Audio Note™ Signal Capacitors
BIG Capacitor News!
31st March 2008
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 establishand 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!
Due to the problems that have emerged with the paper in oil signal capacitors I have decided that we should replace any faulty Audio Note copper foil paper in oil caps that any of you have, all you need to do is send them back to me here at Montefiore Road in Hove and they will be replaced free of charge with one of the new mylar versions, no questions asked. One thing though, you need to mark each capacitor up with what is wrong with it, if you don’t mind.
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.
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.
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
| Order Code | Value | Max DC Voltage | Physical Size | UK retail Excl. Vat |
| CAP-4860 | 2.2uF | 630 volt | N/A | |
| CAP-4870 | 3.3uf | 630 volt | N/A | |
| CAP-4880 | 4.7uF | 630 volt | N/A | |
| CAP-4890 | 6.8uF | 630 volt | N/A | |
| CAP-4900 | 10uF | 630 volt | N/A | |
| CAP-4910 | 0.001uF | 630 volt | 15 mm x 28 mm | £ 6.25 |
| CAP-4920 | 0.0015uF | 630 volt | 15 mm x 28 mm | £ 6.25 |
| CAP-4930 | 0.0022uF | 630 volt | 15 mm x 28 mm | £ 6.25 |
| CAP-4940 | 0.0028uF | 630 volt | 15 mm x 28 mm | £ 6.25 |
| CAP-4950 | 0.0047uF | 630 volt | 15 mm x 28 mm | £ 6.25 |
| CAP-4960 | 0.0082uF | 630 volt | 15 mm x 28 mm | £ 6.25 |
| CAP-5001 | 0.01uF | 630 volt | 15 mm x 28 mm | £ 6.50 |
| CAP-5010 | 0.015uF | 630 volt | 15 mm x 28 mm | £ 6.50 |
| CAP-5020 | 0.022uF | 630 volt | 15 mm x 28 mm | £ 7.10 |
| CAP-5030 | 0.033uF | 630 volt | 22 mm x 34 mm | £ 7.10 |
| CAP-5040 | 0.039uF | 630 volt | 22 mm x 34 mm | £ 7.10 |
| CAP-5050 | 0.047uF | 630 volt | 22 mm x 34 mm | £ 7.30 |
| CAP-5070 | 0.068uF | 630 volt | 22 mm x 44 mm | £ 7.30 |
| CAP-5075 | 0.082uF | 630 volt | 22 mm x 44 mm | £ 8.00 |
| CAP-5080 | 0.1uF | 630 volt | 22 mm x 44 mm | £ 8.60 |
| CAP-5120 | 0.15uF | 630 volt | 22 mm x 44 mm | £ 8.60 |
| CAP-5130 | 0.18uF | 630 volt | 22 mm x 44 mm | £ 8.60 |
| CAP-5150 | 0.22uF | 630 volt | 22 mm x 44 mm | £ 9.90 |
| CAP-5160 | 0.33uF | 630 volt | 35 mm x 54 mm | £ 9.90 |
| CAP-5380 | 0.39uF | 630 volt | 35 mm x 54 mm | £ 9.90 |
| CAP-5200 | 0.47uF | 630 volt | 35 mm x 54 mm | £ 11.50 |
| CAP-5250 | 1uF | 630 volt | TBA | TBA |
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.
