Comments on: A Complete Guide to Design and Build a Hi-Fi LM3886 Amplifier http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/ Raspberry Pi, Arduino, and DIY Electronics Projects and Tutorials Mon, 22 Jan 2018 02:48:22 +0000 hourly 1 By: Patrick http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-15419 Thu, 21 Dec 2017 17:17:59 +0000 http://www.circuitbasics.com/?p=421737#comment-15419 Great article! Would it be possible to provide the PS schematic or the gerber files for the PCB board?

Thanks

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By: 0rphu http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-15127 Tue, 19 Dec 2017 17:40:42 +0000 http://www.circuitbasics.com/?p=421737#comment-15127 Truly fantastic stuff you got here! I just finished my build based on your tutorial, with minor changes. I used single sided PCB, but tried sticking to your layout as closely as possible and changed some components – especially the Mundorfs for something readily available (and a bit cheaper ­čśë ). When I powered it up it sounded… different. At least to me, but I’ve been listening only to Yamahas for the past 10 plus years. Now after a couple of hours of listening to the LM3886 I must say it really sounds great! But it wasn’t so from the start – either I wasn’t used to the sound or the amp needs some time to burn in (which many people say is a myth). At first, the sound stage seemed too narrow to me and some of the songs sounded somehow odd – mostly metal tunes, in some the mids sounded somehow hollow. I think the sound my LM3886 amp produces is much sweeter and softer than my Yamaha. That’s why death metal sounds… odd :D. Also the imaging and mids either improved quite a bit in time or I just wasn’t paying attention at first. But I was astounded. I listened to songs I heard hundreds of times with a slack jaw. Amazing! Also, due to the sweeter and softer nature of the sound I’m able to comfortably listen to it on a volume which I would hardly stand listening to on the Yamaha.

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By: dave http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-13621 Sun, 03 Dec 2017 14:22:20 +0000 http://www.circuitbasics.com/?p=421737#comment-13621 Fantastic tutorial. It explained so much.

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By: Brad http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-12526 Wed, 15 Nov 2017 17:21:00 +0000 http://www.circuitbasics.com/?p=421737#comment-12526 Absolutely top-notch. A person with or without electronics knowledge can follow this quite easily. This helped me have the courage to continue with my own Gainclone amp project. THANK YOU.

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By: MBBS http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-10219 Sun, 15 Oct 2017 23:28:23 +0000 http://www.circuitbasics.com/?p=421737#comment-10219 Thank you for posting.

Very similar to Neurochrome design procedure, except Neurochrome uses Crest factor for RMS Power.

Possible options:

Use two smaller transformers and put bridge and caps on amplifier board. Use low ESR bulk storage caps and minimize inductance lengths. Keep all unregulated storage caps close to the LM3886 with proximity based on parasitic inductance effects. Meaning, small caps closest to LM3886. The combination of bulk caps should provide low impedance current throughout the frequency band for the load. Also, at the same time provide IC centric decoupling of the supply.

Heat sinks for Natural Convection should be exposed to room air flow. However If amp is run at near full load (not likely) heating effects of the transformer and bulk storage caps should be cooled as well. (This is where you find air flow holes across the entire top and bottom of enclosure.) Use the metal tab version of the part. Published Rth of plastic is optimistic.

Weakest link: Supply large bulk storage caps. The design should specify based on cap heating RMS Ripple current effects (ESR), which basically translate into Capacitor life expectancy. So depending on the capacitor supplier used, the design may have larger bulk capacitance, divided into multiple smaller caps in parallel as needed that can satisfy the RMS ripple requirement. Also, some airflow spacing is needed around the caps.

Hope the above was helpful.

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By: selman http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-9504 Sun, 08 Oct 2017 12:58:00 +0000 http://www.circuitbasics.com/?p=421737#comment-9504 Hi.
Some designs used only these parts For input:
1-Rb and Rin
2-Cim,Rb,Rin
3-Rb,Rin,Cc
4-Cin,Rin,Rb,Cc
Is there any order we should follow?
Rb before Rin or Rin before Rb?
Cin after Rin?
Cc before Rb?
Cc before or after Cin?
Can I use Cin and Cc in The between of Rin and Rc?…….
Thanks.

