Sure Electronics New Tripath Board tc2000+tp2050

[mfong]

I haven't. As I said, haven't touched the board. I just happened to have the 3 other options available while I was waiting for E-bay. To be accurate, for me the board works best (as is) when it gets 31 volts 3 amps.

It'll be a while before I play around with the board itself. I know Red Wine is doing 24 volts SLA and Virtue seems to be talking about 30 volts 10 amps. Winsome does 24 volts. I don't know what any of these folk did about adapting the feedback to the voltage. I think the battery folk do 24 just because it's easiest to get 12 volt batteries and chargers. 36 volts I guess is doable, but there have to be other changes to deal with it. I did think what Seth Krinsky had to say about the more current the better was at least interesting.

 

[v-bro]

Three 12V batteries in series are likely to present a dangerous voltage for this amp as they may be 14V each (or more!) when fully charged. With a few cap changes and an STA517B you will get away with it for sure. Or some of the Apogee chips, or even some other STAxxxx range which can handle higher voltage...

Don't get me wrong, I do agree higher voltage can make a dramatic difference! Yet it is paramount to achieve top performance to adapt the amplifier to work well with it. The feedback in these amplifiers is just one, there is also modulator gain and voltage sensing, just to name two more.... And yes, more current, but only up to a certain point. It's like a fire will be put out quicker with more water, but at a certain point more water won't make a difference any more. The time lag in extinguishing a fire is voltage sag in an amplifier power supply in this metaphore, a thing that can easily be measured with? An oscilloscope!

 

[sendler]

32v is the stock setting

The output feedback/ gain resistors come set for 32v. The 36v, 10 amp Meanwell supply that Sure sells sounds great adjusted down to 32v and is a great deal at $50. Any thing smaller is really just pinching pennies. Go for the nice power supply right off the bat when you are ordering your amp in the first place. They are a steal. Sure tells everyone to use 24v because they were afraid of the early, fanless heatsinks running too hot but none of my blue, second version heatsinks has ever even felt warm to the touch running on 32v. I also have run on two car batteries (and three), 24.8v which is slightly better sounding than the AC supply but not worth the trouble for me to use on a regular basis. The fact that they sound slightly better at 25v at all does tend to debunk the theory that optimum feedback voltages are crucial. As long as you are under the peak value you can get great sound. I wouldn't go above 32v with out changing the resistors.

 

[sendler]

Mono

I'm planning on starting my mods tonight. I'm thinking about the input cap and coil mods. I'd like to do one channel at a time and use a splitter to run the same signal through both channels and see what the differences are. I was also thinking about adding the zobel. I got some Dayton caps .47uF for the zobel and 1.5uF and 2.2uF caps for the input. I'm going to try the Coilcraft ser1360 series, Coilcraft SER1360 Power Inductors , as my output filter inductors.

Question is what would people suggest as the ideal order of test? I'd like to do one step at a time and test it. Should I do coils first? Input caps? Zobel?

I don't know how revealing it will be listening in mono. It would be better to have two boards.

 

[sendler]

Wurth XXL coils sound best

Hi Troupes, time has come to tackle the cores. But a bit at a loss for which ferrite rings I should buy. Maplin's ones are too big - 35mm wide. Jab electronics have a page of them, any of these suitable ?

JAB Electronics Micrometals & Farite Cores

BTW: replaced the Obbligato input caps with Claritycap SA's, wonderful improvement.

I have tried everything and I like the Wurth XXL the best.

 

[sendler]

No noise in mine

A few days ago I posted that although I had placed the fan on the amps heatsink on a separate battery and regulator I could still hear some residual noise of the fan through the speakers (very low level).

I thought at the time this was caused by electrical issues, maybe the radiation being picked up by some part of the board, so I tried caps across the fan inputs, re-routing the fan supply wires, but it now seems to be not the case.

If one presses the heatsink pushing it harder against the chip, or indeed just holding the heatsink between thumb and forefingers the noise is gone. In other words the noise/vibration of the fan is somehow mechanically picked up by the chip and them amplified.

Further checking shows that If I tap around the board with my finger nail with my ear to the speaker drivers I can in fact hear any noise my finger makes amplified through the drivers. Once again this is at a very low level but it makes one think.

I suspect that as the heatsink is basically spring loaded to the chip the contact is not as good as it could be at the interface, (probably not ideal for heat dissipation purposes either) and this may be the cause of the issues minor though it is.

If somehow these amps are microphonic then at high volume levels or when the amp is placed in a speaker cabinet to drive the speakers direct we may in fact be getting some feedback at certain frequencies colouring the sound which would not be heard at idle or low volumes.

