Phew, that is a difficult question Mike 
. I have to say that the differences are minute. However, I can mention that the TDA7294 has more power reserve than the LM1875 amps; it can go louder without distortion. Not that I play my music that loud, but still. The TDA7294 is highly comparable to the LM3886 and LM4780 (basically two LM3886's in one package) with sonical qualities and power. With optimal rail voltages the LM7294 would probably be the most powerfull chipamp. I favour the LM3886 and TDA7294 a little bit above the LM4780. Not because of how it performs, but because of practicalities; it is easier for the LM3886 and TDA7294 to transfer heat since two chips have a higher contact area. And it makes it more convenient to build dual mono with separate PSU's etc. If you want a little bit more power I would go for the TDA7294(v)/(h). Also the TDA7294 is able to handle a lot of current; it does not matter if you put 4 or 8 ohms as load, the power that it can deliver stays constant. From the other hand from all PCB's I used I like the LM4780 PCB the most; that PCB is really well thought out (Pavel Dudek / PA-Sjöström). For example, for the other PCB's I had to add a Thiele network, latching relays etc, while the LM4780 PCB had already accounted for it.
I think from all chipamps I have build so far the LM1875 has surprised me most. For such a little chip with relatively low power, it performs really well and responds really well. I think it has a very high damping factor, maybe even more than the other chipamps, but have not measured that yet. And it allows for very compact design, although the LM7294 is also quite compact. Especially for an amp with this amount of power and conventional topology (class D is even more fun in a small package)
. I have to say that the differences are minute. However, I can mention that the TDA7294 has more power reserve than the LM1875 amps; it can go louder without distortion. Not that I play my music that loud, but still. The TDA7294 is highly comparable to the LM3886 and LM4780 (basically two LM3886's in one package) with sonical qualities and power. With optimal rail voltages the LM7294 would probably be the most powerfull chipamp. I favour the LM3886 and TDA7294 a little bit above the LM4780. Not because of how it performs, but because of practicalities; it is easier for the LM3886 and TDA7294 to transfer heat since two chips have a higher contact area. And it makes it more convenient to build dual mono with separate PSU's etc. If you want a little bit more power I would go for the TDA7294(v)/(h). Also the TDA7294 is able to handle a lot of current; it does not matter if you put 4 or 8 ohms as load, the power that it can deliver stays constant. From the other hand from all PCB's I used I like the LM4780 PCB the most; that PCB is really well thought out (Pavel Dudek / PA-Sjöström). For example, for the other PCB's I had to add a Thiele network, latching relays etc, while the LM4780 PCB had already accounted for it. I think from all chipamps I have build so far the LM1875 has surprised me most. For such a little chip with relatively low power, it performs really well and responds really well. I think it has a very high damping factor, maybe even more than the other chipamps, but have not measured that yet. And it allows for very compact design, although the LM7294 is also quite compact. Especially for an amp with this amount of power and conventional topology (class D is even more fun in a small package
)
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Thanks mhouston!
Sure, no problem! If you wan't to go for the LM4780; PA-Sjöström offers some very nice PCB's, probably for the last time. Check PCB Wiki, and PA03 thread
I've posted some pictures of my LM4780 a few pages back in this thread. Here is a little video of my PA03 amplifier btw PA03 video
Sure, no problem! If you wan't to go for the LM4780; PA-Sjöström offers some very nice PCB's, probably for the last time. Check PCB Wiki, and PA03 thread
I've posted some pictures of my LM4780 a few pages back in this thread. Here is a little video of my PA03 amplifier btw PA03 video
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Here is a few pics from my newest toy ..a phono stage form the past with a few small refinements .
Some brief description can be found here http://www.diyaudio.com/forums/solid-state/298164-phono-stage-past.html and since a member has been sarcastic with my drawing skills i think i am going to use that and call it :
The Dotless phono stage ...
At this stage I am playing with variety of hfe and choice of semis and parts
Kind regards
Sakis
Some brief description can be found here http://www.diyaudio.com/forums/solid-state/298164-phono-stage-past.html and since a member has been sarcastic with my drawing skills i think i am going to use that and call it :
The Dotless phono stage ...
At this stage I am playing with variety of hfe and choice of semis and parts
Kind regards
Sakis
Attachments
Hand made ( spray paint ) Mark, I am producing a few prototypes to see exactly what semis i am going to use , what grade from hfe aspect , and a bit of mixmatching regarding caps ...
The board is home brew and originally was 2 sides so we had to remove the one side and didn't look nice So spray paint it will be ....
We have ordered nice made boards but will take some 20 days in between id like to complete measuring and define my variables
I like to measure a complete device not simulation ...
Kind regards
Sakis
The board is home brew and originally was 2 sides so we had to remove the one side and didn't look nice So spray paint it will be ....
We have ordered nice made boards but will take some 20 days in between id like to complete measuring and define my variables
I like to measure a complete device not simulation ...
Kind regards
Sakis
Long time member but first time posting pics in this thread. My son asked me to build him an amp. I decided on Apex designs. I built him a P30 preamp and an A40 power amp. The P30 is all Apex except for the remote volume and channel select. I has a MM3 phono stage, TB3 tone circuit and the P30. The P30 is powered with the A class PSU +-24V, the MM3 and TB3 are each powered by their own +-18 Shunt PSU. For the A40 I used the layout designed by Alex. It is running on +-59V rails. 20,000UF per rail. The cases were purchased from the DIY audio store and I did all the drilling and labeling myself.
The system sounds fabulous and powerful.
Blessings, Terry
The system sounds fabulous and powerful.
Blessings, Terry
Attachments
Here's another one. Doug Self preamp.
Attachments
Member
Joined 2009
Paid Member
Check out Waterloo engraving. You can get your panels laser etched for almost nothing.
Yes, i caught that earlier when we were working out the balance control. I should have taken a new picture.