source of difficult to get transistors is ceitron on EBay (Consolidated Electronics) or BDent: B+D Enterprises - Transistors
cheers,
I used Mouser 71-LVR-5-0.22. You will have to stand them up though.
Amp has been running for 2 years now, sounds great.
Amp has been running for 2 years now, sounds great.
Thanks, I'll shop around per the suggestions. I couldn't find the preferred transistors.You can use these 0.22 5W resistors:
Power Resistors 0 22 Ohm 5W Metal Plate Non Inductive x4 USA Genuine | eBay
or if you trust Chinese vendors:
10pcs 0 22R 220MR 5W 10 Non Inductive Resistor | eBay
BPR56 is low inductance series.
MJE are not so good for Q10 to Q12. Use recommended transistors or similar. Good source of difficult to get transistors is ceitron on EBay (Consolidated Electronics) or BDent: B+D Enterprises - Transistors
cheers,
Thanks! Appreciated!I used Mouser 71-LVR-5-0.22. You will have to stand them up though.
Amp has been running for 2 years now, sounds great.
I'm sure the answer is yes, but just to be 100% :
for Q10-13 Is it a bad idea to use a ksa1381E with ksc3503D. I know the gain is different.
for Q10-13 Is it a bad idea to use a ksa1381E with ksc3503D. I know the gain is different.
Also, anybody use the soft-start/ DC protect with 63V rails? Didn't want to run a second transformer, but the relays are little light for the power I think...
The 1381E/3503D will be OK. If you would like both to be E rank contact me.
Any of the transistors that are mounted to a heatsink and are not totally encased in plastic need an insulator. I like the silpads. They are available and no need for goop.
If you need I have njw0302/0281 and mjw3281/1302 Mouser also has these.
For your .22r resistors. Plenty of choices. I added .2r to the search. I don't know how long the resistors can be and still fit.
Through Hole Resistors | Resistors | DigiKey
Any of the transistors that are mounted to a heatsink and are not totally encased in plastic need an insulator. I like the silpads. They are available and no need for goop.
If you need I have njw0302/0281 and mjw3281/1302 Mouser also has these.
For your .22r resistors. Plenty of choices. I added .2r to the search. I don't know how long the resistors can be and still fit.
Through Hole Resistors | Resistors | DigiKey
Evanc, thanks for the reply/ kind offer. I'll have another look around and let you know how I make out.
I don't mind a vertical resistor, I just didn't know if there was something special about th noble resistors
I don't mind a vertical resistor, I just didn't know if there was something special about th noble resistors
There should be plenty of resistors that will fit the board. many people use the cement wirewounds. I have also used the Non-Inductive current sense resistors.
There should be plenty of resistors that will fit the board. many people use the cement wirewounds. I have also used the Non-Inductive current sense resistors.
Maybe I suck at the search on digi-key(I definetly do), but to me, if I want to stick with a 5W on the canadian site, I am left with:
2-1623788-5 TE Connectivity AMP Connectors | Resistors | DigiKey
Unless I want to buy in bulk. As far as I can see this is OK, but I cant tell if it will fit the board or not.
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