I used VISHAY VTA 55. Solely because people had spoken favorably of bulk foil and they are on 50% clearance sale. They replaced metal foil by Takman.
I cannot comment on how they compare to other bulk foil or the more exotic naked resistors. But in sensitive spots around tubes, they just cleared up the sound more like wire than a resistor. If I were to build the amps again, I would just go to bulk foil from any vendor looking for the best price and be happy with it. In fact more recently building a tube output for a DAC, I tried vintage SHINKOH - Tantalum. I thought they really masked the sound with a bit of a fuzzy sound. Replaced these with home made manganin which was best in class.
Replacing an Allan Bradley feedback resistor with Caddock USF series had similar effect. The AB was a poor choice here. Ultimately I ended up with the USF paired with an old Riken. The Riken adds a little warmth but without masking the sound. I think at this stage it is like seasoning. Putting in what simply sounds good to your ear in a particular spot.
I cannot comment on how they compare to other bulk foil or the more exotic naked resistors. But in sensitive spots around tubes, they just cleared up the sound more like wire than a resistor. If I were to build the amps again, I would just go to bulk foil from any vendor looking for the best price and be happy with it. In fact more recently building a tube output for a DAC, I tried vintage SHINKOH - Tantalum. I thought they really masked the sound with a bit of a fuzzy sound. Replaced these with home made manganin which was best in class.
Replacing an Allan Bradley feedback resistor with Caddock USF series had similar effect. The AB was a poor choice here. Ultimately I ended up with the USF paired with an old Riken. The Riken adds a little warmth but without masking the sound. I think at this stage it is like seasoning. Putting in what simply sounds good to your ear in a particular spot.
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It's a critical distinction to understand that bulk foil resistors are very different in construction from thin film and thick film resistors, to say nothing of carbon composition!
Vishay exclusively makes the very thin nickel-chromium alloy foil which is cold-rolled, possibly from a much thicker wire stock. They sell the foil to various resistor manufacturers who make the finished product under license; the entire resistor is highly engineered and every aspect of its design and construction contribute to the extremely low temperature coefficient, voltage coefficient, and low self-inductance. .01% tolerance is commonly available and there are darn few audio applications that need even that much precision! I believe nearly all bulk foil resistor products are non-magnetic, including the wire leads.
Even the z-foil is stated as being a nickel-chromium alloy, doubtless with other elements in the mix and special processing to ensure very high stability of the finished product. Many, if not most, metal film resistors and wirewound resistors also use nickel-chromium alloys as their resistive element; of course, other materials are also used depending on the resistance range (especially below 1 ohm), cost, and quality standards for the finished specific parts.
Tantalum film (tantalum nitride) is an alternative used in some popular and pricey "audiophile" resistors, but it's nearly impossible to find clear specifications and technical details on those parts, so they remain something of a mystery to me.
I don't normally like thick film resistors for audio, but Caddock appears to be a clear exception to this rule. The main difficulty I have with Caddock parts is the bulkiness of the product. No clear ideas why Caddock's technology is as good as it is.
Vishay's catalog just for bulk foil resistors covers many dozens of models, some highly specialized for highest stability and others for moderate power dissipation, very low or high resistance values, resistor arrays and surface mount. It's worth a visit to their site to study the descriptions of the various models.
VPG - Home Page
At one time I used Ebay to obtain bulk foil resistors at fairly reasonable costs, but they aren't showing up quite as much as they did a few years ago. I bought a box of nearly 100 2K S102 resistors for $14, but more often sellers demand more than that for a single resistor.
Does anyone know of similar sites like Ebay where electronic parts can be readily found?
Vishay exclusively makes the very thin nickel-chromium alloy foil which is cold-rolled, possibly from a much thicker wire stock. They sell the foil to various resistor manufacturers who make the finished product under license; the entire resistor is highly engineered and every aspect of its design and construction contribute to the extremely low temperature coefficient, voltage coefficient, and low self-inductance. .01% tolerance is commonly available and there are darn few audio applications that need even that much precision! I believe nearly all bulk foil resistor products are non-magnetic, including the wire leads.
Even the z-foil is stated as being a nickel-chromium alloy, doubtless with other elements in the mix and special processing to ensure very high stability of the finished product. Many, if not most, metal film resistors and wirewound resistors also use nickel-chromium alloys as their resistive element; of course, other materials are also used depending on the resistance range (especially below 1 ohm), cost, and quality standards for the finished specific parts.
Tantalum film (tantalum nitride) is an alternative used in some popular and pricey "audiophile" resistors, but it's nearly impossible to find clear specifications and technical details on those parts, so they remain something of a mystery to me.
I don't normally like thick film resistors for audio, but Caddock appears to be a clear exception to this rule. The main difficulty I have with Caddock parts is the bulkiness of the product. No clear ideas why Caddock's technology is as good as it is.
Vishay's catalog just for bulk foil resistors covers many dozens of models, some highly specialized for highest stability and others for moderate power dissipation, very low or high resistance values, resistor arrays and surface mount. It's worth a visit to their site to study the descriptions of the various models.
VPG - Home Page
At one time I used Ebay to obtain bulk foil resistors at fairly reasonable costs, but they aren't showing up quite as much as they did a few years ago. I bought a box of nearly 100 2K S102 resistors for $14, but more often sellers demand more than that for a single resistor.
Does anyone know of similar sites like Ebay where electronic parts can be readily found?
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You are using K or C foil resitors? S102K pdf, S102K description, S102K datasheets, S102K view ::: ALLDATASHEET :::
what can you say about sound?
Yes there is lots of bulk metal foil resitors, but what model is the best for audio, mayby it is no difrence in sound if we copere s102 C/K between New naked TX2575
what can you say about sound?
Yes there is lots of bulk metal foil resitors, but what model is the best for audio, mayby it is no difrence in sound if we copere s102 C/K between New naked TX2575
As I've stated before, bulk foil resistors are all pretty much the same product. Only the z-foils tend to stand out for their higher stability.
There's almost nothing I can say about the sound; I expect resistors to not have any 'sound' of their own at all. Bulk foil resistors seem to be the best in that aspect.
There's almost nothing I can say about the sound; I expect resistors to not have any 'sound' of their own at all. Bulk foil resistors seem to be the best in that aspect.
Yes like you say, i need transparent resistor. Z-foils are more expensive than another, but it is sense to use them?
I can bay s102K K is z-foil in good price. But it is packet version resistor. This is good choice?
I don't know what you mean by that. Do you have a part number?
Are z-foil resistors a better choice? Maybe. In theory, the better quality part. Is it worth the extra expense to you? I can't answer that question for you.
I Have E86C-6N30P-QB2/250 SE amplifier. For now:
In shunt step ladder i have holco resistor and waithing for vishay s102C
E86C-in anode i have anode choke so i dont have resistor near bulb,in kathode im waiting for Vishay s102k in grid, and thinking about shinkoh tantalum
6N30P In kathode is MK132 and it is good, thinking aboout shinkoh tantalum in grid
QB2/250 i have in kathode mills mra5, stil dont know what to put in grid, in grid i have fixed bias with SAC grid choke bypased by 470K resistor. Any propositions?
In shunt step ladder i have holco resistor and waithing for vishay s102C
E86C-in anode i have anode choke so i dont have resistor near bulb,in kathode im waiting for Vishay s102k in grid, and thinking about shinkoh tantalum
6N30P In kathode is MK132 and it is good, thinking aboout shinkoh tantalum in grid
QB2/250 i have in kathode mills mra5, stil dont know what to put in grid, in grid i have fixed bias with SAC grid choke bypased by 470K resistor. Any propositions?
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