i just won a pair of infinity intermezzo 2.6 (powered bookshelves), and was wanting to build a chip amp to drive them. they woofer is powered, but the tweeter needs an amp. so basically, i would be JUST powering the tweeter.
i was wanting to use the LM3875, as i have a few of them sitting around. as far as the power supply section goes, should i use higher powered supply, to give better clarity, because ive heard (and experienced), with lower voltage supplies, the bass is heavier, but you loose detail. so im wondering if i should use a transformer with maybe 24v secondaries?
any advice? (oh, btw, these speakers DO benefit from good clean power. underpowered, they will sound a bit harsh, so i cant sacrifice TOO much power from the chip).
i was wanting to use the LM3875, as i have a few of them sitting around. as far as the power supply section goes, should i use higher powered supply, to give better clarity, because ive heard (and experienced), with lower voltage supplies, the bass is heavier, but you loose detail. so im wondering if i should use a transformer with maybe 24v secondaries?
any advice? (oh, btw, these speakers DO benefit from good clean power. underpowered, they will sound a bit harsh, so i cant sacrifice TOO much power from the chip).
yes .. boston acoustic is the other company that comes into mind 
just thought of it ..
btw sorry for jacking your thread ..
anyway .. peter recommends 22V for the secondaries
i think that 22 should be quite sufficient, as 24 is closing in on the limit for the chips themselves afaik .. although you could probalby use 25-26 before the limit
22V gives you an approximate 38 watts into 8ohms ..
there was a graph somewhere .. that peter posted ..
its from the lm3875 data sheet, so you can check in there (if i can remember correctly, its at the end of the data sheet)
just thought of it ..
btw sorry for jacking your thread ..
anyway .. peter recommends 22V for the secondaries
i think that 22 should be quite sufficient, as 24 is closing in on the limit for the chips themselves afaik .. although you could probalby use 25-26 before the limit
22V gives you an approximate 38 watts into 8ohms ..
there was a graph somewhere .. that peter posted ..
its from the lm3875 data sheet, so you can check in there (if i can remember correctly, its at the end of the data sheet)
just so im clear on this one, is that 22v supply BEFORE the rectifiers, or after? (ie - transformer with 22v secondaries?)
if so, that would work out well. i could actually try 24v too, since i have the transformers to do so.
i may keep the speakers, or trade them in for the B&W 805's. who knows....
if so, that would work out well. i could actually try 24v too, since i have the transformers to do so.
i may keep the speakers, or trade them in for the B&W 805's. who knows....
sorry, my bad
it is before rectification ..
after rectification it provides you with about 31V i think
with 24V secondaries you should get about 34-35V, so you would be getting about 57watts or so ..
maximum voltage (listed in the datasheet) is 84V, so 42V rails ..
with 34 you're pretty safe i'd think
it is before rectification ..
after rectification it provides you with about 31V i think
with 24V secondaries you should get about 34-35V, so you would be getting about 57watts or so ..
maximum voltage (listed in the datasheet) is 84V, so 42V rails ..
with 34 you're pretty safe i'd think
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