Does more than 120 matter for my tube?

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ajhess

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Does more than 120 matter for my tube?
« on: 13 Jan 2019, 02:03 pm »
Hi all.
I've been catching up on the Modwright Transformer Tube Rolling thread (83 pages!!). The Transformer is a sort of DAC/preamp/streamer. I'm interested in trying the EML Mesh 5U4G rectifier in my device, but the threads warn of early death if the voltage is too high to the tube. Luckily, my Transformer has had the modification to lower the voltage going to the rectifier to below 5v. BUT...my house current is higher than 120. I have a CyberPower CP1500AVRLCD UPS, which is supposed to keep the output to within 5% of 120. The highest I've seen is 127. Usually it's 123-4.

What does this mean for the voltage that the rectifier will see? Am I in danger of zapping the tube? The Transformer uses an oversized toroidal transformer (not sure if that is relevant).
Thanks,
Andrew

toocool4

Re: Does more than 120 matter for my tube?
« Reply #1 on: 13 Jan 2019, 02:19 pm »
I don’t think you should be using this on your amp, this UPS is line interactive and simulated sine wave.
Line Interactive means it will track the voltage coming in, since you say your voltage fluctuates this UPS will also fluctuate in it’s output.
Simulated Sine Wave, your amp wants pure sine wave to be at it’s happiest.

timind

Re: Does more than 120 matter for my tube?
« Reply #2 on: 13 Jan 2019, 02:23 pm »
I'm not familiar with any of your equipment, but I have a similar situation with a vintage Fisher tube amp and high mains voltage. After checking the voltages, wow were they high compared to the schematic. I hooked up a variac and brought the AC voltage down to 115 and the Fisher's voltages were well within spec.

I now simply use the variac when listening to the Fisher.

FullRangeMan

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Re: Does more than 120 matter for my tube?
« Reply #3 on: 13 Jan 2019, 03:10 pm »
+1 on the Variac if it can be fine tuned in 1 or 2V.

Rusty Jefferson

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Re: Does more than 120 matter for my tube?
« Reply #4 on: 13 Jan 2019, 03:53 pm »
I agree with toocool about using the UPS.  You're likely to get better sonic performance removing that from your system than upgrading to a $300 rectifier.   :D

Power fluctuates.  Many of us can't afford power re-generators, and still have good sounding systems. 

Elizabeth

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Re: Does more than 120 matter for my tube?
« Reply #5 on: 13 Jan 2019, 04:31 pm »
Just to say yeah high voltge is not good for electronics. (Low voltage is bad for motors)
The Variac reads like a good idea if the voltage is consistently over.. Even if it varies.. keeping the voltage for that component between 112 and 119 would be way better for it than 120 to 127

Bob2

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toocool4

Re: Does more than 120 matter for my tube?
« Reply #7 on: 13 Jan 2019, 05:44 pm »
Power fluctuates.  Many of us can't afford power re-generators, 

A regenerative power conditioner does not have to cost and arm and a leg. I use a Double conversion pure sine wave regenerative power conditioner, I would not be without one now. The power supply in my flat fluctuates from 225V – 239V, in the UK we use 240V. I have set my power conditioner to put out 240V no matter what comes in, I have constant 240V to my setup. Fluctuating power supply is not good for any equipment.

Elizabeth

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Re: Does more than 120 matter for my tube?
« Reply #8 on: 13 Jan 2019, 06:37 pm »
I agree power fluctuates..
It may not be perfect for equipment. but the vast majority of folks with endless electronics (mainly TVs..) don't have any problems with the endlessly fluctuating power they are stuck with. So I call it a minor problem best left alone.. unless you know it is a problem for your stuff.

ajhess

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Re: Does more than 120 matter for my tube?
« Reply #9 on: 13 Jan 2019, 09:22 pm »
I should have mentioned that my amp is a Sony TA-4650 VFET amp. One of the things I've read will kill it is using a variac--something about low voltages killing the VFETs. Maybe that's not an issue if it's just to keep it at 120v?

