You bet!

Haha, Thank you!

Thanks!

It's the latest MKII version. I can't help what other reviewers say nor do I understand why they would rave about a product this defective, and I also can't help this amp fails miserably to produce anywhere near it's advertised specs. Another friend of mine on audiokarma tested a MKII out of the box and got the same results I did. Numbers don't lie but if you are happy with your amp, great. I know better and so do many other folks who have listened to this thing. And I have to LOL at the "original tubes" comment, those things are horrible! Even the original 300B tubes it comes with are bad. I just have to assume here that these people have just never listened to a good tube amp before or were being paid to promote it. I'm going to be nice and assume the former. Multiple people have done my mods to this amp and universally say things like "wow, I now see how bad this thing really was." It's like taking a blanket out from in front of your speakers. And if an amp has over 10% distortion as it goes into heavy clipping, I'm not sure how folks evaluate "sound staging" and "handling of transients"? All I heard was weak bass, muddy midrange and distorted highs from this amp as it came out of the box. I agree this amp is in "A league of it's own" but not in the same way you are thinking.

@@SkunkieDesignsElectronics The latest version is the Mk III (3) not II (2). And the Mk III appeared over a year ago. So perhaps there is significant differences between the II and III. Again, I ask you to please define or clarify the ways that you judge an amp's sound. You have offered a few additional terms in your reply that I had not heard in the videos. "...weak bass...": does this mean low volume, not going to low cps, what? Please clarify. And "...muddy mid-range...": does this mean many overtones, distorted signal, what. Please elaborate. And I still see no information in your reply that would indicate the kind of sound that you want from an amp: e.g. clear, accurate, articulate sound with a mid-range/treble/midbass forward, or warm balanced presentation with a less forward sound, etc. Please elaborate so that I can have some sense of what you hear and like. Then we will be using a common vocabulary. If you say the sound "stinks" I do not get much information. And, by the way, the others nearly always evaluate things such as transients and soundstage. I suppose there is no particular measuring procedure for these terms, but they do go on to describe the unit's performance in these areas using words that have definitions that most of us know, so that we can get a pretty good idea of what they heard. They're evaluations are subjective for sure, and convey more information than "stinks" does (that is subjective too, unless you have a multimeter that reveals odor). I would suggest you re-consider your assumption that the reviewers I mentioned have "never heard a good tube amp". They have ample experience, both owning, and reviewing, a great variety of good, industry leading tube amps. If your testing, etc., was of the Mk II, then I could see how there could be differences in your view and theirs. They all reviewed the Mk III. Putting the possible differences between the II and III, I still find it hard the differences heard by you and them would be as great. Thanks for your response to my initial post.

@@richardcarroll4495 Mine was the "latest version" as sold by Amazon a few months ago and after some reviewing: the schematic supplied has "MKIII" written on it, the parts inside match this schematic, so I assume it must be that version. They also state the MKIII has "an inductance transformer" which means they added a choke to the power supply, which my version had. I'll admit I'm not an expert on Boyuuange A50 revision history.. The "weak bass" can not only be heard (or not heard because it's just not there), but is easily seen in the frequency response curves as at 100hz the frequency rolls off. Likewise the "muddy midrange" is due to the measurable distortion which does exactly what the term says, it distorts the signal into something different, smearing any details that were previously there. It's clearly audible listening to this and a "good" tube amp. If all you listen to is alto jazz type music with little to no bass track, it probably sounds OK. And if someone A-B listens to this and a SS amp, I could see liking the tube amp sound better, even as distorted as this one is. Just as you have a right to like the way this amp sounds, I have to right to say I think it sounds like crap, especially comparing it A-B to the other 300B amp (and other tube amps) I own, and to this amp after the mods have been done. The difference is not subtle or nuanced. I want to clarify too, even after the mods, the low quality output transformers hold this amp back from what it could be with good iron. As far as these other reviewers, again I can only speculate why they would give an amp, that is this defectively engineered and pumping this much distortion, rave reviews. I want to shy away from claiming they were paid to give these rave reviews, but that does happen. Did they A-B listen to the A50 back to back with another know good tube amp? It's still baffling to me anyone would think this is good if they did that. The numbers don't lie and there is no such thing as "alternate facts" here. This is not what the manufacturer advertises it as: a 7.6W @ 1% distortion amplifier. It doesn't come close to meeting even 1/2 of those. All that said, it's clear you just want to argue here, make excuses for and defend your purchase choice. Very common for people to get their ego tied into their ownership of material things, clouding their perceptions, and I've learned people doing this are rarely rational or interested in actually learning anything. My advice is to ignore my videos, go watch the ones that match your beliefs, defend your purchase choice and enjoy your amp. Have a nice day!

@@SkunkieDesignsElectronics Thanks again for your time and energy taken to respond to my questions. I appreciate it. Regards, Rich

I've tried others, I like the sound of the alum/oil ones.

This is the final schematic, cathode grounded through LED + 200ohm resistor. www.skunkiedesigns.com/boyuurange-a50-mods?pgid=ktb1lluh-4ad9aad6-de55-4454-b972-3f9bdc405f0b

Absolutely, the stock driver tubes are really bad, but honestly without at least the basic mods, replacing the 300B tubes probably isn't worth it.

@@SkunkieDesignsElectronics Thanks. It gives me something to think about... Watching the videos (I've not seen them all yet), I feel confident I could do the jumper wire and the one you ran to ground, at least, but for sure I was going to replace the driver tubes anyway. Doing that, I'll hear how it sounds, and if it's not what I need, then your videos and the soldering iron it is! Again, thanks.

At the end of the day, it didn't make sense as A) there really isn't room on this chassis for larger ones + the chrome plated stainless is so hard to deal with and B) spending $500+ on transformers for a $1000 amp just doesn't make a lot of sense to get some extra bass out of it. A powered sub will do that better and is cheaper.

@@SkunkieDesignsElectronics fair enough.

@@SkunkieDesignsElectronics one more question did you ever measure to see if this amp was true class A ? If so how does one measure it ?

@@skularatna8136 By design, Single Ended (SE) amps have to operate as class A

@@SkunkieDesignsElectronics yes but how does one measure it?