Has anyone here messed around with the LM1875 yet? Will the chip work with the same schematic as the LM3875? I got some today, and started putting together. It sure is nice to be able to use a SMD resistor for the NFB.
Any suggestions for the LM1875? I am just going to try it with the same circuit first.
--
Brian
(as for the photo, I wired the pins backward... pin 1 and 5 are reversed, and am in the process of redoing it now. I just like this picture, because you can see the SMD resistor.)
Any suggestions for the LM1875? I am just going to try it with the same circuit first.
--
Brian
(as for the photo, I wired the pins backward... pin 1 and 5 are reversed, and am in the process of redoing it now. I just like this picture, because you can see the SMD resistor.)
Attachments
Stabist said:
Tangband w3-871s drivers are $12 each, and a good starting point. These should match your budget. I am building some speakers with these now, based on Jim Griffin's ELF 1.5 design. It uses 2 of these per speaker, with the bottom one cutoff above 1khz with a 1.5mH inductor in series with a 4 ohm resistor. The speaker size is 10.5" (H) X 6.5" (W) X 9.25" (D), and has a
--
Brian
Attachments
Bricolo said:
Here is the original thread talking about the TB speakers of Jim Griffin's.
IMHO the simple expedient of rear mounting the 0.5 driver could make these noticeable better speakers for a couple reasons.
dave
Hi!
I have few questions:
- first one - is plexiglass and acrylglass the same thing or not - because sometimes when I read some of those posts I get the feeling as they are same thing and than again - sometimes that they are something completely diferent!?!
- then - how to make a housing out of plexi glass?? Can it be glued somehow (I gues it easily can - but with which kind of glue???)
Why am I asking? - I think it is even a bit more demanding - my idea is to use plexi as a front panel - but I don't want to use screws - can it be glued to Aluminium??
Hmm - the bad news for me is- that LM 1875 and LM3875 are not available her in SLO ... But TDA 2040 and 2050 can be purchased almost everywhere - so - are there any major differences??
Btw - this is my first time to work with OPA - wherer can I find Data sheets for those two TDAs??
Thanks for your help!
LP
Primoz
I have few questions:
- first one - is plexiglass and acrylglass the same thing or not - because sometimes when I read some of those posts I get the feeling as they are same thing and than again - sometimes that they are something completely diferent!?!
- then - how to make a housing out of plexi glass?? Can it be glued somehow (I gues it easily can - but with which kind of glue???)
Why am I asking? - I think it is even a bit more demanding - my idea is to use plexi as a front panel - but I don't want to use screws - can it be glued to Aluminium??
Hmm - the bad news for me is- that LM 1875 and LM3875 are not available her in SLO ... But TDA 2040 and 2050 can be purchased almost everywhere - so - are there any major differences??
Btw - this is my first time to work with OPA - wherer can I find Data sheets for those two TDAs??
Thanks for your help!
LP
Primoz
Primoz,
You can get LM3875 through National's sample program. Texas Instruments also has an excellent sample program, so you can try with OPA548 or OPA549.
I would like to hear if anyone has compared LM3875 and OPA549. Some people said that OPA549 is excellent, but how good in direct comparision with LM3875? I hope it's better because I have a couple of them and plan to bulid a gainclone with them.
You can get LM3875 through National's sample program. Texas Instruments also has an excellent sample program, so you can try with OPA548 or OPA549.
I would like to hear if anyone has compared LM3875 and OPA549. Some people said that OPA549 is excellent, but how good in direct comparision with LM3875? I hope it's better because I have a couple of them and plan to bulid a gainclone with them.
Hmm - what's a National sample program??
Btw - are this TDAs (2040 or 2050) so bad comparing to LM1875 or 3875?!?
I can easilly buy any of those two TDAs tomorow ... But as said - LMs a more dificult to get
Or - I saw a sugestion by Thorsten to use TDA 1514 (by Philips) - I can buy here 1514 A SIP9 ... Is that Ok?? - and what does this A SIP9 mean??
Sorry for so many dumb questions - but this is the first time I'm trying to do something with OPA ... And every begining is hard ...
Thanks again ...
