I have some CAD plans for a heatsink spacer block if anyone is interested. It can be made from 12mm x 10mm thick aluminum bar stock. Basically a 50mm long x 12mm x 8.7mm thick (at thickest point) bar with two M3 holes 36mm apart. The elevated mesa contacts the thermal pad on the TPA3255 chip. 0.3mm thick silicone spacer heat sink insulator sheet needs to be used in between the block and the chassis along with nylon shoulder washers to prevent the dirty chassis ground from contacting the clean amp ground. This block is meant to be used with 10mm long M3 standoffs (hex brass ones) on the 4 corners of the board to clamp it to the chassis with enough pressure to clamp the silicone thermal spacer sheet in place.
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It seems that this amp sounds pretty good with a 400VA linear trafo making 53vdc using an LT4320 active bridge and 44,000uF of bulk capacitance. Even the buffer uses some nice Vpower power supply boards. This amp on a plank is working really well and is reported to have an inaudible background noise level. Cannot tell it is even on. This amp shown here is courtesy of Vunce. Nice build Vunce!
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Sorry, it’s many weeks away. Due to the holidays, the manufacturing house in CA won’t be able to start until first week of January. The lead time of having mass production on a complex board like this is long because a trial unit has to be built with the automated pick and place machine, then heated and then tested. Then inevitably, a part of two has an error (200+ components). That must be tracked and found. Once confirmed then the whole batch is made. It took 3 months last time. I hope it’s going to be 2 months this time. If we are lucky maybe 6 weeks. Some of it is scheduling as there are competing assembly line jobs.
The unit above is from the first batch earlier this year.
The unit above is from the first batch earlier this year.
44,000 uF …
What is the standard amount of capacitance?
This is much higher - what was the reasoning? at some stage could this build be compared to the standard, on some music that’s bass heavy?
Hi otto88,
I wanted to try a linear psu with this amplifier. I utilized screw terminal caps I have on hand and cobbled together a nice psu. You could definitely use smaller caps if you wanted. Even with this busy looking setup, this is one of the quietest backgrounds I’ve had with an amplifier.
I will try an SMPS unit also.
I wanted to try a linear psu with this amplifier. I utilized screw terminal caps I have on hand and cobbled together a nice psu. You could definitely use smaller caps if you wanted. Even with this busy looking setup, this is one of the quietest backgrounds I’ve had with an amplifier.
I will try an SMPS unit also.
Hey folks, free TDA7293 Xmas amp pcb giveaway here:
Xmas Amp - Dibya's TDA7293 by Jhofland
Merry Christmas!
Xmas Amp - Dibya's TDA7293 by Jhofland
Merry Christmas!
Recently, I have tried Micro-Audio (Cresnet) SMPS630-SO and very happy with it. Super quiet and it has all the features that make it user friendly. Like remote turn on. Auxiliary regulated +12v, +/-12v, 3.3v and 12v is always on. Also open collector remote output to shut down a relay. It drives the BTSB in an always on config and totally avoids turn on or off pop. I think for causal domestic use, a 600w PSU is plenty for two of these amps. They run more than say 100w per channel so 400w should be ok. Sami, the owner of Cresnet is super helpful and responsive to DIY needs. There are 800w ans 100w models too I think.
A copper shim is fine - just make sure it doesn’t bump into nearby SMT caps on the underside. I found that genuine AMP brand Faston spades make excellent thermal conductor pads for this. Two of them stacked gives them needed offset from a heatsink. Combine with thicker one and 10mm standoffs.
A copper shim is fine - just make sure it doesn’t bump into nearby SMT caps on the underside. I found that genuine AMP brand Faston spades make excellent thermal conductor pads for this. Two of them stacked gives them needed offset from a heatsink. Combine with thicker one and 10mm standoffs.
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hi there
i did some reading about step-up converters (planning to use one in my setup) and it seems that those are incapable to deliver advertised power (talking about popular units from aliexpress).. and it's not a surprise
. yet what's strange is how much power those produce
limiting factor is input current; 1.2kW units produces ~300W max (probably not safe for long term usage), so keep that in mind
below is video review of 1.2kW unit
Review of 1200W 20A DC Input 8V-60V Output 12V - 80V Boost converter - Robojax - YouTube
i did some reading about step-up converters (planning to use one in my setup) and it seems that those are incapable to deliver advertised power (talking about popular units from aliexpress).. and it's not a surprise
. yet what's strange is how much power those producelimiting factor is input current; 1.2kW units produces ~300W max (probably not safe for long term usage), so keep that in mind
below is video review of 1.2kW unit
Review of 1200W 20A DC Input 8V-60V Output 12V - 80V Boost converter - Robojax - YouTube