Hi there.
Been exploring the Chinese market of tube output transformers to look for SET ‘formers 3.5k primary. Difficult to get through:
Been exploring the Chinese market of tube output transformers to look for SET ‘formers 3.5k primary. Difficult to get through:
- aliexpress search function is innefective with keywords (is there a trick to retrieve only pertinent results and not everything but what one is looking for?)
- there appear to be no real brands and references other than those attributed by vendors (has anyone identified brands and model numbers that can be searched for?)
- a given model gives rise to various electrical characteristics even on the basics (weight, dimensions). Electrical characteristics are seldom realistic (eg 10hz-39khz @ -0,6dB for a 1,6kg ‘former)
- other culture with OTs: small transformers are privileged often with figures similar to those of reputable models from Japan etc.
There is one brand that I typically go for: HiFi Exquis. Unfortunately their prices have gone up and their range has been reduced.
Amplifier and Transformers store is another one.
But, like almost everything in AliExpress, it is a hit and miss. Ask a lot of questions from the seller, ask for the manufacturer contact details, etc.
Amplifier and Transformers store is another one.
But, like almost everything in AliExpress, it is a hit and miss. Ask a lot of questions from the seller, ask for the manufacturer contact details, etc.
Those KI searches on translated items are a pain.
I have more success using google to search on Aliexpress and TaoBao.
The specs are likely not as good as claimed; maybe stick to sellers offering complete devices and parts and have plenty of positive feedback. If they are using the transformers for their own products, that's probably a better sign than purchasing something from some random seller.
However: Good transformers simply are not cheap, or better: Good transformers are expensive for a reason. There simply is no magic dust factory somewhere in the back streets of Shenzen that could make a world class transformer for nothing. The metal has to be imported, then you need the knowledge, and the machines to create something good/working.
I have more success using google to search on Aliexpress and TaoBao.
The specs are likely not as good as claimed; maybe stick to sellers offering complete devices and parts and have plenty of positive feedback. If they are using the transformers for their own products, that's probably a better sign than purchasing something from some random seller.
However: Good transformers simply are not cheap, or better: Good transformers are expensive for a reason. There simply is no magic dust factory somewhere in the back streets of Shenzen that could make a world class transformer for nothing. The metal has to be imported, then you need the knowledge, and the machines to create something good/working.
Try searching for a bile fever cow instead. No joke. Funny. But not a joke. 🙂
Tom
Tom
Yes, they’re also my favourite. Excellent contact / communication and some interesting products especially on their non aliexpress webpages. The offer on transformers is limited to the only one brand that is actually recognisable - Raphaelite.
https://de.aliexpress.com/w/wholesale-röhren-ausgangs-transformator.html
That works for me (German).
That works for me (German).
Using a 10w audio match transformer , I get about 30w using the 0.5w tap. 2.5w CT and 10w taps.
The caveat is 125 to 20khz. Frequency response. Transformer is good well past 60khz.
The caveat is 125 to 20khz. Frequency response. Transformer is good well past 60khz.
It's an overly literal translation of Chinese words without the right context. A transformer is called a "cow" in slang, typically Cantonese. And "fever" it just means audiophilia so it just means it's for audio. "Bile" is a mistranslation of tube, which is a bulbous object. Essentially it means to say these are transformers for tube audio (or valve audio if you're British). I blame all this on Google Translate, which is responsible for many ridiculous tattoos on people's bodies.
You can find cow bile here on Amazon. This one does not have a fever though. The same transformer is sold by various vendors at prices from $14 to almost $200. Call me cheap, but I bought a $16 version that is no longer listed.
https://www.amazon.com/LICHIFIT-Amplifier-Single-Ended-Machine-Transformer/dp/B0B76XWJW2/ref=sr_1_9
My intention was to use it for a reverb tank driver in a guitar amp, but I found a smaller transformer for the reverb driver. These cow bile transformers do work good as an OPT in a 5 watt SE Fender Champ style guitar amp. I never tried to run music through it.
I found this by searching Amazon for "5k ohm output transformer tube." This brings up a bunch of similar junk, and some "50 watt" transformers that are bigger. There is also a 10 watt open frame version that looks nice. Searching Amazon with the same search string but swapping 4K, 6K, and 10K for the 5K number brings up more stuff, and changing the word "tube" to "guitar" shows even more. The 10K search also brought up the exact 5K OPT that I bought, but it is now $19. It shows that I got them in 2020.
https://www.amazon.com/LICHIFIT-Amplifier-Single-Ended-Machine-Transformer/dp/B0B76XWJW2/ref=sr_1_9
My intention was to use it for a reverb tank driver in a guitar amp, but I found a smaller transformer for the reverb driver. These cow bile transformers do work good as an OPT in a 5 watt SE Fender Champ style guitar amp. I never tried to run music through it.
