Building a Workshop Amplifier with Audiophonics Module - Stereo LM3886 Chipamp.

[@electronicsoldandnew]

Where’s my “Dislike” fan? Can’t believe I may have lost him. I sure hope not. 😊

[@electronicsoldandnew]

He came! Oh Yay!

[@SheikhN-bible-syndrome]

I think the algorithm does it

[@SheikhN-bible-syndrome]

That frequently response is incredible I've never seen a amp do that good over that wide of an audio band

[@electronicsoldandnew]

👍

[@__Dude_]

Hi Manuel, after some thought I decided to buy the same amp board! I am rebuilding (not restoring) an old Monacor SA-500 amplifier, which I aquired some 50 years ago. The specs were horrible (e.g. 10% THD at 20 Watts), so I decided to gut it and just leave the enclosure and faceplate as it was. I was thinking about taking one of the low cost class D amp boards, but the one you found is an "analog" one, for the same price. Hard to believe, but then you tested it, and it looks to be great. And it includes the power supply as well. So thank you for this find!! 😊 😊 😊

[@electronicsoldandnew]

enjoy

[@waynethompson8416]

You absolutely blew me away with this amp!!! My chin hit the floor! 1Hz to over 100,000.00 Hz FLATTER THAN A PANCAKE!!! I hope that you put the model number, address, etc. so that the rest of us could order one of those! I am mega impressed!!!

[@electronicsoldandnew]

i’m actually quite shocked myself. I keep wondering if I was seeing right.

[@paulpaulzadeh6172]

Could you measure THD, open loop BW , clipping at 20k sinus wave , your measurement is simple , what about load with capacitive , inductive load , you need AP555, To do some serious measuring

[@electronicsoldandnew]

I’m a defender of the KISS philosophy 😊 Way too complex for my needs.

[@mackfisher4487]

Excellent job Manuel, I really like your rail method of hanging your homebrew test equipment accessories well thought out.

[@electronicsoldandnew]

👍

[@electrosoundaust]

One word - wow. I hope they ship to Australia!

[@electronicsoldandnew]

I think they do. This thing has been in use for some time now, and has not let me down.

[@OliverWoodphotography]

Those LM chips are amazing. I built an LM3875 amp a few years ago, still use it now, very good sound. Next I think I will try one of these, the 3886 is supposed to be the very best linear amp chip you can buy.

[@electronicsoldandnew]

I also used the LM3875 for quite some time without issues. This one is amazing as a test amp.

[@DerekHerbst747]

Your lab is taking shape rather nicely. It probably consumes one quarter of the power mine does. Almost everything I have is tube technology 🙂

[@electronicsoldandnew]

Wastrel! Probably all the SK2’s you’re testing 😊

[@petercornell2002]

Great vid, thanks. Excellent specs on the amp! Peter

[@electronicsoldandnew]

thanks

[@danielsaturnino5715]

One more tool in the shelf :) and a good one it seems.

[@electronicsoldandnew]

Sure is

[@xyredmax]

Wow, have you seen how much these are now!

[@electronicsoldandnew]

I’m afraid not. Hope I didn’t contribute to a price rise 😊

[@mattvoce1091]

If not using mains earth to chassis be better to use both poles of main switch and switch the active(hot) and neutral, add some heat shrink then you have safer setup!

[@jamesmdeluca]

Greetings: I think your audio signal generator has a sweep function. I have seen it used sparingly, here & maybe another youtube chan. If your gen has presets, please set one for a 20Hz-20kHz sweep and set the scope such that the display completes before it is retrggeredy (if the scope has presets all the better). I presume the gen has a trigger output. This way, at a glance you can display the full bandwidth. I presume you can set other presets to restore your usual settings (if USB computer control is available, that maybe very useful to switch back and forth). I know first time setup is involved, but I am sure you will enjoy the result.

[@electronicsoldandnew]

I’ve tried that 😊 I’m actually working on another way to get an actual bode plot (other than the built-in bode plot function). It’s pretty simple, so stay tuned 😊

[@Steven_Bennett_YT]

Great project with amazing results, please may we have purchase links for the pot, knob and binding posts - thanks

[@electronicsoldandnew]

I’m afraid I had those lying around. I must have bought the posts on ebay. Can’t remember where I got the pot and knob.

[@hestheMaster]

Bloody amazing indeed Manuel ! I'm sure you will be using it very often.😎 I see your "disliker" has shown up!

[@electronicsoldandnew]

You’re right! Thought i’d lost him. I was quite worried 😟

[@chrisvinicombe9947]

Very nice build. Mad bandwidth. Will we be getting a "my new scope" video?

[@electronicsoldandnew]

probably 😊I’ll use it for a while and then comment on it.

[@pneumatic00]

I just use a pair of old computer speakers. Doesn't put out 65 watts. Isn't flat from 10 Hz to 100Khz, doesn't protect its speaker. However, it costs $2 at a garage sale and if you blow it up you go get another pair.

[@electronicsoldandnew]

👍

[@preiter20]

Does Manuel need another amplifier? "You are not my wife"! This made me legitimately lol. I needed a good laugh today. Thanks Manuel!

[@electronicsoldandnew]

We all need a laugh, especially in these crazy times 😊

[@MrVasile]

I SO busted out laughing at that!

[@jamesmdeluca]

Greetings: I was interested in finding your chassis, but think you built it yourself. Probably built the same way as all of your other chassis. Beautiful work BTW.

