czwartek, 24 lutego 2011


In to what extent a condenser behaves approximately ideally, (small losses) depends on the structure and the used materials.
The conductive poles (leader, plates) consist mostly of aluminum (aluminium), tin (SN) or copper (cu). In exotic cases also silver (AG). As insulator (dielectric) with electrolytic capacitors (Elkos) one is used with electrolyte (liquid) pushed aluminum oxide foil, with tantalum Elkos the material tantalum oxide, ceramic(s) with ceramic(s) types and with foil condensers a plastic foil. In exceptional cases oil-soaked, or wachsimraegniertes paper (unfortunately industrially no longer very common) becomes, or mica (English: Mica) assigned. With the latters a very thin silver layer is vapour-deposited on mica as leader material, why they are called also Silver Micas.
The plastic foils consist mostly of Polyaethylenterephtalat PEN, polyester PET, polycarbonate PC, polypropylene PP, polystyrene HP with label name the Styroflex, and/or Polyphenylensulfid PPS. Very rarely teflon ptfe or silvered Mika foil begun.
The plastics (PC, PP) result in the as far as possible standardized designations together with aluminum foil: KC, KP, FKP, PPF. It concerns a metallized plastic foil (PEN, PET, PC, PP, PPS): MKS o. MKY, MKT o. MKH, MKC, MKP o. PPM o. MPP o. MFP and/or MKY o. MKS.
MP condensers (metallic paper) possess paper as dielectric, which either oil-soaked, oil-impregnated or hard wax-impregnated. Older (1980 ago) oelpapierkondensatoren (PIO: PAPERS in oil capacitor) can contain the PCB poisonous in the case of fire! There are it in the cylindrical aluminum cup with screw connection, in the rectangular aluminum cup, or more rarely than axial condensers.
The capacity rises with the surface of the parallel ladder and the isolatormaterialabaengigen dielectric constant. One by sand-yield-like laminating (leader, insulator, leader, insulator...) receives as large a surface as possible in right parallelepiped or cylinder form. The choice of the insulator (dielectric) is always a compromise between capacity increase (- > small design with large capacity) and the quality loss due to the dielectric dissipation factor oppositely behave.
The loss-poorest condensers are developed with mica, teflon, polystyrene or polypropylene. S.g. Dissipation factor D is called also Dissipation factor DF, or angle tangent delta. It indicated with 1kHz and 20°C and lies with foil condensers within the range of 0.005-0.00001 with Elkos: > 0.3-0.02 with 120Hz (the smaller the better!). The dissipation factor rises with the frequency. The reciprocal value of this characteristic is called quality or quality factor. Sometimes the DF also indicated in per cent e.g.: 0.1% = 0.001.
The causes of the losses are apart from the dielectric losses the structure-conditioned errors: Small existing inductance (technologytechnology technology), the resistance of the connecting leads and their contacting (soldered connections and/or. ferrousmagnetic materials). The resistance losses, in particular with Elkos, are combined as serial verlustwiderstand into the value ESR (Equivalent Series Resistor). This lies in the order of magnitude of 5-30mOhm. Inductance (order of magnitude 10-200nH) causes that a condenser works starting from an upper critical frequency (resonant frequency) no more than such, but than coil. The upper critical frequency can be with Elkos with 10kHz! With foil condensers the value is with some MHz.
THERE a further, rarely in the data sheet (only for MIL) indicated loss characteristic, is the dielectric absorption (in %) (> > cables). It describes a kind memory feature with condensers (recovery volume-meet, MEMORY effect). Seems smaller THERE to be present even if the tangent delta is small. Smallest values supply HP, PP, mica and teflon condensers. The order of magnitude is enough from approx.. 0.01% with high-quality PP condensers to > 10% with Elkos and MPs. Ungepolte Elkos are somewhat better. Often older high-estimated oelpapierkondensatoren surprisingly possess a quite high since value from 2 to 20%! Tolerable is actually only one value to 1%. Fortunately the influence of a high since value can be reduced by a low impedance wiring strongly (e.g. with the employment in frequency switches).
A high-quality condenser is supplied with a capacity tolerance of 0.5-5% (Elkos 10-20%).
