Felix project

rajacat · « **Reply #260 on:** 16 Aug 2009, 06:49 pm »

I'm using the Coilcraft 3717A in front of an Acopian 5V 3.5 amp power supply that I use for my Bolder SB3. It hums.

Do I need a larger coil for this or would a DC blocker be the cure? What would be the cap values for a DC blocker?

I also use a felix(8177RC JW Miller) in front of my Mhdt Constantine DAC where it made a noticeable improvement but it hums too.

BTW I'm using a Felix on the DC output of the Acopian that I built with audiophool caps. The verdict on this is still uncertain. I'm still experimenting.

I just used some caps I had laying around: 2.2uf Obbligato PIOs, 0.1uf Russian teflons, .01 Russian teflons.

Don't laugh

but it's not as dangerous as it looks. In fact I've probably put about 50 hours on this setup. Finishing details and enclosure will follow. Any implementation comments/advise would be appreciated

Roy

TomS · « **Reply #261 on:** 16 Aug 2009, 06:58 pm »

Your power supply only requires power of about 20w so I would think that coil should be just fine. Unfortunately there's only a couple ways to find out about the DC, measure it as Occam said with a scope or just build up a basic DC blocker and see what happens.

Occam · « **Reply #262 on:** 16 Aug 2009, 08:10 pm »

Good greif Raj,

You're humiliating those capacitors.

For that level of audiphiliac obscession, I'd expect the dc filter to cook breakfast, complete with cappucino.
Forget the DC filter's front end caps (at this point in the power supply chain you're not concerned with noise coming out towards the ac line) and use something like 2 or 3 paralleled 10uf Vishay MKT1822 or Rifa MMT 50volt caps, or if you must be all audiophile, an appropriate voltage < 50uf Blackgate electrolytic. I simply use a 33uf 35v Panasonic FM electrolytic. Using large caps with long wire leads compromises much of their intrisic qualities for this use because of the necessary long leads with their comparitive high inductance.

Ryan,

The anti-paralled electroytic caps need to be rated above the two diodes drop, so conseratively, a minimum of 6.3v, which is what Brystron uses. Their size must be able to pass the peak current draw which would vary according to the system draw. Anything above around 8,200uf each would work for a smaller system, where for a larger system using most of a 20 amp circuit's capability would need around 33,000uf.

Regardless of whether you actually have DC superimposed on your AC lines (or loose windings/laminations), I'd recommend a a larger current capability CMC on your amp. Comparing the current draw of your component (by whatever calculation) to the nominal rating of a CMC isn't simple. The rating is typically for a given temperature rise, 35C above ambient, for a given RMS current draw. An amp typically is far from a sinusoidial current draw.

Regards,
Paul

peranders · « **Reply #263 on:** 16 Aug 2009, 09:25 pm »

Occam, have you thought of that if you really want 20 A through your mains wires you probably won't hear the transformer hum. A design rule would possibly to have caps which can handle the current at least.

peranders · « **Reply #264 on:** 16 Aug 2009, 09:27 pm »

Quote from: yan6 on 16 Aug 2009, 06:03 pm

Oh, I should have used more words. He is a great guy, he stepped up to rescue the group buy. He has saved many people a lot of money by taking it on.

Thanks, but I think you should wait and see how it goes. I have saved some at least but I'll hope everything.

rajacat · « **Reply #265 on:** 17 Aug 2009, 08:04 pm »

Quote from: Occam on 16 Aug 2009, 08:10 pm

Good greif Raj,

You're humiliating those capacitors.
For that level of audiphiliac obscession, I'd expect the dc filter to cook breakfast, complete with cappucino.
Forget the DC filter's front end caps (at this point in the power supply chain you're not concerned with noise coming out towards the ac line) and use something like 2 or 3 paralleled 10uf Vishay MKT1822 or Rifa MMT 50volt caps, or if you must be all audiophile, an appropriate voltage < 50uf Blackgate electrolytic. I simply use a 33uf 35v Panasonic FM electrolytic. Using large caps with long wire leads compromises much of their intrisic qualities for this use because of the necessary long leads with their comparitive high inductance.

Hi Paul,

Well....I guess I'll start over again.

Did you notice an improvement when you installed the Felix in the DC output of your SB power supply? Nobody else has given a review of this particular application of the Felix.

-Roy

BobM · « **Reply #266 on:** 17 Aug 2009, 08:13 pm »

I recently built another Feliz to use on my LCD flat panel TV in the bedroom. I've been meaning to do this for some time now but never got around to it. I do have one on the main plasma in the living room and noticed a nice improvement there.

Now the LCD I have in the bedroom is a no-name brand with a so-so picture. It is not the main TV so I never gave it a whole lot of thought and just thought it was a cheapo LCD. Well the Felix changed that in a big way. The improvement was fairly dramatic. If you haven't put one of these on your flat panel TV then you really don't know what you are missing.

There is a buzz coming from the transformer when the TV is turned on. Perhaps it is streeing a little because of the draw, or perhaps the coils are not wound as tightly as they could be. So it could be a mechanical buzz that a little silicone or Gorilla Glue would cure. Don't know, but don;t care too much either since its very low and inaudible unless your ear is right next to it.