Btw - are this TDAs (2040 or 2050) so bad comparing to LM1875 or 3875?!?
I can easilly buy any of those two TDAs tomorow ... But as said - LMs a more dificult to get
Or - I saw a sugestion by Thorsten to use TDA 1514 (by Philips) - I can buy here 1514 A SIP9 ... Is that Ok?? - and what does this A SIP9 mean??
Sorry for so many dumb questions - but this is the first time I'm trying to do something with OPA ... And every begining is hard ...
Thanks again ...
Search keyword: TDA2050
TDA2040 and TDA2050 are good amplifiers.
My favo is now TDA2050. Is has higher bias, 90mA
and that is not so much a ClassB but more like ClassAB amp.
Most chip amps are pure ClassB.
Recently we had a thread, where I gave a lot of input of TDA2050.
With schematics and details.
I think it is easier to use, and more stable, safer to deal with,
than those a bit faster power-chips, with some higher powers..
We have read about people here blowing up one after the other
of those chips.
TDA2050 is a perfect Power-IC Amp for use
in bi- and tri-amplified active speaker systems.
---------------------------------------------
A search - Why do not people use search more often?
maybe they do.
www.diyaudio.com is also a great archive - library
where lots of good information is stored - as years go by.
Just as well as search with www.google.com on the web,
we can do searches here.
------------------------------------
Result of search "TDA2050":
http://www.diyaudio.com/forums/sear...d=118885&sortby=lastpost&sortorder=descending
7 threads where TDA2050 is mentioned
of which 3 threads are specifically dealing with TDA2050
Do your own search of "TDA2040"
----------------------------------
Regards to Stabist
a guy who is interested in TDA2050, just as
/halo is
This is a GOOD question.Stabist said:Btw - are this TDAs (2040 or 2050) so bad comparing to LM1875 or 3875?!?
I can easilly buy any of those two TDAs tomorow ... But as said - LMs a more dificult to get
Thanks again ...
TDA2040 and TDA2050 are good amplifiers.
My favo is now TDA2050. Is has higher bias, 90mA
and that is not so much a ClassB but more like ClassAB amp.
Most chip amps are pure ClassB.
Recently we had a thread, where I gave a lot of input of TDA2050.
With schematics and details.
I think it is easier to use, and more stable, safer to deal with,
than those a bit faster power-chips, with some higher powers..
We have read about people here blowing up one after the other
of those chips.
TDA2050 is a perfect Power-IC Amp for use
in bi- and tri-amplified active speaker systems.
---------------------------------------------
A search - Why do not people use search more often?
maybe they do.
www.diyaudio.com is also a great archive - library
where lots of good information is stored - as years go by.
Just as well as search with www.google.com on the web,
we can do searches here.
------------------------------------
Result of search "TDA2050":
http://www.diyaudio.com/forums/sear...d=118885&sortby=lastpost&sortorder=descending
7 threads where TDA2050 is mentioned
of which 3 threads are specifically dealing with TDA2050
Do your own search of "TDA2040"
----------------------------------
Regards to Stabist
a guy who is interested in TDA2050, just as
/halo is
Thanks a lot!
Sorry - you're right - I really could use search - but I was reading this last long posts about this GC and all - and TDAs (almost) were never mentioned ... So I just forgot to check it out ...
Will certanly repait my mistake now ..
Hmm - after reading some stuff from datasheet - I allready leaned a bit towards 2050 - now you're also claiming that it is a better choice - so I'll probably really do my GC with 2050 ...
Sorry - you're right - I really could use search - but I was reading this last long posts about this GC and all - and TDAs (almost) were never mentioned ... So I just forgot to check it out ...
Will certanly repait my mistake now ..
Hmm - after reading some stuff from datasheet - I allready leaned a bit towards 2050 - now you're also claiming that it is a better choice - so I'll probably really do my GC with 2050 ...
I think you will be happy with TDA2050.
I have seen the former version TDA2040
used in serious Active Speaker Biamp designs.
I will order someones myself.
They cost almost nothing. Even less if I buy 10-pack.
I will use one for a subwoofer, probably.
