Mark...
The lm4780 could easyli be feed with 2x24vac, giving the amp more power from scratch 🙂
Just my 2 cents here, will leave you for the lm3875... Just giving youre some ideas!
Jesper.
The lm4780 could easyli be feed with 2x24vac, giving the amp more power from scratch 🙂
Just my 2 cents here, will leave you for the lm3875... Just giving youre some ideas!
Jesper.
Please don't confuse me more 🙂 I think I am just starting to slightly understand this one.
A DIY stereo amp is my aim, and I like the idea of separate Amp boards (maybe I have been conned by the major brands about audio separation being the best).
Is the LM4780 just two LM3875s in one package?
Jesper, I like the sound of more power, but I think being sensible in my case for this moment will be more beneficial. If I can work out the basics and get a good understanding around the LM3875, then maybe I could look at different designs.
Think I will stick with this design, as I can get the PCBs and parts together, learn about how to chose a transformer etc and learn from mistakes 🙂
Mark....
The lm4780 is a stereo (2)channel amp. Chip, capable of approx. 2x60watt
Should be plenty plenty enough for 89dB speakers... Mine is feed from an 2x24vac torid (1000va) just because, it was what i had in drawer.
A single 4780, would be easyer for you to build, instead of two 3875 i think.
Jesper
The lm4780 is a stereo (2)channel amp. Chip, capable of approx. 2x60watt
Should be plenty plenty enough for 89dB speakers... Mine is feed from an 2x24vac torid (1000va) just because, it was what i had in drawer.
A single 4780, would be easyer for you to build, instead of two 3875 i think.
Jesper
How would the LM4780 be easier to build?
From what I can see I would still need the same layout - transformer - rectifier - 2xamps.
I don't want to do a single amp build as I won't learn (maybe wrong term), but if I go for two amp boards I should be able to learn basics and more.
Any advantages of the LM4780 over the LM3875 other than higher output from the box?
From what I can see I would still need the same layout - transformer - rectifier - 2xamps.
I don't want to do a single amp build as I won't learn (maybe wrong term), but if I go for two amp boards I should be able to learn basics and more.
Any advantages of the LM4780 over the LM3875 other than higher output from the box?
Off subject, but having just hooked up a small denon poweramp I have been reminded that I have been missing out.
Having used my AV receiver Sony as pictured for years, i think I have become used to ESR drift. If this little Denon amp is similar to what I am expecting from a gainclone then I am excited
Having used my AV receiver Sony as pictured for years, i think I have become used to ESR drift. If this little Denon amp is similar to what I am expecting from a gainclone then I am excited
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Hi,
Just add a volume pot to the Denon, makes a lot more sense.
rgds, sreten.
If you aready have a nice little amplifier, no point building one.
Something more exotic ?
Death of Zen - A new Class-A power amp
Capacitance Multiplier Power Supply Filter
Minimalist Discrete Hi-Fi Preamp
Note the last one for CD is passive, and how you
would add a volume pot to the Denon amplifier.
Just add a volume pot to the Denon, makes a lot more sense.
rgds, sreten.
If you aready have a nice little amplifier, no point building one.
Something more exotic ?
Death of Zen - A new Class-A power amp
Capacitance Multiplier Power Supply Filter
Minimalist Discrete Hi-Fi Preamp
Note the last one for CD is passive, and how you
would add a volume pot to the Denon amplifier.
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It is sad to be 2 LM3886 as it also has mute.
LM4780 needs the same schematic as a single 3886, just on one board. Not much difference. You should look at the schematics, learn what each component does. Shouldn't go with a more complex amp if you don't know the basics. So LM4780 and LM3886 amp will be nearly the same. LM4780 is used usually to bridge the 2 amps to get more juice.
Hi,
well abit of an update after doing more researching.
I think the LM4780 will be a better solution for me seems easier to learn on. Transformer wise I was looking at
120VA 230v to 2x18v
does this seem to fit the bill?
I was having a word with a senior design engineer today at work trying to see if there is one main formula you could use to see what specific transformer you need, well now I know just how hard it is matching a transformer to a audio amplifier.
Will be working on a BOM at the weekend to go with the audiosector kit, and do some drawings and upload them so I can see if I will be making any mistakes.
well abit of an update after doing more researching.
