component valus and tolerances

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jestaudio
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component valus and tolerances

Post by jestaudio »

Having only just finished one build i,m considering another, has anyone ever published a "shopping list" of all the components needed with specific tolerances for resisters etc :?:
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Colossal
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Re: component valus and tolerances

Post by Colossal »

I'm not aware of such a list. The choice of resistors (or any component in an amplifier) is highly subjective based on the contribution that the materials themselves (i.e. carbon film, metal film, carbon composition) lend to the tone, the precision of the part desired, and the price the builder is willing to pay for precision and perceived value, etc. The quantity and value needed of each part varies with design. If you want to build up a drawer system for your bench with lots of values to choose from, then economies of scale kick in and you can realize some cost savings to some degree by buying in bulk. As far as tone goes, some builders are highly sensitive to precision and composition, others are less discriminating and just base their choices on price or availability (or even if they can get things for free or e-cycling). Some select one material choice such as carbon composition for specific locations within an amp or throughout for vintage replicas. As you can see, there are many factors to consider.
jestaudio
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Re: component valus and tolerances

Post by jestaudio »

hmmmmm, yes i get your point, just trying to be lazy really although wattage ratings for resistors would be usefull as would voltage rateings for the caps, my basic assumtion is that most of the reisistors will be either carbon or Dale items
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Colossal
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Re: component valus and tolerances

Post by Colossal »

jestaudio wrote:hmmmmm, yes i get your point, just trying to be lazy really although wattage ratings for resistors would be usefull as would voltage rateings for the caps, my basic assumtion is that most of the reisistors will be either carbon or Dale items
Well for wattage ratings, you can check out various schematics. Generally, for power supply dropping resistors, you want 2W or higher and at the very least 0.5W in a preamp.
jestaudio
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Re: component valus and tolerances

Post by jestaudio »

availibility is always the issue in the uk but looking at the layouts most of the components should be easy enough to source, correct me again if i,m wrong but 600v should be more than adequte for the electrolytic caps and the caps on the preamp board :?:
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Colossal
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Re: component valus and tolerances

Post by Colossal »

jestaudio wrote:availibility is always the issue in the uk but looking at the layouts most of the components should be easy enough to source, correct me again if i,m wrong but 600v should be more than adequte for the electrolytic caps and the caps on the preamp board :?:
Yes, 600V is a good number and adequate. If you have a 100W amp pushing high voltage (such as for KT88s or something), for your power supply you may want to place your reservoir caps in series to double the voltage rating for an extra margin of safety. Typical capacitors used for power supplies range from 350-500V depending on the value, manufacturer, and configuration (e.g. axial vs. radial).
diagrammatiks
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Re: component valus and tolerances

Post by diagrammatiks »

600vdc would be fine for the caps.

From the discussions on resistors it seems like rn65s are a pretty safe bet. You might want to go to a power resistor for your b+ droppers though.

after that it's just personal preference. My favorite is the rlr32 for the non power supply section, rs2b .1 percent for bias, and rs or rw series for power supply.
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