Audio Note™ Signal Capacitors


Audio Note Copper Foil Capacitor 0.22uF 630v, Solid AN 99.99% Pure Silver leadout wires
Picture of 630v, 0.22 uFvolt copper foil capacitor


As you may already have seen on the other parts/components sections the slide in the value of the pound makes it necessary for us to adjust our Sterling prices this and general cost increases.

BIG Capacitor News!

Well, the really big news is that we have moved all our copper foil signal capacitors away from using a paper dielectric to using the same mylar that we use in the silver foil, but we retain the oil, so all our copper foil signal capacitors are now oil filled using mylar instead of paper, one slight abnormality, we have two print machines for these caps and for one of them we have not got the new print blocks that say “copper foil/mylar in oil” yet, so they still say paper in oil, however the print is now white instead of black, so we can see the difference, I know this is confusing, but it is temporary, I can assure you!

Why did we move to oil filled mylar from oil impregnated paper you may well ask?

When truth be told we have been experiencing increasing problems with the failure rate of our paper in oil capacitors over the past 3 to 4 years and despite a major research program into the causes of this increasing break down rate we have really come up with a blank, which makes me suspect that the cause has to do with subtle changes in the chemistry of the paper, the oil or some other key part of the caps, possibly due to new environmental requirements imposed on the production of the paper, who knows? Anyway, when it became obvious that we were unable to fully establish and rectify the cause, my engineers and I decided to give mylar a go again as the first experiments we did with oil imperegnated mylar was not sonically satisfactory, so this time we changed the construction to oil filled, the materials sealing the capacitor and the way we connect the foil ends to the wires and voila! After some running in, the new mylar/oil filled capacitors actually sound better in most respects than the old paper signal caps they replace, only real drawback in my view is that they take nearly twice as long to run in and sound quite a bit worse than the old paper/oil type when they are new, so there you are, you don’t get something for nothing!

As mentioned in both the Audio Transformer and Wire & Cables Sections, the cost of most raw materials has gone through the roof over the past 3 - 4 years, our bulk purchasing of foils, wire, HiB and nickel have only started seriously affecting our cost over 2007, in spite of this I have decided not to increase our prices yet, although if the cost of the raw materials do not stabilise or come down over the next few months, prices will have to rise.

Audio Note Mylar Copper Foil Capacitors with AN 99.99% Pure Silver Leadout Wires
New Copper and Mylar capacitors which are identified by their white printing.

Audio Note™ Tin Foil Signal Capacitors.

In all our Level One amplifiers, such as the OTO Phono Push Pull, we use the green ERO MKP metalized polyester capacitors, these cheap and cheerful industrial capacitors have been chosen through extensive listening tests against practically every commonly available polypropylene, polycarbonate, polystyrene and polyester capacitor on the market. They are far from perfect, but from a sonic standpoint they are purely detractive, meaning that they lose information rather than add it (which every polypropylene, Teflon etc. capacitor I have ever heard does to excess).

We used to use the Jensen made aluminium foil signal caps in our Level 2 and Level 3 products, and although I was never 100% happy with the sound of these (when am I ever?), they were less flawed and thus far better than any of the alternatives and we still use them in many of our products across the range.

When we stopped using Tobias Jensen in Denmark to make our branded custom paper in oil capacitors about 8 years ago and started our own production of copper foil paper in oil (now mylar in oil) and silver/mylar signal capacitors, we decided against reinstating the aluminium foil type for reasons of sound and instead started exploring other materials, such as tin foil and various composite foils.

The resulting dry tin foil signal caps have now been on the market for a few years, and the move away from the copper paper in oil prompted us to introduce an oil filling in the tin foil caps as well, since this then makes the processes the same across the board for the tin and the copper foil signal caps, the oil filled tin caps do offer slightly improved sound compared to the dry versions.

The high capacitance values will be available some time in early 2008, until then no prices are available.

Audio note Tin Foil Capacitors with AN 99.99% pure silver leadout wires, for hifi audio equipment
The Audio Note™Tin foil – mylar film signal capacitor, 0.1uF/630 volt and 0.22uF/630 volt versions

