[DIY] Replacing/upgrading Capacitors on the Aune T1 (image heavy)

[creatip123]

First off, this is NOT my original idea/concept. I know a bit about soldering, but don't know squat about electronic components. I got the tutorial from here: http://www.head-fi.org/t/633006/aune-t1-usb-tube-dac-amp-discussion-thread-see-first-post-for-faq/6165#post_10977354

 

That's the main tutorial, and that's the main thing you'd need, should you want to try this project. The steps in that tutorial is very systematic and easy to understand, even for novices like myself. This post is more like a supplement to that tutorial, providing more step-by-step pictures. So it's best to read the original tutorial, and if you're still a bit puzzled, refer to this post.

 

All the credits should go to the original author in the link above. I only take credits for the additional pictures, and the craziness of actually attempting the mod with novice skill

 

Also, in the original tutorial, the author modded the case to have a little gap in the bottom plate of the T1, to give way for bigger/taller capacitors. I managed to squeeze all the capacitors in place, by bending it north and south, so I could close the casing tightly as original. The main reason is because I live in a tropical country, where dusts and dirts are abundance, so I don't want them to get into the inside.

 

A few points beforehand:

 

1. The Aune T1 already got quite decent capacitors already, Nichicon and ELNA, which are already good and used a lot in audio devices. So you might want to take this into consideration, whether you still want to upgrade or not

 

2. Only do this project if you're:

- Proficient in fine electronic modding (soldering mainly). If you are good with electronic modding, then you can do this mod with confidence, should be a walk in the park for you.

- Or, ready to do a gamble on a $200 device. A lot of things could go wrong, so take the worst case scenario into your consideration. I'm a novice at project like this, so I did this project with the $200 gamble in my mindset before I even started.

 

3. Take care when installing new capacitors, don't mistake the polarities of the legs. From what I read on the net, ceramic capacitors (like the Cerafine) could explode if the polarities are flipped.

 

 

First, this is the list of the replacement capacitors needed, taken from the original tutorial:

 

 

When I shopped for the caps, I couldn't find the exact types of the capacitors, so I ended up with Panasonic M (instead of FR), and ELNA Cerafine (instead of Silmic II). I actually regret using Cerafine caps. I'll tell you why later. 

 

 

These are the original caps from the T1. You can see they are low profiles/height.

 

 

These are the replacement caps

 

 

The height differences is the main problem in this project, because the circuit board and component size is a VERY tight fit to the casing. You absolutely can't assemble the casing back to the original state if you install the replacement caps in upright positions. 

 

Let's get on with it then. You can get the complete requirements and tools in the original tutorial.

 

 

Take a last good look at this beauty. It may be bricked and becomes a paper weight, should you do something wrong *insert ominous suspense music*
 

Needless to say, unplug all cables, and the tube.

 

The original tutorial tells you to get a friend to help with this project, in the un-soldering capacitors part. If you're working alone, like me, a third hand (clamp, vise, etc) is a MUST. You'll bang your head if you don't have a third hand.

 

 

This is the finished project. Use this picture as a reference of the placements and bending of the replacement caps. You don't have to tell me, it looks like crap. I bent them that way because I want to keep the case tightly closed, which I couldn't do if they're installed in upright position. All the new capacitors' body is covered in electrical tapes. This is because they're bent sideways, so there's a risk of the metal body touching other components' contacts and cause a short. 

 

There are a total of 4 sets/pairs of capacitors to replace. I numbered them in the picture according to the order I replaced them. Number 4 is hidden in the back of the headphone amp board (in the other side of the number 3)

 

 

Use a razor blade to pry open the rubber feet at the bottom, to reveal 4 screws. Pry it carefully, as the rubber feet are re-usable. Remove all screws and the bottom plate should fall right off.

 

 

Put every removed bits in a container to avoid loosing them.

 

 

Pull the volume knob carefully (might be a bit hard, because it got some glue on the potentio), and take off the washer installed in the potentio shaft, the white arrow in the picture. The top plate should be loose by now. Push it open with a small screwdriver from the bottom.

 

 

This is when the top plate is off. You can see right through the unit, because the bottom plate is already taken off earlier.

 

 

From the bottom view, you can see it actually got 2 PCB circuits, the main unit, and the headphone amp unit (red circled). We have to take off the headphone amp first. Unscrew the 2 screws (red arrows). Wiggle the PCB board CAREFULLY, as they're connected to the main board with 2 sets of metal pins. Do not use excessive force, or you'll damage the board. When the headphone amp board is off, take off the white connector with black cables. That is the RCA jacks connector. Wiggle it off with your fingers/fingernails. 

 

 

After the headphone amp board and the white connector are removed, turn the unit around, and unscrew the black screws, to take off the main unit board. We're ready for real works!! You can plug your solder to heat it up now. Get everything ready (soldering tin, flux, third hand clamp/vise, etc). We're gonna un-solder the capacitors from the boards.