I've done a bit of reading on this forum and it looks as if most devices that will put out 120v are $$$$. Can anyone recommend an affordable device that will keep my devices at 120 regardless of input voltage?

Thanks

toocool4

Re: Does more than 120 matter for my tube?
« Reply #10 on: 13 Jan 2019, 10:17 pm »
ajhess not sure how much is a lot or how much you are willing to pay, have a look at this thread this is what I use https://www.audiocircle.com/index.php?topic=152774.0. I had to change the fans and add a resistor. A member contacted me as he had picked up a second-hand one for a low price and wanted to know the fans / resistor I used to modify it.

Here is how it works https://www.youtube.com/watch?v=vI0_b0X4KXk

FullRangeMan

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Bob2

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Re: Does more than 120 matter for my tube?
« Reply #12 on: 14 Jan 2019, 02:12 pm »
Quote
This is a typical Variac precision seems 10V.

Possibly. This is recommended by Bob Latino who knows a little bit about tube things...

A discussion of higher voltages and it's affects on tube based gear: http://dynacotubeaudio.forumotion.com/t3938-122v-and-above-why-not-address-the-issue

S Clark

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Re: Does more than 120 matter for my tube?
« Reply #13 on: 14 Jan 2019, 02:25 pm »
This is a typical Variac precision seems 10V.
That's why you measure with a VOM before you turn on your device.  I have a Victor TT-81 running on a variac for the purpose of feeding it 100V.  Just occasionally check to see if it has drifted. 

ajhess

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Re: Does more than 120 matter for my tube?
« Reply #14 on: 14 Jan 2019, 04:28 pm »
Everytime I get back into my audiophile interest, my head starts spinning! It's all the arcane info and mega $$$.  :duh:

My main concern is providing 120v to my Modwright Transformer with the EML Mesh rectifier (haven't bought it yet...more stuff to sort out!). Then I read about the benefit to the sound....yeah, but sorry, I can't spend $$$ on this.

And a variac...I can't see myself and my wife and kids adjusting that thing all the time.

I'm starting my research, but would any of these do the job of keeping 120v while cleaning up the juice? I know that you get what you pay for, but can I get most of the way with one of these:

https://www.amazon.com/Tripp-Lite-LC1800-Conditioner-Outlet/dp/B0000514G8/ref=sr_1_1?s=electronics&ie=UTF8&qid=1547482829&sr=1-1&keywords=tripp+lite+conditioner

https://www.amazon.com/Furman-AC-215A-Conditioner-Auto-Resetting-Protection/dp/B003PJ6NPO/ref=sr_1_4?s=electronics&ie=UTF8&qid=1547482829&sr=1-4&keywords=tripp+lite+conditioner

https://www.amazon.com/Tripp-Lite-Conditioner-Regulation-LS606M/dp/B00006B83G/ref=sr_1_5?s=electronics&ie=UTF8&qid=1547482829&sr=1-5&keywords=tripp+lite+conditioner


toocool4

Re: Does more than 120 matter for my tube?
« Reply #15 on: 14 Jan 2019, 04:39 pm »
ajhess i don't know if they will work, why don't you contact the amp manufacturer before you buy them to see what they say?

ajhess

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Re: Does more than 120 matter for my tube?
« Reply #16 on: 14 Jan 2019, 07:46 pm »
Well, that would be Sony, and this amp is almost 50 years old. My concern is with the preamp/DAC/streaming device with the sensitive rectifier tube. I should state the obvious--while this set up matters to me, we're not talking rarified world of audiophilia. If I can get an affordable (~$100ish?) device that will keep them fed at 120v and maybe take care of the worst of the line trash, I'd be happy. Any thoughts?

FullRangeMan

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Re: Does more than 120 matter for my tube?
« Reply #17 on: 14 Jan 2019, 11:15 pm »
That's why you measure with a VOM before you turn on your device.  I have a Victor TT-81 running on a variac for the purpose of feeding it 100V.  Just occasionally check to see if it has drifted.
Can you adjust how many Volts? or fine tune by how many Volts?