Advice and interest check for a Nano Stereo Amplifier built for beginners.

[sureshkuranjalayil]

Dear Friends,

After seeing a lot of excellent DIY projects by our forum members, many of us may have developed interest in doing some DIY audio projects

I would like to build a good quality but low cost amplifier as a beginning and seek advise and suggestions from our experienced forum members to proceed further in this regard. If other forum members are interested we can also go in for a Group Buy for components, cabinet etc.

First advice is required for finalizing a suitable schematic for this amplifier build. Some LM 3886/LM 4766 based amplifer PCB/Kit is available in Eby India.

2 x LM3886 68Watt IC + PCB + DIY Kit Components (Two Economical Sets) | eBay

PCB for LM3886 68W RMS amplifier IC | eBay
LM4766 40+40W RMS amplifier IC with PCB | eBay

Some kits are available fom Vegakits, Mumbai also:

Catalogue

How good are these amplifers?

After finalzing the schematic, advise on power supply, cabinet etc are also required.

Looking forward for experts advise /suggestions and also beginners interest in this project.

Best regards,

Suresh Babu

 

[novice-akki]

+1 to the initiative

Would love to get my hands dirty with something similar, in fact I've messaged the same reseller seeking advice on the same points as discussed here like power supply, cabinet etc.

 

[novice-akki]

Here's the reply I got from ebay reseller, must admit the gentleman is extremely prompt and sales is not his only motive seems to be seasoned DIY'er

Following are the other components and associated costs to get the best performance:-
1. All resistors are to be 1% Precision Resistors: Rs.21
2. 100uF and 22uF Electrolytic caps should be of reputed make: Rs.10 for Keltron (I dont have Nichicons)
3. 1uF Box Cap should be replaced with 2uf Box Cap, 2.2uF preferred: Rs.42
4. Big Power bank Capacitors for filtering: Rs.285=>I have to go home and re-check stock/price
5. Mica Insulators + Good Thermal paste: Rs.25 => plastic sleev for nut/bolt is used one and I will give it for free.
6. 100nF Ceramic Caps to be replaced with Box Polyester Caps : Rs. 20
7. 95mm Flat-type extruded Heat-Sinks if you don't have and you want new one's, then I can Pre-Order for you. That would cost you Rs.900 for one pair. If you want used one that I have (AMD CPU Heat Sinks) that would cost you Rs.400 Each. These one comes with 3mm thick copper shims!!!
8. 220pF and 47pF capacitors will remain ceramic, I will try and get you Film Caps: no costs here.
9. 2 x 10Amp Bridge rectifier: Rs.40
10: 18-0-18 250VA Transformer (nearly 1kg+) + Snubberizing Setup: Rs.1150+42
OR 18-0-18 150VA Transformer + Snubberizing Setup: Rs. 750+42
11. PCB Cost for 2 PCB's: Rs.112
12. LM3886 IC x 2: Rs.500
13. RCA Connectors: I will inquire and quote the price. Do you want gold plated ones or normal ones?

 

[keith_correa]

Check this. Maybe you can send a PM to Linuxguru and see if he still has kits available.

 

[sann]

Hi Suresh, You can also consider Amp Camp Amp #1 from Nelson Pass, its a single-ended class A amp, would sound different than the chip amps and wouldnt cost much.

You can read about it at: Amp Camp Amp #1 - diyAudio
-sann'

 

[sachu888]

Hi Suresh, You can also consider Amp Camp Amp #1 from Nelson Pass, its a single-ended class A amp, would sound different than the chip amps and wouldnt cost much.

You can read about it at: Amp Camp Amp #1 - diyAudio
-sann'

I already have PCBs for few forum members.Layout is by Rudi Ratlos of Diyaudio. FM Nraghunadh may complete it this month.
I hope to build it in July 1st week.

Regards,
Sachin

 

[sureshkuranjalayil]

Thanks for sharing the information.

Cost of this LM 3886 based amp build seems to be around Rs.4000/- excluding cabinet, connectors etc. I think the completely build amp would cost around Rs.5000/-.

Our experienced forum members may please suggest whether it is good project that can be undertaken by a newbe. My preferene is a low cost project as it is for getting some learning experience.

