ferringo Posted October 26, 2013 Posted October 26, 2013 Hi Gurus, Have been told that using a step down transformer from 230 volts to 120 volts will degrade the performance on the Preamp. Which is suitable to use, step down or isolation transformer? Thank you for reading. Regards
Guest Muon Posted October 26, 2013 Posted October 26, 2013 (edited) Email Tortech in Sydney, they do all the toroidal stuff, step-downs and even provide solutions for studios and such, but the studio stuff would be very expensive and over kill really. I used a step down from them for a little EL84 amp and It was fine. The other option is to have a Tech' replace the transformer/s with ones suitable for here. Maybe a better option over all. Edit:No guru, but responded anyway Might help the real guru's if you add some details like the make and model of the Pre. Edited October 26, 2013 by datafone
ferringo Posted October 26, 2013 Author Posted October 26, 2013 (edited) Hi Oh ya missed out the important equipments; 1) Adcom GFA 5802 power amp..max power consumption 1440va......USA set 2) Audible Illusions Modulus 3A preamp.....USA set 3( Micro Seiki BL 91 TT......USA set Using step down torodal transformer 3000 va. Made in China. Edited October 27, 2013 by ferringo
pete_mac Posted October 26, 2013 Posted October 26, 2013 Personally, I'm wary of Chinese stepdowns. I saw one go 'poof' recently without blowing the in-line fuse. It was thrown away and a Tortech was purchased instead, and the owner is a happy chappy once again.
Sir Triode Posted October 26, 2013 Posted October 26, 2013 (edited) I purchased a Tortech stepdown last year (one of their off the shelf models) and it suffered from a low level hum. Returned it and got them to build me a custom one with no hum - tested it onsite to make sure it was ok and it was but it too hummed when used at home. They allow returns so if it doesn't work for you, you can return it for a refund. The chief engineer over there is a very nice chap. Edited October 26, 2013 by triode12
Volunteer sir sanders zingmore Posted October 26, 2013 Volunteer Posted October 26, 2013 Did you work out why the hum? It didn't know the words 7
Zaphod Beeblebrox Posted October 26, 2013 Posted October 26, 2013 (edited) Hi Gurus, Have been told that using a step down transformer from 230 volts to 120 volts will degrade the performance on the Preamp. Which is suitable to use, step down or isolation transformer? Thank you for reading. Regards You have been informed incorrectly. If anything, using a step-down transformer (particularly an 'R' core type or an 'EI' type transformer) is likely to improve mains isolation. At the very worst, expect no improvement in performance. BTW: A proper isolation transformer (as opposed to the more common, autoformer) will provide the above advantages. Autoformers, not so much. Edited October 27, 2013 by Zaphod Beeblebrox 1
gparker777 Posted October 26, 2013 Posted October 26, 2013 Aside from Tortech what are some other hum-free brands ?