The Audio Note™ Tin/Mylar Signal Capacitors

Please note: dimensions may vary depending on availability of the cans

CAP-4910 0.001uF 630 volt 15 mm x 28 mm £ 8.75
CAP-4920 0.0015uF 630 volt 15 mm x 28 mm £ 8.75
CAP-4930 0.0022uF 630 volt 15 mm x 28 mm £ 8.75
CAP-4940 0.0028uF 630 volt 15 mm x 28 mm £ 8.75
CAP-4950 0.0047uF 630 volt 15 mm x 28 mm £ 8.75
CAP-4960 0.0082uF 630 volt 15 mm x 28 mm £ 8.75
CAP-5001 0.01uF 630 volt 15 mm x 28 mm £ 9.10
CAP-5010 0.015uF 630 volt 15 mm x 28 mm £ 9.10
CAP-5020 0.022uF 630 volt 15 mm x 28 mm £ 9.94
CAP-5030 0.033uF 630 volt 22 mm x 34 mm £ 9.94
CAP-5040 0.039uF 630 volt 22 mm x 34 mm £ 9.94
CAP-5050 0.047uF 630 volt 22 mm x 34 mm £ 10.22
CAP-5070 0.068uF 630 volt 22 mm x 44 mm £ 10.22
CAP-5075 0.082uF 630 volt 22 mm x 44 mm £ 11.20
CAP-5080 0.1uF 630 volt 22 mm x 44 mm £ 12.04
CAP-5120 0.15uF 630 volt 22 mm x 44 mm £ 12.04
CAP-5130 0.18uF 630 volt 22 mm x 44 mm £ 12.04
CAP-5150 0.22uF 630 volt 22 mm x 44 mm £ 13.86
CAP-5160 0.33uF 630 volt 35 mm x 54 mm £ 13.86
CAP-5380 0.39uF 630 volt 35 mm x 54 mm £ 13.86
CAP-5200 0.47uF 630 volt 35 mm x 54 mm £ 16.10
CAP-5250 1uF 630 volt 35 mm x 60 mm £ 22.50

The Audio Note™ Silver & Copper Foil Signal Capacitors.

Our own production audio signal capacitors range is now complete with the addition of the 0.39uf/630 volt capacitor, this is the best and most competitive range of audio signal capacitors available by some considerable way.

The new copper and silver foil signal caps are available in a range that is specifically targetted at the single-ended triode amplifier market, although most values will also be usable in other types of valve amplification.  

I think, however, that apart from the considerable improvement in price, the fact that the new copper foil capacitors are considerably better sounding than anything, including the previous Jensen-made copper signal caps, makes them even better sonic value. The improvement is due to the use of greatly improved materials, better production methods and tighter production tolerances, plus the fact that the new caps are encased in copper instead of aluminium, glass or plastic.

We stock the following standard values in copper foil in paper in oil,

Please note: dimensions may vary depending on availability of the cans

Order Code Physical Size Value Max DC Voltage UK Retail Ex. Vat
CAP-3010 35 mm x 67 mm 2.2uF 630 volt £ 63.75
CAP-3020 35 mm x 94 mm 3.3uF 630 volt £ 78.75
CAP-3030 54 mm x 75 mm 4.7uF 630 volt £ 105.75
CAP-3040 54 mm x 95 mm 6.8uF 300 volt £ 138.00
CAP-3050 54 mm x 95 mm 10 uF 300 volt £ 171.75
CAP-3110 15 mm x 30 mm 0.001uF 600 volt £ 19.50
CAP-3120 15 mm x 30 mm 0.0015uF 600 volt £ 19.50
CAP-3130 15 mm x 30 mm 0.0022uF 600 volt £ 19.50
CAP-3140 15 mm x 30 mm 0.0028uF 600 volt £ 19.50
CAP-3150 15 mm x 30 mm 0.0047uF 600 volt £ 19.50
CAP-3160 15 mm x 30 mm 0.0082uF 600 volt £ 19.50
CAP-3170 15 mm x 30 mm 0.01uF 600 volt £ 26.25
CAP-3180 15 mm x 30 mm 0.015uF 600 volt £ 26.25
CAP-3190 15 mm x 40 mm 0.022uF 600 volt £ 26.25
CAP-3200 15 mm x 40 mm 0.033uF 600 volt £ 26.25
CAP-3210 15 mm x 40 mm 0.039uF 600 volt £ 26.25
CAP-3220 15 mm x 40 mm 0.047uF 600 volt £ 26.25
CAP-3230 15 mm x 40 mm 0.068uF 600 volt £ 26.25
CAP-3240 20 mm x 40 mm 0.1uF 600 volt £ 30.00
CAP-3250 20 mm x 40 mm 0.12uF 600 volt £ 30.00
CAP-3260 20 mm x 50 mm 0.15uF 600 volt £ 30.00
CAP-3270 20 mm x 50 mm 0.18uF 600 volt £ 30.00
CAP-3280 20 mm x 50 mm 0.22uF 600 volt £ 30.00
CAP-3290 20 mm x 50 mm 0.33uF 600 volt £ 30.00
CAP-3300 20 mm x 50 mm 0.39uF 600 volt £ 36.00
CAP-3310 35 mm x 53 mm 0.47uF 600 volt £ 39.75
CAP-3320 35 mm x 53 mm 1.0 uF 600 volt £ 49.75


Standard Stock Audio Note™ Silver foil values.

