Fortunately the surge didn't destroy my headphones, but if I didn't have the Capacitor blocking DC, I wonder if there might have been a different outcome?
After that jarring series of events, I think I'll leave well enough alone...
But, at least you now have a baseline comparison with which to judge your capacitor replacements/upgrades, you can tune for *least* audible degradation as compared to the shorted caps.
Warning: this mod makes the amp DC coupled. Be sure that you do not have DC on the inputs. That usually is the case. But if, just if, there is DC on the inputs now or ever during an output failure of the source, then you can damage your headphones permanently. Obviously this mod is completely at your own risk.
In the picture above I just soldered four jumper leads on the bottom of the board, where the small, gold-and-black colored Elna capacitors are soldered through. On the top of the board these are marked as C122, C123, C124 and C125. You could also cut those capacitors and tie their leads together. That might be easier, but obviously irreversible. Soldering jumpers is a bit more fiddly but allows you to undo the mod when you want.
To my ears, this mod gives an immediate and significant improvement in clarity and three dimensionality. Loving this!
Interesting little confused on the whole process so think I better not attempt it. Been super happy with the improvement’s the 12BH7a has bought to my system. Even using the inexpensive cbs 12BH7a made huge improvement to the sound. Highly recommend if you have a TA20 to pickup a set of 12BH7a to try out.
Fortunately the surge didn't destroy my headphones, but if I didn't have the Capacitor blocking DC, I wonder if there might have been a different outcome?
So where are the caps you shorted out in your TA-20? Which stage(s)? Either way, the idea is to stop DC from passing through the Amplifier to the output, so you don't damage your speakers (headphones).
So you didn't short all of the coupling caps in all of the amp stages? So DC is still blocked at earlier/later stages?
Yes, the big black film capacitors are still there and block DC to the headphones. Can’t really omit those on tube amps (that is what the difficult discussion on diyAudio was about when someone proposed tube amps with no coupling caps).
TA-20 mod #2: adding bypass caps to the output coupling capacitors!
There's a loose piece of solder just above C18 which I removed afterwards. I didn't take a picture after.
Though we have no room to swap the stock output capacitors for something better, we can improve them by adding some bypass caps! Here I have added four Vishay MKP1837 0.01 μF (10 nF) caps, one per output cap. For those who don't know them, they're quite famous as bypass caps -- Google and you will find out this is an audiophile favorite.
The previous mod where I shorted the input caps is easy to know if you can hold a soldering iron, and has a large payoff. This mod is a lot trickier to solder and has a smaller effect, but an audible effect still! It tends to make music sound more natural, with better micro-definition in all registers. Psycho-acoustically this may be perceived as a little brighter, with precise soundstage, more "hi-fi" and less mellow sounding, which depending on your taste may either be a good or bad thing. Your perception may vary of course.
Here's how you do it. Earlier I wrote about how top expose the top of the board in the unit. It would be oh-so easy if we could just solder those Vishays on the bottom but unfortunately we can't: the Vishays are a pinch too thick so the bottom plate would not fit anymore. So at the top of the board they have to go.
There is very little headroom above the existing output caps (those big black film capacitors branded as xDuoo's own). The chassis is recessed there. So what's important is that you tuck them right in between the two pairs of caps, in the little "valley" that's between them. Use a plier to bend the leads outward and try positioning them. If you put the pairs of bypass caps close and to the center of the output caps, you can manage to just have leads sticking out on both ends for both bypass caps.
When you got the position, use some hot glue to hold them in place.
Now finely position the leads. Again because the headroom in the case is limited, it is very important that you keep the leads as low as possible. If they are too high, they might touch the casing and I don't want to find out what happens when you short them to ground like that. Fortunately you have an excellent gauge of which height is safe: the existing output caps. Again bend the leads so that they reside in the valley, in the horizontal plane flat with those big caps. Make sure they don't stick out above that height.
Now comes the finicky part of connecting the leads of the bypass caps to the leads of the existing output caps. For that I just used some jumpers or clipped-off leads from stuff you soldered before. I leave it up to your best soldering skills. What I did was first apply some solder on the jumper as well as on the leads of the existing caps. Then I soldered the jumper to the base of the existing caps, not 100% right but in such a way that they at least stay put. I then soldered the jumper to the lead of the bypass cap, and finally got back to the base connection to fix that up.
When you're done, you can use something straight to check that the leads are no higher than the big black caps and you're good to go.
Remember that like other caps, these too need burn-in. Happy listening
Sorry for the late reply, i have had a very busy schedule the last few months, and it'll stay that way until june unfortunately. Which also means i haven't had as much time as i'd like to listen to music.