Sam Z Posted October 27, 2013 Posted October 27, 2013 (edited) Bahahaha @ whatmore There's a lingering myth going around that stepdowns are a no-go for high-end audio, and it's simply not true. I use them personally with no problem. ZB and others who understand the theory will say the same, as above. Aside from Tortech, you could try Harbuch... There are probably some other old time transformer manufacturers who do good work too. But I can vouch for Tortech, they're very good and they know their stuff. Edited October 27, 2013 by Sam Z
metal beat Posted October 27, 2013 Posted October 27, 2013 (edited) I bought a 500 watt 240 volts to 100 volts Isolation transformer from Tortech last week. They added a 2nd outlet and a bit more step down to get the voltage closer to 100 volts for no extra. This is due to overvoltage in my area where mine is between 245 and 251 volts, averaging about 248 volts. My voltage from the Tortech is now between 103 and 106 instead of the 111 and 113 volts it was before. the transformer still has some mechanical hum if you put your ear close, however in my dedicated room I can't hear it. btw, the transformer sounds better on my shelf than sitting on the carpet, tighter bass more natural upper frequencies. Maybe I should try it on Stillpoints LOL Tortech are a nice company and recommended. cheers Edited October 27, 2013 by turntable
TP1 Posted October 27, 2013 Posted October 27, 2013 A couple of things: 1. Depending on your budget, you can get a step down / isolating / balanced power supply for quite reasonable cost from the UK. I also have few of their 3KVA balanced power supplies - something you have to pay thousands for elsewhere and these make a very big difference to the sound. In fact probably the best bang for your buck sonic upgrade: http://www.airlinktransformers.com/balanced_power_supply/conditioning_balanced_power_supply/JACBS0500/ http://www.airlinktransformers.com/balanced_power_supply/ 2, As Turntable has indicated, acoustic isolation for transformers / power conditioners seems to have a positive affect
metal beat Posted October 27, 2013 Posted October 27, 2013 A couple of things: 1. Depending on your budget, you can get a step down / isolating / balanced power supply for quite reasonable cost from the UK. I also have few of their 3KVA balanced power supplies - something you have to pay thousands for elsewhere and these make a very big difference to the sound. In fact probably the best bang for your buck sonic upgrade: http://www.airlinktransformers.com/balanced_power_supply/conditioning_balanced_power_supply/JACBS0500/ http://www.airlinktransformers.com/balanced_power_supply/ 2, As Turntable has indicated, acoustic isolation for transformers / power conditioners seems to have a positive affect Hi Tasso What is your output voltage on your 500 watt step down to 100 volts? Are the large 3KVA balanced power supplies hum free? Something that large would be difficult to keep quiet one would imagine.
warren2503 Posted October 27, 2013 Posted October 27, 2013 Hi I have a Tortech special wound transformer I was using with a Herron vave preamp absolutely silent , I no longer need it , if you want to buy it from me pm me , if it's not as quite and as good as I say I'll give you the Monet back
metal beat Posted October 27, 2013 Posted October 27, 2013 Hi I have a Tortech special wound transformer I was using with a Herron vave preamp absolutely silent , I no longer need it , if you want to buy it from me pm me , if it's not as quite and as good as I say I'll give you the Monet back Size, output voltage?
ferringo Posted October 27, 2013 Author Posted October 27, 2013 (edited) Thank you all. Well the toroidal step down transformer output 3000va , 220 volts to 110 volts made in China had been used for about a month. Touch wood, is running perfect no humming. I noticed its doesn't get warm or heated up after running for 3 hours. Btw will get in touch with "Tortech" for a high grade step down transformer What about the "isolation transformer? Any recommendation? Which is more applicable for high end audio? Cheers Edited October 27, 2013 by ferringo
TP1 Posted October 27, 2013 Posted October 27, 2013 (edited) Hi Tasso What is your output voltage on your 500 watt step down to 100 volts? Are the large 3KVA balanced power supplies hum free? Something that large would be difficult to keep quiet one would imagine. To measure voltage i am using one of those power consumption thingy's and it only operate for 240v. But the power coming out of the wall at the moment is 252v My balanced transformers actually have a 20V lower output than input. I asked Airlink if they could do that as an act of kindness to my gear, which they did for a small sum ( $30 I seem to remember). So today, all my hifi gear is seeing 232 v . Buzzing only happens when DC is present in the mains - Transformers do not pass DC ( good thing) but it does cause them to vibrate. 95% of the time they are totally silent and for the remaining 5% I seem to have it under control. A few things that I have observed with regard to transformer hum: 1. I use dedicated lines from the mains but a tiny bit of DC can still find its way back to the transformers. In my case the biggest culprits are 12V lighting dimmers ( which I have removed - if you want ambience, light a candle!), and certain kitchen appliances. 2. The large toroidal transformers are secured in a metal case by means of a central bolt. Keeping the bolt tight and even damping the inside of the metal box helps quite a bit to reduce the audible effects of hum when it strikes. If i was to purchase any more transformers, I would probably ask Airlink if they could pot the transformers with resin which I understand can reduce audible vibrations significantly. One project that I have put off since getting most of it under control is putting a neoprene cushion between the big toroid and the metal base of the case to see if that will make it totally silent. 3. DC can be prevented from entering transformers by some form of DC blocking circuit as per below. http://sound.westhost.com/articles/xfmr-dc.htm For high current applications (13A) , the capacitor values would need to be pretty large. In the USA, there is the Hum Buster, but I can't find an equivalent 240V device. Power regenerators can avoid the problem but at this point they are not within the same bang for your buck ballpark as the Airlink balanced power supplies IMO. Edited October 27, 2013 by Tasso
ellrotts Posted October 27, 2013 Posted October 27, 2013 A stepdown/ Iso TX wont change anything. all it will do is improve safety in the event of a fault and step down voltage. your power is "stepped down" and up likely 50 times before it gets to your house. which retard said it would change the sound?