I found this by searching Amazon for "5k ohm output transformer tube." This brings up a bunch of similar junk, and some "50 watt" transformers that are bigger. There is also a 10 watt open frame version that looks nice. Searching Amazon with the same search string but swapping 4K, 6K, and 10K for the 5K number brings up more stuff, and changing the word "tube" to "guitar" shows even more. The 10K search also brought up the exact 5K OPT that I bought, but it is now $19. It shows that I got them in 2020.
I bought a pair of transformers for £6 each on ali which look suspiciously similar to those.
https://www.aliexpress.com/item/100....order_list.order_list_main.39.74a61802a7Z7fP
They do what they say on the tin.
https://www.aliexpress.com/item/100....order_list.order_list_main.39.74a61802a7Z7fP
They do what they say on the tin.
Are any of these transformers investigated as possibly being actual audio transformers?
I have a suspicion that the transformers industry in China probably doesn't know what they are building them for, they just build what sells.
Vendors are probably providing them with a turns ratio and intended current from each winding.
Has anyone cut one apart to investigate interleaving?
My suspicion is that there's no interleaving of primary and secondary.
1 primary winding 1 secondary winding.
Power bandwidth.
This is where a good audio transformer will Excell and a repurposed generic power transformer will fall short.
I tend to buy antique American made transformers for this reason.
I would never consider buying a transformer who's audio performance at power is unknown, unless it's for pennies on the dollar, literal scrap value, I don't have to ship it, and I think I have a use for it...
I would not be buying mystery Transformers from the far east based on word salad. Specs are not offered, only word salad.
Good luck finding antique, single ended transformers from an American manufacturer. We used single ended in the cheapest of tvs and table radios. Hifi was (and in my opinion still is) push pull.
I have a suspicion that the transformers industry in China probably doesn't know what they are building them for, they just build what sells.
Vendors are probably providing them with a turns ratio and intended current from each winding.
Has anyone cut one apart to investigate interleaving?
My suspicion is that there's no interleaving of primary and secondary.
1 primary winding 1 secondary winding.
Power bandwidth.
This is where a good audio transformer will Excell and a repurposed generic power transformer will fall short.
I tend to buy antique American made transformers for this reason.
I would never consider buying a transformer who's audio performance at power is unknown, unless it's for pennies on the dollar, literal scrap value, I don't have to ship it, and I think I have a use for it...
I would not be buying mystery Transformers from the far east based on word salad. Specs are not offered, only word salad.
Good luck finding antique, single ended transformers from an American manufacturer. We used single ended in the cheapest of tvs and table radios. Hifi was (and in my opinion still is) push pull.
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I opened this thread with the belief that there’s some interesting OPT also made in China. The difficulty is to locate/identify the good stuff.
I was surprised how well a small cheap but well built amp el84 SE , equipped with small OPT, could sound - granted: on 100+dB loudspeakers. I think the production quality has largely increased in 25+ years, but keeping track of products and DIYers’ first hand experience with these (as the OPT are barely identifiable with brands and model numbers) is extremely difficult.
I was surprised how well a small cheap but well built amp el84 SE , equipped with small OPT, could sound - granted: on 100+dB loudspeakers. I think the production quality has largely increased in 25+ years, but keeping track of products and DIYers’ first hand experience with these (as the OPT are barely identifiable with brands and model numbers) is extremely difficult.
you seeem to think the chinese are living in the stone age.
There are at least a few experienced winders that have been around for many years with good reputation in local DIY community in China. Their irons may be cheaper in comparison with ISO or Hashimoto, but can be similar to or more expensive than likes of hammond or lundahl - model dependent of course. Good irons need quality materials which are not cheap no matter where the irons are made.
I know a few of winders there invested in AP audio analyzer and can give certain test results.
You just have to find them. That’s the hard part if you don’t speak the language/can’t navigate through the historical posts on local DIY forums to see what local DIYers have said.
I know a few of winders there invested in AP audio analyzer and can give certain test results.
You just have to find them. That’s the hard part if you don’t speak the language/can’t navigate through the historical posts on local DIY forums to see what local DIYers have said.
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I can confirm, as a person who travels often to China, and works for a chinese company, that they are not living in the stone age.
They do interleaving, some suppliers even advertise that, show coils etc. But it is true that many do not supply the minimum information required, and sometimes you have to use pliers to extract meaningful info out of the seller.
I bought a while ago a pair of 15W 3.3K SE transformers, at around £25 each, they worked pretty well. I'm sure that established manufacturers like Edcor, Hammond and the likes can do better, but hey, it was a very good value for money. Below the bandwidth measured at 9Vrms/8ohms output in a very simple PSE setup, bang-on -3db @20Khz, as the seller advertised. That's good value in my book: