TC Electronics Switch amp

[darkfenriz]

Originally Posted by Kurt von Kubik

The point is that the switch does not perform significantly worse @ high power than @ low power delivery,...

Actually there is a significant degradation of switching performance, when an amp enters continous inductor current mode and this gets worse with inreasing current.
But I agree that oversizing is not needed nor desirable, because switching mosfets work fine with their square SOA.

[Kurt von Kubik]

Originally Posted by darkfenriz

Actually there is a significant degradation of switching performance, when an amp enters continous inductor current mode and this gets worse with inreasing current.
But I agree that oversizing is not needed nor desirable, because switching mosfets work fine with their square SOA.

Yes - Right you are!
But not with this one, and that is due to the 3 different feedback loops, as mentioned in the first post.
The only thing I think it will not like, is purely capacitive loads, as it is not designed to feed anything like that.

[Hurtig]

Originally Posted by ttako

Hi,

is this 60A peak = 42.5Arms????
meaning the max Prms to be 42A x 42A x 4Ohm in bridge?? (=7700W) meaning, that just the DC voltage rails are the limiting Factor? (70V/1.4142 x 2= ca 100V in bridge mode =2500W rms??)
i highly doubt these 60A peak seeng just 1 TO220 device there per switch...

Thanks,

Tamas

It will deliver 60Amps peak! Only for short periods, but still... It does 60Amps.

The module is rated at 230 watt@8ohms continuously. My guess is 450 watt@4ohms.
We have been playing on 4 ohm speakers at levels where we need to leave the room, and still the temperature of the module is less than 30 degree C.

I think you are looking for a non-existing problem. We have not yet found any music, that will the amp more than 30 degree C, when mounted on a small piece of aluminum (No heatsink). And trust me... we did try!

[KLe]

Hi Kurt

Is this a brand new module with the same name, ie ZapPulse 800XE, incorporating the new technology?

Or the old module, ie ZapPulse 800XE, incorporating the new technology?

thanks

[Kurt von Kubik]

Originally Posted by KLe

Hi Kurt

Is this a brand new module with the same name, ie ZapPulse 800XE, incorporating the new technology?

Or the old module, ie ZapPulse 800XE, incorporating the new technology?

thanks

Hey Kle!

It is the current module incorporating the 3 feedvack loops, I do not really know if there was an earlier module, since I´ve never really had any interest in LC gear.

It was first when the designer showed me the current module and told about the peticulars about it, and also made me listen to it, that I became interested in the technology.

Originally he was asked to look at the LC modules, to see if they could also be incorporated in some of TC´s pro-gear i.e. studiomonitors, guitar amps, and Lab Gruppens PA amps and so on. But they were discarded all of them, because of lack of stability amongst other things.

So he had to start of from scratch, and I think the result is impressing, at least when a high quality buffer and good suplies are used.

[AP2]

Hi,
this module is good but ...I think that is not new technology. 3 FB are good and not easy to do, one for digital to digital to adjust the stretch near the rail voltage (PWM) and the other two (when you can do) fixed a few little things .. including the filter(Toroidal) response at audio frequencies.
Problem is PSU for amplifier not for ..lamp!
Best Regards

[Kurt von Kubik]

Originally Posted by AP2

Hi,
this module is good but ...I think that is not new technology. 3 FB are good and not easy to do, one for digital to digital to adjust the stretch near the rail voltage (PWM) and the other two (when you can do) fixed a few little things .. including the filter(Toroidal) response at audio frequencies.
Problem is PSU for amplifier not for ..lamp!
Best Regards

Whether this is new technology or not, I do not really know.
But the fact is, that 2 feedback loops was patended by B&O and is still the foundation of ICE power, which by far is the most powerfull and stable class D for general purpose.

The TC takes this a bit further, by incorporating the 3.rd loop, which provides dampingfactor hundreds of times larger than all other class D amps, and also THD + N is pretty impressing.

The powersupplies though are IMHO pretty much a matter to consider, just as well as a really good buffer is.

Btw. TC patended the technology, which might be an indicator of first time ever.

[Eva]

The two feedback loops on ICEpower are redundant. The same result may be achieved with a single post-filter loop and an output filter and layout having low parasitics. That's UcD, although it may be considered as having two loops because the signal taken from the output follows two different paths. In general, I think that a "single" feedback loop (like that) can do it all, but it may include several poles.