Audio Note Silver Foil Capacitor 1.0uF 600v, Solid AN 99.99% Pure Silver leadout wires
Audio Note™ 1.0uF/600volt silver foil capacitor

Please note: dimensions may vary depending on availability of the cans

Order Code Physical Size Value Max DC Voltage UK Retail Ex. Vat
CAP-7786 34 mm x 15 mm 0.0028 uF 600 volt £ 95.00
CAP-7788 34 mm x 15 mm 0.0047 uF 600 volt £ 95.00
CAP-7790 34 mm x 15 mm 0.0082 uF 600 volt £ 95.00
CAP-7780 34 mm x 15 mm 0.001 uF 600 volt £ 95.00
CAP-7791 32 mm x 15 mm 0.01 uF 500 volt £ 95.00
CAP-7792 32 mm x 15 mm 0.015 uF 600 volt £ 110.00
CAP-7796 32 mm x 15 mm 0.022 uF 600 volt £ 120.00
CAP-7798 32 mm x 22 mm 0.033 uF 600 volt £ 130.00
CAP-7800 32 mm x 22 mm 0.039 uF 600 volt £ 145.00
CAP-7802 32 mm x 22 mm 0.047 uF 600 volt £ 155.00
CAP-78021 32 mm x 22 mm 0.056 uF 600 volt £ 160.00
CAP-7803 32 mm x 22 mm 0.068 uF 600 volt £ 175.00
CAP-78031 40 mm x 22 mm 0.082 uF 600 volt £ 185.00
CAP-7804 40 mm x 22 mm 0.1 uF 600 volt £ 195.00
CAP-7806 40 mm x 35 mm 0.15 uF 600 volt £ 210.00
CAP-7810 40 mm x 35 mm 0.22 uF 600 volt £ 225.00
CAP-7812 53 mm x 35 mm 0.33 uF 600 volt £ 300.00
CAP-7816 53 mm x 35 mm 0.39 uF 600 volt £ 335.00
CAP-7820 53 mm x 35 mm 0.47 uF 600 volt £ 395.00
CAP-7840 35 mm x 75 mm 1.0 uF 600 volt £ 540.00
CAP-7850 54 mm x 75 mm 2.2 uF 600 volt £ 995.00
CAP-7860 54 mm x 95 mm 3.3 uF 600 volt £ 1,750.00

The above silver foil capacitors use a fine mylar film instead of a paper in oil dielectric, we have found this to be the best compromise between sound and reliability, and those of you who have tried these copper encased silver foil signal capacitors can confirm the fact that the new Audio Note™ silver caps are better by miles than anything else, no mean feat when you also look at the prices, the only possible improvement over the Audio Note™ silver signal capacitor is an interstage transformer, which removes the need for a coupling cap altogether!

Our specially made mylar/oil caps have an immediacy, life, colour, lack of harshness and evenness of dynamic behaviour across the frequency range (or as I prefer to call it, the harmonic envelope!), which is guaranteed to brighten up your day! Recommended as replacements in old and new valve amplifiers alike (and even in the odd transistor amplifier), and essential for DIY projects.

In line with the best environmental standards, all Audio Note™ oil filled mylar  capacitors contain only non-toxic, biodegradable vegetable oil, the mylar dielectric enhances longevity and sound quality, to ensure optimum performance all round. 

I show here a group shot of some of the Audio Note™ Copper and silver foil capacitors, the large capacitor at the back is a 6.8uF 300 volt copper foil capacitor suitable for either speaker crossovers or power supply applications. These capacitors are very heavy and should be mounted with suitable care to prevent the lead out wires breaking in transport.

Audio Note Tin, Copper and Silver Foil Capacitors, AN 99.99% Pure Silver leadout wires
Tin Foil, Copper Foil and Silver Foil Capacitors. Tin and Copper versions have solid leadouts while the Silver has litz cable.


As you can see from the above picture each of our signal capacitors are marked with a line on the right, this marks the start of the foil. It is my experience that the Audio Note™ sound the best when the start of the foil is “facing” the incoming signal.

We are getting an increasing number of requests for the delivery of matched pairs of both copper and silver foil capacitors, which in combination with increased use of matched pairs in the production of M6Phono and M8Phono pre-amplifier have made it necessary to invest in a proper calibrated test instrument for testing large numbers of capacitors, so we are now able to offer a matching service at £ 2.00 per capacitor, order code: CAP-MATCH.

I have to make the following clear as well, when we match the copper foil/mylar in oil capacitors this is done at room temperature, since the temperature co-efficient of these caps is fairly high, the value can change by several percent if the capacitor is close to a heat source, such as a valve or a dropper resistor. This will result in a variance in the capacitance and especially if the capacitor is in a RIAA network will effect some minor change in the frequency response.

Component Warranty

This does not apply to the replacement scheme mentioned in the new section at the start of this paper.

All the above capacitors are guaranteed for 3 months, with the following conditions,

1.)    They must be returned to the factory here in the UK within 7 days of failure and no later than 3 months after purchase.
2.)    They must be accompanied with a receipt of purchase, which clearly show a purchase date.
3.)    A note giving us a brief description of how and where the capacitor was used and how long it lasted and what the failure was.

No capacitor will be replaced without the above being complied with, and there will not be exceptions made to that rule.


All material copyright Audio Note (UK) Ltd., unless otherwise stated. Audio Note (UK) Ltd. reserve the right to change, modify, add to, or remove any of the content of this site at any time without prior notice. Further, images on this site may differ from current models or specifications.