Hello friends, I'm still learning and asking.
Is this noise that comes out of the opt normal? Is it oscillating?
I am using a square wave at 1khz, 1vpp.
I tried it with sine wave and at some frequencies it does the same thing, is it something bad?
I have it connected with a load, the oscilloscope and a function generator.
Another question that I was looking for in the forum and I didn't know how to search for it.
Thank you for your time and wisdom.
Is this noise that comes out of the opt normal? Is it oscillating?
I am using a square wave at 1khz, 1vpp.
I tried it with sine wave and at some frequencies it does the same thing, is it something bad?
I have it connected with a load, the oscilloscope and a function generator.
Another question that I was looking for in the forum and I didn't know how to search for it.
Thank you for your time and wisdom.
Oh, that is so frustrating!
It has happened to me.
When you say 1V signal, is that the input signal, or is it the output transformer's secondary signal voltage into a proper load resistor?
If the amplifier is putting out no more than its rated maximum power, and you are using a non-inductive resistor load (for some that is an 8 Ohm 100 Watt or more rated).
Using a 25 Watt resistor to test a 15 Watt amplifier will result in burnt fingers when you touch the resistor.
The output transformers can "Sing". Some do, some do not.
Really good ones do not sing, Even some cheap ones do not sing.
Really bad luck is when the output transformer puts out more sound than the tweeter.
Just what output transformer make and model are you using?
Have Fun!
It has happened to me.
When you say 1V signal, is that the input signal, or is it the output transformer's secondary signal voltage into a proper load resistor?
If the amplifier is putting out no more than its rated maximum power, and you are using a non-inductive resistor load (for some that is an 8 Ohm 100 Watt or more rated).
Using a 25 Watt resistor to test a 15 Watt amplifier will result in burnt fingers when you touch the resistor.
The output transformers can "Sing". Some do, some do not.
Really good ones do not sing, Even some cheap ones do not sing.
Really bad luck is when the output transformer puts out more sound than the tweeter.
Just what output transformer make and model are you using?
Have Fun!
is the input voltage with a load resistor of 8ohm 15w, which really doesn't get very hot
the oscilloscope at the output shows 14V pp (10.2Vrms)
It is an OPT made by a company in my country, with some renown, they were the only ones I could get here, it is based on the Hammond 1608a, but only with an 8ohm output
I don't hear any noise when I listen to music, but if the opt makes that sound with that frequency, does it mean that if my music at some point passes through 1khz, will it resonate like that?
Should I try to improve it in some way?
Is it a design issue or am I trying to get better OPT?
Thanks for giving me your knowledge friends
If I'd hear anything, I'd guess it's just magnetostriction.
Hopefully your device was loaded appropriately when you injected signal to the input?
Best regards!
Hopefully your device was loaded appropriately when you injected signal to the input?
Best regards!
If you change the frequency does it sing at the new frequency? If yes, there is nothing bad. I would not bother looking for another transformer.
You can try to improve it by holding the laminations tighter.
Output transformers "sing" for two reasons. First, core magnetostriction. Amorphous and supermalloy cores have very low magnetostriction, so transformers with these cores are free from this problem. Second, windings expand and contract in response to their alternating magnetic fields. This problem is minimized by quality impregnation.
Transformer vibration causes distortion because a transformer acts as electro-mechanical and mechano-electric transducer. Transformer buzzing can be also picked up by microphonic tubes. These kinds of distortion are strongly frequency-dependent (mechanical resonances) and cannot be detected by conventional THD methods.
Transformer vibration causes distortion because a transformer acts as electro-mechanical and mechano-electric transducer. Transformer buzzing can be also picked up by microphonic tubes. These kinds of distortion are strongly frequency-dependent (mechanical resonances) and cannot be detected by conventional THD methods.
mrpunkk,
The amplifier output of 10.2 Volts rms into an 8 Ohm load resistor, is 13 Watts rms.
I was confused by your Post # 7:
Did you get 10.2 Volts rms with the 8 Ohm load resistor connected across the output transformer secondary?
Or, did you get 10.2 Volts rms with the output transformer secondary Un-loaded?
Un-loaded secondaries might be more likely to "Sing".
I think you should listen to your amplifier and speakers, and see if you are satisfied with the sound.
In other words, can you "Enjoy the Music" on your system?
You should be able to enjoy listening to a system, even though it is not listed among the worlds top 20 systems (or top 100 systems, or even the top 500 systems).
I have had some output transformers that sing fairly quietly with full output power, but only at one or a few frequencies.
I have not found that a problem.
Example: when the loudspeakers are across the room, the amplifiers are across the room too. Any low level singing from certain music notes are not going to be nearly as loud as the sound from the loudspeaker.
Relax, Listen, you may be surprised (and your blood pressure will go down by 10 points).
The amplifier output of 10.2 Volts rms into an 8 Ohm load resistor, is 13 Watts rms.
I was confused by your Post # 7:
Did you get 10.2 Volts rms with the 8 Ohm load resistor connected across the output transformer secondary?
Or, did you get 10.2 Volts rms with the output transformer secondary Un-loaded?
Un-loaded secondaries might be more likely to "Sing".
I think you should listen to your amplifier and speakers, and see if you are satisfied with the sound.
In other words, can you "Enjoy the Music" on your system?
You should be able to enjoy listening to a system, even though it is not listed among the worlds top 20 systems (or top 100 systems, or even the top 500 systems).
I have had some output transformers that sing fairly quietly with full output power, but only at one or a few frequencies.
I have not found that a problem.
Example: when the loudspeakers are across the room, the amplifiers are across the room too. Any low level singing from certain music notes are not going to be nearly as loud as the sound from the loudspeaker.
Relax, Listen, you may be surprised (and your blood pressure will go down by 10 points).