My brother would also want an active sub.
For his 5.1 surround.
-----------------
I have long time been planing a biamp active system
with 12dB Linkwitz filters Using OP amps.
One can simple put the crossover at the input
of each amplifier.
And the amplifiers, 4 of them, are put on the speaker box,
or at least close to the speakers.
Sometimes you need a simple Amp in the LAB, for testing something.
To use a TDA2050 is a quick solution.
----------------------------------------
I have said it before:
"IC-Power Amps are democratic amplifiers."
You need not to be a amplifier expert to build with them.
Most can manage good with them.
And they fit the WALLET of most normal people,
Not to mention all the students we have at the forum.
VERY DEMOCRATIC little things - I would say!
----------------------------------------------------
halo - cheerleader for "the ordinary man team"
I have seen the former version TDA2040
used in serious Active Speaker Biamp designs.
I will order someones myself.
They cost almost nothing. Even less if I buy 10-pack.
I will use one for a subwoofer, probably.
My brother would also want an active sub.
For his 5.1 surround.
-----------------
I have long time been planing a biamp active system
with 12dB Linkwitz filters Using OP amps.
One can simple put the crossover at the input
of each amplifier.
And the amplifiers, 4 of them, are put on the speaker box,
or at least close to the speakers.
Sometimes you need a simple Amp in the LAB, for testing something.
To use a TDA2050 is a quick solution.
----------------------------------------
I have said it before:
"IC-Power Amps are democratic amplifiers."
You need not to be a amplifier expert to build with them.
Most can manage good with them.
And they fit the WALLET of most normal people,
Not to mention all the students we have at the forum.
VERY DEMOCRATIC little things - I would say!
----------------------------------------------------
halo - cheerleader for "the ordinary man team"
halojoy said:
The 1st gainCard style chip-amp i read about used a TDA20x0 -- all with favorable review. Whether it sounds better than LMxxxx is probably as much down to implementation as anything.
If you can get some, just go for it. Most of the investment is in the power supply and that can be recycled/reused if you decide to try something else.
dave
After more extended listening on the week-end and a comparison between the gainclone and the Aleph 5's I can report the following:
There was no clear "winner" . Both amps driving my 4ohm 90db speakers ( it has been reported that the gainclone does not mate well with 4ohms) at normal listening levels were quite close.If you want to split hairs then the gc was a little better in soundstage and instrument positioning with perhaps a more extended detailed top end and slightly forward presentation without sounding harsh or bright. The Alephs were a bit warmer with more extension at the bottom end and the sounstage placed further back.
In case you think my Alephs were perhaps not up to par I should say that they replaced some pretty good amps from Naim and Jadis that I had been using.
I should also say that both amps were being run balanced from a Bosoz preamp. The balanced input on the gc (as in the Aleph) sounds more dynamic and has a deeper and wider soundstage.I should also say that the gc did not have the best possible PS with only one 120VA trafo(although I don't use more than about 4-6V output on the amp). I wonder what would happen with good dual mono PS. I think my next project will be a good PS driving the LM3886 which is designed for 4ohm loads.
This comparison confirmed certain thoughts about the future of audio DIY and audiophile components in general.
I believe that although the hi-end components do not sound that much better than what was available 20 years ago what has happened with technology is that the low end of the market is much closer sound wise to the top end than it ever was. The law of diminishing returns in audio is more obvious (and more painful)
to us audiophiles. However your average 300 euro or usd micro system today is leagues ahead of what was available two decades ago and that is good ,I guess, for everybody.
It also confirms to me that well designed amplifiers today sound more alike than different.Of course as fanatic audiophiles we like to exaggerate these differences but I think sometimes we miss the wood for the trees, which is to enjoy music after all. In the end what we tend to do is get our system to sound a certain way to suit out preferences.
I think with the technology that we now have it is easy to have an excellent sounding system with very little outlay whether bought or DIYed. This system will get almost maximum detail and dynamic retrieval from most modern mediums.I think the problem now lies in recording technology and methods and that is where the real limits are and not anymore in good domestic equipment.