 

 

I forgot to take a picture of my working desk setup, so I take this picture later on (when everything's done), with a random PCB (that's a USB hub's PCB actually ), to show the setup. So I clamped the PCB tightly but safely (take care not to clamp small components. find an empty area of the board to clamp). I put a USB fan blowing from behind, the black arrow, and I un-solder the capacitors from the front side, the white arrow. The fan's purpose is to help cool the capacitor's body and prevent it from overheating, due to the heat of the soldering gun. This way, you (hopefully) could save the original capacitors.

 

I'm gonna tell you straight up: the original soldering are hard as a rock!! They need quite a lot of heat to melt them. My solder is a 25W-150W soldering gun (push the button, and it's 150W), and it melt WBT soldering tin with no problem. However I had a hard time un-soldering the original capacitors. I had to stick the solder tip in the original solder tin for around 10 seconds, sometimes more. 

 

These are the steps:

- Melt the original soldering

- Use a soldering vacuum sucker (dunno the technical name) to suck the tins while they're still liquid. Repeat until there are minimal amounts of soldering tins left

- Melt the original soldering while pulling the corresponding capacitor from an angle. Hold the board with one of your finger (usually middle finger). DON'T pull the capacitor with only the clamp holding the board in place, you'll risk snapping the board.

 

Do it 1 set at a time, take off a pair of the original capacitors, solder the new ones in. Don't take all of them off first, to avoid installing wrong capacitors. 

 

 

I replaced the biggest capacitor pair first, the 3300uF pair. You have to bend them first before soldering. Bend them to place, and then solder the legs from the back side. If you solder the legs first, you won't be able to bend them freely.

 

The second pair (bottom right pair, or refer to the reference picture in the earlier part of this post) is pretty straightforward. Unhook them, and install the replacement pair, bending them forward toward the middle of the board.

 

The third pair is a bit unique, because we're gonna solder it backward. Meaning we're not gonna install them on the side of the original caps, but from the back side. Needless to say, take care not to mistake the polarity of the caps' legs. 

 

Because of the tight spaces, for the third pair, you'd want to unhook the original caps first, then put the boards back in the casing, the main board and the headphone amp board. After that, plug the new caps in place, and find an empty space where they could be bent. Problem is, the way I bent it, the legs are in a big risk of touching each other, which is a big no-no. So, what to do?

 

 

I happened to have 2mm heatshrink tubes lying around, so I used that as isolators for the legs, kind of cable shielding. 2mm is actually a bit loose, 1mm would be ideal.

 

 

This is the third pair installed (refer to the reference picture). This was actually the hardest pair to install, as they got to squeeze between minimal empty spaces left.

 

 

Turn the headphone amp board around, and install the fourth pair. This pair is also pretty straightforward. Just bend them sideways, and solder the legs. 

 

OK, we've gone through hell, so take a breather, get a cup of coffee, or cigarettes, or something. When ready to continue:

 

Do a last inspection of the replacement caps, especially the legs' polarities. Are they installed correctly or not? If yes, then we can start assembling everything back. Cut/clip the remaining caps' legs to tidy things up.

 

Carefully assemble everything back. If everything goes well, you shouldn't encounter any problem assembling it back together. 

 

The steps:

 

1. Put the main board in place, screw it in place with the 2 black screws

2. Plug the white connector (RCA jacks') back into place

3. Carefully plug the headphone amp board back into place, screw it in place with the 2 silver screws

4. Put the top plate back on, and screw the potentio's washer back, to hold the top plate in place

5. Put the bottom plate back on, and screw it in place with the 4 long screws. Re-stick the rubber feet.

6. Plug the volume knob back in place

 

You're now ready for testing the upgraded version of your T1. 

 

1. Plug the power and data cable back, but don't turn it on just yet

2. Get the worst tube you have, usually the stock tube

3. Plug in the worst sound device you have, i.e. a cheap earbuds, etc.

4. Turn the volume knob position to the lowest volume, turn it on, and try playing a song, while slowly turning the volume up

5. If everything goes well, replace the tube and sound device with your main ones

6. Enjoy!!

 

 

Here's my personal opinion/impression of the upgraded T1 with Cerafine caps

 

- The volume got a bit louder, so I have to turn the volume lower (physical volume knob, or window's volume) to get my initial hearing volume

 

- I said above that I regret a bit about using Cerafine caps instead of Silmic II caps. After some googling, turns out the two types got different elements in the inside. Cerafines are using ceramic, while Silmic II are using some kind of silk. It's logical that they give different sound characteristics (http://www.hificollective.co.uk/components/cerafines.html)

 

- With Cerafine caps, I got wider soundstage, attenuated mid frequency, and crisper details/more separations. It's not in any way bad sounding, but for me, it sounds too 'solid state-ly'. I lose a bit of the warmness and richness of lower mid frequency. The basses/kicks got a little tighter.