As far as the changes i haven't really heard any sort of "burn in" effects, even though i sort of expected it. I guess that means the changes have been subtle if any compared to the stock caps. I am gonna give the caps some more time before i swap them for the Jantzen caps, and at that point any changes should be apparent. At least when comparing Mundorf to Jantzen.
However, it seems like the stock caps are adequate from my hearing at least But i will update more on this matter later.
As far as the MT-603 goes i have to say that it haven't been all i wanted it to be. The TA-26 as a preamplifier still beats it handily as far as sound quality goes. But as a "tubeifier" it does its job. Nothing more, nothing less. I will however remove it from my current setup when i find the time to fiddle with it, as the best possible sonics i've heard through my setup is setting the TA-26 up as a pre for the Atrox V2. The sound of those two combined is actually very close to what i would imagine high end sounds like (without any "real" high end references in head-fi at this point). In many ways it would be a similar setup to the TA-20 as the tubes preamplify the class A Atrox amp, however the Atrox seems to scale well. And with the power output it has it just keeps everything so controlled, clear and immediate all at once, but with those tubey "edges".
Today switched up my system and instead of using the oriolus ba300s as the preamp i‘m using the ta20 as the preamp by running the lxr output with a 4.4 adapter into the oriolus that’s connected to headphone. Running it like the has created a ground loop humm.
If I touch the ta20 or wires humm goes away. Not sure why that is so figured I would ask.
Sorry for the late reply, i have had a very busy schedule the last few months, and it'll stay that way until june unfortunately. Which also means i haven't had as much time as i'd like to listen to music.
As far as the changes i haven't really heard any sort of "burn in" effects, even though i sort of expected it. I guess that means the changes have been subtle if any compared to the stock caps. I am gonna give the caps some more time before i swap them for the Jantzen caps, and at that point any changes should be apparent. At least when comparing Mundorf to Jantzen.
However, it seems like the stock caps are adequate from my hearing at least But i will update more on this matter later.
As far as the MT-603 goes i have to say that it haven't been all i wanted it to be. The TA-26 as a preamplifier still beats it handily as far as sound quality goes. But as a "tubeifier" it does its job. Nothing more, nothing less. I will however remove it from my current setup when i find the time to fiddle with it, as the best possible sonics i've heard through my setup is setting the TA-26 up as a pre for the Atrox V2. The sound of those two combined is actually very close to what i would imagine high end sounds like (without any "real" high end references in head-fi at this point). In many ways it would be a similar setup to the TA-20 as the tubes preamplify the class A Atrox amp, however the Atrox seems to scale well. And with the power output it has it just keeps everything so controlled, clear and immediate all at once, but with those tubey "edges".
Yup, music can be distracting, especially when it sounds sooo great!
I was looking at these Jantzen Audio 8.2uF 800V Z-Silver Capacitor as potential replacements - but I would need to do more research, as I suspect there are even "better" caps:
Today switched up my system and instead of using the oriolus ba300s as the preamp i‘m using the ta20 as the preamp by running the lxr output with a 4.4 adapter into the oriolus that’s connected to headphone. Running it like the has created a ground loop humm.
If I touch the ta20 or wires humm goes away. Not sure why that is so figured I would ask.
I don't think the 4-pin XLR headphone output is supported as a device driver input - you are experiencing the hum due to a ground loop - try using the RCA Output from the TA-20 instead.
If you do want to try to make that work - IDK if that is possible; Do you have another output of the Oriolus also still connected to an input on the TA-20 or another output/input connected to the Oriolus from other devices?
I'd try disconnecting all devices from the TA-20/Oriolus - if you haven't already done that - to reduce the chance of ground loops.
Also, swap the power inputs to both the Oriolus / TA-20 once they are only connected together; If they are plugged into the same power outlet/strip, try 2 different outlets, and if they are on different outlets try putting them both on the same one.
I wouldn't try "cheater plugs", that break the Ground Pin contact to the power outlet for both or either device... you could touch both at the same time and create a current path - and Zap!
Yup, music can be distracting, especially when it sounds sooo great!
I was looking at these Jantzen Audio 8.2uF 800V Z-Silver Capacitor as potential replacements - but I would need to do more research, as I suspect there are even "better" caps:
I don't think the 4-pin XLR headphone output is supported as a device driver input - you are experiencing the hum due to a ground loop - try using the RCA Output from the TA-20 instead.
If you do want to try to make that work - IDK if that is possible; Do you have another output of the Oriolus also still connected to an input on the TA-20 or another output/input connected to the Oriolus from other devices?