Dielectric | Constant one (etar ) | Dissipation factor (tangent delta)
Ceramic(s) > 50 0.001
PP 2,3 0.001 0.00005
HP of 2,5 0.0001-0.0003
Mica 4-8 0.0001-0.0002
Oiled paper 3-4 0.0001-0.0002
Air 1 < 0.00001
C[pf ] = 0,00885 * etar* A/A A=Flaeche in mm², a=Abstand in mm
For the audio employment the linearity and the hysteresis characteristics over the frequency are crucial.
Before trip into the world of the magnetism: The characteristics of magnetic materials µr change with the field strength and thus with the river. S.g. the B-H or hysteresis curve represents the magnetic flow density and/or induction as a function of the field strength. It can be taken up over the following connection electrically with a Osziloskop: U(t) = L di/dt (river i into inductance = x axis, tension at inductance = y axis). It has usually the form of two flattens, transferred s-foermigen curves, which are connected above and down and describe a surface. Ideally last only a straight line.
Also condensers possess due to the not ideal dielectric etar characteristics in analogy to magnetic world in a "hysteresis curve" to be represented can. The connection can be taken up likewise electrically with a Osziloskop: i(t) = C du/dt (tension u at the condenser = x axis, river i in the Kondesator = y axis). Are it shown also here, if also not so clearly, curves and even surfaces.
In both worlds change the upward gradient of the curves (L, and/or C), the s-form of the curves (linearity errors) and the surface between the curves (losses) with the frequency!
Oiled paper types offer here the best linearity and have quasi no hysteresis characteristics. They are closely followed types of Polystyren (KS) and polypropylene (PP). Ceramic capacitors, tantalum and aluminum Elkos show clear Nichlinearitaeten and hysteresis behavior, which are also still strongly periodical.
A further quality parameter is the impulse maximum stress (Slew rate) of a condenser. This indicated in V/µs and gives a statement about it to what extent a condenser for the processing of impulses, thus signals with fast climbing time (square wave signals), is suitable. This value does not appear very frequently in the data sheet of a condenser. The range of values is with 1..10000 V/µs ! and is proportional to the tension strain and acceptable current load. The best values supply here MKP, FKP and kp of condensers. The employment of these condensers is inevitable with digital transmission circuits (S/P DIF) and in high-quality loudspeaker frequency switches. Into these also still MP condensers come into question.
Unfortunately in the data sheet of a condenser did not describe, but in the audio employment very importantly, are the Mikrofonieempfindlichkeit and the mechanical resonance behavior. The layering (conductive foil dielectric.) can turn out by the current flow, by electrostatic forces and through from the outside influencing mechanical forces (sound) in motion. Develops inevitably a modulation with the information signal with the consequence of rattles/clinks. In the discipline mechanical absorption behavior MP condensers, which as dielectric oil-soaked paper contained seem, to be very good. There are also MKV condensers of newer design the oil contained. Tin foil condensers (KP-SN) are likewise recommended.
Problem of long-term Konstanz: By drainage the capacity of the Elkos is reduced!, also oelpapierkondensatoren can be affected by it. With Elkos those is maximally indicated to ambient temperature for this reason. Standard is 85°C with high-quality types is enough the value to 105°C and/or 125°C. The life utility of a 85° Elkos amounts to when the used under 20° up to 20000 hours. Increases the Umgebungstemperator to 40° sinks in such a way it to 5000.
The construction volume is proportionally to the capacity and the tension strain and in reverse proportional to dissipation factor. A large design the danger disturbances to be conditionally always caught, or which parallel arranged condensers affect each other mutually (cross talk by capacitive coupling) and/or by Mikrofonie are affected.
The tension strain is separately indicated for equal and alternating voltage. The alternating voltage value is with approx.. 50-60% DC voltage value. THERE a useful side effect of high tension strain is a low ESR and a concomitantly smaller dissipation factor D and. Condensers with high tension strain have usually better acoustic characteristics.
The correct polarity is necessary actually only with Elkos. These are meant also for the enterprise of DC voltages with small wechselspannungsanteil. Unfortunately in addition, with foil condensers klangliche differences show up ever after like rum he are operated. This cannot be explained at present. Unfortunately the print is not always an orientation. There only one test and an inquiry with the manufacturer help.
