Discrete components based amp vs Chip amps, which is easier to achieve for n00bs ?

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Building a discrete amp means there's more to go wrong. You have to obtain the correct parts, and some may only be available from industrial suppliers that have large minimum orders and only ship using expensive courier services that charge whopping customs fees. There are more chances of installing the parts incorrectly, especially if you have made substitutions. If you buy from vendors in China, there's a good chance of the parts being rejects or counterfeit. Counterfeit parts might work for a while, but fail when you turn the volume up, and then you'll learn why amplifiers should have DC fault protection.

At higher power levels, it's probably cheaper to buy a used consumer or (semi)pro amplifier, unless you can obtain parts very cheaply. Budgeting $100 each for a case, transformer, heat sinks, filter caps, and each channel isn't unreasonable.
 
Building a discrete amp means there's more to go wrong. You have to obtain the correct parts, and some may only be available from industrial suppliers that have large minimum orders and only ship using expensive courier services that charge whopping customs fees. There are more chances of installing the parts incorrectly, especially if you have made substitutions. If you buy from vendors in China, there's a good chance of the parts being rejects or counterfeit. Counterfeit parts might work for a while, but fail when you turn the volume up, and then you'll learn why amplifiers should have DC fault protection.

At higher power levels, it's probably cheaper to buy a used consumer or (semi)pro amplifier, unless you can obtain parts very cheaply. Budgeting $100 each for a case, transformer, heat sinks, filter caps, and each channel isn't unreasonable.

I have the case and the connectors with me but the rest....🙁
 
If you used the same power supply with the chip amp and the kit amp, but the kit amp seemed to put out a lot more power, then I suspect there may be something wrong with the chip amp. You say you have an 8 ohm load, that shouldn't be stressing the chip amp too much.

Can you put up some details of the chip amp. Maybe you used a smaller heatsink with it or were unable to run it at full power due to less gain or something.

Just curious, if you had success with the kit amp why you aren't using that?
 
If you used the same power supply with the chip amp and the kit amp, but the kit amp seemed to put out a lot more power, then I suspect there may be something wrong with the chip amp. You say you have an 8 ohm load, that shouldn't be stressing the chip amp too much.

Can you put up some details of the chip amp. Maybe you used a smaller heatsink with it or were unable to run it at full power due to less gain or something.

Just curious, if you had success with the kit amp why you aren't using that?

This is the kit amp I have now
Wintek - 68W Mono (LM3886)


The earlier one...wasn't that good but it was very loud.
The reason for changing that amp was one of the channel (right) kind of had a fault. The sound coming out from the speakers was sort of muffled and without any detail.

BTW, I got an offer just now from ebay.in seller for 1. BP300 (LM3886x6) - 300W 2. Toshiba 1943/1952 + TL072/5532 based amp with good quality pcb and imported audiophile grade caps.
 
SpiKe protection is an odd bird. As I mentioned earlier, I found it kicking in even though my sink was well below 40C. It seems to have some sort of predictive thing - you are about to demand to much current so I will limit you.

It's OK to put two chips on a single heat sink, try it on the other amp's sink.
 
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Thanks for the recommendation 🙂

BTW, for the construction of the PeeCeeBee or any other amp, would there be any requirement to use "exotic" capacitors and metal film resistors ?
Also, how much power the PeeCeeBee can o/p ?
Only six transistor & you don't need exotic part, I have my friend here just build using what he can buy locally (except for the Lateral Mosfet)
He really love the sound 🙂 50 watt of the PeeCeeBee sound is enough, but you can push it to 100 watt max (but at some risk)
also there is some parts need to matching & you need more resistor to buy.
carbon resistor will do but i guess metal film is better & easier to match.
You can try to read the thread to find more info...

