Topping PA5 fix - D01 Module Replacement for everyone

[Lräk]

I’d really like to get one if you’d be willing to ship to USA. I could send send payment by PayPal to cover your costs, labor, and shipping.

Me Too. I've got 2 PA5's so I can experiment on 1 for fun.

 

[newfangled]

I’m interested in purchasing one of these boards to get a dead pa5 back up and running.

 

[notsodeadlizard]

Oh my God, why did they hide this nonsense in compound-filled modules?
Is it to look more impressive?
There is not a single engineering argument for such a decision.
Moreover, it even contradicts common sense.
Such tricks have already been, Mark Levinson did it, if my memory serves me right.
Funny.

 

[Snix]

Please start working on these modules for LA90D lol

 

[gamerpaddy]

i could never spend this much on a amp just for taking it apart

 

[Gphoton]

Hi Gamerpaddy, success! I ordered both dip boards and populated surface mount single sided boards with 1656 stage1 1602 stage2 op amps. Unfortunately I damaged the main board desoldering the D01 module by pulling out the trace pin on Left tip input. I used an ohm meter to find the right input capacitor pin near the volume control that must go to Left-tip input by process of elimination on the other three inputs. Sure enough there was an open connection. Jumpered it with a wire and left channel now works! Thank you! I socketed the board to allow module swaps easily. -GPhoton.

 

[genfreeciv]

> gamerpaddy
I sincerely appreciate your contribution.
I started getting noise from the left, so I immediately ordered a DIP8 version and four OPA1612s. However, the day before the goods arrived the noise was gone and I had no more problems.
I am now following the saying 'if it ain't broke, don't fix it'.
In my case, I use the PA5 with the volume at the 2 o'clock position, which has never caused me any problems, but when my child misbehaved and turned the volume to the max, a problem occurred.
After a while of setting it back to the 2 o'clock position, the problem disappeared.

By the way, the parts on the surface-mount PCB are really small - I'm really glad I went for the DIP8.

 

[BrianTran132]

Reporting back. I had JLC assemble the DIP version and used 4x OPA1612's. My left channel now works flawlessly.

Thanks for the fix gamerpaddy!

 

[john11]

Do you think removing the potting compound before ever powering up a virgin PA5 would be another way to solve this amp's many issues. I mean is it necessary to buy a new module, can the stock one be scraped clean of potting compound as an easier alternative fix

 

[antcollinet]

Do you think removing the potting compound before ever powering up a virgin PA5 would be another way to solve this amp's many issues. I mean is it necessary to buy a new module, can the stock one be scraped clean of potting compound as an easier alternative fix

You won't get the potting compound off without damaging the module. It is like a hard resin.

 

[gamerpaddy]

with a lot heat ( hot air, around 300°C) the resin becomes brittle and you can scrape it off very carefully using a needle and tweezers. but you might rip off some parts in the process, the resin cant be dissolved or melted without damaging the pcb inside.

 

[Roland68]

with a lot heat ( hot air, around 300°C) the resin becomes brittle and you can scrape it off very carefully using a needle and tweezers. but you might rip off some parts in the process, the resin cant be dissolved or melted without damaging the pcb inside.

First heat it to make it brittle, then put it in isopropyl alcohol, create a little vacuum and dissolve it again to let it soak in. Leave in for 2-3 days. After that, it's usually easy to remove. Nothing happens to the electronics.

 

[john11]

I'm finding it a little amusing that china which has a reputation for borrowing other people's intellectual property, are now potting their stuff to prevent it from being borrowed, although i am sure this does not apply to topping who have never borrowed anybody's stuff

 

[Lräk]

Update: Just installed @gamerpaddy module and it works!!! Too late to crank it up so I will update again tomorrow.

 

[Lräk]

First heat it to make it brittle, then put it in isopropyl alcohol, create a little vacuum and dissolve it again to let it soak in. Leave in for 2-3 days. After that, it's usually easy to remove. Nothing happens to the electronics.

Now that I've got the D-01 module off, I'm curious to open it up. Can I put it in an air fryer for the heat?

 

[JeffS7444]

To what extent is PCB design part of the module's "secret sauce"?

 

[Roland68]

To what extent is PCB design part of the module's "secret sauce"?

The circuit is the well-kept secret, although it isn't. It is based on TI white papers with modified values.
Very similar to the well-kept secret of a legendary German 25K preamp, also based on TI's whitepapers.

If Topping had just left the circuitry on the motherboard, nothing would have happened. They have all the anger and loss for nothing .
If another manufacturer had copied the circuit, they would have introduced the same error as always, just like AIYIMA with the A7, Breeze Audio or even Fosi Audio with the new V3.

 

[Lräk]

Update: Just installed @gamerpaddy module and it works!!! Too late to crank it up so I will update again tomorrow.

I had the PA5 cranked up as loud as I could go without my neighbors calling the police. Works and sounds GREAT.

I have the case off and the 4 IC's on the module are warm to the touch. Doesn't get any hotter after an hour at a fairly high level (my ears couldn't take much more). The heat sink is also just slightly warm. As someone said earlier, Topping should have put the vents at the front where the warmer components are. Maybe they thought the cooling needed to be at the outputs, but I couldn't feel any heat other than the heat sink and where the original D-01 module was.

 

[gamerpaddy]

@Lräk
Good to hear!
Heat is no problem. not only the chips run cooler but since there is no resin around, nothing will break solderjoins anymore. it should last basically forever.

if you heat the old module the resin becomes brittle, but only while its hot. once it cools, it becomes hard again. putting it in a air fryer wont work.
you need to break away chunck by chunk while heating it with hot air, it needs to be over 250..300°C. its tideuos and you get burnt, a lot
didnt had luck with heating and putting IPA on it. also tried WD40 to creep in there and loosen it from the board.. didnt work either.
once the bottom resin layer is gone, you might be able to pry the board out of the housing, but it might bend or rip off components in the process.



I got a few more modules in stock.
recently made a new batch since a bunch of people wanted one and i ran out of my first batchand prototypes pretty quickly.
worldwide shipping. if you dont know how to desolder or missing the required tools i can offer to replace it.
but only within EU because dealing with customs back and forth is a pain.

 

[RandomEar]

Hey, @gamerpaddy . Have you thought about having the module / the repaired PA5 measured to see how it performs? I think that would be super interesting. Since you are in europe, maybe @VintageFlanker could help out with that (if he is interested). Would be quicker and cheaper than sending it to Amir.