Teapo caps in Mytek Stereo96ADC!?

[mtl777]

Out of curiosity, I opened up my Mytek Stereo96 ADC, a supposedly high end converter, to take a look at the components inside. To my surprise, I saw two Teapo 4700uF 16V caps in the power supply. Here's a link to the user manual where you can see the component layout on page 6.

http://www.mytekdigital.com/download...al-v5-2005.pdf

The Teapo caps are C64 and C65. Now, according to the BadCaps.net forum, Teapo is a cheap Chinese brand that is one of the bad caps they found in motherboards.

http://www.badcaps.net/forum/showthread.php?t=388

So I'm wondering what these caps are doing in a well-renowned converter that cost me almost a thousand bucks. Surely Mytek could have used better quality caps for that price.

It may be that these caps don't really matter much in the circuit, but I'm not an electronics expert to judge that. I'm just a guy handy with a soldering iron who can do only simple component changes. So maybe I shouldn't worry about them as long as my unit is working, which it is. But in my noviceness I can't help thinking that replacing them with better quality caps would yield a noticeable improvement in performance or at least guard against the possibility of failure which seems likely considering the bad rep of Teapo caps. All of a sudden I'm getting the urge to replace these caps. Would you recommend replacing them? If so, what better caps would you suggest?

Your inputs would be greatly appreciated. Thanks in advance!

[philtubes]

Hello, I bought a Taiwanese Dac, opened the lid and there they were, 5 Teapo caps in the power supply. I don't know if they work well for power supply's but they're reputation precedes them so I replaced them with Rubycon's. I don't know if one of the caps was dented from the factory but it was slightly malformed so out they came.

Phill

[tritosine]

hopefully ESS takes care of these so called "pro audio" converters

[mtl777]

Originally posted by philtubes
Hello, I bought a Taiwanese Dac, opened the lid and there they were, 5 Teapo caps in the power supply. I don't know if they work well for power supply's but they're reputation precedes them so I replaced them with Rubycon's. I don't know if one of the caps was dented from the factory but it was slightly malformed so out they came.

Phill

Thanks for sharing your experience. What particular Rubycons did you replace the Teapo with? Did you notice a sonic improvement after the replacement?

[jitter]

Originally posted by mtl777
So I'm wondering what these caps are doing in a well-renowned converter that cost me almost a thousand bucks. Surely Mytek could have used better quality caps for that price.

It's likely that Mytek only does the designing and leaves the manufacturing up to an OEM. I work for an OEM, so I see this on a daily basis. They give the OEM the data needed to manufacture (part of) the product. Most of the time the products undergo at least a functional test before they are shipped from OEM to the customer. Some customers let the OEM do everything so that they only have to shift boxes, for others it's just part of a bigger product that they build themselves.
If Mytek only specifies values and not specific types and/or brands, then the OEM will simply use what's available at the moment for a good price. Some customers do specify certain components (where needed) more closely and leave the choice of the others to the OEM. IMO this is one of the reasons why professional (studio) equipment is often made with pretty standard components with exceptions in key positions (but don't expect BG caps or anything esoteric). Making something down to a price is another (very valid) reason (spending € 1 more on a component during manufacturing might translate to a € 100 increase in selling price). BTW, if you open some lower high end stuff (like Primare D20 or Micromega DAC1) you will mostly find only (slightly better than) standard stuff but in a far less compromised design compared to cheap mainstream products.
There's a good chance you will find other brands in ADC's that were produced in another batch than your's.

It may be that these caps don't really matter much in the circuit, but I'm not an electronics expert to judge that. I'm just a guy handy with a soldering iron who can do only simple component changes. So maybe I shouldn't worry about them as long as my unit is working, which it is. But in my noviceness I can't help thinking that replacing them with better quality caps would yield a noticeable improvement in performance or at least guard against the possibility of failure which seems likely considering the bad rep of Teapo caps. All of a sudden I'm getting the urge to replace these caps. Would you recommend replacing them? If so, what better caps would you suggest?

Your inputs would be greatly appreciated. Thanks in advance!

Maybe Teapo has learned from the past and manufactures better stuff now? C64 and C65 are smoothing caps. They are in front of the voltage regulators, therefore IMO their effect on the overall sound quality of the ADC would be relatively small.
If there were tell-tale signs, like bulging, I'd replace them immediately but if they seem to be OK, I wouldn't worry. If you still need some piece of mind, you might replace them with caps of a more reputable brand (should be cheap enough to do it anyway). Maybe you could even go for something higher spec like BGs (might get more expensive, though)...

[philtubes]

Hello, I replaced them with YXF series 105 degree long life Rubycons. As far as a difference in sound it is hard to say because I replaced all the caps on the board with Rubycons at the same time, the other caps I replaced were cheapy Honsing caps. I definately noticed an overall improvement in sound with better density and solidity, the old caps had a wispier sound quality. I bought my caps from www.garrettelec.com, they have great prices and free shipping with USPS. I replaced something like 24 caps total for less than $12.00 and have some caps left over. Good luck.

Phill

[mtl777]

Jitter, thanks for the info on the OEM practices. That explains why some crappy caps get into high-end converters sometimes.

Phill, I was looking for Rubycon ZLH but couldn't find any. Well, there are ZLH in Newark but I'll have to pay an extra $20 to send them over from the U.K. to the U.S. So I settled on Nichicon HE from Digikey which I heard is also very good. We'll see.

Thanks everyone for your inputs!

[jitter]

Originally posted by mtl777
Jitter, thanks for the info on the OEM practices. That explains why some crappy caps get into high-end converters sometimes.

This makes it sound a little as if the OEM is to blame, but don't forget that OEMs do not have specific knowledge of the designs of their customers. They don't need to. A pcb-layout and bill of materials is enough to produce a product. There'll probably be no one wondering if e.g. a Nichicon would be better than a Teapo... As I wrote, when the designer thinks it's important, more detailed specs than just e.g. 470u/63V, will be given.

The fact that Teapo and Honsing caps made it onto your ADC probaby means that the whole product (or at least the electronics) were made in China. It's logical they'd use Chinese caps.
The OEM I work for is in industrial electronics which means that "standard" quality is something from a reputable brand. Think Philips, BC/Vishay, Nichicon and the likes.

"High-end" is surrounded by a lot of mysticism and suggestion. But often a good design using pretty common components is at the heart of it and doing a wonderful job. Look at the attachment, it's the inside of a Micromega DAC1. High end for reasonable money. No esoteric component to be found...

[philtubes]

Mtl777, that was Rubycon YXF not ZLH, oh well, hope the Nichicons work out for you, should be a nice upgrade over the Teapo, at least you are changing them out before they go bad.

Phill

[mtl777]

Yeah, I looked at the YXF but I thought it was too tall at 31.5 mm and would bump against the top cover (the original Teapo is 16 x 25 mm). Then I saw the ZLH which has the right size and very good specs. Unfortunately it's so hard to find. So I settled on Nichicon HE which also has good specs and is 25 mm tall though bigger 18 mm diameter but it will fit as the board is not crowded.