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240V to 220V step down transformer


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Both the transformers are autoformers, ie not isolation transformers.  You need to get an isolation transformer.  Tortech make these as well (although they're more expensive) and are highly recommended.

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Guest jakeyb77
20 minutes ago, Bronal said:

Both the transformers are autoformers, ie not isolation transformers.  You need to get an isolation transformer.  Tortech make these as well (although they're more expensive) and are highly recommended.

Yep for the tube amp get the isolation one as stated above.

I have Tortech and Wallcan units and like them both 

Edited by jakeyb77
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Why do you need one.

what is your mains voltage

does it vary day to night

The percentage difference prob won't have any effect on grid and anode voltages, if it does they will be same for both.

A mains reg would be a better proposition imo 'if ' needed.

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1 hour ago, bazzle said:

Why do you need one.

what is your mains voltage

does it vary day to night

The percentage difference prob won't have any effect on grid and anode voltages, if it does they will be same for both.

A mains reg would be a better proposition imo 'if ' needed.

I beg to differ, 220 to 240v will be a shade off 9.1% increase, on a 6.3v heater that takes it to 6.9v.

Add to that many people in lots of areas get higher than 240 at the wall and this is not great for a tube's longevity, and when looking at other operating points in the circuit also it means the amp is not functioning as intended/designed.

 

Or maybe I'm just picky :|

Edited by muon*
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and unless you have a ground loop issue, I would say not to use isolation transformer on the same unit.

and have it as separates if you needed in future , the cost will be similar to a custom built, and you have two units.

 

with amps , the less things in between outlet to the amp the better, as anything is going to effect dynamics, regardless of price.

unless it's to solve a bigger problem, amps should be plugged directly to wall with simple surge protection.

 

Edited by delphi17
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I pm to OP but thought write here to share my experience. 

 

In my experience, the valve amp may have following issues without a step down transformer:

 

More hum sound;

The amp will run warmer. So as the tubes. Therefore less useful life for tubes. 
 

when running Tortech itself has no hum or any noise, dead quiet.  

Edited by TDX
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2 hours ago, muon* said:

I beg to differ, 220 to 240v will be a shade off 9.1% increase, on a 6.3v heater that takes it to 6.9v.

Add to that many people in lots of areas get higher than 240 at the wall and this is not great for a tube's longevity, and when looking at other operating points in the circuit also it means the amp is not functioning as intended/designed.

 

Or maybe I'm just picky :|

for tubes, the difference is a lot. I don’t think you are picky. 

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11 hours ago, Bronal said:

Both the transformers are autoformers, ie not isolation transformers.  You need to get an isolation transformer.  Tortech make these as well (although they're more expensive) and are highly recommended.

Totally agree. Just brought one from Tortech and made a huge improvement on my 300b which was rated 200 to 230v

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13 minutes ago, stereonut said:

Totally agree. Just brought one from Tortech and made a huge improvement on my 300b which was rated 200 to 230v

Did you get the isolation custom made?

how much was it ? 
thank you 

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4 minutes ago, delphi17 said:

Did you get the isolation custom made?

how much was it ? 
thank you 

No, I just bought the one listed in OPs thread. About $300 landed to me.  I didn’t find any issue at all.  But I wasn’t experience enough to tell if isolation can be even better.

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6 hours ago, delphi17 said:

Did you get the isolation custom made?

how much was it ? 
thank you 

Yes - custom made. From memory around $270 inc Express Post to Perth. I discussed my amp with them and they took it from there. 

SN

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I have the Tortech 240v to 220v non-isolated ones and for my many valve power/pre amps that I own I use this Korean beauty that allows me to dial in the voltage that I want. I also check in circuit heater and filament voltages as well at the valve sockets to ensure those toobs are getting the right AC or DC heater voltages.

 

20200620_234031.jpg

Edited by xlr8or
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I've got one of these on the way from McChanson. Cheaper option than the Tortech. Will hopefully fix some hum issues with my 220V tube amp!

 

https://www.ebay.com.au/itm/1-x-200VA-Step-down-transformer-240V-220V-factor-0-93-fused-for-Valve-amp-1/114245673813?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

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1 hour ago, Bassline Junkie said:

I've got one of these on the way from McChanson. Cheaper option than the Tortech. Will hopefully fix some hum issues with my 220V tube amp!

 

https://www.ebay.com.au/itm/1-x-200VA-Step-down-transformer-240V-220V-factor-0-93-fused-for-Valve-amp-1/114245673813?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

200va?

 

Hope it's low consumption.

 

What amp?

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