Cheapest power supply transformers?

[Austin]

Well I'm having NO trouble getting on that train. I go to great pains to make my personal amps exactly how I want them. And on some days I love them. I can actually play guitar without the distraction of evaluating the tone. Which is, to my mind, a great and rare accomplishment as a designer. But... Other days I just can't get a good sound out the same amp!?! This happens with all things created equal as the hardware goes. I've tested operating parameters and wall AC, etc.


The only possible difference between when I like my tone and when I don't is my state of mind.

This very true about many things in life.. I notice this more as I get older I spose. Wise words anyway.

[Steve Conner]

The way to find out is by studying the classic amp and pedal circuits that people like. Unfortunately if you do this, you'll find there is no consensus, there isn't a guitar sound on earth that isn't liked by someone or other. One man's wine is another's malt vinegar.

Frequency response is also important, it is another dimension of sound that has very little to do with distortion. Many of the classic circuits amplify some frequencies more than others. The Marshall stack gives a huge bass and upper midrange boost.

I can't do that spectrum analysis right now, but I can tell you what you'd see. Classic guitar amps that use NFB use about 10dB of it across the whole band. So, with the feedback applied, the harmonics would go down by about 10dB, but some higher order ones would appear, according to Baxandall's theory of "distortion of distortion".

The feedback also changes the frequency response by damping the speaker resonance, but you don't see this when you test with a dummy load in the lab.

[Chuck H]

Very good points and info. JL Hood makes a point to cover these things in his book. And again, it boils down to what the player/primary listener likes. The new high oeder harmonics and lower speaker damping from NFB are important qualities for certain genre of guitar tones. While higher distortions of 2nd and 3rd harmonics and less damping is impotant for different types of sounds. Though they are similar, in general, they are very different tones to the user.

I like the "distortion of distortion" analogy. Not covered here much. But very true and valid.

And frequency response is a broad subject. It can infere the amps dynamics at frequency or the final EQ . And is often refered to in regard to a combination of these two things. IMHE as a tweaker/designer if you can hear your way into what an amp is doing in these areas you can maximize any decent amp to exploit it's strengths. I hope that's not too vague and guru like. That's really not the intention. Quite the contrary.

[jim1976]

Hey Austin,
I just stripped a couple of transformers to selvage the cores for a project, but I just happened to come across an inverter 12v to 240v. You know you could use one for a cheap power supply for an amp just put a rectifier in after the inverter you could run a couple of el84s off a 150w inverter and there cheap! and 12v is enough to run the heaters might just need a regulator to keep the voltage down from full charge of 14.4v. Could be the green amp if you have a solar panel.

[Enzo]

CHuck, aside from your attitude, your environment also changes.


I used to tour as a sound man. I also served as a house sound man at a local large dance club. Visiting bands could hire me to run the large house system, useful when they were used to running a much smaller system from the stage. I got to know that room and its sound so well, I could honestly tell you if it started to rain outside. Does it ever rain where you are? (joking) First set, there were not many bodies in the club, then as the place filled up, bodies absorbed the sound, and I had to compensate. Then as the place was full, the sound still changed over the next couple sets as the humidity rose along with the smoke content of the air. Sweating, breathing bodies humidify the air. I wouldn;t be surprised that barometric pressure has an effect on how you hear.

[Chuck H]

I wouldn;t be surprised that barometric pressure has an effect on how you hear.

Or even how sound waves are affected as they make their way to my ears! FWIW, attitude or otherwise, I do recognise that rainy days are usually good So... Either I'm hyper sensitive or hyper variable. As are the circumstances on the sound waves and my attitude!!! I'm just happy as hell that I can enjoy my own amps, as the designer/builder, at all. Based on the years getting to that place I think it's a great accomplishment.

When I don't like my tone I just turn off my amp and play my acoustic Happy in the knowledge that it will pass.

I appreciate the insight.