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3E Audio 260-2-29A : TPA3255 / HA3588 CoilCraft / PFFB Fully differential.

CamRector

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Here's my effort at a 6ch build with these boards.

Some notes:
  • Yes, a little more cable management would be good. I've tried to make sure cables are twisted and there's no crossing of the signal wires with any other wiring.
  • This is a low power build, utilising a Meanwell GST220A36-R7B 36v AC adapter. It's plenty of power for my use at home: active 3 way with high-efficiency drivers, high passed at 100hz. Subs are on a separate amp. Although not technically difficult, I had a strong preference not to do any AC/mains wiring myself.
  • I left capacity in the chassis for a 4th board if I ever need another 2 channels
Very happy with how it's turned out. I won't claim to be able to hear the low distortion, but the low noise is undeniable: effectively silent with my ear 10cm away from a 107db tweeter.

View attachment 346722
Awesome build! Man how do you guys get those wires twisted so good?!
 

antcollinet

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Awesome build! Man how do you guys get those wires twisted so good?!

Normal technique is hold one end of the wires somehow (Vice, pliers, tied to something). Put the other end of both wires in the chuck of a drill. Spin the drill. Don't over twist to the point the wires are strained.
 

rp86

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Interesting where did you find those XLR/TRS plugs with integrated JST connectors ? Any link ?

View attachment 346724
These are Neutrik NCJ6FA-V-0 with a very simple custom PCB I made. EasyEDA and Gerber exports attached if anyone wants to use. (Use at own risk, I'm not an engineer)

1706869489717.png
 

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rp86

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Awesome build! Man how do you guys get those wires twisted so good?!
Thanks! Flexible wire was definitely the key for me, it made it quite easy. My previous attempt at an amp build using stiff wire was horrific.

Normal technique is hold one end of the wires somehow (Vice, pliers, tied to something). Put the other end of both wires in the chuck of a drill. Spin the drill. Don't over twist to the point the wires are strained.
Wish I'd known that 2 weeks ago! Thanks for the tip!
 
OP
daniboun

daniboun

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These are Neutrik NCJ6FA-V-0 with a very simple custom PCB I made. EasyEDA and Gerber exports attached if anyone wants to use. (Use at own risk, I'm not an engineer)

View attachment 346775
Nice done and could be very useful --)) thx
 
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daniboun

daniboun

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This is a low power build, utilising a Meanwell GST220A36-R7B 36v AC adapter. It's plenty of power for my use

220W / 3 (36V / 6,1A) will provide only 73W / Module; more or less 2A / Module...
In my humble opinion you are not far from 35W / 4R and around 30W / 8R. Is that enough for you?
 

rp86

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Yeah, plenty for my use. Nominal sensitivities of the drivers running off this are 95db, 95db, 107db; absolute minimum sensitivity drops to 90db within any driver's passband. (FaitalPro 8HX200 coax and 8PR200 midbass).
 

longwaytofall

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Hello all,
I am building a pair of 4 channel amps and a single channel amp for car audio use. Each of the 4 channel amps uses one of these 260-2 units, and the single channel will use a 480-1. This is my first time building amplifiers, and I have plenty of questions about many things, but the roadblock I have currently is doing the differential to single ended input conversion. The car audio DSPs only have single ended output, unfortunately, so I ordered the 1612 OP amps to add to the boards. The user's guide is not very clear, unfortunately, as they show the U1 and U2 sockets, but not U3 and U4, where the op amp and resistor are added. Further complicating the matter is that U1/U3 and U2/U4 are not identical, so it is unclear to me based on the guide what exactly I should be doing. Like I said, this is my first time and maybe it is clear what needs to be done by those with more experience. I am attaching a photo of the sockets, would someone be able to circle and draw arrows where I should be moving the resistors?
Thank you!
AMP.jpg
 
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daniboun

daniboun

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Hello all,
I am building a pair of 4 channel amps and a single channel amp for car audio use. Each of the 4 channel amps uses one of these 260-2 units, and the single channel will use a 480-1. This is my first time building amplifiers, and I have plenty of questions about many things, but the roadblock I have currently is doing the differential to single ended input conversion. The car audio DSPs only have single ended output, unfortunately, so I ordered the 1612 OP amps to add to the boards. The user's guide is not very clear, unfortunately, as they show the U1 and U2 sockets, but not U3 and U4, where the op amp and resistor are added. Further complicating the matter is that U1/U3 and U2/U4 are not identical, so it is unclear to me based on the guide what exactly I should be doing. Like I said, this is my first time and maybe it is clear what needs to be done by those with more experience. I am attaching a photo of the sockets, would someone be able to circle and draw arrows where I should be moving the resistors?
Thank you!

Try to zoom in here this could help you.
This user just added Soic8 to DIP8 adaptors here. The module is configured for SE mode

photo_2023-10-16_15-16-09~2.jpg
 

longwaytofall

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Thank you so much! The manual is much more clear now, I think the confusion came from the fact that they show removal of resistors from U2 and adding one on U1. In reality, they are removed from U1 and added back to U1. Same for U2. Maybe the manual can be updated? Many thanks again.
 

Treborha

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Is a 1g tube of thermal paste enough to cover the entire surface of the amplifier's heatsink?
 

longwaytofall

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I used 5g, along with 4 small thermal pads (I had leftover from mounting lm3886 to heatsink) in the corners to be sure I was spacing it away from the chassis. The heat sink is connected to the input ground, and while I am still learning about ground loops and the like, I figured isolating it and being able to decide where I wanted to ground it would be preferable. All that said, it looks like the heatsink is only making contact with the board in a small area, so if you used a small strip of thermal paste in that area I'm guessing it would be fine.
 

jkorten

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Interesting where did you find those XLR/TRS plugs with integrated JST connectors ? Any link ?

View attachment 346724
For my amps I bought silver coated multi conductor copper wire and crimped the JST connectors on and soldered the other ends onto the XLR connector. You can buy the JST and the wire at Digikey. But you do have to have a rather expensive crimping tool. Sometimes you can find them on ebay.
 
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daniboun

daniboun

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For my amps I bought silver coated multi conductor copper wire and crimped the JST connectors on and soldered the other ends onto the XLR connector. You can buy the JST and the wire at Digikey. But you do have to have a rather expensive crimping tool. Sometimes you can find them on ebay.
I am also making my own cables. Check my Bamboo and Ash projects )
 

CamRector

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Just waiting on my IEC.
Nothing too special here
4channel 3e
Micro Audio SMPS1k
Mundorf caps
I really like these Ghent cases. Not flashy but super clean install.
 

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daniboun

daniboun

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Just waiting on my IEC.
Nothing too special here
4channel 3e
Micro Audio SMPS1k
Mundorf caps
I really like these Ghent cases. Not flashy but super clean install.

Well done ) When you have time to listen, please share your feelings )
 

brunes

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Mostly finished. Dual mono with micro audio smps. Modushop case. Drilling the holes for the 3e boards was a bit tricky and not perfect but they are in! Thanks for all the help and support from you guys.
just started to listen...
 

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daniboun

daniboun

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Mostly finished. Dual mono with micro audio smps. Modushop case. Drilling the holes for the 3e boards was a bit tricky and not perfect but they are in! Thanks for all the help and support from you guys.
just started to listen...

Very nice, I see that you have carefully wrapped your cables. The result is really cool! Well done man!
Keep us informed of your listening now) :)
 
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