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).
re-read the first paragraph...
"the woofer is powered, but the tweeter needs an amp. so basically, i would be JUST powering the tweeter. "
"the woofer is powered, but the tweeter needs an amp. so basically, i would be JUST powering the tweeter. "
Yes, I did read that but couldn't see the logical reason for supplying a speaker with a powered woofer but nothing for the tweeter!
Is there a reason why the speaker comes like that?
Is there a reason why the speaker comes like that?
yeah i know, that sounded strange to me too
but i've seen speakers like that before .. JBL and .. um .. blah .. another one, but i can't think of it now
but i've seen speakers like that before .. JBL and .. um .. blah .. another one, but i can't think of it now
its not an "active" speaker, its simply a powered speaker. who knows why both arent powered, but typically, the sub is usually just powered.
but in any event, any advice on my original question???
but in any event, any advice on my original question???
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 🙂
ok, sounds good. i can easily find that transformer.
now i just need to decide if i want to keep those, or go with the b&w's... decisions, decisions...
now i just need to decide if i want to keep those, or go with the b&w's... decisions, decisions...
well if you do choose to go with the 805s, let me know how they sound ..
i'm going to be in the market for a new set of speakers in a few months time .. late this year/early next ..
one thing i'd like is something more efficient .. but i wouldn't rule those out 🙂
i'm going to be in the market for a new set of speakers in a few months time .. late this year/early next ..
one thing i'd like is something more efficient .. but i wouldn't rule those out 🙂
i have heard them a few times before, they are nice. i can also get the KEF reference 201's for the same price (retail on those is $3500). ill shop around a little bit first of course. but its not a HUGE deal, because they arent costing me any money, and its just for my bedroom.
- Status
- Not open for further replies.