[@electronicsoldandnew]

Yes, the chassis is really DIY using a square 65mm aluminium element, with the top cut off.

[@alfredneumann4692]

If you adjust the output impedance, you have a ultralongwave transmitter. :-)

[@electronicsoldandnew]

True. I’ll connect an antenna instead of a speaker cable 😊

[@jake359nl]

Nice project...and well done! Could you please make a video of how you designed that frontplate in Illustrator? I can't find those symbols in any library.

[@electronicsoldandnew]

I did not use pre-made symbols. Everything is designed simply using the line and polygon tools. There are simpler software packages for this, but I use illustrator as the measurement function is very accurate.

[@davidward9935]

Manuel, thank you again for the wonderfully educational videos. I see you put the potentiometer on the input without any buffer. Will it have an affect on the input device? Should you put a low preamp op-amp before the potentiometer to keep from loading the device under test? Thank you for making me think about the things I studied 40 years ago in high school radio and tv repair classes when tubes were still king but the transition was full on. Best regards, David ka4mep

[@electronicsoldandnew]

The input impedance that the device under test will see is the pot, and in fact, if you test a circuit, that circuit should do an impedance. In fact, sometimes it needs to see one to work properly. The input impedance is also quite high here, which is also a good thing. Adding an opamp buffer would make this an unrealistic load.

[@geirendre]

Nice kit and really cheap also. See they have a lot of kits including Bluetooth receiver modules...

[@electronicsoldandnew]

Yes they do. I have bought some stuff from them in the past, with good results.

Hi Manuel. Can you please tell me (us) more about your Dual AC supply? Is that one transformer with taps? How much VA? Any link? And did you put fuses in it or how do you protect it? Thanks.

[@electronicsoldandnew]

It’s just a simple transformer that has all these taps, which makes it useful. I think it’s about 50VA. I use a 500mA fuse on the primary as a simple protection.

[@Michlag]

For the bandwidth experiment, couldn'T you do a sweep between 10/100kHz? Would that work to get a curve plotted on the scope?

[@electronicsoldandnew]

No, I’d meet the Bode Plot function which I haven’t figured out how to use yet 😊

[@sklgy]

Is this amp also usable to with a set of old stereo speakers? I am looking for a small amp that I can use in my eurorack as multipurpose audio rack.

[@electronicsoldandnew]

That’s exactly what I use them with. I don’t use good speakers in the workshop in case I damage them in testing equipment.

[@sklgy]

@@electronicsoldandnew Perfect, then thank you for guiding me to this module. It is exactly what I was looking for then! Also do you maybe have any tips on powering it with my eurorack uZeus module? It has +5 +12 and -12 and 16 pin headers to connect to.

[@sincerelyyours7538]

Nice amp! I'll add it to my wish list. Was wondering when you'd trade up your old Rigol DS1052 scope. Looks like you got a nice one!

[@electronicsoldandnew]

the rigol earned a break 😊

[@Michlag]

Hi Manuel, question: has the frontplate stickers applied? I mean, adobe illustrator ---> print on sticker (how? Got it done somewhere?) ---> apply the stiker? Regards, Mike

[@electronicsoldandnew]

Illustrator, printed on overhead transparency sheet, stuck with transparent spray glue.

[@flemmingchristiansen2462]

Nice one. Did you leave the board hanging by the chips? I believe that fine amplifier deserves better, as a lab. amp. you don't want to risk those solder joints to fail over time. Just a thought.

[@electronicsoldandnew]

No, standoffs are being made to support it. The chips get quite warm, so cold solder joints are a real worry.

[@flemmingchristiansen2462]

@@electronicsoldandnew I Know -belt and suspenders but it is sitting in a working environment, bumping the box when plug it in and out, vibrations on the shelf on top when you work at the instruments. The are some heavy components on the board, might react hard on small vibrations.

[@Michlag]

Hey, new scope?

[@electronicsoldandnew]

Yes, Christmas came early 😊

[@Michlag]

@@electronicsoldandnew congrats!

[@sean-ci3tv]

make a virtual earth in case mains switch fails to chassis?

[@electronicsoldandnew]

I’m going to have to change the rail system I use so that the various units don’t connect to each other. Then I’ll earth the chassis without any problem.

[@rossthompson1635]

@@electronicsoldandnew You are gathering a fabulous collection of accessories under your shelf there. Will there be an end-piece on the amp section to prevent contact with the mains switch?

[@electronicsoldandnew]

i definitely need to insulate it. maybe an end piece or hot glue (?).

[@rossthompson1635]

@@electronicsoldandnew I know it is under your control in the workshop but I'd be inclined to go for enclosing it rather than glue - just never know what might make its way in there. You could perhaps get one of those boots that goes over chassis mount IEC plugs cpc.farnell.com/bulgin/14064/insulation-boot-20a/dp/CN08377?mckv=s1Exx1fLn_dm|pcrid|224645161149|kword||match||plid||slid||product|CN08377|pgrid|45968746254|ptaid|pla-925788073354|&CMP=KNC-GUK-CPC-SHOPPING&gclid=Cj0KCQiA48j9BRC-ARIsAMQu3WSEo_YngRfHXWfHZpSy7ainmVC1D_YRkLgbz7irDE4Xk_nj_R1sSxMaAvbxEALw_wcB

[@BjornV78]

You can't have to many amplifiers ;-)

[@electronicsoldandnew]

👌

[@SheikhN-bible-syndrome]

That's a ic amp not a chip amp a chip amp would be something like the ne5532