Could you fit one Modushop 250 X 80 X 40 heatsink inside the Galaxy 330x280 chassis? If you used fully vented top and bottom panels, that might work. Two 250mm sink brackets would allow you to attach the top and bottom to the sink. That would require a couple new holes to drill per top/bottom panel, but not very much customization. Next up in size for the Galaxy is 330x350, I think.
Alternatively, you could find a 280x80 heatsink somewhere, drill holes for the front and rear panel attachment points, and and make your own L brackets with aluminum for the top/bottom attachments.
Alternatively, you could find a 280x80 heatsink somewhere, drill holes for the front and rear panel attachment points, and and make your own L brackets with aluminum for the top/bottom attachments.
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Scott,
that aluminum bar 0.75"/3"x10" by itself is a great heat spreader and a good heatsink too, together with one of the sides of your case will make a good enough heatsink.
Lowering the secondary voltage to 2x20-22v for sure will make a difference. 300va could be lowered to 250va.
https://diyaudiostore.com/collectio...oducts/mini-disspiante-2u?variant=12171525828 is not good option for you? I know it cost more...
that aluminum bar 0.75"/3"x10" by itself is a great heat spreader and a good heatsink too, together with one of the sides of your case will make a good enough heatsink.
Lowering the secondary voltage to 2x20-22v for sure will make a difference. 300va could be lowered to 250va.
https://diyaudiostore.com/collectio...oducts/mini-disspiante-2u?variant=12171525828 is not good option for you? I know it cost more...
asuslover:
Terrific -- that's what I had hoped to hear! I do hope your confidence is based on experience. Lowering the secondary voltages to 22V shouldn't be a problem. I'd prefer to keep the toroid at 300VA if possible, as my plan has been to order a custom unit from Antek that would also include a second (low current) pair of 13V secondaries that will power the buffers, source relays and front panel LEDs; happily, Antek doesn't balk at custom orders (but they don't offer 250V toroids). And, of course, the second pair of secondaries will steal a little power from the first pair.
I did look at the mini-dissipante chassis but its internal width is simply too narrow to fit all that I want to cram into this project (and my small apartment-dwelling younger daughter would really prefer something narrower than a standard full width chassis). Yes, that's a little madness talking, but testing my limited skills with each successive project is part of the fun, and I really want this amp to be a noticeable improvement over the LM3875 amp my daughter has been enjoying for the past 14 years.
Thanks for the feedback!
Kay Pirinha:
I didn't think to push back on your initial assumption regarding total dissipation until I had already responded and appreciate your following up. If it turns out that the aluminum bar is inadequate, I'll have to build yet another amp for my kid. Honestly, I can think of far worse problems to have. And I'm comfortable with the risk. Thanks for the honest feedback.
von Ah:
Wow, that's a cool idea but a little more involved than I would prefer. You get bonus points for inventiveness!
I'll post photos when the project is successfully completed.
Regards,
Scott
Terrific -- that's what I had hoped to hear! I do hope your confidence is based on experience. Lowering the secondary voltages to 22V shouldn't be a problem. I'd prefer to keep the toroid at 300VA if possible, as my plan has been to order a custom unit from Antek that would also include a second (low current) pair of 13V secondaries that will power the buffers, source relays and front panel LEDs; happily, Antek doesn't balk at custom orders (but they don't offer 250V toroids). And, of course, the second pair of secondaries will steal a little power from the first pair.
I did look at the mini-dissipante chassis but its internal width is simply too narrow to fit all that I want to cram into this project (and my small apartment-dwelling younger daughter would really prefer something narrower than a standard full width chassis). Yes, that's a little madness talking, but testing my limited skills with each successive project is part of the fun, and I really want this amp to be a noticeable improvement over the LM3875 amp my daughter has been enjoying for the past 14 years.
Thanks for the feedback!
Kay Pirinha:
I didn't think to push back on your initial assumption regarding total dissipation until I had already responded and appreciate your following up. If it turns out that the aluminum bar is inadequate, I'll have to build yet another amp for my kid. Honestly, I can think of far worse problems to have. And I'm comfortable with the risk. Thanks for the honest feedback.
von Ah:
Wow, that's a cool idea but a little more involved than I would prefer. You get bonus points for inventiveness!
I'll post photos when the project is successfully completed.
Regards,
Scott
Thanks for mentioning this because, for certain reason, I couldn't see the original post.Indeed, what to say except the greatest Nit-picker of all times has made a colossal mistake, again. No wonder; to make correct assumptions regarding heat dissipation one must understand at least basics of physics/thermodynamics, or at least have enough decency to refrain from using uneducated guesses as a substitute for real knowledge.
Thanks again
Well, as an honest nitpicker I stood corrected at least, which I usually do. This is in a very contrast to arrant cowards who just limit themselves to blame others for something.
Indeed, what to say except the greatest Nit-picker of all times has made a colossal mistake, again. No wonder; to make correct assumptions regarding heat dissipation one must understand at least basics of physics/thermodynamics, or at least have enough decency to refrain from using uneducated guesses as a substitute for real knowledge.