DC bias: Aluminum Elkos and tantalum Elkos, which have to actually look for nothing in the signal path, improve its characteristics (smaller hysteresis) by put on DC voltage. In vacuum tube circuits generally high DC voltages rest against the koppelkondensatoren (e.g. Annodenauskopplung). This polarization DC voltage does not cause according to experience with foil and oiled paper types, or only small ones, sound advantages. I.e. as klanglich well judged condenser shows here his qualities also as koppelkondensator at the entrance of a transistor output stage!
The area of application of the individual types:
In the signal path (koppelkondensator) of a "High end chain" may not be used Elkos, ceramic capacitors and Tantalelkos (these distort)! Here only MKP are applicable -, kp Styroflex and high-quality oiled paper types.
Aluminum electrolytic capacitors (Elkos) are intended only for the employment at DC voltage in power packs (to sieving and as energy stores and/or load condensers). Elkos rush relatively strongly and cause signal distortions.
In high-quality audio components should in the power pack only good industrial commodity e.g. of: Philips and/or. BC, Siemens, Vishay-Roederstein, Aerovox, Rubicon, F&T, Jamicon and comparable quality with low ESR and foil types joined in parallel (bypass) are used. With inferior commodity sound losses are pre-programmed.
The "sound" of Elkos is temperature-dependent (temperature-dependent ionic conduction in the dielectric). The best temperature range is with approx.. 40° C. This is probably a reason for the preheating time with amplifiers.
Elkos for the employment in switch power packs are intended, are also in similar audio power packs of advantage.
It is of advantage more mehrer smaller Elkos in parallel connection to operate (the ESR is reduced).
New AUDIO Elko types such as Jelmax Rubicon BLACK GATE (graphite foil condensers), BHC Aerovox Slit Foil (slot foils) and t-Net (4Pol) can bring dramatic improvement. This however with tenfold costs! Bipolar BLACK GATE (BGs) type of NX ONE is suitable also as koppelkondensatoren. BGs have 10-300 better intoxication and Verzerrungseigenschften and internal resistance depending upon type around the factor are smaller around the factor 2-10.
The relatively inexpensive ELNA (ROS, Silmic/ROA, Cerafine/RJH/RSH, star GET/RJJ, DynaCap) is likewise recommendable.
These types were developed particularly for audio's application. They are provided and it measures against Mikrofonie were met with OFC copper connections. Sanyo OS-CON are exeptionally also well suitable as Abblockkondensatoren in digital circuits.
The inexpensive Nichikon PL and Panasonic forms a further positive exception FC/HFQ/HFZ/HC, which are comparable to the ELNAs.
Tantalum Elkos and ceramic capacitors are suitable for the DC voltage buffering of individual stages in HF and digital circuits! Ceramic capacitors (X7R, NPO, Sibatit) can be used at best still to the Abblockung of HF and as Koppellkondensatoren with sinusoidal HF.
Gold Cap's (Panasonic)/ SuperCaps (NuinTEK, Panasonic) / UltraCaps (Epcos): These condensers are used like Akkus. They exhibit an extremely high capacity compared with the normal Elkos. With gold Caps the capacity reaches up to 50Farad (typical 0.5-1F). SuperCaps bring it on up to 50F and UltraCaps on unbelievable 100-5000F (1F = 1,000,000 µF!). Unfortunately the tension strain is strongly limited: With Goldcap's on max. 5.5V, with SuperCap and UltraCap max. 2.3-2.7V. GoldCaps and SuperCaps has a quite high internal resistance of up to 0.5Ohm. With the UltraCaps is internal resistance clearly lower (< 1mOhm). They can supply very high Entladestroehme. The price is however also quite high (1200F for approx.. 100€).
Gold Caps often become in digital circuits, as a Akku assigned, which is constantly reloaded over a resistance. Naturally HF suited condensers are necessary as bypass.