It might also be an issue with large coils as if they are simply flopping in the breeze they will provide a potentially large vibration source.

I will look into ways to de-couple the fan mechanically and perhaps get a better connection of the heatsink and then see what residual vibration effects exist after that.

I held the amp in my hand with my ear touching each speaker driver. Very slight hiss in the tweeter and very slight buzz in the woofer. No more than any other amp I have had. Then I started banging on the heat sink with a pencil. Hard. I don't hear any of that banging noise coming through the speakers.

 

[SoldierAnt76]

Fan Noise

I can confirm that the heatsink fan is audible through the speakers. When I stop the fan with my finger, the buzzing noise goes away. When I release my finger, the pitch of the buzzing rises as the fan spins back up. So the two are linked.

It isn't a big deal, but it adds to the background noise you hear when the amp isn't receiving a signal. Maybe replacing the fan with a bigger heatsink is the solution?

 

[soldersmoker]

What's the approximate pitch of this "buzzing noise" you hear? 60/120 Hz? Or higher? I don't hear any such thing and I have 96dB/1W/1m speakers. Do you have the volume cranked up high when you hear the noise?

I'd like to replace my fan on principle, just to remove a moving part that will eventually need replacing anyway. But I never hear any buzzing.

 

[SoldierAnt76]

Fan Noise

The volume is turned up to a moderate level on my 90db speakers. The pitch of the noise changes with the speed of the fan. I can hear it even when I disconnect the audio cables. It's not particularly loud, and it might not even be audible on less sensitive speakers, but it's definitely present in the background.

It might not be an issue with all boards. Mine has the grey heatsink with "MSI" on the fan, and I received it just a week ago.

 

[Zero One]

Hi Sendler My fan is the later ones not the blue one, but it is running off a totally separate battery, so PS doesn't some into it. As far as the noise of the fan itself, it is very quiet, what is able to be heard is a sound that is quiet mechanical in nature though the speaker.

I must emphasis this is very very low level stuff, but I am totally anal retentive when is comes to getting the cleanest sound possible, other wise I would never have built a totally off the grid system (including analogue and digital front ends). I know most folk will never hear a lot of this stuff but my philosophy has been totally eliminate all noise and then optimise from that point on.

There is some low level circuit noise and that will certainly be dealt with but the fan noise is a little louder than that but it is quite possible those listening to amps fed via SMPS will not hear it as it would likely be buried beneath the increased noise of the power supply

I feel that the microphonics (if we can call it that) is indeed related to the heat sink, which is spring loaded to the chips, there is in fact very little effort required to wiggle the sink against the springs. I suspect the heat sink chatters against the top of the chip in sympathy with any external vibration and somehow this translates through the system, by means unknown. Pressing down on the heat sink kills the noise totally.

My intended solution is to A) remove the fan from the top of the heat sink and mount remotely above the chip. B) place small slivers of rubber or balsa between select fins of the heat sink and C) lastly find a way of adding extra pressure to the heat sink without causing any problems with board distortion etc. I will also ensure that all connections, coils and caps are very firmly mounted to the board.

Once this is dealt with residual circuit noise is next on the agenda, to that end all coils are in copper pipe tubes sealed at one end, and there will be double sided copper clad boards on either side of the amp board grounded to a single point. I am also looking at the best place to take the ground off the board, I doubt the current location is ideal, I know from Dacs and Phono pre amps that little things like that can have a reasonable bearing on circuit noise and overall sound.

The test board now has 80 hrs up so I won't add the coils or make other changes till 100 hrs is up which should be Thursday. Even then only one thing at a time. That will include Low ESR caps at the chips (as close as possible) optimisation for 26V (roughly what it runs at of the batteries), possible changes to the 5V line and power routing.

If it all works out then I will build up 6 boards for my 100 db efficient OB system.

Hey V Bro, I agree about the scope, I don't own one but a good friend who is a retired audio tech does and I am sure he would love to spend some time doing serious testing with me.

As always all input is greatly appreciated.

 

[v-bro]

The test board now has 80 hrs up so I won't add the coils or make other changes till 100 hrs is up which should be Thursday. Even then only one thing at a time. That will include Low ESR caps at the chips (as close as possible) optimisation for 26V (roughly what it runs at of the batteries), possible changes to the 5V line and power routing.

41hz AMP4 has the caps miles closer to the chip by default. Note that when placing the caps floating above the board the pin length will diminish the ESR performance.

