First Build: Class D? Gainclone? Transistor?

[nanzer]

Hi,

I'm considering my first build. I'm very new to the community, and am planning on sourcing my parts from Aliexpress (unless they can be obtained cheaper in India?). Currently just planning on a 2.1 channel Amp with atleast 60W of RMS power and minimum distortion. Not sure what impedance load I'll have - I plan to build HiFi speakers in the future, but currently have a 2.1 Boston MCS100 set or 3 Ohm Sony tweeters to choose from.

I've encountered the following ideas so far:
1. Gainclone based on LM4780 (which is basically 2 LM3886's in 1 package) - 1 for Stereo and 1 for Subwoofer. (Rs 2000 each) I plan to couple it with an LM1036 Tone board. (Rs 700) Power will be supplied by 2x 28V SMPS power supplies attached to each other to form a sort-of 28-0-28 pre-rectified system. 10A each supply. Also, I don't understand how nesting works, how can I couple it with an Op Amp for better quality sound? And how much more will that cost if I do it?
2. TPA3116/TDA7294/other Class D amp, again sourced from China. I'm not sure why some people say Class D sounds bad and why it's cheaper, produces less heat, but isn't used in top HiFi builds (to my limited knowledge)
3. The RX-V795 that I'm replacing has 84W Transistors inside it. Would using those or similar ones provide better quality sound?

Just to clarify, I'd rather use or modify a pre-assembled PCB than design/solder my own. Power will be provided using an SMPS, voltage and current is not an issue.

Thanks a lot for your help
Abhayraj

PS - I live in Chandigarh.

 

[jls001]

Do read up on Modulus 86. It's supposed to be one of the best ever implementation of LM3886.

 

[nanzer]

Thanks for the reply JLS!

Unfortunately the Modulus may be a little more expensive than I'd bargained for. I'm currently looking at a TA2022 board - TA2022 from Aliexpress. Can someone advise if this will be suitable?

 

[saikatbiswas82]

What is the sensitivity of your speakers?

I just completed my first DIY amp (will start a thread soon). It's merely 5w/channel amp. It can drive my 90db bookshelves with ease.

One more thing. After a lot of reading and spending money on chipamp based designs, I think 'Class A' designs are better in terms of sq and reliability. IMHO. YMMV.
I will be building another 2 pairs of class A very soon. [emoji4]

I believe class d is the future. Hypex nc400 is a talk of the town now. People who says class d is bad had not listened to any good class d I believe.

I've checked inside my Yamaha A810 as well. To me, my 5wpc amp sounds better than my 100wpc AVR.



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[nanzer]

Thanks for the reply Saikat,
I'll be using the Bose tweeters I have at home as of now. They're part of a surround sound system - each tweeter has 2 drivers, and there are 5 sets of speakers. The datasheet doesn't mention sensitivity at all, and the impedance is "4-8 ohms" (I kid you not)
Once I get more money on hand I'll build a set of good speakers (probably not bookshelves).

 

[MJ23Bulls]

Hi,
I happen to come across this 7294 amp.
YJ TDA7294 amplifier board dual AC26V 0 26V 2.0 channel 2*85W + speaker protection without heat sink-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group

 

[saikatbiswas82]

Thanks for the reply Saikat,
I'll be using the Bose tweeters I have at home as of now. They're part of a surround sound system - each tweeter has 2 drivers, and there are 5 sets of speakers. The datasheet doesn't mention sensitivity at all, and the impedance is "4-8 ohms" (I kid you not)
Once I get more money on hand I'll build a set of good speakers (probably not bookshelves).

No problem at all.

Like Sony, bose never reveals actual specs of their hardware IMHO.

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[GeorgeO]

Hypex is a couple of notches higher in terms of price. I have the UcD 180 they sound very nice, in a 5 channel amp for HT. You cant compare it to the Chip amps

 

[doors666]

whatever you buy, just make sure it atleast comes with a circuit schematic. Without it, it will be very difficult to debug or get help or make changes in case of problems.