TP1 Posted October 27, 2013 Posted October 27, 2013 A stepdown/ Iso TX wont change anything. all it will do is improve safety in the event of a fault and step down voltage. your power is "stepped down" and up likely 50 times before it gets to your house. which retard said it would change the sound? I have heard of a distributor saying that to scare punters away from importing cheaper units from overseas .
ellrotts Posted October 27, 2013 Posted October 27, 2013 as soon as you get between someone and their money they are going to do anything to turn you off getting any option that they wont profit from. A transformer in no way shape or form will affect the "sound" unless its undersized. the only thing that distinguishes a transformer from another transformer is its efficiency. I love audio, but there is so much toss u have to wade through to get into whats real and whats not. Thats why SNA is brilliant, experts everywhere to clear the path for us. 3
hochopeper Posted October 27, 2013 Posted October 27, 2013 Anyone tried the balanced PSUs from Tortech/David Peach?
oceangreen17 Posted October 28, 2013 Posted October 28, 2013 If anything, using a step-down transformer (particularly an 'R' core type or an 'EI' type transformer) is likely to improve mains isolation. At the very worst, expect no improvement in performance. This has been my personal experience. I have used a Tortech isolation stepdown transformer (240 -120 volts) for the last six years with my Audible Illusions M3A preamp and Wadia CDP. No hum, no issues and totally reliable.
Sir Triode Posted October 28, 2013 Posted October 28, 2013 (edited) Anyone tried the balanced PSUs from Tortech/David Peach? Yes, I had a Peach Audio Balanced Transformer before. It didn't work for me - it constricted the dynamics of my system. Highs were shrill. Eventually sold it of for a tidy profit. Picked it up from Ebay in near new condition for only $65. There is nothing in the thing - just one large transformer and a smaller one in a white powder coated steel casing. Edited October 28, 2013 by triode12
hochopeper Posted October 28, 2013 Posted October 28, 2013 (edited) Thanks triode, I'm building a few electronics measurement tools and trying to weigh up balanced PSU vs Isolated PSU for a very low electrical noise environment. When I get the other parts built I'll probably be able to work out (measure) how much the PSU helps/doesn't help but for now I'm doing some research to spend least $$ for best performance. The computer/desk I'm at for doing measurements is also where my main headphone system lives so I'm going to be listening also not just looking at numbers! I bought a 500 watt 240 volts to 100 volts Isolation transformer from Tortech last week. They added a 2nd outlet Interesting, I note the isolation transformers on their website have 'only connect one device to the outlet' warning stickers on them yet the step down transformers don't, yet I can't understand why on earth they'd be different other than the turns ratio in the transformer. I've sent tortech an email ... will let you guys know if anyone's interested. Edited October 28, 2013 by hochopeper
Sir Triode Posted October 28, 2013 Posted October 28, 2013 What about using a power regenerator? I'm sure it can be configured to output 120V from 240V. That is one selling in the UK made for audio for only 499GBP and has been getting rave reviews over there. http://upsmart.co.uk/ag1500-regenerator-1500w-psu-aus-p-1762.html There was a thread about it on SNA too in June: http://www.stereo.net.au/forums/index.php?/topic/53766-power-inspired-ac-regenerator/ 1
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