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> DIY amp club V2, Post your DIY amp here (DIY)

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shinnie
post Jul 12 2017, 09:09 AM

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QUOTE(penmarker @ Jul 11 2017, 11:03 AM)
Can make NAP200 pcb for me or not laugh.gif Mine almost koyak already been soldering and desoldering.
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If it really sound great, why not laugh.gif
penmarker
post Jul 12 2017, 09:20 AM

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QUOTE(shinnie @ Jul 12 2017, 09:09 AM)
If it really sound great, why not laugh.gif
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Serisu bro? tongue.gif From Taobao at least RM70 including shipping etc, if can get from you cheaper and better quality that'll be very great.
shinnie
post Jul 12 2017, 09:25 AM

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QUOTE(penmarker @ Jul 12 2017, 09:20 AM)
Serisu bro? tongue.gif From Taobao at least RM70 including shipping etc, if can get from you cheaper and better quality that'll be very great.
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wuahhhhh.. so cheap.... better grab at china!

Even free labor for PCB drawing, The one time PCB engineering fees also cannot cover the cost. doh.gif
penmarker
post Jul 12 2017, 09:55 AM

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QUOTE(shinnie @ Jul 12 2017, 09:25 AM)
wuahhhhh.. so cheap.... better grab at china!

Even free labor for PCB drawing, The one time PCB engineering fees also cannot cover the cost.  doh.gif
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Lol I have no idea how the pricing is supposed to be. But yea they do have the current production and a newer version.

current: https://item.taobao.com/item.htm?spm=a230r....bucket=2#detail
newer: https://item.taobao.com/item.htm?spm=a230r....bucket=2#detail
shinnie
post Jul 12 2017, 12:52 PM

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QUOTE(penmarker @ Jul 12 2017, 09:55 AM)
Lol I have no idea how the pricing is supposed to be. But yea they do have the current production and a newer version.

current: https://item.taobao.com/item.htm?spm=a230r....bucket=2#detail
newer: https://item.taobao.com/item.htm?spm=a230r....bucket=2#detail
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Usually the taobao engineering fees for
2 layers FR4 1.6mm 1oz 100x100mm = RMB50

at the size for this amplifier, the engineering fees at least >RMB2xx

This post has been edited by shinnie: Jul 12 2017, 12:54 PM
shinnie
post Jul 24 2017, 12:39 AM

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Here are the results after a week of marathon in the progress

user posted image

The goal of first layout:
1. To test the functionality and performance.
2. To test the DC servo making sure the output DC null below 1mV.
4. To draw two Mono block channels in one PCB.
5. To get 0.001THD+N @ 50Watts on my Asus xonar D2X.


Progress:
1. Sent the 2 layers gerber for fabricate, paid for 12 hours urgent fees (RMB200), ship via DHL express via my company account (RM150), arrive here within 5 days. flex.gif
2. Placed ordered for most of the components at element14, and the expensive THAT1200 from oversea that selling at USD5 each, and USD50 for fedex.
3. Ordered some fancies NOVER capacitors from Taobao and ship via DHL express.
4. Note that never ever buy opamps from china/taobao/aliexpress, my engineering team ate the lesson once during developing the 24 bit load cell weighing system few years back. We have wasted at least 3 months time in troubleshooting the hardware stages. Even they are TMALL and claimed that their opamps are genuine and new, DO NOT TRUST THEM.
5. Siap solder...

Results
1. DC servo output work like charm, get unreadable DC voltage on my multimeter.
2. Trust me, it doesn't sound like the LM3886 at all, i mean COMPLETELY different. Maybe this is the power of composite designs.
3. Two 2700k LED accross the Vcc and Vee to make it look like tubey amplifiers. tongue.gif
4. No bleeder network in the design, and no Turn on and off pop/crackers.
5. It ran HOT like class A. rclxms.gif

Going to do list
1. Buy a 100watts 4ohm and 8ohm resistors from taobao and get the measurements from D2X.
2. Hunt for a proper HIFI Outlook casing.
3. Finalize the layout design and add a speaker protection circuit*.