Hey V Bro, I agree about the scope, I don't own one but a good friend who is a retired audio tech does and I am sure he would love to spend some time doing serious testing with me.

As always all input is greatly appreciated.

Okay, well I bet the guys here would love you to post here about your findings!

 

[Zero One]

V-Bro Happy to report back on the tests when done.

I was thinking of mounting the caps under the board, where the chip is, I need to check the options, I will lay the caps flat and rotate the caps to get the positive terminal as close as possible, mounting right at the chips I think would be a problem due to heatsink location I think.

Thanks for the tip.

 

[wwenze]

C) lastly find a way of adding extra pressure to the heat sink without causing any problems with board distortion etc

Washers - put them on the underside of the board and poke the push-pin through them

What's the approximate pitch of this "buzzing noise" you hear? 60/120 Hz? Or higher? I don't hear any such thing and I have 96dB/1W/1m speakers. Do you have the volume cranked up high when you hear the noise?

I'd like to replace my fan on principle, just to remove a moving part that will eventually need replacing anyway. But I never hear any buzzing.

For me the MSI fan buzz is there with no source connected and lowest gain, the frequency follows the RPM of the fan and I suspect it to be the same numerical value.

Won't get to do anymore test on that now that it's gone forever. The entire heatsink which I left on my table disappeared totally, spooky.

 

[sendler]

Not getting it

Hi Sendler My fan is the later ones not the blue one, but it is running off a totally separate battery, so PS doesn't some into it. As far as the noise of the fan itself, it is very quiet, what is able to be heard is a sound that is quiet mechanical in nature though the speaker.

I must emphasis this is very very low level stuff, but I am totally anal retentive when is comes to getting the cleanest sound possible, other wise I would never have built a totally off the grid system (including analogue and digital front ends). I know most folk will never hear a lot of this stuff but my philosophy has been totally eliminate all noise and then optimise from that point on.

There is some low level circuit noise and that will certainly be dealt with but the fan noise is a little louder than that but it is quite possible those listening to amps fed via SMPS will not hear it as it would likely be buried beneath the increased noise of the power supply

I feel that the microphonics (if we can call it that) is indeed related to the heat sink, which is spring loaded to the chips, there is in fact very little effort required to wiggle the sink against the springs. I suspect the heat sink chatters against the top of the chip in sympathy with any external vibration and somehow this translates through the system, by means unknown. Pressing down on the heat sink kills the noise totally.

My intended solution is to A) remove the fan from the top of the heat sink and mount remotely above the chip. B) place small slivers of rubber or balsa between select fins of the heat sink and C) lastly find a way of adding extra pressure to the heat sink without causing any problems with board distortion etc. I will also ensure that all connections, coils and caps are very firmly mounted to the board.

Once this is dealt with residual circuit noise is next on the agenda, to that end all coils are in copper pipe tubes sealed at one end, and there will be double sided copper clad boards on either side of the amp board grounded to a single point. I am also looking at the best place to take the ground off the board, I doubt the current location is ideal, I know from Dacs and Phono pre amps that little things like that can have a reasonable bearing on circuit noise and overall sound.

The test board now has 80 hrs up so I won't add the coils or make other changes till 100 hrs is up which should be Thursday. Even then only one thing at a time. That will include Low ESR caps at the chips (as close as possible) optimisation for 26V (roughly what it runs at of the batteries), possible changes to the 5V line and power routing.

If it all works out then I will build up 6 boards for my 100 db efficient OB system.

Hey V Bro, I agree about the scope, I don't own one but a good friend who is a retired audio tech does and I am sure he would love to spend some time doing serious testing with me.

As always all input is greatly appreciated.

I am definitely not getting any microphonic or piezo electric noise from banging on the blue heatsink with my ear touching the speaker drivers. I'll try one of my third version finned/ fan amps when I get a chance to see if they are any different. Do you have another board? Maybe there is something wrong with yours.

 

[sendler]

Passive cooling

I can confirm that the heatsink fan is audible through the speakers. When I stop the fan with my finger, the buzzing noise goes away. When I release my finger, the pitch of the buzzing rises as the fan spins back up. So the two are linked.

It isn't a big deal, but it adds to the background noise you hear when the amp isn't receiving a signal. Maybe replacing the fan with a bigger heatsink is the solution?

Your passive volume control and internal wiring is picking up the noise. The easiest and cheapest thing for us all to do is change the heatsinks to a slightly larger passive such as the $6 Zalman.

 

[teamacc]

I ran my fan off an 7805 regulator, and most of the noise went away. I think going passive is better though.