The 60A peak current capabilty may easily be real, although that's not very reliable for one pair of MOSFET with such a small heatsink, unless there is time/temperature dependent current limiting. But then the modules should also be rated at 2 ohm, and they aren't. Also, output coils don't look like capable of handling more than 10A rms or so for some time.

For example, my current project can do around 5kw on 2 ohm for 1 second (with time-dependent true-RMS current limiting to protect not only the amplifier but the power source and the load ). Current limit is 75A peak and 25A rms long term, but that's achieved using pairs of parallel MOSFET, and 13 AWG wire on output coils. There are low cost tricks to calculate rms current without expensive multiplier ICs.

[Kurt von Kubik]

Originally Posted by Eva

The two feedback loops on ICEpower are redundant. The same result may be achieved with a single post-filter loop and an output filter and layout having low parasitics. That's UcD, although it may be considered as having two loops because the signal taken from the output follows two different paths. In general, I think that a "single" feedback loop (like that) can do it all, but it may include several poles.

The 60A peak current capabilty may easily be real, although that's not very reliable for one pair of MOSFET with such a small heatsink, unless there is time/temperature dependent current limiting. But then the modules should also be rated at 2 ohm, and they aren't. Also, output coils don't look like capable of handling more than 10A rms or so for some time.

For example, my current project can do around 5kw on 2 ohm for 1 second (with time-dependent true-RMS current limiting to protect not only the amplifier but the power source and the load ). Current limit is 75A peak and 25A rms long term, but that's achieved using pairs of parallel MOSFET, and 13 AWG wire on output coils. There are low cost tricks to calculate rms current without expensive multiplier ICs.

Whether the modules can handle the power specified or not, I do not know, since I did not measure it, but I have no reason to doubt it what so ever. They are indeed very strong.

About the multiple feedback loops vs. only one, then this is THE item in class D amplification.
A feedbackloop around the LPF filter in the output will always be slow, and therefor be audio frequencies only. This given the output impedance will rise with frequency, typical the amping factor ends up around 1-10 @ 20KHz or even worse.
In addition stability is poor.
ICE Power with its extra loop, is both very stable and also has a smoother decrease in dampingfactor than alternatives.
The TC module though has an outputimpedance @ 1KHz measuring a few µ Ohms, giving it several millions in dampingfactor, of which tens of thousand are still available @ higher frequencies.
When listening to it, this is excactly what comes to mind, since it starts and stops completely undramatic and low level information is stunning.

My other amplifier is a huge class A amp rated @ 2*100 Watts of class A power @ 8 Ohms. It can deliver 60A for ever p.ch , and can with easy drive ½ Ohm speakers (of course this would not be class A anylonger). The dampingfactor is around 400 even though it is a non feedback design. So this is a pretty strong amp. But the TC does not seem any weaker, there is sonic differences though, but the strengt and authority of these amps are of comparable magnitudes.
That is what originally impressed me about this module, later on performance has been bettered due to extra attention payed to both supplies and input buffer.
I think TC somewhere has a more detailed datasheet on the module, than the specs supplied by their LC outlet, but unfortunately I cannot seem to find it anywhere.

[AP2]

Hello, I agree with EVA for FB on ICEpower.
Let me clarify a point about class D amplifiers
500w to Kw for commercial audio, requires to solve several problems to class D for audiophile performance.
I concentrated my resources to design new systems of protection for high power, short cut at max power, and innovative clip-control, when audio envelope force HI-current.(I not decrease current but audio signal) in realtime.
I find it fascinating at the time resolve some intrinsic defects of class D (as compared to professional class AB for audiophile). .. former jazz sound reflected lower resolution at high frequencies, voice over 70% of pwm ... contains many harmonics and sound is not pure. raising the percentage of PWM, dramatically increases the IMD and finally, when suddenly we are on high efficiency. what good is power after 80% of the PWM if the sound sucks on this section? (thermal has already won).
-----
For SMPS, all in the market, if carefully measured the amp .. I would take it and run it from windows (to be honest) only for high power are good.
a company is launching a new power supply on the market, truly revolutionary. no inductors and toroids, tested on mospower class AB, delivers 500W RMS (4R) without ripple and EMI.
see audiopower.it
I learned that is based on a new technology "RIPS"(Rotary ignition Power system), the generator current is modulated by the current from amplifier up to 100kHz.
I asked for a DPS-600 Amplifier to measure it ... let's see what happens.