 

- As such, I'm considering about getting a set of Silmic II, which, from what I read, give more 'tube colors', i.e. warm, lush, rich in lower mid frequency. Again, I'm not in any way implying 'Silmic II got better sound than the Cerafine'. It's just the sound I got from Cerafine is not exactly my preference. 

 

Remember, if you do decide to do this upgrade, download the main tutorial first, and treat this post as a supplement to the original tutorial.

[creatip123]

I can confirm that audio capacitors need a bit of break-in time, to settle and get stable sounds. Yesterday (right after the upgrade), the mids and highs are a bit intrusive to the ears. Today, after using it for more than 10 hours, the mids and highs seemed recessed a bit compared to yesterday. Sounds better to me than the fresh install yesterday....

[creatip123]

Like said in the original post above, this mod comes with its share of risks. Big or small depends on many factors, including your own luck.

 

This happened to me, and I just wanna update this:

 

If you read the original post, I was using a set of Elna Cerafine capacitors. After reading some reviews on the caps mods, People say that Elna Silmic II would be more suitable for tube devices. Elna Silmic II is supposed to give a slower, and warmer sound, similar to vintage tube amps. Cerafine is supposed to give faster, more upper mids, and more 'digitized' sounds.

 

With that in mind, I ordered a set of Elna Silmic II to replace the Cerafines I've installed. Guess what, in the process of de-soldering the Cerafines, I wrecked the headphone amp part (the smaller circuit). It was FUBAR-ed. Luckily the main circuit board was still intact and operational. So the T1 lost its built-in headphone amp functionality, leaving the tube DAC and the solid state amp (with RCA in and out). I'd need an external amp to keep using it with my headphone. The only amp I got lying around was the Lepai, so that's what I used. It's decent, but quite loud noise floor.

 

Naturally, I e-mailed the Aune. Worst case scenario, I would have to choose between keep using it with an external amp (no more built-in headphone amp), or get a new unit altogether. Luckily they have only the headphone amp circuit board (with all the components installed, of course) for sale. It's $8 a piece, but quite costly shipping by TNT, around $20. I ordered 2 pcs (1 as backup). When delivered, I proceeded with de-soldering the stock caps. Like I said in original post, the factory soldering is hard as a rock. Guess what, I wrecked those 2 circuit board....again....!!

 

Frustrated and out of option, I ordered them again, this time I ordered 3 pcs. This time I got more lucky, first attempt was successful. I managed to de-solder the stock caps. Then another misfortune struck. The legs of one of the Elna Silmic II 47uF snapped off at the base when installing, completely unusable. Scrounging, I found the Cerafine caps I uninstalled earlier, so those were my only option. So now the configuration is: the 470uF caps are Elna Silmic II, while the 47uF caps are Cerafines. 

 

Put it all together, it worked normally, as intended. Sounds funny at first, because they say new caps needs time for burn-ins. After 2 days, today the sound is much much better. Believe it or not, even with old songs that I played a lot, I found a few sounds/instruments that 'weren't there before'. 

 

It worked out in the end, with a few sacrifices....

[allindaze]

Mind me asking how you "wrecked" the board? I ran across a few issues when trying to desolder the caps from the headphone amp board as well due to one of the leads on each cap being tied to the "ground plane." The ground plane basically runs throughout the entire PCB absorbing all of the heat from the iron and making it difficult to remove the cap on that leg. Turns out I "wreckd" the board due to ripping the solder pad out of place. I was noticing though that the pad on the opposite side was still intact and still making a connection to the ground plane. I have decided that I am going to just scratch the layer of PCB covering the ground plane next to the missing pad and simply put a blob of solder to short the lead to the ground plane and reestablish the connection of the missing pad.

 

Just curious if what you experienced is something similar. Have a good day.

[creatip123]

Mind me asking how you "wrecked" the board? I ran across a few issues when trying to desolder the caps from the headphone amp board as well due to one of the leads on each cap being tied to the "ground plane." The ground plane basically runs throughout the entire PCB absorbing all of the heat from the iron and making it difficult to remove the cap on that leg. Turns out I "wreckd" the board due to ripping the solder pad out of place. I was noticing though that the pad on the opposite side was still intact and still making a connection to the ground plane. I have decided that I am going to just scratch the layer of PCB covering the ground plane next to the missing pad and simply put a blob of solder to short the lead to the ground plane and reestablish the connection of the missing pad.

 

Just curious if what you experienced is something similar. Have a good day.

 

The metal part on the pcb, the shiny thing (dunno what it's called) where solder tins are supposed to stick, got peeled off due to excessive heating (putting the soldering tip on it too long). Without it, soldering tin just won't stick at all. 

[buestad]

I just did the upgrade. I used a solder wick in stead of a suction tool. It is much easier to remove more of the old solder the first time you heat up, and therefore reducing the chance of wrecking the PCB copper. 

 

http://www.head-fi.org/t/633006/aune-t1-usb-tube-dac-ss-amp-discussion-thread-see-first-post-for-faq-updated-on-02-14-15/7785#post_12399552