I'm not being funny but anyone watching your channel can see that you are a far better amplifier designer than any of the Chinese designers working for Willsenton etc. Your reviews carry more weight than any of the other so-called experts giving their skewed reviews too. Your honesty and integrity is refreshing to see, please keep doing what you do.
Stuff the critics, particularly the manufacturer who appears to have acknowledged your expertise by implementing your fixes into the R8 yet is hostile to your objective criticisms of the R300.
Your analytical empiricism yielding results that the strictly subjective, "Reviewers", with egos the size of galactic superclusters is bound to ruffle feathers. Keep up the superb effort as it is very much appreciated by those that want the straight gouge.
You are experienced and objective. Please do not stop with your valid and meaningful analysis. Seems the manufacturer knows that you are right . . . And people who bought it and now get a profund analysis that the schematic is garbage may not like to hear that. Gurus the same . . . Cheers Stefan
If I owned this amp, I'd be very greatful for you finding these issues and going to the effort of finding a fix, especially as you share this information with people to allow them to get the best performance possible.🙂 I can't quite understand why people get pissed off with it. If you have a car and someone has a way to make it faster, nobody kicks off and starts name calling.🤦 This is why I quit various audio forums, really is full of very strange and toxic people who buy or build stuff and are extremely defensive of such because they have to convince themselves that their set-up is perfect. It's an 'audiophile' affliction, a lot of these people are genuinely mentally ill and so caught up in cult like culture around that part of the scene, it's quite ridiculous. Might be worth quitting some of the forums and stick to your own, at least then you can remove people who are genuinely trolling as you wish. It's kind of funny, yet tragic how you only have 8k subscribers, but sadly people wanting facts and gain knowledge is a bit of a niche thing these days it seems. One day, hopefully common sense and facts will be fashionable again.🙏
@@SkunkieDesignsElectronics more than that I'd bet.😂 At least you have dignity, I genuinely don't get how a lot of these so called reviewer's do what they do. Honesty and integrity are dying traits it would seem, everyone has a price or just easily manipulated.🤦 We live in strange times.
Thats awesome! So using this method on matched tubes to see how close they perform takes any doubt out. Maybe even do some fine tube tuning. As for the other issue don't give it any power your energy is much more deserved with the ones here that truly appreciate the effort and meticulous detail you put into your work.
Reviewers rarely state anything negative - Why? - So they can keep reviewing other products. Nice video. I remember a company named Solo Electronics that made tube amps which received great reviews. Their amps were breaking after a few months of use.. Within 2 years the company quietly closed their doors with no support.
It turns out that the R300 has many design issues. And on top there are different versions around. Unbelievable! I hope you are able to determine all these faults for this version and the others. Amazing work. Many thanks for that!
Keep up these great videos they are hugely informative to owners out there don’t let the minority detract your passion and will to share your knowledge and experience with us
I got swept up in the TH-cam praise for the Wilsenton praise. I'm really appreciating your criticism here. I wouldn't have known otherwise. Also I'm finally able to differentiate between the R300 and the r800i... Much appreciate this series.
Thank You for your job! 300B amps remain something I never heard but believe to be audio heaven. I'd be disappointed a lot with these flaws, if I bought one. So I remember the words of an early dealer 30 years ago. They pointed into that direction, that things may not come out as I expected them, if buy this sort of amps.
Pretty amazing how you were able to get the channels to match up nearly identical. Frustrating but also interesting in analytical way and what person doesn't like solving puzzles. You are doing a great job.👍
Yet more proof that when you get a cheap deal the reason is that the product hasn't had sufficient time and effort put into getting the best performance and reliability out of it. Also there is a temptation to just put whatever components in that are the cheapest and available at a given moment in production. Reliability, performance and consistency are what costs money....
Maybe the electronic parts have been calibrated around these chineses tubes or there sommething whit the preamp section. Anyway I've listened to some demo of this amp on youtube and do not like it at all; no precition on the sound in general. Hope you have better luck with you're one. Thank to you're video, I found theme instrutive.
Ms. Stephe, the hell with the critics. My unit came with the 5U4G so “maybe” I don’t have the issues you described but I’m wondering if I should replace those with the 5AR4’s as a precaution. I’ve already replaced the preamp tubes with high quality Psvane-UK models.
transconductance in vacuum is not the same in one batch , this is true even for transistor. BUT with right biasing circuit you can decrease these variation. As I see it you don't have feedback too. So this is even get worse with THD . I usually match my transistor in my amplifier to get lowest feedback . You can build circuits to match these tubes for highest transconductance for vacuum tube too.