Regarding DIY the new chip technology is a little bit scary because it does seem to be very good sounding.Does this mean that audio DIYing will be just a matter of throwing together a basic power supply with a couple of chips and resistors since it wouldn't be worth doing it discreetly? Will it go the way of the computer where DIY is not possible?Perhaps only loudspeaker building will then be left to the amateur fan.
There was no clear "winner" . Both amps driving my 4ohm 90db speakers ( it has been reported that the gainclone does not mate well with 4ohms) at normal listening levels were quite close.If you want to split hairs then the gc was a little better in soundstage and instrument positioning with perhaps a more extended detailed top end and slightly forward presentation without sounding harsh or bright. The Alephs were a bit warmer with more extension at the bottom end and the sounstage placed further back.
In case you think my Alephs were perhaps not up to par I should say that they replaced some pretty good amps from Naim and Jadis that I had been using.
I should also say that both amps were being run balanced from a Bosoz preamp. The balanced input on the gc (as in the Aleph) sounds more dynamic and has a deeper and wider soundstage.I should also say that the gc did not have the best possible PS with only one 120VA trafo(although I don't use more than about 4-6V output on the amp). I wonder what would happen with good dual mono PS. I think my next project will be a good PS driving the LM3886 which is designed for 4ohm loads.
This comparison confirmed certain thoughts about the future of audio DIY and audiophile components in general.
I believe that although the hi-end components do not sound that much better than what was available 20 years ago what has happened with technology is that the low end of the market is much closer sound wise to the top end than it ever was. The law of diminishing returns in audio is more obvious (and more painful)
to us audiophiles. However your average 300 euro or usd micro system today is leagues ahead of what was available two decades ago and that is good ,I guess, for everybody.
It also confirms to me that well designed amplifiers today sound more alike than different.Of course as fanatic audiophiles we like to exaggerate these differences but I think sometimes we miss the wood for the trees, which is to enjoy music after all. In the end what we tend to do is get our system to sound a certain way to suit out preferences.
I think with the technology that we now have it is easy to have an excellent sounding system with very little outlay whether bought or DIYed. This system will get almost maximum detail and dynamic retrieval from most modern mediums.I think the problem now lies in recording technology and methods and that is where the real limits are and not anymore in good domestic equipment.
Regarding DIY the new chip technology is a little bit scary because it does seem to be very good sounding.Does this mean that audio DIYing will be just a matter of throwing together a basic power supply with a couple of chips and resistors since it wouldn't be worth doing it discreetly? Will it go the way of the computer where DIY is not possible?Perhaps only loudspeaker building will then be left to the amateur fan.
Rookie,
i've just finished both opa549 and lm3875 "clones". nobody on the forum seems to want to discuss them as an option, but i tried them as bb chips are usually first rate. they are VERY similar (but i am probably biased). the opa549's have a much higher output current (up to 10a). i've found i prefer the sound with them driven by an opamp like the opa134 (or am i imagining it?). the bass also seems a bit deeper with the 549, although again, i could be wrong. certainly not a bad chip either way. i'm bridging/paralleling a set now........texas instuments have an application bulletin with a schematic for an intergrated amp with tone controls using the opa549/548 and a few others. can't remember where exactly, but worth a look.
i've just finished both opa549 and lm3875 "clones". nobody on the forum seems to want to discuss them as an option, but i tried them as bb chips are usually first rate. they are VERY similar (but i am probably biased). the opa549's have a much higher output current (up to 10a). i've found i prefer the sound with them driven by an opamp like the opa134 (or am i imagining it?). the bass also seems a bit deeper with the 549, although again, i could be wrong. certainly not a bad chip either way. i'm bridging/paralleling a set now........texas instuments have an application bulletin with a schematic for an intergrated amp with tone controls using the opa549/548 and a few others. can't remember where exactly, but worth a look.
yeah, i used a preamp with the chip using the opa2134. it was a rod elliot one. sounds nice (but i don't know if i'm all that fussy with stuff i build myself. pride, maybe?). i definitely prefer it with than without. if i can get up the nerve to do it, i'll try some ad8021 chips that came last week. i wish i had checked if they were surface mount. oh well.
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