Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Tbone55 on April 27, 2019, 09:48:47 am
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Is there a difference in wire wound resistors that are available? I have several wire wound resistors made by Ohmite that I want to use in the bias circuit of an amp I'm building and was wondering if they would be ok in place of the regular wire wound ceramic type typically used. The Ohmite resistors are hole through type and have the wattage rating required (5W). The one good thing about these Ohmite resistors is that they are slimmer in design and use up less space on the board. Has anyone else used these resistors?
Thanks.
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unless you're doing some crazy metrology calibration resistors are "the same". Ohmlite are right up there with Dale for good R's
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Should be fine. What bias supply are you building that requires 5W resistors?
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5 Watts is 5 Watts. If they use tougher stuff the *part* can be smaller, run HOTTER, so you still want about the same amount of air around it.
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Should be fine. What bias supply are you building that requires 5W resistors?
I'm building a dual bias supply circuit. The OT is has dual output impedance, 5k & 2.5K. The amp will be able to use either a 6V6 or an EL34 for the power tube. Depending on which tube I decide to use there will be a mini-switch to change from a 750ohm/5W or both the 750ohm/5W and a 1kohm/5W in parallel. These 5W resistors might be overkill but that's what the plans call for. There's also a mini-switch to switch the impedance of the transformer to match whichever tube I want to use. I'm probably going to start with a 6V6 and see how that sounds and then try an EL34. I didn't think it would matter which type of resistor I used as long as they are 5W. The Ohmite's have a 1% tolerance while the others have 5%.
Thanks.