100W HIFI Amp

[SoundCraft]

I would have the PCB's made professionally, the minimum order here is 20. So, I would get 20 PCB's each for the amp and the power supply.
I could send you the Gerber files for the PCB with on board protection if you want.

Much obliged Aniket,But can I suggest a middle ground ?? can we have the PCB with protection made and you an omit that section and assemble it ?? that way we both (or whoever else is interested) can share the costs ?? As Krishna has said if we get 6 PCB's (if there are no others) then we save some basic costs !

Let me know if it works for you.

 

[Aniket]

Much obliged Aniket,But can I suggest a middle ground ?? can we have the PCB with protection made and you an omit that section and assemble it ?? that way we both (or whoever else is interested) can share the costs ?? As Krishna has said if we get 6 PCB's (if there are no others) then we save some basic costs !

Let me know if it works for you.

Hello Soundcraft,

As I have mentioned earlier that I am going with the modular construction, keeping the protection and soft start on a separate board. I am going away with PCBs without on board protection.
If we are using a separate protection scheme, then we can use a single protection circuit for both the channels. no need for separate protection circuits for each channel, thereby reducing parts count. Also we could have a soft start circuit on the same PCB, using a common power source. In fact we would have less wiring hassle in this scheme. I am not forcing you on this, but just a general advice.
If some members are interested with onboard protection PCB, then I would send over the Gerbers, so that you could have them manufactured at your place, if that's an economical option for all the members.

Regards,
Aniket

 

[SoundCraft]

Aniket like I have already mentioned,Am game to what majority wants !

So if you can start a thread with interest check or ask people in this thread as to what they prefer we can finalise on the same.

 

[Aniket]

I may hereby declare and ask, if anyone is interested in PCBs of this amplifier and the power supply, or the complete kit including the PCBs and parts(including heat sinks), assembled or disassembled then please let me know, so that we could start a group buy or something.

Also, lets have interest check on PCBs with or without on board protection before finalizing anything.

Regards,
Aniket

 

[keith_correa]

Depending on the cost, count me in for 1 assembled kit.

I vote for a separate board for soft-start+protection.

 

[sarith]

I may hereby declare and ask, if anyone is interested in PCBs of this amplifier and the power supply, or the complete kit including the PCBs and parts(including heat sinks), assembled or disassembled then please let me know, so that we could start a group buy or something.

Also, lets have interest check on PCBs with or without on board protection before finalizing anything.

Regards,
Aniket

Aniket, what will be the cost of the complete kit and PCBs?

 

[rbalu72]

Aniket,

I would be interested to get assembled PCBs with on board protection if possible. Am ok even for PCBs without protection and protection pcb with kit separate.

I would be needing a Stereo Amp i.e., 2 channels. I presume your BOM is for a stereo setup. What about power supply board incl transformer, components and cabinet?

Please also suggest what else is required to have complete setup to use this Amp meaning, how to give input to it, speakers etc (any suggestions to procure some quality stuff) as I have to start from scratch if I build this.

I am currently havng Onkyo AVR which is serving for my Audio/Visual needs. So how many connections this Amp will take (this may be a noob question) but what is required if i wish to connect some analog or digital inputs through this Amp..

 

[rbalu72]

@Aniket

Also, since you have already got components and about to construct once PCBs arrive, is there a way you can upload how it sounds over youtube something like that?

 

[Aniket]

@Aniket

Also, since you have already got components and about to construct once PCBs arrive, is there a way you can upload how it sounds over youtube something like that?

Sure, would do.

Aniket, what will be the cost of the complete kit and PCBs?

I have attached the updated BOM for a stereo, 2 channel amplifier full assembled kit. It includes PCBs without on board protection, all components, heatsinks complete kit without power supply. I have done my best to use the best quality components available in the local market in Delhi.

Power supply PCB along with filter caps would be separate. Filter caps would be according to the buyers choice.

Power Supply PCB have the option to install 4 30mm and 3 40mm diameter caps per rail. Here's the cost:

PCB: 350 INR

Bridge Rectifier, KBPC3510 1000V 35A: 70 INR

Euroblock connector: 5 INR

Capacitors:
Hitachi 10000uF63V: 240 INR
Hitachi 15000uF100V: 480 INR
Nichicon 22000uF63V: 640 INR
Cornell Dubilier 10000uF63V: 400 INR
Cornell Dubilier 4700uF63V: 250 INR
United Chemi-Con 10000uF63V: 500 INR
Epcos 6800uF63V: 380 INR
Epcos 4700uF63V: 300 INR
Epcos 10000uF63V: 500 INR
AEC 470n100V: 8 INR
AEC 220n100V: 6 INR

Shipping charges would be extra as per Fedex standard rates.

