" ... peel back the clear covering with tweezers ... The smaller the part, the more care you need to exercise because it's easy to lose them. ... be gentle ... You only need enough pressure to pick them up. ..."
That's another reason for using the parts packages of the R1206 & C1206 and larger variety = the plastic and tape is thicker and much easier to split off single parts, one at a time ...
" ... Avoid drinking beverages with caffeine too ..." ... I suppose this means I will have to give up cigars too ...
Tips? ... Use the larger surface mount devices where ever possible ...
That's another reason for using the parts packages of the R1206 & C1206 and larger variety = the plastic and tape is thicker and much easier to split off single parts, one at a time ...
" ... Avoid drinking beverages with caffeine too ..." ... I suppose this means I will have to give up cigars too ...
Tips? ... Use the larger surface mount devices where ever possible ...
Got back on this today, and this is slow work. I can do about a dozen of these SMDs at a time then I have to stop and rest. It's going to look pretty ugly once finished, so no close up pics from me, but hopefully it will work okay. Just a hint, start with the 0ohm links first to get used to handling the tiny pieces, if you drop one and lose it as I did you can just link the pads with a tiny bit of wire.
I've been playing the amps for a few days now and they were playing nicely until I went to put one amp into standby mode. To put the amp into standby mode (power is still applied to the amp but the outputs are put into a high impedance state) you simply short the reset pin of the TAS5261 to ground. On one amp I soldered wires and a switch to the reset through holes on the board and haven't had any problems switching that amp back and forth so far. On the other amp I just two wires that I twist together since I couldn't find another switch. Well I went to twist them together about 15 minutes ago and made some intermittent contact between the wires and got another impressive fireworks display from the TAS5261 chip and both of the zener diodes in the gate driver supply circuit I was using my 46V supply and playing music when I tried to put the amp into standby. Apparently, the TAS5261 does not like it when the signal on the reset pin bounces. You'd think these chips would be a little more robust even though they are meant to be controlled by a microcontroller. Regardless, it's time to replace some more components...
I was using my 46V supply and playing music when I tried to put the amp into standby. Apparently, the TAS5261 does not like it when the signal on the reset pin bounces. You'd think these chips would be a little more robust even though they are meant to be controlled by a microcontroller. Regardless, it's time to replace some more components...Hi Brian,
you are so good with soldering iron that you have no worries about flames.
I continue to suspect the unregulated PS. Here we have easily +/- 20% variability with our 220V ac. From 46Vdc it would be very easy to have here 40V on daylight and 52V in the night.
Remember that, without feedback, every variation in PS voltage is transmitted directly to the amp.
Did you make some serious sonic test with these amps? I mean with decent source and speakers.
Ciao
Thomas
you are so good with soldering iron that you have no worries about flames
.I continue to suspect the unregulated PS. Here we have easily +/- 20% variability with our 220V ac. From 46Vdc it would be very easy to have here 40V on daylight and 52V in the night.
Remember that, without feedback, every variation in PS voltage is transmitted directly to the amp.
Did you make some serious sonic test with these amps? I mean with decent source and speakers.
Ciao
Thomas
I will get back on this project this week, all the SMDs are mounted apart from the 100n caps, and the through hole just should be easy enough. I had a setback as the junkbox traffo I was going to use seems to have a short somewhere, found that out when I built the PSU, so I need to pull one from something else for testing.
well, I have many questions.BWRX said:
In the TAS5261 data sheet the R3 is 33kohm, but in EVB pdf is 22kohm (OC_ADJ pin - pin 7). This resistor determines fs? why the difference? How to dimension it?
Maybe I'll use a fs of 192kHz or less, because I'm making a T class amplifier with click modulation.
And there is more differences on both schematics (TAS5261 and EVB pdf files). Witch one to follow?
There are some components on the EVB schematic that they say "Not used". Why they were on the schematic if are not used?
How the protection & I/O Logic, VREG, UVP, etc blocks work?
I want more details on internal schematic of TAS5261 so I can make some alterations if needed and understand some other things for my work.
nelsonmf said:
The value of that resistor sets the overcurrent limit threshold. It has nothing to do with fs. There is a table of resistor values and resulting threshold currents in the datasheet.
nelsonmf said:
The fs is solely determined by whatever modulator you choose to use. The TAS5261 is not an all-in-one solution. You need some front end to convert the audio signal into a 0-3.3V PWM signal for the TAS5261. The TAS5261 is only meant to work with PWM inputs up to 384kHz.
nelsonmf said:
Generally speaking it's better to follow the EVB design since they have already tested it. You can of course implement the chip differently than what they recommend. Their design is certainly not the only way the chip can be used.
nelsonmf said:
The I/O digital logic circuits and analog input circuitry operate from the 3.3V supply. The other protection circuitry most likely operates from the 12V supply. How the various features work is described in the datasheet.
nelsonmf said:
I would like more details too! Unfortunately these are not easy to get unless you know someone on the inside or are on the inside.
why metal film resistors?
Hi,
Brian, maybe you can help me.
Do you know if it is really necessary to use metal film resistors with TAS5518-5261K2EVM?
I was wondering if I can use thick film resistors. But the temperature coefficient is much higher than metal film resistors. Is this parameter important in this project?
Nelson
Hi,
Brian, maybe you can help me.
Do you know if it is really necessary to use metal film resistors with TAS5518-5261K2EVM?
I was wondering if I can use thick film resistors. But the temperature coefficient is much higher than metal film resistors. Is this parameter important in this project?
Nelson
Besides me? I don't know, I haven't heard anything from anyone. My one is still working fine but I don't have a sub to use with it at the moment. I didn't get around to fixing the other one that I blew up.
Speaking of this project, Gerd, I got the package I sent you back in December. I emailed you but didnt get a reply.
Speaking of this project, Gerd, I got the package I sent you back in December. I emailed you but didnt get a reply.
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