Dont expect things like minimum distortion or very good sound quality etc from chinese stuff on alibaba or ebay. Most of the designs leave a lot to be desired, component quality is usually shitty and pcb layouts are bad. While many of them will work and might even sound fine, you will know the difference when comparing it to a equivalent well done design with good quality components.

 

[nanzer]

Well I've narrowed it down to this board - TA2022. I selected it over a ton of boards that look like this, mainly because the blue one looks like it has no filtering capacitors etc. The red one claims to have WIMA capacitors, but I can't see any inductor coils on it. Can someone advise, if they know about this stuff?

Also, if I plan to replace onboard components with high quality stuff, where do I source the good components from?

 

[Audiodoc]

Since it is your initial project a simple lm3886 design with high quality components would give decent results as the component count will be small.

 

[saikatbiswas82]

whatever you buy, just make sure it atleast comes with a circuit schematic. Without it, it will be very difficult to debug or get help or make changes in case of problems.

Dont expect things like minimum distortion or very good sound quality etc from chinese stuff on alibaba or ebay. Most of the designs leave a lot to be desired, component quality is usually shitty and pcb layouts are bad. While many of them will work and might even sound fine, you will know the difference when comparing it to a equivalent well done design with good quality components.

One thing I'd like to highlight. I've bought PCBs from China (including Hong Kong), USA, India. Sometimes Chinese components may be fake. I can proudly say that the Chinese PCBs are of the best quality among them all. One just need to select seller carefully.

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[ajeshkumarts]

You cant compare it to the Chip amps

Sir ,

Does this mean hypex UCD 180 is inferior to chip amp ? I heard one recently it sounded good. I was even thinking of building one

 

[saheb11123]

As a first build either a chipamp or a rather simple and popular design is called for like the peeceebee than fm shaan has build is giving kits.

 

[nanzer]

Update: I've placed an order for 2 TA2022 chips (2x90W each), should arrive in 30-40 days. I've also bought an NE5532 based Preamp and Tone Board, which should arrive at the same time. About Rs 1500 each for all 3. I'll add a thread with the build when they arrive!

 

[saikatbiswas82]

I don't buy this idea. First amp could be anything. It could be a complicated one as well. As long as one has the pcb and some soldering skills, anyone can build any amp.

AFAIK, almost no one (except very few) is inventing anything. They are just getting the PCBs from eBay and building beautiful amps. That's it. IMHO. YMMV.

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[saikatbiswas82]

Sir ,

Does this mean hypex UCD 180 is inferior to chip amp ? I heard one recently it sounded good. I was even thinking of building one

It doesn't mean that. I believe ucd180 should be far superior than basic chipam designs. A proper hypex ucd 180 stereo setup might cost you around EUR 400. Whereas a basic lm3886 based chipamp design might cost you INR 5000-7000 (with high quality components).
And I always believed, quality comes at a price.

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[GeorgeO]

Aminder of thediyaudiocrafts is a good source. Recommended!

 

[MJ23Bulls]

Update: I've placed an order for 2 TA2022 chips (2x90W each), should arrive in 30-40 days. I've also bought an NE5532 based Preamp and Tone Board, which should arrive at the same time. About Rs 1500 each for all 3. I'll add a thread with the build when they arrive!

Congrats for taking the dip & best wishes!

 

[doors666]

One thing I'd like to highlight. I've bought PCBs from China (including Hong Kong), USA, India. Sometimes Chinese components may be fake. I can proudly say that the Chinese PCBs are of the best quality among them all. One just need to select seller carefully.

Sent from my Nexus 5 using Tapatalk

There is nothing wrong with chinese pcb manufacturing, sure they can manufacture good pcbs, infact most of the pcbs being made here, the materials are coming from china. Some of the designs and layouts are also quite good, but these are more of an exception than a rule. The problem is when one purchases from ebay or aliexpress based on the cost and the photo, there is a very good chance you will end up with a bad product.