So long as that 200V doesn't cause the resistor to exceed its wattage rating. I'd still prefer to a bit more gentle with the power and rate the resistor a bit over that spec for a non mass produced item. The extra MTBF (Mean Time Between Failures) would be worth it.
A strange observation, perhaps on the coast of the Adriatic only?
Please describe the 'metal sound' for us. THX
Carbon film resistors can work for plate loads, but metal film or wirewound resistors are generally better due to lower noise and better stability. If you're aiming for a warmer tone with some vintage character, carbon film can be a good choice. What’s your specific application?
I have tried 5W Kiwame carbon film to replace the the plate load resistor that originally has metal film 1/2W there. It sounds much more musical!!
Egellings,
You could as an alternative use an RN60-sized metal film part, which has a higher wattage rating. If you ae short on space you can always stand up the parts for closer spacing.
You could as an alternative use an RN60-sized metal film part, which has a higher wattage rating. If you ae short on space you can always stand up the parts for closer spacing.
Much noise on DIY related to resister noise of various kinds.
Has anyone done comparative measurements, and how the results
relate to the signal level likely at that place in the circuit?
Probably orders of magnitude, most home grown amps on DIY
are 2-stage things. Intended for a 2V input signal.
In the distant past we had to deal with mV sources.
How did we ever do that with CC resisters?? 😀
Yeah, I have seen classic tube amplifiers and receivers loaded with carbon composition resistors below decks - I'm currently working on a classic Scott receiver that has tons of the beasties. Why the RIAA section doesn't hiss like an angry snake is beyond me, especially as there are 12AX7s involved, and not the low-noise variety, either. I may just throw up my hands and replace the carbon comps with metal film parts. I think the RIAA preamp also has feedback EQ, so I would not swear on a stack of Bibles that the RIAA accuracy is anything to write home about...
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Resistors make two different kinds of noise. Thermal / Johnson / Nyquist noise depends on resistance value and temperature (only) and is the same for all constructions. Other noises, called "excess" noise, vary with construction and with current flow. So, a resistor in a location with no current through itself, like a grid stop for example, will make the same amount of noise independent of construction, but a plate load will vary.
The lowest excess noise comes from wirewound constructions, then metal film, and the highest comes from bulk (composite) carbon.
All good fortune,
Chris
The lowest excess noise comes from wirewound constructions, then metal film, and the highest comes from bulk (composite) carbon.
All good fortune,
Chris
is not strange, take one guitar amp lets say pcb made to avoid lead dress effects in repeatable build, populate all positions with all carbon film resistors and then the same pcb populate with metal film resistors.. give at the end you observation.
noise- hm. what noise have to do with the overall sound? one question, how many amps did you built in your life?"Less noisy than I'm used to"
what are you speaking about.. noise is 60-90 dB below actual signal.. and character is there not in the noise... minor masking maybe is possible but can be ignored.