My next recommendation is try to get the part that easy to source...
put the parts list & try to find all of them, If you can find most of the part then you ready to make a first discrete amp.
(My first discrete amp was fault & burn 2 woofers because wrong parts choice)

I usually buy some parts online here locally,
now I try the international shipping too 😀

but wait a second, before go discrete do you have made your own PCB?
(LM3886 also can be made without PCB)
(I'm also curious what happen to your 3886, have you try to swap with another speaker)
I using 2 way speaker & it is 8 ohm impedance, I can test any chip amp easily & safe
 
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I kinda think of Lateral Mosfets as exotic in my country.
Hard to get them here.
Yes, that was quite exotic for me too before I know some friend sell it online.
I have info from other DIY friend,
so you need to contact some friends to know where was they buy the part

They also quite expensive, one pair(Renesas J162-K1058) is more expensive than one LM3886 chip but LM3875 is more expensive & more exotic too 🙂

That's why I suggest try to find the parts first 🙂
 
SpiKe protection is an odd bird. As I mentioned earlier, I found it kicking in even though my sink was well below 40C. It seems to have some sort of predictive thing - you are about to demand to much current so I will limit you.

It's OK to put two chips on a single heat sink, try it on the other amp's sink.
OK, I'll do it on sunday.
BTW, does a thermal compound necessory for this, just like mounting a processor heatsink ?

Only six transistor & you don't need exotic part, I have my friend here just build using what he can buy locally (except for the Lateral Mosfet)
He really love the sound 🙂 50 watt of the PeeCeeBee sound is enough, but you can push it to 100 watt max (but at some risk)
also there is some parts need to matching & you need more resistor to buy.
carbon resistor will do but i guess metal film is better & easier to match.
You can try to read the thread to find more info...

My next recommendation is try to get the part that easy to source...
put the parts list & try to find all of them, If you can find most of the part then you ready to make a first discrete amp.
(My first discrete amp was fault & burn 2 woofers because wrong parts choice)

I usually buy some parts online here locally,
now I try the international shipping too 😀

but wait a second, before go discrete do you have made your own PCB?
(LM3886 also can be made without PCB)
(I'm also curious what happen to your 3886, have you try to swap with another speaker)
I using 2 way speaker & it is 8 ohm impedance, I can test any chip amp easily & safe
Yup, I agree.

I kinda think of Lateral Mosfets as exotic in my country.
Hard to get them here.

Yes, that was quite exotic for me too before I know some friend sell it online.
I have info from other DIY friend,
so you need to contact some friends to know where was they buy the part

They also quite expensive, one pair(Renesas J162-K1058) is more expensive than one LM3886 chip but LM3875 is more expensive & more exotic too 🙂

That's why I suggest try to find the parts first 🙂
Yeah, you are right. But the store I'm visiting is quite busy !😛
The shopkeeper is already like..here comes the trouble when he sees me 😀
If you are a bass liker, construct a Symasym. It gives a boomy bass.
If you want a non fatigue amp, construct a Low TIM Leach amp. This is preferred if you listen to the music for long time contineously.

Gajanan Phadte

I'm not a fan of boomy bass. I want "tight" bass which I think I got with the LM3886.
I love details..especially in the higher frequency part as I'm very sensitive to higher frequencies.
 
The specs are:170 mm midrange
2 x 170 mm woofer
25 mm tweeter
Power Handling (RMS / Max.) 180 / 360 watts
Sensitivity (2.8V/1m) 92 dB
Impedance 4 – 8 Ohms
It looks like the 4 drivers are all 8ohms.
The two woofers in parallel will give an effective load of 4ohms.

That would explain the 4 to 8 Ohms impedance.

You thus need to design your amplifier for 4 ohms duty. This is because many of the long term high power events will be at low frequency. This increases the temperature of the output stage and it's driver transistors.

So you are designing for a 200W into 4ohms amplifier. As I said earlier, this is a very different task from a 100W into 8ohms amplifier.
 
It looks like the 4 drivers are all 8ohms.
The two woofers in parallel will give an effective load of 4ohms.

That would explain the 4 to 8 Ohms impedance.

You thus need to design your amplifier for 4 ohms duty. This is because many of the long term high power events will be at low frequency. This increases the temperature of the output stage and it's driver transistors.

So you are designing for a 200W into 4ohms amplifier. As I said earlier, this is a very different task from a 100W into 8ohms amplifier.
Thanks for the heads up 🙂

So, that means more powerful PSU ?
Also, what does it mean for selecting an amp for my immediate build ?

The ebay.in seller I mentioned just recommended me to do the BP300 using LM3886. He is promising to get me all the components including nichicon or better caps and metal film 1% resistors.
Any newbies have done a BP300 here ?
 
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