I'd try disconnecting all devices from the TA-20/Oriolus - if you haven't already done that - to reduce the chance of ground loops.
Also, swap the power inputs to both the Oriolus / TA-20 once they are only connected together; If they are plugged into the same power outlet/strip, try 2 difference outlets, and if they are on different outlets try putting them both on the same on.
I wouldn't try "cheater plugs", that break the Ground Pin contact to the power outlet for both or either device... you could touch both at the same time and create a current path - and Zap!
Yeah I just will have to continue to use the oriolus between the source and the ta20 it’s only has a 4.4 input and output and battery powered. Just thought might sound better using it after the ta20 since it’s the oriolus is a full tube amp. I thought the rca out was more of a bypass than a output and didn’t go thru the tube section of the ta20? Either way don’t think there’s a way to connect it to the rca output.
Plus didn’t hear much of a difference by switching them around. Of course had to touch the ta20 to remove the humm so really didn’t spend a lot time testing. More was curious on what was causing the humm and experimenting.
I was looking at these Jantzen Audio 8.2uF 800V Z-Silver Capacitor as potential replacements - but I would need to do more research, as I suspect there are even "better" caps:
Do you intend that for the TA-20 or TA-26? They won't fit in the TA-20. I've looked at all Mundorf, Jantzen, Audyn and ClarityCap options, and none of them will fit except the most basic ones. And @PetFju confirmed my assumption that the stock ones probably already are in the same league.
As for the TA-26, I don't have it (yet - would be fun to own sometime) but I think you could replace those six red capacitors with something better. Could also be a s single big one. Do they have a capacitance printed on them though? Otherwise you would need to measure them and I don't know if you own such equipment?
I don't think the 4-pin XLR headphone output is supported as a device driver input - you are experiencing the hum due to a ground loop - try using the RCA Output from the TA-20 instead.
If you do want to try to make that work - IDK if that is possible; Do you have another output of the Oriolus also still connected to an input on the TA-20 or another output/input connected to the Oriolus from other devices?
I'd try disconnecting all devices from the TA-20/Oriolus - if you haven't already done that - to reduce the chance of ground loops.
Also, swap the power inputs to both the Oriolus / TA-20 once they are only connected together; If they are plugged into the same power outlet/strip, try 2 difference outlets, and if they are on different outlets try putting them both on the same on.
I thought the rca out was more of a bypass than a output and didn’t go thru the tube section of the ta20? Either way don’t think there’s a way to connect it to the rca output.
Thanks my last thought is the distance btw the to units. The only 4.4 to 4.4 cables are I have are short so there only about 3 inch of space separating them.
@Ufanco - the Green / Yellow Stripe ground wire is easily accessible under the bottom plate. If you remove the plate screws and lift the bottom plate, wiggle that Green / Yellow Stripe wire and see if it is attached securely. A few owners have reported that the screw is loose, and one said the lock-washer was missing, which over time will cause the nut to loosen. A loose ground connection can be a contributing factor to audible noise.
Yeah I just will have to continue to use the oriolus between the source and the ta20 it’s only has a 4.4 input and output and battery powered. Just thought might sound better using it after the ta20 since it’s the oriolus is a full tube amp. I thought the rca out was more of a bypass than a output and didn’t go thru the tube section of the ta20? Either way don’t think there’s a way to connect it to the rca output.
Yes, the RCA output is a passthrough from the input, but I was thinking of functional use without the ground loop problem more than tube buffer effect. Besides why would you need the TA-20 tube buffer effect in your setup if you have a full tube amp that can act as the tube buffer? Perhaps I am missing your need for your set up.
The TA-26 does have an output from the tubes, it's RCA output would work if you need it.
Plus didn’t hear much of a difference by switching them around. Of course had to touch the ta20 to remove the humm so really didn’t spend a lot time testing. More was curious on what was causing the humm and experimenting.
That's good, I go through a lot of that with new equipment, none are immune given the right (wrong?) circumstances.
Having fun is the real win
I got rid of a lot of my noise problems by replacing my cables with interrupted shield cables - kind of a "directional" design. The source side has the cable shield soldered/connected, allowing the length of the cable shield to absorb the RFI/EMI protecting the signal wires, and then at the destination end the shield is lifted or not soldered/connected so that the shield noise signals can't be passed on to the destination device.