Regards,
Suresh

Here's the reply I got from ebay reseller, must admit the gentleman is extremely prompt and sales is not his only motive seems to be seasoned DIY'er

Following are the other components and associated costs to get the best performance:-
1. All resistors are to be 1% Precision Resistors: Rs.21
2. 100uF and 22uF Electrolytic caps should be of reputed make: Rs.10 for Keltron (I dont have Nichicons)
3. 1uF Box Cap should be replaced with 2uf Box Cap, 2.2uF preferred: Rs.42
4. Big Power bank Capacitors for filtering: Rs.285=>I have to go home and re-check stock/price
5. Mica Insulators + Good Thermal paste: Rs.25 => plastic sleev for nut/bolt is used one and I will give it for free.
6. 100nF Ceramic Caps to be replaced with Box Polyester Caps : Rs. 20
7. 95mm Flat-type extruded Heat-Sinks if you don't have and you want new one's, then I can Pre-Order for you. That would cost you Rs.900 for one pair. If you want used one that I have (AMD CPU Heat Sinks) that would cost you Rs.400 Each. These one comes with 3mm thick copper shims!!!
8. 220pF and 47pF capacitors will remain ceramic, I will try and get you Film Caps: no costs here.
9. 2 x 10Amp Bridge rectifier: Rs.40
10: 18-0-18 250VA Transformer (nearly 1kg+) + Snubberizing Setup: Rs.1150+42
OR 18-0-18 150VA Transformer + Snubberizing Setup: Rs. 750+42
11. PCB Cost for 2 PCB's: Rs.112
12. LM3886 IC x 2: Rs.500
13. RCA Connectors: I will inquire and quote the price. Do you want gold plated ones or normal ones?

 

[captrajesh]

Check this. Maybe you can send a PM to Linuxguru and see if he still has kits available.

I had recently corresponded with him as one of my friends wanted a stereo amp; the kits are now costing 6k or so. Add to that the cost of trafo, cabinet and other misc stuff like RCA Plugs, Speaker binding posts, IEC plug, on off button and you can guess what the cost would be.

I already have PCBs for few forum members. Layout is by Rudi Ratlos of Diyaudio. FM Nraghunadh may complete it this month.

I hope to build it in July 1st week.

How much does it cost? Why don't you start a thread?

Cost of this LM 3886 based amp build seems to be around Rs.4000/- excluding cabinet, connectors etc. I think the completely build amp would cost around Rs.5000/-.

Which one are you referring to? This kit is costing only Rs. 685: 2 x LM3886 68Watt IC + PCB + DIY Kit Components (Two Economical Sets) | eBay

 

[sachu888]

Hi capt,
I did start a thread regarding but deleted by mods.I received an infraction from mods that I can't start a interest check thread.I replied him that if I can start a GB but no reply from mod.
It may cost Rs 7000(approx) including everything like finished cab with other hardware.

Regards,
Sachin

 

[stevieboy]

Sachin,

Maybe the way around is to start a thread on it with details of your build. Then when someone shows interest and I'm sure people will, you reply saying that if interested I can organize a group buy for members. This should fit the rules I guess.

Regards

Ps: for every rule there's a roundabout legal way.

 

[sachu888]

Thanks Steve,
I have provided PCbs and parts to Fm Raghunath for cab.he will complete his build first.That will give me an idea regarding final cost and cab design.

Regards,
Sachin

 

[hifisandy]

LM3886 is a decent amp but that kit on the ebay has got the bad quality caps like Mylar... which is bad and not recommended. Ceramic caps absorb all the RF noise in the chassis so one need design to take them off the design... any questions? I have opa549 with which is warmer in sound and i feel they are better overall when compared to lm3886. Even if you check on diyaudio.com people recommend using OPA549 which is from Texas instruments really good and I loved its sound quality... i built 10 boards so that i can use 5 of them and sell to some diy guy who wants it... I have used Elna Silmic2 Capacitors which are supposed to be the best sounding capacitors I have found bass is awesome with these capacitors.

 

[sureshkuranjalayil]

Which one are you referring to? This kit is costing only Rs. 685: 2 x LM3886 68Watt IC + PCB + DIY Kit Components (Two Economical Sets) | eBay[/QUOTE]


Dear Capt:

Cost worked based on the Post # 3 of Novice-Akki.


Regards,
Suresh

 

[sureshkuranjalayil]

LM3886 is a decent amp but that kit on the ebay has got the bad quality caps like Mylar... which is bad and not recommended. Ceramic caps absorb all the RF noise in the chassis so one need design to take them off the design... any questions? I have opa549 with which is warmer in sound and i feel they are better overall when compared to lm3886. Even if you check on diyaudio.com people recommend using OPA549 which is from Texas instruments really good and I loved its sound quality... i built 10 boards so that i can use 5 of them and sell to some diy guy who wants it... I have used Elna Silmic2 Capacitors which are supposed to be the best sounding capacitors I have found bass is awesome with these capacitors.

