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Review and Measurements of Schiit Lyr Tube Headphone Amplifier

Wombat

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Many quote the single-phase LV nominal a.c. mains voltage incorrectly e.g U.S. as 11oV whereas it is commonly 120V and has been for some time. It is common practice to use a voltage - dropping device with old guitar amplifiers to keep their B+ at the correct level.

This proscribed voltage can vary due to proximity to the feeder substation and to loading on the lines. Allowable variation is regulated in many counties.

For example, Australia: https://www.ausgrid.com.au/-/media/Files/Network/Documents/NS-and-NUS/NS238.pdf - see 6.1.1.1. Overall summary on page 3.
 
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FrivolsListener

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Many quote the single-phase LV nominal a.c. mains voltage incorrectly e.g U.S. as 11oV whereas it is commonly 120V and has been for some time. It is common practice to use a voltage - dropping device with old guitar amplifiers to keep their B+ at the correct level.

This proscribed voltage can vary due to proximity to the feeder substation and to loading on the lines. Allowable variation is regulated in many counties.

For example, Australia: https://www.ausgrid.com.au/-/media/Files/Network/Documents/NS-and-NUS/NS238.pdf - see 6.1.1.1. Overall summary on page 3.

Yes, I did mention +/- 10%, although I think the range is 120/240 vac -10/+15%, and I think the international standard for "120" is 100-127vac. Wiki mains voltage and it might get you to that reference.
 

FrivolsListener

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If its a switching supply, as its voltage range implies, it is very unlikely to be a problem.

Unlikely to be THAT problem, yes, but switchers are noisy. You have to work hard to get a clean switcher. Some designers choose to avoid them altogether.
 

Blumlein 88

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Yes, I did mention +/- 10%, although I think the range is 120/240 vac -10/+15%, and I think the international standard for "120" is 100-127vac. Wiki mains voltage and it might get you to that reference.


Most of the USA does the 5% thing either way. The 104 to 127 volt tolerance of -13% to +6% would be a utilization voltage which would apply to high current draws like electrical motors or other machinery under use. Not a few watts audio amp.
 

FrivolsListener

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Most of the USA does the 5% thing either way. The 104 to 127 volt tolerance of -13% to +6% would be a utilization voltage which would apply to high current draws like electrical motors or other machinery under use. Not a few watts audio amp.

Is that the exact tolerance specified? My apologies for getting the number wrong.

Out here in The Last Mile, my voltage did swing between 115 and 126 until the long single-phase circuit was broken into a 3 phase circuit and load balanced.
 

Wombat

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Yes, I did mention +/- 10%, although I think the range is 120/240 vac -10/+15%, and I think the international standard for "120" is 100-127vac. Wiki mains voltage and it might get you to that reference.

I 'Wikied' and considerd this one: http://www.electrical-installation.org/enwiki/Low-voltage_consumers I could not be sure if the entries in the table were correct in all cases and I was not prepared to verify them all. Also, tolerences were not given for voltage variation. Thus I did not post it.
I would suggest individuals obtain such information from their local supplying utility.


Note: I spent a large part of my career in our State Electricity Commission as a Power Systems Engineer - Generation, transmission, sub-transmission, distribution,maintenance, voltage control, load forecasting and generation scheduling. Also high-voltage system safe operation policies, standards, procedures and work practises. Plus accident investigation, fault/failure/disturbance analysis, some design Etc.
I prepared submissions to our Government Minister for Energy,when he requested them.
When I left the organisation I held the highest Engineering management Grade.

for the record I was subsequently A Senior Lead Auditor(ISO 9000 Quality Management System Standards and others) working for an internationally accredited verification organisation. When I put my mind to it my thinking is very clear and rational.

Just sayin', bye-the-bye.
 
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amirm

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According to the web site, 115 or 230 vac.
That is a functionality spec, i.e. it runs in US and Europe. It does not give an acceptable range of voltages. As such, no way to know if your AC power is in spec, or not.

And that is as it should be: consumer devices running on DC power better be extremely tolerant of AC voltage fluctuations. Anything less is just broken.
 

Blumlein 88

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Is that the exact tolerance specified? My apologies for getting the number wrong.

Out here in The Last Mile, my voltage did swing between 115 and 126 until the long single-phase circuit was broken into a 3 phase circuit and load balanced.

Exact percentages do vary some in regions of the USA. Those I posted were some guidelines supposedly used as targets for west coast and east coast power companies.

I had a small involvement in power quality for some large customers in my job prior retirement. Not an EE or anything it was peripheral to my job. Some of the gear in use had full time monitoring of phase, voltage, current. PF was more of an issue than voltage. Pretty rare for the voltage to wander off +/- 3%. We were promised by the power provider +/-5 %. Same situation at least where I was in the early 1980's promised +/- 10 % and sometimes that wasn't managed all that well. So things have improved. Oh and in the 1980's the target voltage was 117 volts and multiples there of.
 

Blumlein 88

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I 'Wikied' and considerd this one: http://www.electrical-installation.org/enwiki/Low-voltage_consumers I could not be sure if the entries in the table were correct in all cases and I was not prepared to verify them all. Also, tolerences were not given for voltage variation. Thus I did not post it.
I would suggest individuals obtain such information from their local supplying utility.


Note: I spent a large part of my career in our State Electricity Commission as a Power Systems Engineer - Generation, transmission, sub-transmission, distribution,maintenance, voltage control, load forecasting and generation scheduling. Also high-voltage system safe operation policies, standards, procedures and work practises. Plus accident investigation, fault/failure/disturbance analysis, some design Etc.
I prepared submissions to our Government Minister for Energy,when he requested them.
When I left the organisation I held the highest Engineering management Grade.

for the record I was subsequently A Senior Lead Auditor(ISO 9000 Standards and others) working for an internationally accredited verification organisation.

Just sayin', bye-the-bye.

So just another keyboard expert know it all pretending to have credentials................................:D
 
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amirm

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Thomas savage

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trl

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Seems that Lyr3 is having much power and measurements are looking very well for a tube amp. AtomicBob did some measurements and I was impressed how good this amp measures. Now I'm curious if Amir can find a Lyr3 to measure it...perhaps with AKM DAC or, why not, with the AD multibit one.
 

watchnerd

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trl

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