 

[Jumpin John]

I got the same result when I first fired up my Sure a couple of weeks ago. The gain is also set on low for the recommended pre-amp setting. I tried it with the fan removed which cured the problem but the heat was getting pretty intense. My next move was to remove the existing wires as close to the fan body as possible and replace them with shielded teflon insulated and wrapped wire I found in a surplus store. While the fan was off, I used aluminum foil tape to shield any part of the thing that wasn't moving. The wires were reconnected to the 5 volt and negative terminal blocks farther from the chip than the original connection and the buzz is pretty much gone. There is a very slight hiss in the left speaker which is connected close to the fan hook-up. With my ear to the right speaker, the hiss is barely audible. With the fan running, the heatsink is very cool to the touch, no meltdown imminent! I was also getting some audible distortion in dynamic bass drum on Kodo's Mondo Head SACD (which is about as dynamic as it gets). I was using a 24 volt, 600ma wall-wart until today when I received a Meanwell clone, 27 volt 13 amp smps from Modders on eBay. In short, distortion is gone and the amp sounds great. My speakers have a double voice coil base driver and need a bit of current, so I suspect that the 600ma was the problem. The amp is driving a pair of Energy Veritas speakers(87db) and the source is a Bryston BP25 pre. It is a great sounding combo, and the Sure is at least equal in hi-frequency and mid range detail to my Bryston 3B-ST ( around 120 watts) but the Bryston will obviously play louder when required and have better control of the bass. The dynamics of the Sure are amazing for an amp of that size and I think the overall sound quality to be far superior to my modded Trends or Sonic Impacts (I have 3 of those). Thanks to all of the leg work from forum members, I am replacing some of the usual suspects on the Sure board. The input caps are Black Gate 4.7 uf N's( contrary to conventional wisdom of no electrolytics in the signal path) because I have a few kicking around, they are small, and I like the sound with Tripath amps. The tank caps are two Pany FC 2200 uF 35v, overkill probably, but again they were what I had. I have some coils coming from Argenhelder because they were mentioned here a few times and they are easy to order on fleabay, quite scientific. The case is a work in progress but I am slowly getting there though I kind of like the bare board look, with wires and caps hanging out.

 

[MikeHunt79]

Looks like it is running on a very high frequency, there's just 1000uF 35V inside now.

Looks like you can drill a few extra holes there in that PCB to swap it for a bunch of smaller caps...

EDIT: I see a 100uF 50V cap on the output as well....

Hi, I eventually got around to finding the switching freqency, with a little trial and error:

An externally hosted image should be here but it was not working when we last tested it.

(apologies for the poor pic)
I measured the voltage on one of the legs of the biggest IC. I think it's either 66KHz or 132KHz, which I think is higher than the Meanwell SMPS, and it seems to sound a little nicer with this SMPS, but there is very little in it.

I'm not really familiar with SMPS's in the same way that I'm familiar with linear PSU's, but am I right in thinking adding too much capacitance would be a bad idea? Are there any calculations or formulas I can use to work out a good figure to aim for?

Right now my plans are to leave the SMPS alone, and have the Sure board with 3000uF of capacitance, so around 4000uF of capacitance in total... I guess thing should be more than enough assuming the switching frequency is 60KHz+?

 

[kristleifur]

(Anecdotal: I'm running a pair of 41Hz Amp11's at 20V without any heatsink at all. They have been running like that for at least half a year. No trouble at all. ... I can't imagine why the Sure needs a fan on the heatsink.

By which I mean: The fan is probably not needed at all. Except in a very cramped and closed enclosure.

 

[sendler]

Failures

(Anecdotal: I'm running a pair of 41Hz Amp11's at 20V without any heatsink at all. They have been running like that for at least half a year. No trouble at all. ... I can't imagine why the Sure needs a fan on the heatsink.

By which I mean: The fan is probably not needed at all. Except in a very cramped and closed enclosure.

That's weird because the 4X100 thread reports numerous failures due to the warped piggyback board not allowing a close seating of the heatsink to the outside two chips. And, Sure went to the fan after first selling the 2X100 with a small fanless heatsink and having some failures when used with voltages beyond 24v. I am hoping to run the newest version heatsink without the fan because they do pollute the critical 5v supply unless you install another dedicated supply. I have some amps in the box but haven't tried it. I will measure the temp and report back. I have been wondering if Sure's biggest problems were caused by the thick rubber adhesive they used to use to glue the heatsinks on with which they have gone away from on the newest heatsink.