I think the LM4780 will be a better solution for me seems easier to learn on. Transformer wise I was looking at
120VA 230v to 2x18v
does this seem to fit the bill?
I was having a word with a senior design engineer today at work trying to see if there is one main formula you could use to see what specific transformer you need, well now I know just how hard it is matching a transformer to a audio amplifier.
Will be working on a BOM at the weekend to go with the audiosector kit, and do some drawings and upload them so I can see if I will be making any mistakes.
Hi,
I think the little Denon sounds good for what it is, enough power etc, but I have just got used to my AV amp sounding bad so anything compared to that is an improvement.
Also I've always wanted to do my own amp, so if I can create something that's comparable or better, hoping for the latter. Then two birds one stone scenario.
Hi,
YMMV but IMO not knowing much it will be hard to better the Denon.
Building amplifiers is an expensive business. My favourite budget
used amplifier is a Pioneer A300X, which can be picked up for
under £60, and would cost a small fortune to replicate DIY.
The build quality is exemplorary, its a really nice amplifier.
(Basically half the price of a used NAD3020, which it
slaughters, and about 3 times the NAD build cost.)
I could build an amplifier, but never have, it is too expensive.
The idea that your creation would be better than anything else
has never crossed my mind, I know how complicated it is.
rgds, sreten.
YMMV but IMO not knowing much it will be hard to better the Denon.
Building amplifiers is an expensive business. My favourite budget
used amplifier is a Pioneer A300X, which can be picked up for
under £60, and would cost a small fortune to replicate DIY.
The build quality is exemplorary, its a really nice amplifier.
(Basically half the price of a used NAD3020, which it
slaughters, and about 3 times the NAD build cost.)
I could build an amplifier, but never have, it is too expensive.
The idea that your creation would be better than anything else
has never crossed my mind, I know how complicated it is.
rgds, sreten.
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That is fairly good! What the big transformers are actually doing for the gainclone, is supporting low capacitance supply. It is 1500uF per rail. AudioSector has got this pressed to the extreme of maximized transformer with minimized capacitance.
Minimized capacitance is a transformer centric (throw cash at it) approach to make the amplifier more layout tolerant, in an especially successful way--It is certainly "less inviting" to screw up and/or modify at random, since the number of such options is minimized. Now that's clever!
I do have other options that are far less expensive, but there is usually failure to build on spec most of the time because of more components, and the off spec (poorly built) variations are not impressive. I don't know why to first alter something so it cannot work right and then complain about that. . . but it is really popular!!! About 5% get built right. As for the rest, those are like a sports car with the tailpipe jammed utterly full of potato.
However, AudioSector's much simpler (and more expensive) power circuit doesn't easily succumb to weird random ad-libbing urges of builders. And there's even a whole forum dedicated to nothing other than keeping AudioSector builders on track and on spec. That's a bit awesome.
Compare amplifiers?
If building an AudioSector amplifier, it is needful to build strictly to the letter, very precisely, with exactly the prescribed brand name and model number carefully checked for each and every piece. Have you seen their forum yet? Audio Sector - diyAudio At that location one can get news of working options. When using overture chips in non-inverting mode, tolerances are slim, and there's not much room to ad lib. Tip: When building one specific designer's amplifier, please be certain to AVOID failure caused by adding in random advices from all over the internet.
OR
In case you'd like a more normal amplifier with easier stability/tone (even if using the same chips) then check out Decibel Dungeon for inverting LM3875 builds. The Decibel Dungeon Gainclone index page with links to all chip amp articles. That is much easier, less expensive, can use some on-hand and/or local components, and is more likely to result in a practical amplifier. Decibel Dungeon Inverting LM3875 and Inverting LM3886, work very much like normal amplifiers and therefore ordinary parts and ordinary specs for things are expected to work most pleasantly.
And now, the rest of the story:
The non-inverting, like AudioSector, is going to work best for highly intelligible television movie soundtracks and/or overcoming dull speakers.
The inverting, like Decibel Dungeon, is going to work best for music replay with a favorable, practical and useful tone that isn't tiring.
The inverting, like Decibel Dungeon, is more stable, so it is a little more tolerant to modifications, using on-hand parts, etc. . .
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