Could you please let me know the approx cost of this OPA 549 based amp build (components and PCB).

Regards,
Suresh

 

[captrajesh]

Cost worked based on the Post # 3 of Novice-Akki.

Okie, got it.

 

[novice-akki]

Posting in this thread because the OP and I are in the same dilemma and also didn't want to start a new thread as it'd lead to redundancy, hope its OK with OP and everyone else.


Please share your views on these kits or kindly suggest a good kit costing ~ $ 100.00 for Whardale 9.1 - 6ohm



Option 1 Kit has quality parts like Solen MKP fast capacitor AC coupling and Nichicion FW audio grade capacitors for decoupling, and low noise Dale resistors

Doubts: Does is it have a power supply board and components AND how good is the design ?




Option 2 kit has acceptable parts and include

1X Power supply board kit
2 X Power Amplifier board Kits
1 X Heat sink
1 X Welding circuit digram(not schematic)

Doubt: is it a good design ?





Option 3 Dual mono kit for $ 90 plus $ 18 shipping seems to be reliable as a few people have built them on other forums,

Non-Inverting LM3886 Dual Mono Kit

- 2 x Amplifier PCBs- 2 x Basic Amplifier Components

- 2 x Power Supply PCBs

- 2 x Basic Power Supply Components

I'd sent an email to them 2 days back but haven't had a reply yet, seems that site hasn't been updated recently, will it be safe to order from them ?


Thanks in advance.

 

[keith_correa]

Did you look into Peter Daniels kits? With the Rs. exchange rate that it is, I think you'd be better off ordering a kit from Siva [linuxguru]. PM him, he will give you good advice.

 

[sachu888]

Did you look into Peter Daniels kits? With the Rs. exchange rate that it is, I think you'd be better off ordering a kit from Siva [linuxguru]. PM him, he will give you good advice.

+1 to Keith.That Chipamp kit is also good.I don't trust Chinese sellers for components.Most of the components sell by Chinese sellers on Ebay are fake.

Regards,
Sachin

 

[novice-akki]

Did you look into Peter Daniels kits? With the Rs. exchange rate that it is, I think you'd be better off ordering a kit from Siva [linuxguru]. PM him, he will give you good advice.

Peter Daniels kit look nice, sending a PM to Siva Sir regd. availability of the kits.

+1 to Keith.That Chipamp kit is also good.I don't trust Chinese sellers for components.Most of the components sell by Chinese sellers on Ebay are fake.

Regards,
Sachin

That's another reason dont want to bite the bullet, truthfully it looks very tempting with quality parts, PCB and shipping all for ~ $70 USD - too good to be true.

 

[sureshkuranjalayil]

Re: Advice and interest check for a Nano Stereo Amplifier build for beginners.

I have decided to build LM 3886 Amplifier.

Ordered PCB from an E-bay seller. Price per PCB is Rs.33/- + Rs.40 Postage. I have ordered 4 PCBs and the total cost comes to Rs.132 + Rs.55 Postage. Hence, the cost of one PCB comes to Rs.46.75

A component list (for two boards) has been prepared based on the data sheet provided by the PCB seller and the advise/suggestions received from our omishra, as under:-

1 1K Ohm Resistor 1/4 Watt MFR 1% 4 Nos.
2 33 K Ohm Resistor 1/4 Watt MFR 1% 10 Nos.
3 10 Om Resistor 5 Watt (or 10 Ohm Carbon Composition or Wire Wound) 2 Nos.
4 2.2 uf 63 V Metal Film Capacitor 2 Nos.
5 220pf - 160 V Polyster Capacitor 2 Nos.
6 22 uf - 40 V Electrolytic Capacitor 2 Nos.
7 47 pF - 16 V Silver Mica/Polyster Capacitor 2 Nos.
8 100 uf - 40 V Electrolytic 2 Nos.
9 100 nf 100 V PP or Polyeter 4 Nos.
10 220 uF, 40 V - Electrolytic 4 Nos.
11 LM 3886 IC 2 Nos.

Tomorrow I am going to Lamington Road to procure these components. Pointers requested from our Mumbai members, from which shop I will be able to get these components.

I have reqested omishra to provide details for Power Supply, Volume control etc. for this amp.

Next step is to get/build a decent looking cabinet for this amplifier. Suggestions/Advise requested from FMs for a low cost solution.

Regards,
Suresh