Photo Flash Elkos exhibit an extreme tension strain (DC 200 - 400V). The capacity lies in the usual framework (100 - 470 µF). These high tensions are needed, in order to ignite flash tubes. They are to be found thus in each camera. They are likewise used like a Akku, which with (Blitz)Bedarf is loaded. Warscheinlich have you also a relatively high internal resistance.
For digital circuits small Wima FKP, FK and MKS is a good choice. Because of the missing connecting leads (small inductance, ESL) are here SMD condensers of advantage (metalisierter polypropylene film).
Into frequency switches bipolar Elkos can be used in uncritical places (thus not in the signal path), e.g. with correction networks and parallel to the loudspeaker. As condenser before central and Hochtoenern they are purest sound killers. This Tonfrequenzelkos is ungepolt, thus suitable for alternating voltage. There are it in the execution with smooth, or rough anode. The smooth anode help to somewhat better characteristics, conditionally in addition, a larger design.
By parallel connection the capacity adds itself. If the capacity is to be erhoet by parallel connection considerably, then as only as possible condensers of same type and structure should be who-turned. An inferior condenser of high capacity (e.g. Elko) a high-quality condenser (HP, PP or kp type) with small value is parallel switched (bypass C) can the quality and mostly also the sound be improved (applies also to power pack Elkos). The reason: The resonant frequency is shifted upward.
Series connection (capacity is reduced), in particular with a cable connection (AC AC coupling), should be avoided! The klangliche quality of series connection is ever worse than those of the worst condenser!

The klanglichen differences of condensers in the signal path can be dramatic.
They can be explained to a large extent by the connections mentioned above (dissipation factor DF and THERE, impulse firmness, linearity, Mikrofonie).
A condenser in the signal path of the preamplifiers or the output stage klanglich convinced, can fail sometimes in the frequency switch before the Hochtoener klanglich, or in reverse. Correct preselection and more extensively heard is thus inevitable. The best results are obtained with MKP, kp, Styroflex and MP condensers (oil-soaked).
An effective means for the improvement of a condenser can be the parallel connection of a very high-quality condenser. This kind of the wiring is called bypass condenser. This bypass C has a very small capacity opposite the basis condenser (e.g. 0,1 - 100 nF). As bypass for condensers in the signal path are suitable, KP's, Styroflex, as well as mica and/or Mica's. As bypass for power packs all foil condensers and also the Micas are applicable. In particular during signal bypass wiring not inevitably an improvement is guaranteed. Often a homogeneous sound result is reached only by employmentone, high-quality condenser. The sound-relevant characteristics of the two condensers must complement each other, form a homogeneous unit. There only trying helps!
With bypass condensers (e.g. mica, kp, Styroflex) worked may these in loudspeaker switches maximally according to experience 5-6% of the main capacity exhibit. With entrance ouple condensers the relationship should be still smaller. To clarify one can do itself this over the critical frequency of the bypass high-pass. This is attached: fg[kHz ] = 160,000/(R[kOhm ] * C[nF ]). Bsp.1: A 1nF bypass condenser (parallel to an entrance ouple condenser) at 47kOhm input impedance works thus already starting from a critical frequency of fg~3.4kHz!. Bsp.2: 100nF before a 8Ohm Hochtoener work only off: fg~200kHz.
A high DF becomes apparent in an indistinct masked illustration. Affects the dynamic structure of the music more highly THERE. The rendition works imprecisely, compressed and a little tone quality-rich. The impulse firmness has similar influence with low impedance loads (high river). Mikrofonieeffekte and thus resonances make the klangbild sharply and roughly, the high clay/tone range work covered and unnaturally.
Oiled paper types are not without reservation recommendable. Due to the high of old types they can in high impedance circuits often discoloured, very softly and even zugehangen THERE to sound. It charms in the in the middle a very colourful klangbild, the basic clay/tone range is very bodyful often, details in the heights however thereby unfortunately very often remains on the distance. If they are from new production and improve THERE and if DF of values exhibit, then they sound often quite bright within the high clay/tone range. Some supply proper an Loudnes effect.
A very positive forms the type praised approximately around the globe: SPRAQUE 196P Vitamin q .