Enjoy,
Bob

Speedskater · « **Reply #267 on:** 17 Aug 2009, 10:46 pm »

Quote from: yan6 on 16 Aug 2009, 05:48 pm

Thanks for the replies, I wondered if something like explanation #2 was occurring. My amp is a Marantz SR4600 specs say 314W on 120V, which puts it in at 2.62A; Still below the 3A rms, but close. I will be building a tube buffed gainclone this fall, which should draw less than the Marantz
When I'm done my vacation I will take it to work and put the scope on it to see if there is any DC. I would like to build the DC blocker anyways any cap values for the blocker?

You can only convert Watts to Volt/Amps when the load is a resistor. For a modern receiver and even more so a receiver with a SMPS or other high tech power supply (aka Carver). The peak current may be surprisingly high! If you have an AC current probe for that O-scope at work, take a look at the AC line current peaks and let us know, I'm sure that it will be interesting.

rajacat · « **Reply #268 on:** 17 Aug 2009, 11:11 pm »

I believe that have I inquired several times and several other posters too about what caps would be appropriate to use for a DC blocker for the Felix project group buy transformers. Can someone please give a recommendation or at least state what value caps they used for their DC blockers?

Thanks,

Roy

peranders · « **Reply #269 on:** 18 Aug 2009, 04:40 am »

You should not draw current through the diodes so the voltage drop over the cap should be less than 0.6 V.

C = U/(2*∏*I)

U = diode voltage drop or zener voltage
I = current

The cap value should be > 10000 uF

rajacat · « **Reply #270 on:** 18 Aug 2009, 04:44 am »

Thank you, peranders

kp93300 · « **Reply #271 on:** 29 Aug 2009, 04:12 am »

Hope more experienced diyer can enlighten me.

I build a Felix and it seems to work well in a Tripath amp.
I am wondering whether the values of the caps need to be symmetrical on both sides of the choke?
What about using 1 uF or higher X2 caps?
Will be be better to have numerous different values on both sides of the choke ?
Thanks
kp93300

kp93300 · « **Reply #272 on:** 10 Sep 2009, 03:32 pm »

Hi
I hope someone can answer my questions.
Is there any reason I cannot try higher value caps such as 10 to 100 uF X2 caps ?
Thanks
kp93300

mgalusha · « **Reply #273 on:** 10 Sep 2009, 03:42 pm »

I have used 1uF X2 caps but if I remember correctly that was the largest one listed when I purchased mine.

Assuming you can get X2 caps larger than 1uF, I'm sure there are limitations as to how big an across the line cap can be but I'm not any sort of expert in that area. I have no doubt someone here will have knowledge of this and hopefully will chime in.

mike

Quote from: kp93300 on 10 Sep 2009, 03:32 pm

Hi
I hope someone can answer my questions.
Is there any reason I cannot try higher value caps such as 10 to 100 uF X2 caps ?
Thanks
kp93300

Big Red Machine · « **Reply #274 on:** 20 Oct 2010, 01:29 pm »

A thread from the graveyard -

I am going to build a pair of Felixes thanks to some folks here with parts and my own resourcefulness. They should be bada$$ for sure with copper plugs, steel cases, ERS cloth, spiked feet, etc. Just procuring the parts now to make a pair for future monoblocks. Also am going to re-wire my dedicated circuit to add a run to the opposite wall so I can use shorter PC's.

Thanks to the nice photos and groovy schematic this device looks like an easy project and I hope to do you all proud.

jtwrace · « **Reply #275 on:** 20 Oct 2010, 01:34 pm »

Quote from: Big Red Machine on 20 Oct 2010, 01:29 pm

A thread from the graveyard -
Thanks to the nice photos and groovy schematic

I was speaking with someone about this last night. Can you post the post #'s for the photos and schematic?

TomS · « **Reply #276 on:** 20 Oct 2010, 01:48 pm »

By the way, you don't really need the PC boards from the group buy. It's almost easier hard wiring them to the back of the outlets. A few guys did that somewhere in this thread and it worked out great.

Big Red Machine · « **Reply #277 on:** 20 Oct 2010, 01:53 pm »

Quote from: TomS on 20 Oct 2010, 01:48 pm

By the way, you don't really need the PC boards from the group buy. It's almost easier hard wiring them to the back of the outlets. A few guys did that somewhere in this thread and it worked out great.

Agree, and when you see the photos you'll know why.

Quote from: jtwrace on 20 Oct 2010, 01:34 pm

I was speaking with someone about this last night. Can you post the post #'s for the photos and schematic?

I'll look in my History log. I copied and pasted all the photos into PowerPoint yesterday.

Big Red Machine · « **Reply #278 on:** 20 Oct 2010, 02:19 pm »

Post 155 and 160 is one method:
http://www.audiocircle.com/index.php?topic=51941.140#lastPost

Post 195 with pcb's:
http://www.audiocircle.com/index.php?topic=25757.180

Post 58 hardwiring and Post 20 for the schematic:
http://www.audiocircle.com/index.php?topic=50284.40

TomS · « **Reply #279 on:** 20 Oct 2010, 02:37 pm »

Note that CMC selection depends on how much current you need. More isn't really better for lower power equipment as the filtering is improved with a smaller choke.