JiM wrote:It's often because of the "equivalent series resistance", which is lower with tantalum. And also better emperature stability, no long-term electrolyte dry-out, etc ...
modman wrote:And do they really make a difference in stompboxes is the big question?
The codes are as follows:
1st band (furthest away from the leads, i.e.top) black 0, brown 1, red 2, looks familiar ? yes its the same as resistors.
2nd band ditto
3rd band orange X 0.001 uF, yellow X 0.01 uF, green x 0.1 uf
4th band (tolerance) white +/- 10%, black +/- 20%
5th band (working voltages) red 250V dc , yellow 400V dc
There are really only four voltage colors for these capacitors.
Brown=100vdc, red=250vdc,yellow=400vdc and blue=630vdc.
analogguru wrote:yes.... since film caps normally have a tolerance of +/- 20 % (except if they are selected and marked as this) the actual value may vary beetween 180n and 260n.
from Ampage forum wrote:Tantalums are good substitutes for Electroilytics but not for mylar, polypropelyne, or polystyrene film caps, or foil caps for that matter. Tantalums are very poor capacitors in terms of Equivalent Series Resistance (ESR) and Dielectric Factor (DF) qualities. The only redeeming quality of tantalums is their low temperature coefficient. In other words, they don't change value much as they heat up.
Film caps on the other hand have lower ESR and DF values than tantalum caps making them better for audio. In general, the capacitor 'quaility' hierarchy is as follows:
1. Electrolytic *** Lowest Quality ***
3. Paper (1950- 60's. These are no longer made)
4. Paper Saturated with Oil (i.e. Vitamin Q style)
5. Mylar (i.e., Polyethylene)
8. Teflon *** Highest Quality ***
In general, you get what you pay for with higher quality caps costing more. Although some poor quality caps, like vitamin Q's, will cost you an arm and a leg because they are built to last forever rather than for sound quaility.
A quick discussion of DF is needed to fully understand why certain capacitors sound better than others. In essence, DF is a measure of a capacitors ability to discharge quickly. The faster a capacitor can discharge, the more accurately it can reproduce music. For, example, polypropylene capacitors sound alot more 'accurate' than mylar capacitors even though both are film caps. They also tend to reproduce high frequencies more accurately and therefore are sometimes perceived to sound a bit brighter.
There is one caveat to a cap having a good DF rating. Vintage guitar amps sound vintage because they used relatively poor quality paper capacitors in their manufacture. In other words, the poor DF of these caps was part of the amplifier's tone. A poor DF cap tends to smear the sound a bit making it less accurate but darker and warmer sounding which, though not desireable for audiophile applications, is a desirable quaility for some guitar amps.
This is not to say that a poor DF rated cap is what you want for your guitar amp. High end amps made today like Matchless or Trainwreck use polypropylene and polystyrene caps deliberately to take advantage of their more accurate sound. More conventional amps, like Marshall and Fender on the other hand, almost universally use electrolytics in their power supply and cheap mylar caps in their audio circuitry. There is a very good reason why a Matchless costs more than a Marshall.
Here's a few final comments on capacitor types:
1. Paper capacitors were used in the 1950-60's because they were cheap to manufacture. Unfortunately, they tend to go bad over time causing constant problems among vintage amp collectors. If you really want to retain the amp's vintage sound without going through the headache of constant repair, replace the original paper caps in a vintage amp with Paper in Oil caps which are the closet things that are still manufactured today. Paper in Oil caps such as Vitamin Q caps have an added benefit in that they are known to last forever and usually never needing replacing.
2. Different capacitor types have tremendous variations in their size for a given amount of capacitance. This is one reason why you don't see Polystyrene caps used alot even though they sound superior.
3. Internal construction of the cap also makes a big diffeence in sound. If a film cap is constructed coaxially, like MIT Multi-caps for example, the cap will have a more accurate sound then a conventionally constructed capacitor.
4. Film caps are always inferior to Foil caps in terms of sound for a given dielectric. A film cap is manufactured by spraying a very thin coating of metal such as aluminum on the dielectric material such as mylar. This technique is used because it saves on cost of materials as well as time and labor. Foil caps on the other hand use thin sheets of metal for the conductors within the capactors. Because of higher cost, you rarely see foil caps used in guitar amps eventhough they are greatly superior.
I hope this information helps somebody.
Users browsing this forum: No registered users and 2 guests