Some (also high-quality) foil types bend klangbild within the high clay/tone range to "gekuenstelten". Straight ones in the employment as condensers before the Hochtoener often oversubscribe it with complex music program in the upper frequency range. They play often on a very high level, in addition, sometimes unmusikalisch, analytically and coldly.
The klanglich best foil condensers surprisingly possess the axial design. These are only manufactured however in mass production on "old" machines. Possibly is the deformation procedure of klanglichem disadvantage. This is partly necessarily if a approximately wound condenser into a rectangular housing fit must. Rectangular housings need less place and can be equipped better automatically.
Condensers, in particular Oelpapiertyen, need a bringing in time of approx.. 100 hours to it to the full rendition quality erbluehen. Before a klangliches judgement is passed upon a condenser of this design, it should have been at least 12 hours with music program or an intoxication signal in enterprise.
Description of sound:
With the change to good foil condensers changed (improves?) itself, with the first clay/tone audibly, the dissolution of detail and the spatial illustration. Often however to deplore that is the tonal balance from the equilibrium turns out. The klangbild will too analytic, the voice against gift becomes more thinly, more bodyless. The bass rendition is under-exposed in relation to the central/high clay/tone range. The high clay/tone range seems to be almost fokusiert. Impulsive music works dynamically and fast in addition, often too hard and unnaturally. Sometimes the klangbild breaks everything open with more complex music passages proper, works then nervously and imprecisely.
Very good condensers open sound spheres, which if one did not experience them yet, not to be considered possible: The low clay/tone rendition becomes outline and more bodyful, the central clay/tone range more cleanly. In addition, the heights get jet strength, it work more quietly. The music separates better from the loudspeakers. It is air on the stage. Tones end cleanly and disappear in the nothing. The energy distribution of the music is inspiring homogeneous. The klangbild remains under all circumstances stable. Briefly expressed: The music works authentically, naturally and in music.
To experience we could do this only with very few condenser types. Most High Tech Folienkondensatoren (MKP and kp) was far from it. Homogeneous often those did not play completely in such a way "perfect" polystyrene and polyester condensers. Some oiled paper types many likewise through. Naturally we could not test all types specified down. Some secured klangliche experiences and realizations came also from colleagues and audiophilen friends.
We want to be allowed to do, and, here also no recommendation deliver, and/or very expensive condensers publicly devaluations. We may betray one however: We were very surprised the klangliche distance of a really good (does not umbedingt excessively expensive) condenser to those are as large, which are to be found usually in the considerable High end devices. It depends also here apparently mainly on the price and deliverability.
Manufacturer list:
Note: The manufacturer and the type are specified. The sequence is arbitrarily, thus without evaluation:
Oelpapierkondensatoren: Jensen and audio note with aluminum -, copper or silberfolie, Ampohm, pro Cap (silberfolie), Sequa, intertechnology (IT), ASC...?
Foil condensers:
TRT (Tomorrow's Research Today): Wonder Cap, InfiniCap (Signature, SETI, Ultima, Almost Ultima, Economy), DynamiCap
REL Cap (Reliable Capacitors): PPFX s MultiCap, RTX, blank, AudioCap: PPF, PPT, blank, PPMF, Exotica teflon TFT, PCU Exotica Cupper Foil PP film, Exotica prime, rear-Rel
Spraque: Orange drop 715P (kp) or 716P PE or PP
Brines: Nearly Cap PP,
Ansar: Supersound SPX (special MKP condensers: low ESR and mikrofoniearm),
Hovland: MusiCap,
Soshin: V2A (Silver Mica),
Mundorf: M-Cap, m-Cap supreme, KP-SN
IT: Audyn Cap, Audyn Cap plus, KP-SN.