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By: Judah http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-9170 Wed, 04 Oct 2017 10:53:20 +0000 http://www.circuitbasics.com/?p=421737#comment-9170 Thanks a lot for this awesome project. This is my first and through the detailed explanation, I’m well able to understand almost all of it.
I have a question though. For the power supply circuit, how can I connect diodes and capacitors to safely give the required voltage and do away with the transformer.
Thanks in advance.

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By: Dave http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-7343 Wed, 06 Sep 2017 22:35:57 +0000 http://www.circuitbasics.com/?p=421737#comment-7343 Thanks for all the hard work. I noticed that in the schematic you have a 100nF cap (Csn). And in the photo under Wiring It All Together, there is a polypropylene cap labelled as a 100nF cap (I assume this is Csn). You explain in the tutorial (and as the actual photo of the cap shows) the actual value of the polypropylene is .22uF. Could you update this info. Thanks.

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By: Jimmy George http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-6427 Wed, 23 Aug 2017 12:00:48 +0000 http://www.circuitbasics.com/?p=421737#comment-6427 I made an amp with LM3876 in 2015. From then on, I have been trying to improve its performance by making modifications. In addition, I wanted to publish a systematic article with instructions on that. However, due to lack of deep knowledge in electronics, the project was lagging behind.

Surprisingly, while searching for “Negative Feedback” of amps, I came here. This is amazing. Though I have no expertise in Physics, was able to understand the technical things in this article. This is far far better than I wanted to publish, or would say – THE BEST. Awesome job, guys.

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By: Chris http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-5527 Sat, 05 Aug 2017 14:38:04 +0000 http://www.circuitbasics.com/?p=421737#comment-5527 Hi! This is _really_ a fantastic guide for a newbie like myself. I would also like to see a follow up post with details on the power supply. And I have a few questions:

Is there any reason why the input capacitor C1 has such a huge voltage rating well above the theoretical maximum of 60.4V from the positive to the negative rail of the power supply? Or is it just because the part is only manufactured like that by Mundorf?

If the latter: Are there any benefits (audio signal quality or other reason) with axial capacitors with such big plates? I was thinking of using one of the smaller WIMA MKP 4 series capacitors for C1. Those are also metalized polypropylene film capacitors, but with a smaller footprint and lower voltage ratings. The drawback is a bigger tolerance (10%), but they are dirt cheap compared to the Mundorf monster cap used here (WIMA MKP4F044706F00KSSD is about 1/7 of the price and way easier to find where I live).

And lastly a tip/request/suggestion for your CSS:

Could you please add a print stylesheet to the website, where all the unnecessary stuff (navigation, newsletter subsciption, social links, footer, etc) is hidden and the content column has full width?

Also, older versions of Firefox have problems when parts of the page are not “display: block”. On this web site it’s the #content-area DIV that is set to “display: flex”, that causes Firefox to print only the header on the first page, then whatever part of the article fits on the second page, followed by third page with just the footer. All other (47) pages of the article and the comments are hidden.

You could even add a DIV at the top of the web page with a .print-only class attribute, that is invisible when the page is viewed on a screen/tv, but would be included in the printed version. In there you could put things like a publishing date and a copyright notice, keywords, a table of contents, (social link) URLs written in full as normal text instead of just blue words in the article, etc.

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By: Simon Jones http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-5411 Wed, 02 Aug 2017 16:11:11 +0000 http://www.circuitbasics.com/?p=421737#comment-5411 Thank you for your excellent work on this guide. I think you’ve completed the most comprehensive and understandable post on this subject. I can’t thank you enough.

