Spectrum Analysis Recommendations

[ViperDoc]

What do you recommend for spectrum analysis? I'm interested in seeing and assessing harmonics and such. I see analyzers that seem to be in the RF range, perhaps too high for audio fundamentals. What is most useful? Thanks.

[Stevem]

After you buy one of those about a week or so later be sure to book yourself a stay for a week or two at a insane asylum, because that’s where you’ll end up!

[Littlewyan]

I use a Picoscope which works ok, but there may be better more dedicated solutions out there. The Picoscope is both an oscilloscope and spectrum analyzer.

[ViperDoc]

After you buy one of those about a week or so later be sure to book yourself a stay for a week or two at a insane asylum, because that’s where you’ll end up!

I've got two young kids, and while I love them to death, I think that's probably worse.

What I'm trying to get at is seeing harmonics, like even versus odd. I want to send a sine wave through my amp input and see what's going on. My 5F8A sounds really good, but there's some extreme tonal sibilance that I'm trying to track down.

[trobbins]

I'd suggest the simplest and cheapest method to display harmonic spectra in the audio range is to use your soundcard and some software. I use REW for this type of assessment, but there are others - there are a multitude of forum threads on this topic. You likely already have a soundcard in your PC or laptop, or even an audio digital interface that effectively acts as a soundcard that is purpose built to acquire audio signals and interface with your PC - if so then this entry path can be a zero dollar option to start you off. For me I use this method for quite advanced audio assessment, and there are many threads on eeking out insane measurement performance levels across a wide range of applications (not just looking at a simple frequency spectrum).

[ViperDoc]

I’ll check that out, thank you for the recommendation.

To the field, how do you search for and reduce odd order harmonic tone in push pull circuits *objectively*?

[Stevem]

A great easy way to play to play around with that is to 100 % balance and then unbalance to a good amount the output of the PI section while taking note of the harmonic over tones and then do the same with the idling points of the output tubes.

You might also want to make a point before you do anything, to play thru a single ended amp cranked out to give you a head start in finding out if you like that more, since a SE amp will pass all of the even order harmonics which can be due to what I posted about above be choked off to a good amount in a PP amp.

[ViperDoc]

A great easy way to play to play around with that is to 100 % balance and then unbalance to a good amount the output of the PI section while taking note of the harmonic over tones and then do the same with the idling points of the output tubes.

You might also want to make a point before you do anything, to play thru a single ended amp cranked out to give you a head start in finding out if you like that more, since a SE amp will pass all of the even order harmonics which can be due to what I posted about above be choked off to a good amount in a PP amp.

More amps. I like where your head's at.

[John_P_WI]

In my past engineering life, a RF engineering God and fellow tube amp builder swore by the Analog Discovery for his home use. Additionally, there is supplemental analysis software such as this: https://youtu.be/7yXUbU5bSGw which will do exactly what you are asking.

John

[ViperDoc]

Thanks, John.