I've seen where you've posted either this, or a similar video, previously. Unfortunately, about the only thing that it demonstrates is that the amp does produce sound.
I don't spend much time on YT but I've come across several such videos over the years. The sound quality ranges from excellent to pretty horrible. As you would expect, this has more to do with the microphones and recording methods used than the quality of the amp.
That said, I would say the sound quality of your video is pretty bad. So it's impossible to tell if the amp sounds good or not. IMO, unless you have a top notch recording setup it's a waste of time to post videos such as this. Which probably explains why the DIY builders who frequent this board don't ever seem to post YT videos of their creations.
Instead, they post schematics and discuss the details of their builds.
I know many here are interested in Spud (single tube per channel) amps. You say this is an upgrade from your previous build. How so? How about posting schematics of the two versions, describe the build process, and explain the evolution of your design?
I don't spend much time on YT but I've come across several such videos over the years. The sound quality ranges from excellent to pretty horrible. As you would expect, this has more to do with the microphones and recording methods used than the quality of the amp.
That said, I would say the sound quality of your video is pretty bad. So it's impossible to tell if the amp sounds good or not. IMO, unless you have a top notch recording setup it's a waste of time to post videos such as this. Which probably explains why the DIY builders who frequent this board don't ever seem to post YT videos of their creations.
Instead, they post schematics and discuss the details of their builds.
I know many here are interested in Spud (single tube per channel) amps. You say this is an upgrade from your previous build. How so? How about posting schematics of the two versions, describe the build process, and explain the evolution of your design?
Surface 2 is a static exciter driving the power tubes. in a para feed drive.
Surface 3 is the static exciter(s) driving a 12au7 in srpp ; driving the power tubes.
recorded from an iPhone XR.
going to add another 6v6 per channel , making the power amp stage an srpp as well....
these are such simple circuits, most others could figure out the schematic.
I don't publish my fixed biasing...i don't publish plate neutralization. or PA power tube voicing.......i choose to keep that to myself at the moment . . . .
Surface 3 is the static exciter(s) driving a 12au7 in srpp ; driving the power tubes.
recorded from an iPhone XR.
going to add another 6v6 per channel , making the power amp stage an srpp as well....
these are such simple circuits, most others could figure out the schematic.
I don't publish my fixed biasing...i don't publish plate neutralization. or PA power tube voicing.......i choose to keep that to myself at the moment . . . .
... unfortunately ????? what you mean "unfortunately"???
At least my videos are real sound from the amp and speakers. Not fake sound pumped into the feed, after the fact............
maybe your sound quality is pretty bad.
from my end, sound quality is pretty glorious to me... and I did not have to spend 4 or 5 grand to builds it.
I would put Surface up against any McIntosh, or Jolida, or Primaluna any day.....
Surface 3 Full Build - YouTube
Your videos prove functionality. Also you're naming things after poor quality laptops made by Microsoft.
Completely agree, might as well just upload another cat video. Sounded like a tranny radio playing from the bottom of a well.
In agreement again.
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For some unknown reason, cat videos are actually quite popular. The stray that follows me around outside however, does not want to be a Youtube video star.
My favorite term is "Disco played through a cell phone."
Seriously, there are quite a few videos of people playing their amps or other musical creations on Youtube, including a couple of mine. The usual reasons are to show off the great sound, demonstrate functionality, or to demonstrate or explain certain aspects of the design, construction, or features.
Demonstrating aspects of the sound quality when less than "high end HiFi sound" is a feature, usually works out OK. The differences between two cranked guitar sounds, or the sonic nuances of a music synthesizer module are usually obvious in a Youtube video.
Attempting to demonstrate true high end sound quality on Youtube is not possible due to their compression algorithm. The sound quality seems to vary with the video quality being used. To get anything decent requires good equipment in the audio portion of the production and a video format of at least 1080 HD. Here we are still dealing with the sound quality of good MP3's. You are also limited by the sound quality at the viewer's end. Over 50% of ALL Youtube viewing is done on a cell phone. A good deal more is heard through cheap computer speakers.
Using words like "static exciter" or "plate neutralization" with no clues as to what you really mean, no schematics, and mediocre sound quality doesn't convey an useful information to someone who has built a few amps but is still trying to learn something, so I fail to see the point.
I'm not trying to bash your videos, since my own are less than stellar, but I watched them all the first time you posted their links, and came away confused, and learned nothing.
