I purchased a pair of SIT1 mono's from Japan, which are currently en-route to myself in Europe. I realize only now that Japan runs on 100V and not 120V.
I was planning to adjust from 120V to 240V via wiring the dual primary transformer in series.
I guess, with these Japanese amps, I won't be able to do so... WHOOPS!! Live and learn 🙂.
I suppose I need to replace with appropriate transformers? If anyone has the original AnTek part number that would be appreciated.
Note I reached out to First Watt directly some time ago with a similar question but did not get a response, therefore asking here.
I was planning to adjust from 120V to 240V via wiring the dual primary transformer in series.
I guess, with these Japanese amps, I won't be able to do so... WHOOPS!! Live and learn 🙂.
I suppose I need to replace with appropriate transformers? If anyone has the original AnTek part number that would be appreciated.
Note I reached out to First Watt directly some time ago with a similar question but did not get a response, therefore asking here.
Look on the rear of the amplifier, it will state the power consumption.
Purchase a 240v auto transformer with a 100volt tapping at 50% more Wattage rating than your amplifier.
Something like this;
https://uk.farnell.com/mercury/651-031uk/step-down-converter-300w-230v/dp/4266204
https://uk.rs-online.com/web/c/?sea...n=attributes.Secondary_Voltage_Rating=115V ac
https://www.mouser.co.uk/ProductDetail/Hammond-Manufacturing/170A?qs=jcD/CkGBYeNPgHPl82fYuQ==
etc etc.
I doubt you will find one with a 100volt tapping but you never know.
Purchase a 240v auto transformer with a 100volt tapping at 50% more Wattage rating than your amplifier.
Something like this;
https://uk.farnell.com/mercury/651-031uk/step-down-converter-300w-230v/dp/4266204
https://uk.rs-online.com/web/c/?sea...n=attributes.Secondary_Voltage_Rating=115V ac
https://www.mouser.co.uk/ProductDetail/Hammond-Manufacturing/170A?qs=jcD/CkGBYeNPgHPl82fYuQ==
etc etc.
I doubt you will find one with a 100volt tapping but you never know.
Thank you. I really rather would prefer to replace the internal transformer and bring this to original design spec vs. adding in an additional transformer.
A step down transformer would be the easiest way. Something with outlets already incorporated. Did you check the power cord? Does it have a gnd? Generally Japanese stuff come with 2-prongs IEC and power cable. What I am saying is that other mods to gnd wiring besides trafo may be needed. Maybe very simple stuff.
Not necessarily. The easiest and most pain free way is to replace the power trani with a 240V primary, whatever V secondary one and be done with it.
eg. 240 V Pri / 2 x 20 V Sec., 300 - 400 - 500 VA.
eg. 240 V Pri / 2 x 20 V Sec., 300 - 400 - 500 VA.
Yes, this is my thinking. If anyone here has a non-Japanese SIT1 and could lift the cover and send a pic of the AnTek transformer with secondary config and part # this would be massively appreciated!
Maybe, maybe not. I would like to know how the power cable is setup: 2 or 3 prong, gnd or no gnd.
Is it legal to power a metal chassis without GND? Seems like eventually that might cause some serious issues…
Not with a class I device sold in Europe. The serious issue is that it won’t be safe. Most love their partner, children and pets and would not like their beloved to have electrical shocks caused by an erroneously converted hobby device. The general picture is that those that do such endeavours are not capable to do the necessary conversion.
I sometimes wonder what energy and kerosine is used to fly 100V stuff to 240V areas and vice versa, the energy used by people and servers to answer these riddles. And how the contraptions look after adding conversion transformers. And if the created situation is technically just as good as buying the stuff in ones own area.
I sometimes wonder what energy and kerosine is used to fly 100V stuff to 240V areas and vice versa, the energy used by people and servers to answer these riddles. And how the contraptions look after adding conversion transformers. And if the created situation is technically just as good as buying the stuff in ones own area.
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Yes, no chassis GND is not safe, period.
The things one goes through to acquire out-of-production unobtainium SIT amplifiers 🙂. This is a one-off as an individual so I do not feel too bad out the environmental impact.