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By: nheco http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-4771 Sat, 22 Jul 2017 16:37:31 +0000 http://www.circuitbasics.com/?p=421737#comment-4771 Congratulations for the excellent post!
I assembled the circuit exactly like the one in the guide, with the following changes in the PSU: 24-0-24 250 VA transformer and 4x 10000 uf 50V, having + -32.8 volts dc. In the rest everything is equal to the circuit. The sound is fantastic, however I can not reach it but the power is far from expected. What could be wrong?
Can you help please.
Thank you.
Nheco

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By: Robert http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-4679 Fri, 21 Jul 2017 09:09:17 +0000 http://www.circuitbasics.com/?p=421737#comment-4679 Hi, I really enjoyed reading this ! I don’t have the patience to start this project can you advise me on where to find a really good lm3886 assembled board. also have an 8 ohm load and looking for Lm board with at least 80w/ channel.

Thanks again,
Rob nyc

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By: Raf http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-4558 Sun, 16 Jul 2017 12:32:23 +0000 http://www.circuitbasics.com/?p=421737#comment-4558 Hello Circuit Basics. I really enjoyed reading this awesome guide! I would like to know if there is a way to buy the power supply PCB instead of making it from scratch. Thank you.

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By: ─▒BRAHIM DILEK http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-4346 Sun, 09 Jul 2017 11:11:10 +0000 http://www.circuitbasics.com/?p=421737#comment-4346 Hello , this is a real complete guide for building a high quality amplifier. However I am almost a new graduate of Electrical Engineer and not sure if I can handle the processes. Anyone has any idea on how to be qualified in order to build this amplifier without major mistakes ? Thank you in advance.

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By: dimitris http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3622 Sat, 10 Jun 2017 07:38:17 +0000 http://www.circuitbasics.com/?p=421737#comment-3622 Excellent post! I would like to ask some questions. Firstly , if we want a volume control for this amplifier, how we will achieve it?
Second is there any need for preamp as my audio source would be a laptop or a smatphone.

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By: Liwei Sheng http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3581 Wed, 07 Jun 2017 16:55:39 +0000 http://www.circuitbasics.com/?p=421737#comment-3581 Wow, best guide about building LM3886 amplifier. I would not call this basics. There are many deep understandings beneath the guide. I like the way you treat ground connections. But I think three wire transformer output should also do just fine. I would like a kit to same the time to order them. I do not care particular brands of capacitors or any other components as long as their specs meet requirements.

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By: Evan http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3496 Fri, 02 Jun 2017 15:08:44 +0000 http://www.circuitbasics.com/?p=421737#comment-3496 First off – thank you for the great tutorial and the breakdown of each step. As an electrical engineering student, I love getting the chance to truly understand the process of creating the design.

Second, I’m trying to design the amp to go with a pair of Bose Interaudio 4000 speakers, which have a rating of 10-100W and 4-8 ohms. Since they do not have a specific value, but instead a range, should I make the calculations using the higher values, as a worst case scenario or sorts?

Thanks for the help!

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By: Konig Heniker http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3468 Wed, 31 May 2017 22:01:42 +0000 http://www.circuitbasics.com/?p=421737#comment-3468 Best tutorial you’ve ever made and one of the best available online. I hope you’ll make more of those overly detailed explanations, amazing knowledge source.

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By: ed linssen http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3422 Mon, 29 May 2017 09:17:13 +0000 http://www.circuitbasics.com/?p=421737#comment-3422 Hi Jos├ę,
You are supposed to place R4 (20 Ohm) between pins 3 and 9 directly ON the chip.
Good luck,
Ed

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By: Jos├ę Luiz fonseca http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3417 Sun, 28 May 2017 23:43:38 +0000 http://www.circuitbasics.com/?p=421737#comment-3417 Hi, friend,

I┬┤ve got the PCB but when I started to put the components , I didn┬┤t find the holes for R4. Did you forget it?
I have a transformer that feeds 22V at 7A.. I can use it, no?

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By: ed linssen http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3412 Sun, 28 May 2017 20:50:38 +0000 http://www.circuitbasics.com/?p=421737#comment-3412 Hi Darren,

I see that on the photograph of the parts family, the names of the two mica C’s are reversed.. The 680 is in fact the smaller-, the 47pF is the bigger one!
So the silkscreen is correct….
Success with the build,
Ed

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By: Darren http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3375 Thu, 25 May 2017 18:40:44 +0000 http://www.circuitbasics.com/?p=421737#comment-3375 I don’t know if I am misreading your schematic but it appears that your board silkscreen is mislabeled. The two silver mica capacitors (47pF and 680pF) appear to be reversed in your pictures. the footprint size of the components appears to be reversed if C2 sets the high frequency roll off of the amplifier then this would be the 680pF capacitor (the lager of the two) this is reflected in the picture of your components laid out with labels.
As C13 is used to stabilize the amplifier I would just like confirmation that the parts list and silkscreen are correct. Thank you.

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By: ed linssen http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3353 Tue, 23 May 2017 21:19:10 +0000 http://www.circuitbasics.com/?p=421737#comment-3353 no comment, just want to follow this very nice thread!

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By: Phil http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-3134 Fri, 12 May 2017 05:34:41 +0000 http://www.circuitbasics.com/?p=421737#comment-3134 Awesome writeup, many thanks! Quick question, I’m making these amplifiers to work in my car, so I will be using a 12V-30V DC transformer to power it. Should I still include a ground loop protection circuit or is it not needed for this approach?

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By: Sascha http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2712 Tue, 25 Apr 2017 07:02:58 +0000 http://www.circuitbasics.com/?p=421737#comment-2712 Thanks a lot for sharing this wonderful job. I will definetly try a build on my own.
Sascha

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By: Victor Faucheret http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2662 Sat, 22 Apr 2017 05:20:15 +0000 http://www.circuitbasics.com/?p=421737#comment-2662 thank you so much for your posting of the parts list as well as the power supply schematic and values!!

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By: fran├žois http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2586 Mon, 17 Apr 2017 00:16:49 +0000 http://www.circuitbasics.com/?p=421737#comment-2586 Great post!!!!
Thanks.
Just a question: if I want to use a volume control, how should I set the input resistor to limit dc offset due to input bias current?

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By: Aus_Roh http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2481 Sat, 08 Apr 2017 07:38:38 +0000 http://www.circuitbasics.com/?p=421737#comment-2481 A very nice explanation. A lot of effort obviously went into this. Many thanks! Many thanks too for the fantastic links.

You seem to know what you are doing as well as having a lot of experience. Thus, I was wondering if you could state the specifications of your amp, (distortion and noise characteristics) so it can be compared to other LM3886 designs, so see if one needs to improve anything.

Also, I would try to slide the capacitors away from the heatsink more on the PCB design so that the modules would have a longer life in many years time before breakdowns.

How come you amp isn’t picking up hum or the local AM radio station when its not in a shielded box?

Crazy input capacitor!

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By: Gerontius http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2442 Wed, 05 Apr 2017 03:33:38 +0000 http://www.circuitbasics.com/?p=421737#comment-2442 Nice work! I wish I had had this guide years ago when I first tried building an LM3886 amp. I second the request for component details, such as the voltages of the caps that can’t be read, if possible.

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By: naresh http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2426 Tue, 04 Apr 2017 05:17:27 +0000 http://www.circuitbasics.com/?p=421737#comment-2426 Thank you for sharing this documented design guide for LM3886.

A request .Could you also consider doing a solid state discrete power amp with dual dc power supply.

A pre-amp with tone controls would be also be a welcome.

There are many circuits on the net but again they do not explain any design aspects completely.

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By: Pietro Di Zinno http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2412 Mon, 03 Apr 2017 13:33:25 +0000 http://www.circuitbasics.com/?p=421737#comment-2412 True nice complete job! (y)

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By: Bob Pendergast http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2411 Mon, 03 Apr 2017 12:40:31 +0000 http://www.circuitbasics.com/?p=421737#comment-2411 Top quality work.

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By: Robert L. Pendergast N5JYW http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2409 Mon, 03 Apr 2017 12:38:54 +0000 http://www.circuitbasics.com/?p=421737#comment-2409 Beautiful job. Congratulations and thanks for the details.

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By: Circuit Basics http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2385 Sat, 01 Apr 2017 02:47:32 +0000 http://www.circuitbasics.com/?p=421737#comment-2385 The transformer only outputs AC, so the 18V rating is AC voltage. The amp needs about +-30V DC though. When you convert the transformer’s AC voltage to DC on the power supply, the voltage actually increases to about 25V due to the bridge rectifier.