Most Youtube viewers come there for entertainment, or to learn something. Which audience are you trying to reach, and how have you done that?
What do I mean by "unfortunately"?
Simply that there is no information about your amp at all in the video. OK, you built an amp and it plays music. That may be impressive to some YT denizens who are amazed that someone can actually build their own amp but to anyone who is interested in DIY a video of an amp playing music is totally useless.
And as far as the sound quality goes, I tried to make it clear that I was talking about the sound quality of the video. I'm sure (well, I would certainly hope) that the amp itself sounds much better.
All I can say is that, listening on my system, I've heard a wide range of sound quality from similar YT videos and the the sound quality of the video in your first post is certainly near the bottom in terms of recording quality. And, no, I'm not listening on a cell phone or little desktop computer speakers.
The sound quality of the Surface 3 video that you added is considerably better but, again, it only shows that the amp functions.
Based on the title, "Surface 3 Full Build", one would expect to see a description of the circuit and a detailed video with a step-by-step demonstration of the build process. Yet there is absolutely nothing about the "build". So the title is totally misleading and the video is totally useless to anyone who is interested in building amps. But the sound quality is better.
Are you seriously suggesting that someone should be able to figure out the schematic of your amp based on your video???
In terms of technical understanding I'm not that sharp compared to most folks on this forum. But I doubt that even those with the most extensive technical knowledge are psychic. Which is why schematics are useful, certainly to someone like me, but even to those who have probably "seen it all before".
So, besides useless videos of amps simply playing music, what do you publish?
So I looked up the term "static exciter" and found nothing that seemed to relate to audio, only industrial stuff about generators or something. I couldn't see any connection but I figured it was probably due to my technical ignorance.
I figured that, when I looked at the thread today, I'd find a detailed discussion of the pros and cons of using a static exciter. And learned comments, which I probably wouldn't understand, about the benefits of "plate neutralization".
Imagine my surprise when I read George's (Tube Lab) post . . .
I did find some info on "neutralization" but it seems to relate to oscillations in radio frequencies and not audio. It's all over my head though.
Neutrodyne - Wikipedia
Neutralization
I thought his other comments were spot on too . . .
What, exactly, is the point of simply posting a video of amp playing music and then refusing to discuss it any meaningful way?
Seriously.
There's very little that's truly "new under the sun" when it comes to tube amps but some of us are still learning and the bottom line is that forums like this are for sharing information.
The people who are highly respected and seen as having the most credibility are the ones who share their ideas and are willing to take the time to explain their methods.
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Neutralization is a term that was very common in RF (Radio Frequency) amplifiers that used vacuum tubes. There should be no need to neutralize an audio amp, but some means to suppress parasitic oscillations in vacuum tube amps may be needed in when high Gm tubes are used, especially when paired with a mosfet. A hand full of resistors or ferrite beads is all that's needed. That's generally not even required with 12AU7's and 6V6's though.
The term "exciter" is also found in RF amplifiers, usually to describe the stage before the final RF amp, or all stages up to the final RF amp. I have never heard the word used outside of the RF context, and / or paired with the word "static."
Crack open any ARRL handbook (ham radio) dated before say 1965, and you can find "exciter" and "neutralization" described in detail, with plans and methods to neutralize a tube amp. They do not apply here.
I was an RF engineer at Motorola for most of my 41 year RF design career. I have never needed to neutralize an RF amplifier, but they were all silicon, GaAs, GaN or SiC based.
Maybe Mr. Moore is an old ham radio guy, so am I. That's why I recognized the words.
My old boat anchor AM transmitters (Barker and Williamson using 6146's) will sometimes need neutralization when swapping tubes. But as Tubelab say these are RF apps.
tube amps ( RF or otherwise ) can break out into parasitic oscillations and motorboating.
I just make sure the gain stages are well clamped down....
most folks already know about mounting grid and screen resistors right on the tube socket to help mitigate said issues..... that said, I do tend to use larger grid resistors on the power tubes to help rail them in.....
I was never a HAM, although I did do some LMR work in San Jose.
Mostly I was ET in the Navy, before I became a professional RF design engineer.......
I just make sure the gain stages are well clamped down....
most folks already know about mounting grid and screen resistors right on the tube socket to help mitigate said issues..... that said, I do tend to use larger grid resistors on the power tubes to help rail them in.....
I was never a HAM, although I did do some LMR work in San Jose.
Mostly I was ET in the Navy, before I became a professional RF design engineer.......