Sorry about the rant here...but I gotta tell somebody!
As many of you know, I am building my own amps now and am currently putting the finishing touches on my website before it goes live (by Jan 1). So, just to get all of the information I can out there about it's capabilities/limitations, I decided to test the amp to see what level of output tube mismatch it would handle before it starts to hum and act weird.
As I've said before, it can take 6L6s, KT66s, EL34s or 6550s and any of thier variants. All of my previous testing has been with matched pairs. So I grab a pair of 6L6s that are 10mA apart from one another...no hum and great tone. Next, I grab a set of EL34s that are around 10mA apart and they also sound great with no hum. All I have left at this point to throw at it are a set of EL34s that are 20mA apart...once again no hum and great tone.
Wanting to find the point of failure is an obsession of mine so I decided to take the experiment to what I felt was an extreme...one 6L6 and one EL34. They biased a full 30mA apart from one another but the amp didn't hum and the tone was great...and different...a mix of EL34 and 6L6 character that I hadn't heard before. Almost impossible to describe but I will include a clip of it on my website.
Meanwhile...still not satisfied that I had found the edge of capability, I set it up with one EL34 and one 6550...a full 60mA difference between the two at idle. I got a little bit of low level hum but not enough to pi$$ off a recording engineer. This combination sounded like nothing I've ever heard before. Warmth and clarity in the cleans and heavy crunch with a warm clean tone in the background at the same time...sounded like I was playing two amps at once; one clean, one dirty. This will be on a clip on the website too.
I apologize about tooting my own horn about this...its got me pretty excited and I obviously didn't design this capability into the amp. And to think, I was contemplating adding a bias balance or separate bias adjustments for each power tube sometime in the future so I could explore this...guess I can cross that off the list!
Is anyone aware of an amp out there that can do this?
As many of you know, I am building my own amps now and am currently putting the finishing touches on my website before it goes live (by Jan 1). So, just to get all of the information I can out there about it's capabilities/limitations, I decided to test the amp to see what level of output tube mismatch it would handle before it starts to hum and act weird.
As I've said before, it can take 6L6s, KT66s, EL34s or 6550s and any of thier variants. All of my previous testing has been with matched pairs. So I grab a pair of 6L6s that are 10mA apart from one another...no hum and great tone. Next, I grab a set of EL34s that are around 10mA apart and they also sound great with no hum. All I have left at this point to throw at it are a set of EL34s that are 20mA apart...once again no hum and great tone.
Wanting to find the point of failure is an obsession of mine so I decided to take the experiment to what I felt was an extreme...one 6L6 and one EL34. They biased a full 30mA apart from one another but the amp didn't hum and the tone was great...and different...a mix of EL34 and 6L6 character that I hadn't heard before. Almost impossible to describe but I will include a clip of it on my website.
Meanwhile...still not satisfied that I had found the edge of capability, I set it up with one EL34 and one 6550...a full 60mA difference between the two at idle. I got a little bit of low level hum but not enough to pi$$ off a recording engineer. This combination sounded like nothing I've ever heard before. Warmth and clarity in the cleans and heavy crunch with a warm clean tone in the background at the same time...sounded like I was playing two amps at once; one clean, one dirty. This will be on a clip on the website too.
I apologize about tooting my own horn about this...its got me pretty excited and I obviously didn't design this capability into the amp. And to think, I was contemplating adding a bias balance or separate bias adjustments for each power tube sometime in the future so I could explore this...guess I can cross that off the list!
Is anyone aware of an amp out there that can do this?
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