The things one goes through to acquire out-of-production unobtainium SIT amplifiers 🙂. This is a one-off as an individual so I do not feel too bad out the environmental impact.
You have the unique opportunity to run the amps off a purpose-built step down balanced "isolation" transformer (also known as balanced isolation configuration).
If were in your shoes, I would order a toroidy audio grade 1200VA or 1500VA 240VAC (or 2x120VAC) primary, 2x50VAC secondary transfomer. The transformer primary is hooked up to the mains (add a fuse and maybe a beefy line filter and soft start circuit). The transformer secondary is wired in series with the center tap grounded (neutral or ground). That center tapped 100VAC will give you serious common-mode rejection of any nasties that appear on the mains, plus the FW amps will get DC-free AC.
Apart from having the cleanest possible power, that would also allow you to run both amp as they are without any modification.
Btw, the 50Hz/60Hz discrepancy should not be an issue, because both frequency standards are being used within Japan.
If were in your shoes, I would order a toroidy audio grade 1200VA or 1500VA 240VAC (or 2x120VAC) primary, 2x50VAC secondary transfomer. The transformer primary is hooked up to the mains (add a fuse and maybe a beefy line filter and soft start circuit). The transformer secondary is wired in series with the center tap grounded (neutral or ground). That center tapped 100VAC will give you serious common-mode rejection of any nasties that appear on the mains, plus the FW amps will get DC-free AC.
Apart from having the cleanest possible power, that would also allow you to run both amp as they are without any modification.
Btw, the 50Hz/60Hz discrepancy should not be an issue, because both frequency standards are being used within Japan.
And then discover the thingie has 2 x 115V primaries used in parallel for the japanese market 😀
It maybe is good to wait for arrival and then open the device(s).
It maybe is good to wait for arrival and then open the device(s).
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Legal? Who cares? The amp police? The important thing is that in many EU countries, maybe all, and 220V mains and the fact that the neutral is NOT grounded at the electrical panel like US and Japan, you need to have the gnd at the plug.
Definitely wait and see how it's wired.
Ah, that I did not know.
Yes I will wait for its arrival, and then I will figure out which AnTek transformers I need to order. Thanks all for the replies.
Yes I will wait for its arrival, and then I will figure out which AnTek transformers I need to order. Thanks all for the replies.
N is of course connected to PE one way or another and we have 230V (more often close to 245V). PE is for ones own and others safety whatever one may think of the legal part. In developed countries such stuff is regulated for the benefit of public health/common interest.
PE is not GND! I noticed in Japanese made audio sometimes Audio GND is connected to chassis instead of PE. Could not get my head around that. Usually it therefor has hum issues.
PE is not GND! I noticed in Japanese made audio sometimes Audio GND is connected to chassis instead of PE. Could not get my head around that. Usually it therefor has hum issues.
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maybe you'll get lucky and see some redundant wires in primary, when you open it
anyhow, if you opt to use autoformer, as some suggested, that's substantially worse option than replacing xformer in amp
been there, tried
if nothing else, it results in worse line-regulation (measure of xformer quality), simply involving more links in chain
not so important with amps in A Class as with B Class amps, but anyway
my personal OCD allows variacs and additional autoformer only as work tools and temporary solutions
hey, but that's me
edit: and yes - safety GND is no discussion issue; fact - every proper autoformer is having undisturbed safety GND connection
anyhow, if you opt to use autoformer, as some suggested, that's substantially worse option than replacing xformer in amp
been there, tried
if nothing else, it results in worse line-regulation (measure of xformer quality), simply involving more links in chain
not so important with amps in A Class as with B Class amps, but anyway
my personal OCD allows variacs and additional autoformer only as work tools and temporary solutions
hey, but that's me
edit: and yes - safety GND is no discussion issue; fact - every proper autoformer is having undisturbed safety GND connection
Based on my limited experience, it is not likely that the original transformers were made by Antek. It is more likely that they were made by Plitron.
With some, but not all, Plitron transformers there are appropriate primary configurations for 100 / 115 / 230V mains.
Mainly, your idea to simply wait to see what's in the box is wise vs. wondering.
Here is an example of the primary side of one reasonably common Plitron used in some First Watt Clones. I have no idea whatsoever if it is the same as what may have been used in a production SIT1.