I would like to emphasize a point here, some of the hifi commercial products doesn't come with speaker/headphone protection, these engineers are just too confident on their designs that their amplifiers will not go wrong in any circumstances.
penmarker
post Jul 24 2017, 10:29 AM

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When you buy stuff from taobao do you use agents? It's a little hard when I want to get things from there especially cases that cost extra for shipping.
shinnie
post Jul 25 2017, 01:11 AM

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QUOTE(penmarker @ Jul 24 2017, 10:29 AM)
When you buy stuff from taobao do you use agents? It's a little hard when I want to get things from there especially cases that cost extra for shipping.
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I dont use agents.. yes, the heavy cases will cost a lot for the shipment fees.
shinnie
post Aug 18 2017, 10:15 PM

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Finally, the casing arrive! XLR, RCA and Banana connectors are readt too!
user posted image

This post has been edited by shinnie: Aug 18 2017, 10:17 PM
penmarker
post Aug 21 2017, 12:06 AM

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QUOTE(shinnie @ Aug 18 2017, 10:15 PM)
Finally, the casing arrive! XLR, RCA and Banana connectors are readt too!
user posted image
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rclxms.gif rclxms.gif
Looking forward for the end result
b3x
post Sep 10 2017, 10:35 PM

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i am not sure if this been asked before, but have anyone build Objective2 before in this forum? was it hard? whats the sentiment like?
And is it possible to buy O2 PCB from China (taobao or ali)? got link?
or any DIY headphone amp that supports RCA input to recommend that can buy off Ali or taobao?
penmarker
post Sep 10 2017, 11:18 PM

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QUOTE(b3x @ Sep 10 2017, 10:35 PM)
i am not sure if this been asked before, but have anyone build Objective2 before in this forum? was it hard? whats the sentiment like?
And is it possible to buy O2 PCB from China (taobao or ali)? got link?
or any DIY headphone amp that supports RCA input to recommend that can buy off Ali or taobao?
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The board can be bought from the official website
https://www.jdslabs.com/mobile/products/30/...-circuit-board/
And the link below that page brings you to a resource site that allows you to check on the bill of materials and other information.

I've never built it but it looks straightforward enough.
b3x
post Sep 11 2017, 09:13 AM

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QUOTE(penmarker @ Sep 10 2017, 11:18 PM)
The board can be bought from the official website
https://www.jdslabs.com/mobile/products/30/...-circuit-board/
And the link below that page brings you to a resource site that allows you to check on the bill of materials and other information.

I've never built it but it looks straightforward enough.
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oh thanks! seen this before but didnt know can use the same PCB for RCA. Board is USD5.99 but shipping is usd13 lol. DIY kit without enclosure is usd59. enclosure is another USD30 i think..
OR maybe wait for massdrop again, around USD79 if i remember correctly. Now is just to justify the need lol.
penmarker
post Sep 11 2017, 09:56 AM

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QUOTE(b3x @ Sep 11 2017, 09:13 AM)
oh thanks! seen this before but didnt know can use the same PCB for RCA. Board is USD5.99 but shipping is usd13 lol. DIY kit without enclosure is usd59. enclosure is another USD30 i think..
OR maybe wait for massdrop again, around USD79 if i remember correctly. Now is just to justify the need lol.
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Well you can put in a different enclosure with RCA holes and wire them to the mini jack input. Same wiring since RCA is single ended and shares the ground.
But that's always the case for USA products, they cost a lot to ship so usually if needed I'll just buy in bulk for stuff so can get more out of the shipping charges. Like just last week I ordered some 2SC2922 for my amp because the Chinese kit came with counterfeits. They cost $28 for 4 pcs but the shipping is $20. But digikey offers free shipping for orders of $50 and above so I bought a bunch of transistors that I was gonna order from E14 or RS (shipping is free from those sites but they didn't have 2922).

I would recommend spending some time searching through Taobao and AliExpress for headphone amp keywords. The easiest I think would be the Lehmann Clone for desktop and CMoy for portable. Remember that they will always provide counterfeit parts if it is expensive so that's why you can get a LT1083 power supply kit for less than RM30 when the LT1084 regulator alone costs more than RM40 from reputable dealers.
b3x
post Sep 11 2017, 03:09 PM

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QUOTE(penmarker @ Sep 11 2017, 09:56 AM)
Well you can put in a different enclosure with RCA holes and wire them to the mini jack input. Same wiring since RCA is single ended and shares the ground.
But that's always the case for USA products, they cost a lot to ship so usually if needed I'll just buy in bulk for stuff so can get more out of the shipping charges. Like just last week I ordered some 2SC2922 for my amp because the Chinese kit came with counterfeits. They cost $28 for 4 pcs but the shipping is $20. But digikey offers free shipping for orders of $50 and above so I bought a bunch of transistors that I was gonna order from E14 or RS (shipping is free from those sites but they didn't have 2922).

I would recommend spending some time searching through Taobao and AliExpress for headphone amp keywords. The easiest I think would be the Lehmann Clone for desktop and CMoy for portable. Remember that they will always provide counterfeit parts if it is expensive so that's why you can get a LT1083 power supply kit for less than RM30 when the LT1084 regulator alone costs more than RM40 from reputable dealers.
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thanks sifu for the guidance! maybe i should start lookin into amp that deliver vastly different sound than dac-x6!
penmarker
post Oct 15 2017, 12:32 AM

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I got some time and extra parts lying around so I made this 8 ohm 50W dummy load for amplifier testing. The case was actually a tray from Daiso. Probably needs at least some shellac/wood oil/clear spray for protection but for now it works.
Attached Image Attached Image

For the past few days been testing out the amp I completed redoing recently
Attached Image
It was the same NAP200 clone, however it came with fake Sanken 2SC2922 last time so I took the time to order extra transistors along the original 2922 and matched their HFEs for total replacement. I got the liberty to do that will all but the driver and output transistors because of cost reasons. Also the driver transistors were out of stock for a while for some reason?

So the amp now sits on my living room rack
Attached Image

Started to do the measurements. Nothing too fancy, just the dummy load with a DSO.
Attached Image

Measurement results. Nothing too fancy too since its a basic scope.
https://imgur.com/a/9EUUS
Test tones were taken from an online generator. The DAC and Lehmann Black Cube as preamp could be adding its own coloration into the signal so keep that it mind.
http://onlinetonegenerator.com/

Scope reading is pretty grungy because my laptop has a bad battery and adapter. Need to change or at least get something like iFi iUSB cleaner.
shah_ty
post Oct 25 2017, 04:20 PM

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QUOTE(b3x @ Sep 10 2017, 10:35 PM)
i am not sure if this been asked before, but have anyone build Objective2 before in this forum? was it hard? whats the sentiment like?
And is it possible to buy O2 PCB from China (taobao or ali)? got link?
or any DIY headphone amp that supports RCA input to recommend that can buy off Ali or taobao?
*
I got all the electronic components and PCB but don't have the time to solder all of it together sweat.gif
Im selling the extra PCB for the O2 here

This post has been edited by shah_ty: Oct 25 2017, 04:27 PM
b3x
post Oct 26 2017, 11:30 AM

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QUOTE(shah_ty @ Oct 25 2017, 04:20 PM)
I got all the electronic components and PCB but don't have the time to solder all of it together  sweat.gif
Im selling the extra PCB for the O2 here
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check PM
shinnie
post Jan 29 2018, 09:56 PM

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Woooottt, i have received my PCB and casing finally, cant wait to solder it up!

Global feedback loop like what modulus86 did!

Attached Image Attached Image
penmarker
post Mar 21 2018, 06:17 PM

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Well it comes to nobody's surprise that I am not good at building.
Here's a gallery of my current project anyway.

https://imgur.com/a/VgR46

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