Thanks & Regards,
Aniket

 

[Aniket]

Aniket,

I would be interested to get assembled PCBs with on board protection if possible. Am ok even for PCBs without protection and protection pcb with kit separate.

I would be needing a Stereo Amp i.e., 2 channels. I presume your BOM is for a stereo setup. What about power supply board incl transformer, components and cabinet?

Please also suggest what else is required to have complete setup to use this Amp meaning, how to give input to it, speakers etc (any suggestions to procure some quality stuff) as I have to start from scratch if I build this.

I am currently havng Onkyo AVR which is serving for my Audio/Visual needs. So how many connections this Amp will take (this may be a noob question) but what is required if i wish to connect some analog or digital inputs through this Amp..

Hi rbalu72,

The updated BOM is for stereo(i.e 2 channels) amplifier, for the power supply you would need a separate power supply board, main filter capacitors, transformer.

For the transformer and cabinet I would suggest you to source these from your place. It would need a 35-0-35V,300VA transformer for 100W+100W into 8 ohms. For transformers with VA rating less than 500VA soft start really isn't necessary. The protection circuit could be made on a separate PCB with it's auxiliary transformer.

If your AVR has volume control(of course it would have) then you wont need a preamp for volume control for this amp. But, if you need tone controls then surely you would need a preamp, that could be integrated in the amp itself, in the same cabinet. Then you would have an integrated amp.

Please also mention your AVR model, so that we could guide you more.

Regards,
Aniket

 

[rbalu72]

I have Onkyo AVR HT-R370 which has the connectivity options as in

. It does not have any pre-out or something like that which i just learned in another thread in DIY of this forum.. So not sure how i will drive this amplifier (can i connect RCA audio out of a dvd player directly to input of this amp?, I am noob and i need some clear suggestion as i dont want to endup with something unusable)

So the BOM is INR 4042, Power supply PCB + components per your post is INR 4129 (hope this can drive both channels of stereo). So roughly both of these will be INR8200. correct me if my understanding is incorrect.

Apart from this, you do not recommend any protection circuit inlieu of the Transformer being used, but if i still want to include it, how much the pcb+components of protection board comes upto?

What would be the recommended Ohm of the output speakers i mean, can it drive any speaker set or a spec?

which class of amplifier this amp belong to?

 

[Aniket]

I have Onkyo AVR HT-R370 which has the connectivity options as in

. It does not have any pre-out or something like that which i just learned in another thread in DIY of this forum.. So not sure how i will drive this amplifier (can i connect RCA audio out of a dvd player directly to input of this amp?, I am noob and i need some clear suggestion as i dont want to endup with something unusable)

So the BOM is INR 4042, Power supply PCB + components per your post is INR 4129 (hope this can drive both channels of stereo). So roughly both of these will be INR8200. correct me if my understanding is incorrect.

Apart from this, you do not recommend any protection circuit inlieu of the Transformer being used, but if i still want to include it, how much the pcb+components of protection board comes upto?

What would be the recommended Ohm of the output speakers i mean, can it drive any speaker set or a spec?

which class of amplifier this amp belong to?

Yes your receiver doesn't have a pre out. Yes you can and you should connect the RCA from you DVD player directly to the input of the amp(Provided your DVD player has volume control, analog or digital).

You got it right, the BOM is 4042 INR for a stereo amp kit. For the PSU one board would drive both channels. which caps have you selected and calculated the BOM for?

Regarding the protection circuit, it has to be made on a separate PCB, soft start could also be added on the same PCB if you need it, it could be assembled on a general purpose PCB and would cost ~ 600 INR including the auxiliary transformer for it's power supply.

Regarding the speaker impedance, it depends on the power supply voltage.
This amp would deliver 120W into 8 ohms at a max suplly voltage of +/-50V DC.
for 4 ohms load, you need to lower the rails to +/-45V DC. this is the max supply voltage for using a 4 ohm load. Better use a 30-0-30V AC transformer to get ~42V DC. It would do ~150W into 4 ohms.
For 6 ohms load stick to the max supply voltage of +/-45V DC.

Use the supply voltage according to the impedance rating of your speakers.

This is a Class AB amp.

Regards,
Aniket

 

[rbalu72]

You got it right, the BOM is 4042 INR for a stereo amp kit. For the PSU one board would drive both channels. which caps have you selected and calculated the BOM for?

