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Old 23rd August 2012, 08:51 AM   #11
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Quote:
Originally Posted by pra3718 View Post
LM1875 bridge for 4R Load with lower power supply. So each chip would see as 2R Load.
It takes 8 chips per each channel. It is a pair of 4-chip parallel amplifiers.
That is a gigantic mess.

TDA7294 and TDA7293 has a similar sound. There is a ready made TDA7293 parallel amplifier designed for easily driving 4 ohm speakers. That one simple little 2xTDA7293 board is perhaps more doable than an 8 chip LM1875 board.
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Old 23rd August 2012, 09:14 AM   #12
AndrewT is offline AndrewT  Scotland
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The TDA chipamps are also current strangled.
There is only so much output device in a chipamp. Fit in two devices for a quasi complementary output stage and there is little room left for the rest of the IC.

All chipamps based on the extended To220 package will always have an output stage current limit that is low compared to a discrete output stage using far more "tab" area.
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Old 28th August 2012, 11:15 AM   #13
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The TDA chipamps are also current strangled.
There is an escape plan that doesn't require ballast resistors for paralleling. There might be enough current capacity that way.
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Old 28th August 2012, 11:41 AM   #14
AndrewT is offline AndrewT  Scotland
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Originally Posted by danielwritesbac View Post
..........There is an escape plan ..................
Yes, don't bridge !!!!
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Old 28th August 2012, 03:25 PM   #15
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Originally Posted by AndrewT View Post
Yes, don't bridge !!!!
The LM1875 is also very dynamic which is great until you find out it is really hard to parallel that thing beyond 2x, almost enough to drive a modest size 4 ohm speaker and still needs a current dumper/limiter protection at the power circuit as a cheat. Thus "don't bridge" is excellent advice.
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Old 7th September 2012, 03:17 PM   #16
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LM1875 Bridge isn't good for LM1875 MONO.
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Old 8th September 2012, 01:32 AM   #17
fakeout is offline fakeout  Canada
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Quote:
Originally Posted by danielwritesbac View Post
TDA7294 and TDA7293 has a similar sound.
Just to confirm, are you saying the TDA7294 sounds similar to the LM1875?
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Old 8th September 2012, 03:02 PM   #18
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Originally Posted by fakeout View Post
Just to confirm, are you saying the TDA7294 sounds similar to the LM1875?
I am saying that is doable.

Similarity
I would use 330uF power caps on any of those chips (in addition to regular power board, of course). This works well for TDA7294 and LM1875 alike, and the tone is quite a bit similar.
Discrepancy
I would set the TDA7294 to medium gain because it is a miller comp amp wherein if you increase the gain, quality decreases proportionately. That inconvenience may incur the need of a preamp for computer, phone and digiplayer. Conversely, LM1875 is capable of high gain without a problem.

And, the MyRef project shows how to override the tone of the LM3886 with a small signal op-amp and in this case the "sound of" is the small signal op-amp that serves as pilot--nesting types give much better tone than a regular LM3886 or omission based gainclone.
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