Sure Electronics New Tripath Board tc2000+tp2050

[MikeHunt79]

I found quite a nice box today that would be ideal for the this sure board:


I managed to squeeze a TA2020 amp board and 12v SMPS in there, but the Sure TK2050 board also fits with room to spare, but not enough for a SMPS however:


If anyone recognises this box, does anyone know who sells them? I was given this one a while back, and have no idea where they obtained it either, but it would be a good enclosure if only for the shielding, it's 1mm thick steel which I imagine should work well.

Originally Posted by sendler

Most of the Tokos, Sagamis, and the Coilcraft GA3416 ect, coils with 10uH values, are too small for a TK2050 amp. We need something closer to a 10 amps rating. I have the Coilcraft SER2915L-103 installed and they sound pretty good but have some blurring of the top octaves compared to the Ferroxcubes. Maybe ok for the woofers. I'm still hoping for something better off the shelf.

This may be good news for people who want to bi-amp. You could use Coilcraft SER2915L-103'x on the left channel to power the woofer, and Ferroxcubes for the right hand channel to power the tweetwe. I'm planning to bi-amp, are there any drawbacks with mixing output inductors on the same board?

[sendler]

Originally Posted by MikeHunt79

This may be good news for people who want to bi-amp. You could use Coilcraft SER2915L-103'x on the left channel to power the woofer, and Ferroxcubes for the right hand channel to power the tweetwe. I'm planning to bi-amp, are there any drawbacks with mixing output inductors on the same board?

There might be a slight difference in the relative volume between the channels.

[sendler]

Originally Posted by Neil Davis

The gapped ferrite toroids are OK for applications where you need the toroid form-factor (such as an existing board layout), but there are better ferrite core solutions. The gapped toroid is going to have EMI issues from fringing around the gap.

It's worth noting that the older IR amp described in the class D app note used the 106-2 core, but all of the newer IR reference amps use the Sagami enclosed "low-distortion" gapped ferrite inductors (see this page: International Rectifier - Audio Reference Design Kits).

Toko, Sagami and Coilcraft all make "low-distortion" shielded gapped ferrites that should work as well as the Ferrocube core, or better. The picture isn't very good, but maybe you can see how this Coilcraft GA3416 is made. It's a dual inductor, so there are two identical chambers. Each chamber is an enclosed EP-type construction (see Magnetic core - Wikipedia, the free encyclopedia), with a 1mm gap on the center slug and flat "tape" wire. I haven't opened up a Toko yet, but I'm guessing it is similar.

Attachment 147311
Attachment 147312

So the dual coil package is just for miniturization to fit two coils onto one footprint? Or is there an electrical/ distortion advantage for balanced amps depending on how you wire up the phase of the output legs?

[Neil Davis]

Originally Posted by sendler

Most of the Tokos, Sagamis, and the Coilcraft GA3416 ect, coils with 10uH values, are too small for a TK2050 amp.

?? IR uses the Sagami 7G17A to get over 400W at less than .01% distortion (see IRAUDAMP7D). That's a lot more than what you will get from a TP2050.

Of course, if you want something a lot bigger, see if you can buy some of the shielded ferrites from Virtue Audio. My understanding is that they had Coilcraft develop that inductor for them.

Regarding your other questions:

MPP cores are available from CSW ByteMark: Products : CWS ByteMark, largest supplier of toroids, ferrite cores, iron powder cores, MPP cores and RF cores

And yes, I think the dual coils are completely independent, for two-channel use or for common-mode filters where two coils are used on the output. (But I don't know for sure.) So they save board space.

[sendler]

Originally Posted by Neil Davis

?? IR uses the Sagami 7G17A to get over 400W at less than .01% distortion (see IRAUDAMP7D).

Those are worth a try. Where can we buy them?

[Lostcause]

Originally Posted by sendler

Those are worth a try. Where can we buy them?

They look a lot like the AMP6 basic inductors from 41htz....

[MikeHunt79]

Originally Posted by sendler

There might be a slight difference in the relative volume between the channels.

That is not a massive problem for me, as I can easily adjust the volume of each channel from my crossover. I think I may give this a try.

[Neil Davis]

Originally Posted by sendler

Those are worth a try. Where can we buy them?

According to the parts list in the amp7 data sheet they are available from either Inductors, Inc or ICE Components. You might want to check some of the other parts lists to see if IR lists some other vendors.

Inductors, Inc shows stock on two of the 10uH parts. ICE doesn't list any Sagami parts at all.

If you are interested in duals, AVNET has the TOKO DAEPW-M163S. They had 12 the other day--I left you 4

Also, you might want to put some thought into the filter values that you are using. The "textbook" Tripath filter works very well for 4 ohm loads, but it is possible to get some serious (and very audible) peaking in the 20KHz range at load impedances in the 6-8ohm range. I can't say anything else about this because it is based on measurements that I've seen that were done by someone else, and I don't have permission to release that information. But I noticed that some of the comparisons you described were with different filter values, so some of the differences you heard between the inductors may be due to filter peaking rather than the inductor properties. For a good discussion on class D output filters, take a look at this article: Understanding output filters for Class-D amplifiers | Audio DesignLine. That peak in Figure 3 can have a surprisingly big impact on the sound of this amplifier.

[sendler]

Originally Posted by Neil Davis

According to the parts list in the amp7 data sheet they are available from either Inductors, Inc or ICE Components. You might want to check some of the other parts lists to see if IR lists some other vendors.

Inductors, Inc shows stock on two of the 10uH parts. ICE doesn't list any Sagami parts at all.

If you are interested in duals, AVNET has the TOKO DAEPW-M163S. They had 12 the other day--I left you 4

Ordered the last 4. Thanks for the tip. Inductors inc is working on getting me the Sagamis.

[dr_vega]

So I wound 8 air-core inductors and installed them in the amps for my bi-amped mains (the sub is still running Arjen inductors).

Sendler, after winding 22 turns of 18 gauge wire, I can readily appreciate what you did winding 60 turns of 14 gauge. You are the man!

Well, my system already sounded damn good and I didn't think there was that much room for improvement. I really wound the coils just to say that I did and have them look cool hanging off the amps.

Boy was I stunned! The improvement was dramatic. Much more than installing the Arjen coils. Even more than changing the input caps. First, the attacks are faster and cleaner. And the sustain dies out more smoothly and completely.

Those two things hit me immediately. Especially piano sounded more real, more alive, more vibrant.

More listening revealed gains in held notes, which are richer, warmer, and more involving than before.

The net effect is music with more vitality, more lushness, more jump. It's a joy to listen to.

I'm listening to the Concord Jazz Super Audio Sampler (SACD) and it is pure bliss. So much life. So much warmth and crispness.

I'm not generally effusive about improvements and mods, but this is really special. I've always heard that a coil is the worst thing you can put in the audio path, far worse than caps. It makes sense that improving the coils will bring big rewards. But high quality coils are expensive, so I haven't upgraded them much in the past. And I've never used air-cores before.

But cost is no longer a barrier. These 8 air cores cost me $8 for wire and $2 for formers. Plus a couple of hours of work. And what a payoff.

I have not shielded them yet, so I imagine I'm annoying any of my neighbors listening to Rush Limbaugh. Tomorrow I'm going to make some aluminum foil condoms wrapped in paper for insulation and see how they work. I won't try to ground them to start with.

I encourage everyone to give these air-cores a try. The coils aren't too hard to wind, you get the hang of it after a couple. And they're easier to install than the Arjen coils because their size necessitates longer leads which make soldering them easier.

No downsides, except the EMI and we'll figure that out, I'm sure.

-dr_vega.