Regarding the speaker impedance, it depends on the power supply voltage.
This amp would deliver 120W into 8 ohms at a max suplly voltage of +/-50V DC.
for 4 ohms load, you need to lower the rails to +/-45V DC. this is the max supply voltage for using a 4 ohm load. Better use a 30-0-30V AC transformer to get ~42V DC. It would do ~150W into 4 ohms.
For 6 ohms load stick to the max supply voltage of +/-45V DC.

Use the supply voltage according to the impedance rating of your speakers.

OOPS ..:lol: I just summed up costs of capacitors and components from

PCB: 350 INR

Bridge Rectifier, KBPC3510 1000V 35A: 70 INR

Euroblock connector: 5 INR

Capacitors:
Hitachi 10000uF63V: 240 INR
Hitachi 15000uF100V: 480 INR
Nichicon 22000uF63V: 640 INR
Cornell Dubilier 10000uF63V: 400 INR
Cornell Dubilier 4700uF63V: 250 INR
United Chemi-Con 10000uF63V: 500 INR
Epcos 6800uF63V: 380 INR
Epcos 4700uF63V: 300 INR
Epcos 10000uF63V: 500 INR
AEC 470n100V: 8 INR
AEC 220n100V: 6 INR

So where from I can get PSU components/BOM ? I thought the above capacitors are all required.., how to know which cap is 30mm and which is 40mm, as per your note it can take 4 30mm and 3 40mm per rail and so it may require about 14 capicotrs in total assuming there are 2 rails . Help please to decipher PSU components.

So if i choose 35-0-35 300va transformer, will it be able to drive any kind of speaker set or i need to procure a specific impedence speaker set? I am not really particular about the max wattage the amp can deliver as long as the audio quality is super and is sufficient for a 12'x20' living room (its obvious that i wont be listening it at its full volume) .

As a owner of the design, which capacitor do you suggest/recommend to go with?

 

[Aniket]

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You could install a total of 6 or 8 capacitors on the attached PSU board depending on their size. either 4 30mm or 3 40mm capacitors per rail. not 14
Also, 6 bypass caps either 220n or 470n.
I could source all the parts and capacitors I mentioned.

If you are going with 35-0-35,300VA transformer, that would suit 8 ohms load, and generally majority of the floorstanders or bookshelfs that are rated at 6 or 8 ohms.

300VA is the absolute minimum rating for the transformer, better go for a 500VA.

If you are using a single PSU board for both channels, I would advice you to go for Nichicon 22000uF63V caps, 3 per rail and total 6 caps.
Or if you are planning for separate PSU for each channel, then use Hitachi 10000u63V caps, 3 per rail and total 6 caps per board.
In either way you would have a solid, powerful PSU.

For your room size, when paired with good and efficient speakers, 100+100W is enough to rattle your households.


Regards,
Aniket

 

[rbalu72]

Thanks Aniket for clarifying...

So I just created a small spreadsheet with cost estimate at

Please confirm if this is correct. Count me in and i will confirm once i hear your youtube trial is uploaded.

 

[Aniket]

Thanks Aniket for clarifying...

So I just created a small spreadsheet with cost estimate at

Please confirm if this is correct. Count me in and i will confirm once i hear your youtube trial is uploaded.

Yep, you got it right.

Regards,
Aniket

 

[rbalu72]

@Aniket,

can this be used as a speaker protection module for this amp ? Wintek - Speaker Protection Module

 

[Aniket]

@Aniket,

can this be used as a speaker protection module for this amp ? Wintek - Speaker Protection Module

In fact you could use any protection circuit, as far as it has some delayed start up and DC protection.
Talking about this protection kit, maybe you would require two of these for a stereo amp.
It doesn't have a soft start circuit i think.

 

[Aniket]

PCB with speaker protection and soft start is also on the cards, currently working on it. It would have its dedicated smallish transformer, any 0-9 or 0-12V 10~20VA would do. 3 relays would be required, one for the soft start(12V DC coil, 250V10A AC contact rating) and two for the speakers(6V DC coil, 250V10A contact rating),
Also delivery of the amplifier and PSU PCBs are delayed because of the Holi vacations, would receive them by 22nd March. waiting anxiously :licklips:

Cheers,
Aniket

 

[rbalu72]

PCB with speaker protection and soft start is also on the cards, currently working on it. It would have its dedicated smallish transformer, any 0-9 or 0-12V 10~20VA would do. 3 relays would be required, one for the soft start(12V DC coil, 250V10A AC contact rating) and two for the speakers(6V DC coil, 250V10A contact rating),
Also delivery of the amplifier and PSU PCBs are delayed because of the Holi vacations, would receive them by 22nd March. waiting anxiously :licklips:

Cheers,
Aniket

So does this mean you are going integrate speaker protection and softstart onto AMP board or this will be a standalone PCB for this purpose ?