SCR acoustics: MKP, KP-SN,
WIMA: MKP-4, MKP-10, FKP, Snubber
ROE, ERO (Vishay Roederstein): KP OF 1830, KP OF 1836, MKP 1837, MKP 1846,
Westlake: Styroflex,
Leclanche: PPM,
Eton: PPM,
Kimber: Kimber Cap
Arcotronics: Kp of 72,
ICW: metalisierte PP, ASMPF series,
audience: AuriCap,
Bennic: Type XPP and PMT,
Cornell double: PP,
Epcos: Kp and MKP,
ICEL: Kp and MKP,
Ampohm: FP-APPROX.,
V-Cap (teflon film with tin foil),
There are also oil-soaked polypropylene condensers:
MKV types (engine condensers) e.g. by Siemens,
Mundorf: MCap supreme silver/oil (oil-soaked silberfolien MKP)
NOS commodity (New Old Stock):
ERO: Kp of 1832, kp of 1834, KP1836, MKP 1841, MKP 1842, MKP 1845, MKT 1813, MKC 1864, EROFOL, EROID, old polyesters.
Styroflex by NFS, EMZ and Siemens.
Cornell Dubilier: Black Cat,
Spraque: Black Beauty, 730P,
Siemens: B23500, B23501, MKP B32650, MKP B32655,
Some foil types of: Western Electric, AT&T, Aerovox...
Oiled paper of: Spraque, CSC (Vitamin q 196P, 188P, 91P, 191P), KEMET, Mallory, west Cap CP05A1, ICAR PR20, SP25, CCR25, Caratt, Sangamo, shape, Ducati, Wireless Thomas, Pyramid, Leclanche...
Russian oiled paper or MKPs ...
Old ERO, Siemens, Valvo, Philips, Bosch, Frako, F&G, CCIT, SEL, MF... Miltaer or BP MP's in the round or rectangular metal cup
Some these types e.g. the MP's was manufactured already 1955 and is today, also as used condensers, very desired.
Jelmax Rubicon: BLACK GATE type: To FK/K, PEEP, SKZ/WKZ (high volt), Ungepolt: N/NX (High quality)
Rubicon YXA, YXF, YXG, ZL, ZLH
ELNA: ROS, Silmic/ROA, Cerafine/RJH/RSH, star GET/RJJ/DynaCap
Sanyo: OS-CON, SG
Nichikon: PL
Panasonic: FC/HFQ/HFZ/HC
BHC Aerovox: Slit Foil, t-Net
Philips and/or. BC,
EPCOS (Siemens),
Vishay Roederstein (ROE),
Vishay BCcomponents 128 SAL RPM (80% wechselspannungsanteil stand)
F&T (FischerΤ)
Jensen Four polarize Elko
J & J
United Chemicon LXV
More bent
NOS Elko types: Mallory Twistlok, Sprague atom, Frako
Mica (Silver Mica): Siemens, Richard years, El Menco, Micamold, Sangamo
The price margin of a condenser is enough depending upon value and quality of 0.15 (with standard types) to 40, - € (with special audio condensers) per piece! With Exoten such as oiled paper with copper or silberfolie of 100, - until 1000, - € per piece!!
A 10000µFBlack gate can up to 360€ cost.
SMD condensers are however always second (or last) choice, there these only as MKT, MKC, ceramic(s), tantalum or electrolyte Elko be available and besides with ferrousmagnetic nickel contactings are provided. Within the digital range however SMD condensers, due to the missing connecting leads, have which always represent a small inductance, clear advantages.
With us in the signal path only special one, klanglich selected axial WESTLAKE Styroflexkondensatoren and special Oelpapiertyen is used, or DC-COUPLED if possible.
With loudspeaker systems we begin in the central and high clay/tone range oiled paper, MKP and kp condensers.
(we thank Mr. Thorsten let us delete for its tips regarding Ansar, Black gate, OS Con, Elna Silmic/Cerafine/Starget..)

Further empiric reports are gladly accepted!
to further information
Also resistances affect the sound
"are modern trend" metal and metallic oxide of layer resistances regarding the tolerance, which temperature coefficients and the intoxication behavior the "old" coal mass and carbon film resistors consider. They are manufactured however predominantly with top caps from iron or with a nickel contacting (smd) and are thus ferrousmagnetic.
The bad sound characteristics of elements in the signal path (intermodulation distortion), magnetized by iron and nickel, the influence, should in High end circles actually admit to be!
Not coiled and cap-free coal mass -, coal mixture layer -, metal foils -, metal glaze and tantalum around of resistances are non-inductive and possess better impulse characteristics. From cost reasons, bad availableness or high manufacturing tolerance (selecting necessarily) they are however hardly used.
