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Model: | AC filter according to JR |
Category: | Power Conditioner/Surge Protector |
Suggested Retail Price: | 60 $ |
Description: | Low cost high performance AC conditioner |
Manufacturer URL: | Not Available |
Review by Lukasz Fikus on May 04, 1999 at 05:51:51 IP Address: 195.94.192.18 |
Add Your Review for the AC filter according to JR |
I tried to audition commercial AC conditioners, but I was frustrated by wrong changes brought to my system. Things worsened instead of improving.
Then I understood those guys are :
1. trying to do it by specs - the more dB of attenuation the better
2. Trying to make a buck by over-engineering
3. in effect choking my premium music system performance.I decided to make my own - after all it is one of the simplest tasks an EE can get.
I followed a suggestion of a man of experience - Jon Risch. See his design guidelines elsewhere in the net.
After building two small prototype filters I liked the result so much I decided to make a full blown unit.
I used a box that is of a standard "Japanese amp" size and looks just plain.
Inside I mounted a subfloor of plywood for attaching the components.
I installed 4 heavy duty AC outlets with high IP rating and good contact.
I skipped the IEC AC inlet and wired the main supply AC cable directly to the inside of the unit.
I terminated the incoming AC cable at the DIN rail type 1:10 wire splitters - one in - 10 out, without any discontinuity.
From the E, L, and N points I went straight to the AC outletsd by means of a choke, to minimize the number of joints and stuff like that.
I did not use any fuses as they are absolutely unnecessary.
The CHOKES:
16 ga (1,3 mm) motor wire wound around the ferrite rods about the diameter of a finger, lenght of two fingers.
The winding is located in the center, and trakes 30 turns for small current components and 20 turns for mono amps.
This translates to 70 uH for the former, and 50 uH for the latter.
The wire is only about 0,5 m (2 ft ) long, so DCR is non - measurable, in any case smaller than 0,01 ohm.
At the input side of the coil there are the caps - polystyrene type 600 V rated foil, 0,1 uF. They are connected in triangle - E-L, E-N, L-N.
In patalell to those there are the varistors - the 300 VAC rated, coin sized, beige ones. They are a little higher in voltage than the book says, but this is better than being on the lower side. For storms this protection is good enough.
So there is a common cap and varistor triangle at the input, one pair of live and neutral coils to each outlet - 8 coils in total, glued with hot melt to the plywood.
at the outlet terminals I have again a capacitor between L and N (o,o1 uF 600 VAC) and the same type of varistor.
All earth wiring is 1,5 mm yellow and green with a separate earth toggle switch next to each outlet - you can disconnect earth individually for every component !!!
Input cable is Audio Agile (Germany) shielded audio grade AC cable and a "lawnmower" grade plug.
NO SEPARATION TRANSFORMERS INSIDE is engraved on the faceplate as a logo.The sound:
the improvement is bigger than any cable swap I ever listened to, however extreme.
For example, in a piece with three conga players playing large drums with naked hands you can hear MUCH BETTER the drum skins, the sound of hands (yes, they sound too!) and the body of the drum. The 3-d effect is stunning.
The micro-events happen very clearly and naturally, music is more liquid, clean, analog-like natural.It is impossible for me to live without it.
The unit also will protect the delicate digital part of my CDP i case of any funny shit coming from the AC line in case of a storm or switching noises.My AC cables are organized well without the nasty splitter into splitter into splitter manner I used to deploy.
There is no choking effect on the dynamics of the music, unlike with the commrcial design I tried before.
Total cost:
1 USD per rod = 8 USD
1 USD total motor wire
2 USD total hook-up wires
2 USD per 5 varistors total
4 USD caps total
25 USD nice brushed alu box
2 USD per outlet, 8 USD total
10 USD AC cable 1 m.
2 USD AC plug
2 USD per 4 heavy duty toggle switches
1 usd for the glue
2 hours mounting timeTOTAL: 65 USD
Recommended without hesitation for systems costing from nothing to infinity (mine is worth circa 20 000 USD list)Lukasz
Product Weakness: | May seem to limit a little the brutal raw sound of rock music. |
Product Strengths: | Improves important factors of the sound, has no down-side effects, organizes cabling, protects gear. |
Associated Equipment for this Review: | |
Amplifier: | ARG LAbs tubed monos 100 W |
Preamplifier (or None if Integrated): | ARG labs all tubed. |
Sources (CDP/Turntable): | Wadia 16 |
Speakers: | All Scanspeak top of the line DIY |
Cables/Interconnects: | All Audio Note Silver |
Music Used (Genre/Selections): | all kinds (mainly ethno and fussion) |
Room Size (LxWxH): | 9m x 5m x 3m |
Room Comments/Treatments: | none |
Time Period/Length of Audition: | 1 month, 4 systems |
Type of Audition/Review: | Product Owner |
Thanks for posting this. I was thinking about doing something very similar and am glad to see that you are happy with the results. The only thing that i would have done differently would have been the use of heavier wire than 16 gauge for the chokes. This would be fine for low level components, but not for an amp and other components (in my opinion).If you can, please email me a list of where you got all of your components from and part numbers. I would like to try and build one of these with some slight alterations. Sean
>
Sean,The parts are all called out in my note, the substitution of higher grade parts (i.e., the caps being styrene) is a good idea, but the only thing is that they may not be AC line rated. A good grade of PP caps with sufficient voltage rating (at least 400 VDC for US 120VAC) should perform adequately if you really wna tthe better parts.
As for the inductors, the ones I specify in my note have a short length of heavy gauge wire. I also strongly recommend the powdered iron cores over the ferrite, if you can find them. Remember, inductance values over about 150-200 uH will begin to potentially limit dynamics.
Jon Risch
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