46 ohm 1/4 watt... Where can I get them?
I'm working on an American Bass 750.1. The power supply gate resistors in this amp are 46 ohms. Not having a lot of luck. Unless I try ebay, lol. Ewww...
I'm working on an American Bass 750.1. The power supply gate resistors in this amp are 46 ohms. Not having a lot of luck. Unless I try ebay, lol. Ewww...
I can bet that 47 ohm or 2x paralleled 91ohm behave the same...sometimes the manufacturers are strange...
46 ohms isn't a standard value; you may find yourself looking for quite a while. 1% tolerance on a 46 ohm resistor means that it can range from 45.54 ohms to 46.46 ohms and be within tolerance. You might consider acquiring several 1% 46.4 ohm resistors and selecting the lowest value of your batch; they are likely to be between 45.95 ohms and 46.86 ohms.
Are these 46 ohm resistors being used in a position where better than 1% tolerance is required?
Are these 46 ohm resistors being used in a position where better than 1% tolerance is required?
The OP states "Gate resistors".
In which case they are gate stoppers (killing local oscillations) so no current, no power and 10% tolerance more than good enough.
In which case they are gate stoppers (killing local oscillations) so no current, no power and 10% tolerance more than good enough.
Gate resistors are typically used in series between the driver circuit and the gates of the FETs.
If those are gate resistors tolerance is not that critical at all.
Standard 47 ohm resistors are more than fine.
Probably even 100 ohm resistors (or anything in between) will be fine.
Manufacturers often specify weird values (perfectly functional of course), I guess to throw copycat builders OFF or thwart non "official" authorized shop repairs.
A very weak protection in any case.
I have seen many amplifiers where *all* values are non standard 1% away ones for no visible reason, of course manufacturers who buy in bulk pay same price as standard values.
Standard 47 ohm resistors are more than fine.
Probably even 100 ohm resistors (or anything in between) will be fine.
Manufacturers often specify weird values (perfectly functional of course), I guess to throw copycat builders OFF or thwart non "official" authorized shop repairs.
A very weak protection in any case.
I have seen many amplifiers where *all* values are non standard 1% away ones for no visible reason, of course manufacturers who buy in bulk pay same price as standard values.
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For a gate stopper, 20% tolerance is probably sufficient. Which then raises the question of why someone would go to all the effort of procuring a run of non-standard 46 ohm resistors when 47 ohm resistors are cheap and readily available. Something doesn't add up.
Thanks for the replies.
They are the ps gate resistors (46 ohm 1/4 watt 5% I think, lol), they are the originals. 3 of the 6 in that bank are burned up. Values are still in tolerance, but burnt up. The drivers and everything else with the amp are fine. He had one break legs and 2 others in the bank failed. I was only going to replace the bank and resistors. I'm not a fan of replacing them with 47 ohm without replacing them all (even though I realize the difference is minimal). Which I guess I could...
I attached a pick of one of the good ones. They all read between 45.9 and 46.3ohm.. mostly being 46.0 (which is technically still in tolerance for a 47ohm too, lol). So either the bands are actually violet and not blue, and the resistors are all way on their low side... or this amp uses 46 ohm gate resistors, lol.
What color does the band look to you guys? I mean I usually go by other side and stuff, just cause it's hard to tell sometimes. I've been repairing AB amps for awhile. This would be the first amp I've had needing 46 ohm gates. Just for some reason these bands all look blue to me.
They are the ps gate resistors (46 ohm 1/4 watt 5% I think, lol), they are the originals. 3 of the 6 in that bank are burned up. Values are still in tolerance, but burnt up. The drivers and everything else with the amp are fine. He had one break legs and 2 others in the bank failed. I was only going to replace the bank and resistors. I'm not a fan of replacing them with 47 ohm without replacing them all (even though I realize the difference is minimal). Which I guess I could...
I attached a pick of one of the good ones. They all read between 45.9 and 46.3ohm.. mostly being 46.0 (which is technically still in tolerance for a 47ohm too, lol). So either the bands are actually violet and not blue, and the resistors are all way on their low side... or this amp uses 46 ohm gate resistors, lol.
What color does the band look to you guys? I mean I usually go by other side and stuff, just cause it's hard to tell sometimes. I've been repairing AB amps for awhile. This would be the first amp I've had needing 46 ohm gates. Just for some reason these bands all look blue to me.
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Again, don´t go behind the call of duty trying to source 46 ohm resistors, 47 is perfectly fine.
As said above there´s practically no current going through them, no voltage drop, no dissipation.
It will make NO difference to amplifier´s functionality.
Save your OCD to get same or very close switching Mosfets, *there* you will find a lot of variation and it´s significant.
As said above there´s practically no current going through them, no voltage drop, no dissipation.
It will make NO difference to amplifier´s functionality.
Save your OCD to get same or very close switching Mosfets, *there* you will find a lot of variation and it´s significant.
In the future, if there is a question about the value like here, look at the tolerance band. This is a ±5% resistor. That makes it limited to the E24 values that have only one value between 43 and 51 ohms.
It's definitely purple or violet which is 7, so it should be 47 but if you buy 47 ohm resistors you might get 45...49ohms and that is not a problem.You can put 39...51 ohm there and nothing bad will happen.
I have hundreds of 47 ohm. Maybe it's just my new lighting that is throwing me off. I agree the pic looks more violet. Thanks again everyone.
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