The sound profit with the employment in the correct place is considerable and comparable with the differences with condensers!
The employment of relatively strongly rushing coal mass resistances (e.g. all Bradlay OFF, Morganite, CCIT) provides for a very sonoren sound, which is warscheinlich jointly responsible for the warm sound of old tube amplifiers. This resistances are however only available as very expensive NOS commodity (new old Stock) and become with prices of up to 3, -€ per resistance acted! The tolerance deviation of these resistances is with up to 20% and depends besides on the air humidity.
Coal mixture layer resistances have comparable sound characteristics are however (still) available (tolerance deviation 5-10%).
Coal mass coal film and/or carbon film of resistances likewise still manufactured of: Company. Riken and Kiwame in Japan (High end prices!) This resistances rush less and are long-term-more stable.
Note: Some years ago the "Morganite" was dissipated still for 1 Pfennig/Pfennig as residual items.
A certain "sound portion" due to the noise is not to be laeugnen.
Resistances from solid leader material (e.g. metallic film) white usually only thermal noise up. Layer resistances from coal deliver a noise potential with direct current flow additionally . For this stromrauschen statistically varying transition resistances between individual crystals of the material are responsible. The frequency response is for instance 1/f, so that this effect comes particularly with deep frequencies to carrying (sparkle-rush). This kind of noise sounds itself better, than the "white noise" and is probably a reason for the fact that some people prefer kohlewiderstaende. Since the noise potential to the direct current by the resistance is proportional should this be kept as small as possible.
Thermal noise is, relatively independently of the type of the resistance, proportionally to the resistance value (ohm) and in reverse proportional to the achievement (2W types less than 0.5 W rush). This effect is smallest with wirewound resistors. Kohlewiderstaende form the tail light also here.
The inductance of a resistance due to the easily coiled metal or carbon film, and/or the bifilaren coil of a wirewound resistor is very small. Likewise it behaves with the capacity between the connecting leads. Both periodical parameters are usually negligible in the audio range (critical frequency within the MHz range).
Decision ducks an influence on the sound have the mechanical resonance characteristics. The mechanical suggestion is caused by the current flow and by sound effect from the outside (Mikrofonie). These oscillations lead to a change of the electrical signal flow and thus too rattle/clink. Coal mass resistances possess a homogeneous conductive body (graphite), which apparently positively affects the mechanical vibration response.
Best choice regarding "side effect-free" metal foils are -, metal glaze and tantalum around of resistances, which are supplied to tolerances of 0.1-2%.
Central price resistances such as HOLCO (metallic film with copper caps), Vishay DALE CMF55, VITROHM, (metal glaze), ISABELLENHUETTE, PBH (metal foil manganin), HFC (wirewound resistor).. and high price resistances such as SHINKOH, Soshin TAF, ICR, VTC (Tantalum), CADDOCK (thick film technology), Riken, raw POINT (Bifilare Drahdwiderstaende without caps).., Metallic film resistances with brass caps lie depending upon maximum stress and accuracy in price regions of: 1-15, -€ / piece.

Far companies audio resistances manufacturing: IRC (metal glaze), Fukoshima (well-known wise wire resistance), MPC (metal band resistances), Skelton, TDO (Metaloxid), Mills (metallic film), Shalcross, Tokyo the on
Note: Since short Holcos and Shinkohs are not any longer manufactured.
Also praised metallic film resistances of the company Beyschlag (Berlin), are underlaid for Welwyn RC55 these.
As SMD Bauelemt only very few of these high-quality resistances are available: Holco, IRC Tantalum and Vishay Bulk Foil - natural at a high price!
How always helps only heard also here!
With loudspeaker frequency switches (also in highest price regions) in the signal path, before the Hochtoener, from cost reasons or ignorance of metallic oxide layer resistances MOX (with stahlkappen) or wirewound resistors (CR-Ni-wire, cemented) are still inserted. We begin already since long metal foil resistances .
With us only non-magnetic, klanglich selected become in the signal path
Coal mixture layer -, metal foil or metal-glazed film of resistances assigned, or if possible up
Resistances does without (direct coupling).