The design description from WBC comes down to lifting the shield ground at the destination end. That keeps the shield borne induced noise out of the TA-26:
The WBC RCA cables got rid of all the of the Topping A90 RCA noise except for the PC GPU noise borne by the USB power wires (iDefender+ got rid of that). I also have a $100+ filtered power strip, but with that alone, before the WBC cables and iDefender+, the filtered power strip wasn't enough to get rid of all the noise.
During normal listening with the TA-26 Volume knob at the highest listenable setting, with or without music, I don't hear any hum.
I also use the XLR cables with lifted shield at destination design, sold per channel, buy two for a stereo pair:
1 Foot – Quad Balanced Microphone Cable Custom Made by WORLDS BEST CABLES – Using Mogami 2534 Wire and Neutrik NC3MXX-B Male & NC3FXX-B Female XLR Plugs. https://www.amazon.com/gp/product/B00WU1BP10
It is good practice to solve such grounding / ground loop issues - even if you can avoid them by "not doing that", some day those skills will come in handy in a pinch situation.
Thanks my last thought is the distance btw the to units. The only 4.4 to 4.4 cables are I have are short so there only about 3 inch of space separating them.
Shorter cables are better for noise reduction as long as the cases aren't touching. In fact shorter is generally - I can't think of an exception right now - better for reducing cable induced noise. The cables are little antennas that can pick up induced RFI/EMI, the lifted shield cables help, but shorter lengths also help.
You might be thinking of your own bodies effect when you bring your hand close to a tube or chassis and you hear an audible change. Your body is a huge antenna picking up RF, if you touch a radio antenna you can improve/degrade the reception because of that. You are also a grounding substitute - or an actual ground if you have bare feet standing in salty water, and anything close to ground in between.
When I set up a transmitting station I have to make sure a ground bar system is in place with long rods pounded into the ground - salted into their hole as they are pounded into the ground. Yes, I stand on a ladder and pound steel rods into the ground 7'-10' are best, and yes the ground is soaked for days before-hand to make the soil soften by absorbing as much moisture as possible. It often takes a couple of days in short stretches to pound it in.
Also you can use shorter 3' copper rods and tie them together, but you have to design the attachment such that all the rods share the load.
What I am saying is a good/great grounding system is important. Your home may already have such a grounding system that you can tap into, either by running a thick wire to the already installed ground bar, or by simply connecting to the metal running the ground to your end of the home.
Alternatively there are also products to "bust the hum", some work with any setup some are unique to the makers products, ifi has released a few items to try:
iFi Groundhog+ Does your system suffer from an irritating buzz or hum that decreases when you touch it? It’s missing an earth/ground. You need the Groundhog+. https://ifi-audio.com/products/groundhog/
iFi GND Defender
The optimum configuration for each system is one Ground/Earth for the whole system. If a system has multiple Grounds/Earths, then it often creates unwanted ground loops. These systems will then have an annoying low-frequency hum (emitted from the speakers).
Current solutions either jeopardize (i) both safety and EMI shielding (e.g. cheater plug), or (ii) EMI shielding. And most are single country (US) uses only. The GND Defender in the correct way, intelligently detects a ground loop and will cut the ground for that component. https://ifi-audio.com/products/gnd-defender/
Another Power/Ground related item I need and use is the:
iFi iDefender+
Is your audio still taking a beating from buzz and hum?
iFi’s iDefender+ is for those battling with noisy audio due to unwanted ground loops in their audio chain. https://ifi-audio.com/products/idefender-plus/
Topping has recently come out with the:
HS01 - USB 2.0 High Speed Audio Isolator, which accomplishes the same effect of blocking the noise borne across the USB ground/power wires: https://www.tpdz.net/productinfo/733226.html
I have 2 DAC's connected to my PC, the D90 MQA and the FiiO M15, I use both frequently, I use both an HS01 and an iDefender+
After replacing my cables with the WBC shield lifted cables, replacing my USB DAC cable with a Jenving USB 2.0 cable all of my noise was gone, but when I gamed or ran CUDA based software the GPU "song" would rise up - coming up the power/ground wires of the USB cable - the iDefender+ detects that signal and nullifies it, that was the last change I need to make to remove all the noise between my A90 and D90 MQA devices.
Another way to remove ground loops is to detach from the power line and use a battery driven Pure Sinewave AC source. They are out of stock now, but this one has enough battery storage to run my D90/A90 for 10+ hours. RavPower say they will restock, but it has been "Sold Out" for weeks:
It is important to find an AC power source that has a true/pure sine wave for running audio devices, there are many out there that are not - for running power tools.
So there are lots of things to do to work out the ground loop / grounding problem and similarly the RFI/EMI noise, I've only listed a few.
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