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By: cd http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2380 Fri, 31 Mar 2017 11:43:53 +0000 http://www.circuitbasics.com/?p=421737#comment-2380 Would be awesome to have links to getting the chosen audio components too.

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By: Luis Pe├▒a http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2372 Thu, 30 Mar 2017 05:05:31 +0000 http://www.circuitbasics.com/?p=421737#comment-2372 Thanks for the explanation. I have a question though, if you said your amp will need +-30V, why would a +-18V transformer be enough?

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By: Victor H Faucheret http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2346 Mon, 27 Mar 2017 10:28:17 +0000 http://www.circuitbasics.com/?p=421737#comment-2346 The best post I’ve ever seen on LM3886. Congratulations! A complete schematic, as well as components values for the power supply will be greatly appreciated, Thank you so much in advance.

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By: Martin Arh http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2223 Mon, 06 Mar 2017 14:37:37 +0000 http://www.circuitbasics.com/?p=421737#comment-2223 Thanks. The best article ever. I learn a lot, specially about grounding.

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By: Wil http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2200 Sat, 04 Mar 2017 07:04:41 +0000 http://www.circuitbasics.com/?p=421737#comment-2200 Thank you for this really great article.
Do you think you could post the exhaustive list, brandd and referenced of the components ?
thanks.

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By: Enrico http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2124 Tue, 14 Feb 2017 22:09:52 +0000 http://www.circuitbasics.com/?p=421737#comment-2124 Thank you for sharing this.
Shouldn’t you also consider the voltage drop on the rectifier diodes, when you calculate the maximum voltage required by the amplifier?
thanks.

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By: alejandro http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2114 Fri, 10 Feb 2017 15:19:53 +0000 http://www.circuitbasics.com/?p=421737#comment-2114 Great project; thank you for sharing. The LM3886 is an excellent component and you explained “who to do better”.

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By: Asok Sen http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2111 Tue, 07 Feb 2017 18:04:59 +0000 http://www.circuitbasics.com/?p=421737#comment-2111 Thank you very much for your detailed explanation, I”m searching for the same.

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By: Vince http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2109 Tue, 07 Feb 2017 11:10:09 +0000 http://www.circuitbasics.com/?p=421737#comment-2109 everything were very well explained. thanks for sharing.

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By: George Riad http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2096 Fri, 03 Feb 2017 17:33:11 +0000 http://www.circuitbasics.com/?p=421737#comment-2096 I enjoyed every moment of the explanation, Great work and thank you for sharing

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By: marco http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2085 Sun, 29 Jan 2017 15:22:13 +0000 http://www.circuitbasics.com/?p=421737#comment-2085 Great job, very well explained. Thanks

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By: Brian Stover http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-2080 Sat, 28 Jan 2017 23:34:28 +0000 http://www.circuitbasics.com/?p=421737#comment-2080 Love the post. Great detail and explanations of the individual aspects of the circuit. I also really like how you supplied the calculations for determining the size of the components. As others have stated, I’d love to see a followup on the power supply. If not a full post cover it, could you at a minimum post a link to the pcb?

Thanks!

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By: Mustafa Kamal http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-1889 Thu, 17 Nov 2016 11:42:19 +0000 http://www.circuitbasics.com/?p=421737#comment-1889 Great post and well explained. If possible please post on Power Supply, Speaker Protection, Soft Start and Pre-Amp.
Thanks…………..

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By: Pero http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-1871 Tue, 08 Nov 2016 13:59:27 +0000 http://www.circuitbasics.com/?p=421737#comment-1871 Hey, great job! thanks for sharing. Cant wait to see post on power supply!

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By: Jeffery Lockmiller http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#comment-1867 Mon, 07 Nov 2016 17:52:32 +0000 http://www.circuitbasics.com/?p=421737#comment-1867 I use the LM3886 on my biamped mains. A single chip for each tweeter and a parallel pair for the woofers. This setup drives them quite well.

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