Picture of 0.22 uF/630 volt copper foil
capacitor
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,
| Order Code | Physical Size | Value | Max DC Voltage | UK Retail Ex. Vat |
| CAP-3010 | 35 mm x 67 mm | 2.2uF | 300 volt | £ 42.50 |
| CAP-3020 | 35 mm x 94 mm | 3.3uF | 300 volt | £ 52.50 |
| CAP-3030 | 54 mm x 75 mm | 4.7uF | 300 volt | £ 70.50 |
| CAP-3040 | 54 mm x 95 mm | 6.8uF | 300 volt | £ 92.00 |
| CAP-3050 | 54 mm x 95 mm | 10 uF | 300 volt | £ 114.50 |
| CAP-3110 | 15 mm x 30 mm | 0.001uF | 600 volt | £ 13.00 |
| CAP-3120 | 15 mm x 30 mm | 0.0015uF | 600 volt | £ 13.00 |
| CAP-3130 | 15 mm x 30 mm | 0.0022uF | 600 volt | £ 13.00 |
| CAP-3140 | 15 mm x 30 mm | 0.0028uF | 600 volt | £ 13.00 |
| CAP-3150 | 15 mm x 30 mm | 0.0047uF | 600 volt | £ 13.00 |
| CAP-3160 | 15 mm x 30 mm | 0.0082uF | 600 volt | £ 13.00 |
| CAP-3170 | 15 mm x 30 mm | 0.01uF | 600 volt | £ 17.50 |
| CAP-3180 | 15 mm x 30 mm | 0.015uF | 600 volt | £ 17.50 |
| CAP-3190 | 15 mm x 40 mm | 0.022uF | 600 volt | £ 17.50 |
| CAP-3200 | 15 mm x 40 mm | 0.033uF | 600 volt | £ 17.50 |
| CAP-3210 | 15 mm x 40 mm | 0.039uF | 600 volt | £ 17.50 |
| CAP-3220 | 15 mm x 40 mm | 0.047uF | 600 volt | £ 17.50 |
| CAP-3230 | 15 mm x 40 mm | 0.068uF | 600 volt | £ 17.50 |
| CAP-3240 | 20 mm x 40 mm | 0.1uF | 600 volt | £ 20.00 |
| CAP-3250 | 20 mm x 40 mm | 0.12uF | 600 volt | £ 20.00 |
| CAP-3260 | 20 mm x 50 mm | 0.15uF | 600 volt | £ 20.00 |
| CAP-3270 | 20 mm x 50 mm | 0.18uF | 600 volt | £ 20.00 |
| CAP-3280 | 20 mm x 50 mm | 0.22uF | 600 volt | £ 20.00 |
| CAP-3290 | 20 mm x 50 mm | 0.33uF | 600 volt | £ 20.00 |
| CAP-3300 | 20 mm x 50 mm | 0.39uF | 600 volt | £ 24.00 |
| CAP-3310 | 35 mm x 53 mm | 0.47uF | 600 volt | £ 26.50 |
| CAP-3320 | 35 mm x 53 mm | 1.0 uF | 600 volt | £ 34.50 |
Standard Stock Audio Note™ Silver foil values.
Audio Note™ 1.0uF/600volt silver foil capacitor
| Order Code | Physical Size | Value | Max DC Voltage | UK Retail Ex. Vat |
| CAP-7786 | 34 mm x 15 mm | 0.0028 uF | 500 volt | £ 47.00 |
| CAP-7788 | 34 mm x 15 mm | 0.0047 uF | 500 volt | £ 47.00 |
| CAP-7790 | 34 mm x 15 mm | 0.0082 uF | 500 volt | £ 47.00 |
| CAP-7780 | 34 mm x 15 mm | 0.001 uF | 500 volt | £ 47.00 |
| CAP-7791 | 32 mm x 15 mm | 0.01 uF | 500 volt | £ 47.00 |
| CAP-7792 | 32 mm x 15 mm | 0.015 uF | 500 volt | £ 61.00 |
| CAP-7796 | 32 mm x 15 mm | 0.022 uF | 500 volt | £ 64.00 |
| CAP-7798 | 32 mm x 22 mm | 0.033 uF | 500 volt | £ 68.00 |
| CAP-7800 | 32 mm x 22 mm | 0.039 uF | 500 volt | £ 72.00 |
| CAP-7802 | 32 mm x 22 mm | 0.047 uF | 500 volt | £ 76.00 |
| CAP-78021 | 32 mm x 22 mm | 0.056 uF | 500 volt | £ 78.00 |
| CAP-7803 | 32 mm x 22 mm | 0.068 uF | 500 volt | £ 80.00 |
| CAP-78031 | 40 mm x 22 mm | 0.082 uF | 500 volt | £ 88.00 |
| CAP-7804 | 40 mm x 22 mm | 0.1 uF | 500 volt | £ 92.00 |
| CAP-7806 | 40 mm x 35 mm | 0.15 uF | 500 volt | £ 103.00 |
| CAP-7810 | 40 mm x 35 mm | 0.22 uF | 500 volt | £ 121.00 |
| CAP-7812 | 53 mm x 35 mm | 0.33 uF | 500 volt | £ 156.00 |
| CAP-7820 | 53 mm x 35 mm | 0.47 uF | 500 volt | £ 194.00 |
| CAP-7840 | 35 mm x 75 mm | 1.0 uF | 500 volt | £ 275.00 |
| CAP-7850 | 54 mm x 75 mm | 2.2 uF | 500 volt | £ 510.00 |
| CAP-7860 | 54 mm x 95 mm | 3.3 uF | 500 volt | £ 880.00 |
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.
Tin Foil, Copper Foil and Silver Foil Capacitors. Tin and Copper versions
have solid leadouts while the Silver has litz cable.
Directionality
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, see the drawing below.
This shows the position of a pre-amplifier output capacitor.
Matched pairs of Audio Note™ Capacitors
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.
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 puirchase.
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.
Updated, 31st March 2008. PQ
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