I am trying to get from wall outlet 120v@60Hz to 120v@54Hz as the supply for a guitar amp power transformer. I'm guessing a DC inverters output can be dialed in to another frequency other than 60Hz? Any suggestions, links or comments are very much appreciated by this novice and thanks for a great forum.

 

Where on Earth are you that uses 120VAC 54Hz mains?

 

It's an experiment to see the effect on the transformer, tubes, and end sound of the amp.

 

What a waste of time, 10 Hz won't make any difference..

 

In a nutshell, there is no difference in audio performance.

AAC is not renown for serious discussion among audiophools.

 

I'm just looking for the means to get there. Would a DC inverter do it? Is there a way to adjust frequency on an inverter? An oscillator of some sort? A Variable Frequency Changer?

 

What a waste of time, 10 Hz won't make any difference..

I know right! I thought that too but this is the result of a long study and conversations of how we arrived at 60 cycles and 110v to begin with. It was apparently Edison and some sort of compromise for 110v and 60 was chosen for our 60 seconds/minutes standard.

 

In a nutshell, there is no difference in audio performance.

AAC is not renown for serious discussion among audiophools.

I have a few tricks for the audio but in general I agree

 

I know right! I thought that too but this is the result of a long study and conversations of how we arrived at 60 cycles and 110v to begin with. It was apparently Edison and some sort of compromise for 110v and 60 was chosen for our 60 seconds/minutes standard.

And how we ended up with 60 minutes/hour and 24 hours/day is another interesting discovery.

 

And how we ended up with 60 minutes/hour and 24 hours/day is another interesting discovery.

Yes it is. I started investigating when I found the 432Hz music standard had changed to 440Hz for no reason and the sneaky way it happened made me think

 

Ok so far on my late night hunt I found an article that says applying a lower frequency to a 60Hz transformer will result in higher current, higher heat, much less efficiency and burnout. So, I build the correct transformer for X frequency, another project.

But to arrive at 54Hz it looks like I need an oscillator circuit ?

 

The only problem you may run into, I have seen transformers that will run on 60Hz but saturate on 50Hz. The core was not quite big enough.

 

Why not use an alternator type generator and adjust the motor speed for the required frequency. Honda used to make one with a resonant mechanical indicator (that looked like a small moving iron meter) so that you could adjust the frequency to 50 or 60 Hz or anywhere between.

 

Why not use an alternator type generator and adjust the motor speed for the required frequency. Honda used to make one with a resonant mechanical indicator (that looked like a small moving iron meter) so that you could adjust the frequency to 50 or 60 Hz or anywhere between.

I cant attach it to a guitar amp

 

Have you considered a single-phase variable frequency drive? The output may not be a well filtered sine wave, but they are used to reduce the speed of synchronous motors.

 

Have you considered a single-phase variable frequency drive? The output may not be a well filtered sine wave, but they are used to reduce the speed of synchronous motors.

Yes thank you I think it may be the closest thing I've found so far

 

You can, as mentioned, consider a VFD. However, take a look at your original posted drawing. Your transformer outputs 375 VAC center tapped and at 75 mA. The very next step in the power supply is To Rectification so the end result is DC. The frequency you start with be it 60 Hz, 50 Hz or 54 Hz really matters not since it will become DC and get filtered. Since your drawing reflects 6.3 VAC @ 2.5 Amp this is likely the filament voltage for the tubes (valves) in the amplifier. You have a high plate voltage and a 6.3 volt filament voltage. The frequency of the mains voltage you start with is not going to matter. The end result is going to be a filtered DC plate voltage for the amplifier tubes / valves so it matters not what we start with as to AC mains frequency.

Ron

 

You can, as mentioned, consider a VFD. However, take a look at your original posted drawing. Your transformer outputs 375 VAC center tapped and at 75 mA. The very next step in the power supply is To Rectification so the end result is DC. The frequency you start with be it 60 Hz, 50 Hz or 54 Hz really matters not since it will become DC and get filtered. Since your drawing reflects 6.3 VAC @ 2.5 Amp this is likely the filament voltage for the tubes (valves) in the amplifier. You have a high plate voltage and a 6.3 volt filament voltage. The frequency of the mains voltage you start with is not going to matter. The end result is going to be a filtered DC plate voltage for the amplifier tubes / valves so it matters not what we start with as to AC mains frequency.

Ron

Yes you are correct, but the little AC that will be filtered, or not filtered, is what I would like to examine. 54Hz/108Hz hum or buzz is welcome in the early stage, only for experimenting if we can take advantage of it. Sometimes the inaudible can affect the audible.

 

You could use another audio amp feeding a suitable transformer. Then run a sine wave oscillator into the amp.
That way, you can test voltage change by altering the driving amp volume too.

 

Yes you are correct, but the little AC that will be filtered, or not filtered, is what I would like to examine. 54Hz/108Hz hum or buzz is welcome in the early stage, only for experimenting if we can take advantage of it. Sometimes the inaudible can affect the audible.

OK but something to keep in mind is in your drawing with a 380 VAC 75 mA transformer the best power out you can hope for is about 28 Watts of RMS power, before any other losses. Your existing transformer is designed for 50 or 60 Hz input line frequency depending on geographic location. It is also designed for a sine wave input so any inverter used should have a TSW (True Sine Wave) output and be capable of providing at least 28 Watts. Personally if I were doing this I would likely try a 1/2 HP VFD (Variable Frequency Drive) since that is way more power than you need. Single Phase VFDs off the boat from China can likely be had relatively inexpensive. I know in the US that Leeson (the motor guys) made single phase VFDs but can't give you much other than the name Leeson. I would just make sure you find a VFD with a true sine wave out.

Ron