Thanks again
Now it's your turn to tell all the others en detail where exactly was my mistake.
It depends on how hard you drive the amp.
Also no matter how tight you are for space you can always add a small fan. You get some crazy small fans these days.
That are silent. Even the smallest movement of air inside the amp makes a world of a difference.
I would build it and if its over heating would add that fan. I like to have a display on all my amps which shows voltage / amps / and temp. The Temp display also controls the fan. i.e. turn on at 60c turn off at 45c.
All these add on boards are a few bucks from amazon or ebay.
That bar is quite thick. So I would also look into cutting a criss cross pattern of groves on it to form some kind of fins to increase the surface area. I would use my angle grinder mounted to a stand to do it in a pinch. There are other ideas like giving it a rough texture, drilling holes anything that would increase its surface area.
chinoy (et al):
Until a couple of days ago, this project had essentially stalled. The premise for it was that my daughter and I would build it together (just like its predecessor, which we built 14 years ago). I'm retired and have plenty of time on my hands but my daughter, a very busy journalist who lives 100 mi / 160 km away, has struggled to find the time to visit. She's home with us briefly and, yesterday, we spent the day soldering, making great progress. She seems energized and committed to our next build session, and I am optimistic we can complete this integrated amp project in the next 8-10 weeks.
I very much appreciate the counsel regarding various ways to cool the heatsink and improve its efficiency. As you suggested, I'm going to wait until there's an issue before adding a fan or cutting/drilling into the heatsink. That said, it's good to know we have options should problems arise.
Regards,
Scott
Until a couple of days ago, this project had essentially stalled. The premise for it was that my daughter and I would build it together (just like its predecessor, which we built 14 years ago). I'm retired and have plenty of time on my hands but my daughter, a very busy journalist who lives 100 mi / 160 km away, has struggled to find the time to visit. She's home with us briefly and, yesterday, we spent the day soldering, making great progress. She seems energized and committed to our next build session, and I am optimistic we can complete this integrated amp project in the next 8-10 weeks.
I very much appreciate the counsel regarding various ways to cool the heatsink and improve its efficiency. As you suggested, I'm going to wait until there's an issue before adding a fan or cutting/drilling into the heatsink. That said, it's good to know we have options should problems arise.
Regards,
Scott
So have the original boards and have completed wiring them up. This is my first Chip amp and from what I have seen they can be touchy. Any special instructions on power on for first time. Should you power on at lower PS voltages like +/- 12vdc?? I have the servo version wired up. Did I read correctly that I need to leave out C17 and C2 and jumper to ground??
Thanks
Thanks
Ok. I did try before I read this though. At steady state I was getting 4mV offset. But I have strange behavior playing music on 8 ohm speaker. 30vdc rails. When I turn up music and drum or bass sound is beating the amp cuts out during the thump of bass, keeps rhythm of the bass line. Turn it down some and it plays normal. It's not very loud maybe low 80dbs
Hello everybody!
After reading through all the posts in this thread, phuuu... I'm ready to start building the X-Mas Amp.
What an interesting project with the TDA7293 and what a great work, some have put into this.
Thanks Dibya, Jhofland and everyone else who contributed to this. 🙏
I pour some Jul Glögg (mulled vine) and grab some gingerbread cookies and get started. 🌲❄️☃️
Best Regards!
Örjan
After reading through all the posts in this thread, phuuu... I'm ready to start building the X-Mas Amp.
What an interesting project with the TDA7293 and what a great work, some have put into this.
Thanks Dibya, Jhofland and everyone else who contributed to this. 🙏
I pour some Jul Glögg (mulled vine) and grab some gingerbread cookies and get started. 🌲❄️☃️
Best Regards!
Örjan
Almost done with the circuit boards! Unfortunately, I had forgotten the copper wire to L1, 1µH.
Have ordered a roll of copper wire today.
Couldn't decide which version to build of Xamp. I have three circuit boards, so I build a board with carbon film resistors for R1, R2, R3, R4 and R6.
"As Dibya pointed out, and spec'd in notes on schematic and BOM, the gain setting resistors R1 and R3 should be carbon film for best harmonic profile of dominant H2 vs H3"
The second board I build with Metal film 1% and 0.1% resistors
Will be interesting if I can hear any difference.
The amplifier that sounds best to my ears, I will build on the third card.
Have ordered the following and with any luck will arrive before Christmas:
• Chassis for the output stages
• Components for the Power Supply
Wishing everyone a Very Merry Christmas! ❄️🌲☃️🎅🎁
Have ordered a roll of copper wire today.
Couldn't decide which version to build of Xamp. I have three circuit boards, so I build a board with carbon film resistors for R1, R2, R3, R4 and R6.
"As Dibya pointed out, and spec'd in notes on schematic and BOM, the gain setting resistors R1 and R3 should be carbon film for best harmonic profile of dominant H2 vs H3"
The second board I build with Metal film 1% and 0.1% resistors
Will be interesting if I can hear any difference.
The amplifier that sounds best to my ears, I will build on the third card.
Have ordered the following and with any luck will arrive before Christmas:
• Chassis for the output stages
• Components for the Power Supply