It does have GNFB but what I am finding is not typical of normal tube amps. This issue isn't related to transconductance directly, that in itself is not going to double the THD.
It could be output transformer , what if you disconnect output transformer and just load bias it with resistor then make THD measurement. It would give you some idea if it is output transformer .
I may have asked You that before. But then I forgot: Can You please build a Bottlehead 300B power amp kit? They advertise with a special circuitry and I want to know Your opinion about it. Thx.
It likely is. Part of this may be their desire to design an amp with insanely high input sensitivity, as this makes many users believe it has more power than it actually does. "I never turn it up past 1/4 volume it has so much output power!" I see this in most made in China amps.
Very interesting. Question, how long are you letting the tubes warm up before you’re running the tests? I’ve found tubes sound very different after 30 mins of being powered up. I would think if they sound different after 30 mins, they would measure differently after 30 mins?
That's why there are jump cuts in the video, there is at least 20 minutes of warm up time. And I have tested that, I haven't measured any major difference between a 5 minute warmup and a 30 minute one. We are talking 10ths of a % and this is seem mostly in the frequency response, not power vs THD.
@@SkunkieDesignsElectronics Thanks! Tubes are not “fast audio” :) Swapping out tubes and listening is a slow process. I would have thought the differences in distortion from cold to hot would have been greater, thanks for sharing your findings!
@@SkunkieDesignsElectronicsOK. Filament voltage identical on both sides? Tube sockets have no cold joints? Sorry, just throwing up ideas as this is quite weird.
Steph I love that most of the mods you do are easily done and require cheap parts only. Gives people a chance to buy these China amps and get them working better.
@@lysippus agree these amps should leave the factory in a functional state, but I think it is great that she tries to get the most out of these amps by avoiding more expensive mods like OPT swaps etc. Great news for anyone that has already bought one and has the oppotunity to get it up to scratch for as little as possible. I get the feel that steph would be fine dling these videos for us if it wasn't for the unfortunate abuse.
I'm not being funny but anyone watching your channel can see that you are a far better amplifier designer than any of the Chinese designers working for Willsenton etc. Your reviews carry more weight than any of the other so-called experts giving their skewed reviews too. Your honesty and integrity is refreshing to see, please keep doing what you do.
Nevermind the critics Stephe. You're doing a very thorough and excellent analysis on the 300B. Really looking forward to your next modifications! 👌
Stuff the critics, particularly the manufacturer who appears to have acknowledged your expertise by implementing your fixes into the R8 yet is hostile to your objective criticisms of the R300.
Ignore the hater's.
Your analytical empiricism yielding results that the strictly subjective, "Reviewers", with egos the size of galactic superclusters is bound to ruffle feathers. Keep up the superb effort as it is very much appreciated by those that want the straight gouge.
I wish I could give you more than one thumbs up!
You are experienced and objective. Please do not stop with your valid and meaningful analysis.
Seems the manufacturer knows that you are right . . .
And people who bought it and now get a profund analysis that the schematic is garbage may not like to hear that.
Gurus the same . . .
Cheers
Stefan
If I owned this amp, I'd be very greatful for you finding these issues and going to the effort of finding a fix, especially as you share this information with people to allow them to get the best performance possible.🙂
I can't quite understand why people get pissed off with it. If you have a car and someone has a way to make it faster, nobody kicks off and starts name calling.🤦
This is why I quit various audio forums, really is full of very strange and toxic people who buy or build stuff and are extremely defensive of such because they have to convince themselves that their set-up is perfect. It's an 'audiophile' affliction, a lot of these people are genuinely mentally ill and so caught up in cult like culture around that part of the scene, it's quite ridiculous.
Might be worth quitting some of the forums and stick to your own, at least then you can remove people who are genuinely trolling as you wish. It's kind of funny, yet tragic how you only have 8k subscribers, but sadly people wanting facts and gain knowledge is a bit of a niche thing these days it seems. One day, hopefully common sense and facts will be fashionable again.🙏
I could likely triple my subs if I just made videos about how wonderful everything is...
@@SkunkieDesignsElectronics more than that I'd bet.😂 At least you have dignity, I genuinely don't get how a lot of these so called reviewer's do what they do. Honesty and integrity are dying traits it would seem, everyone has a price or just easily manipulated.🤦 We live in strange times.
Thats awesome! So using this method on matched tubes to see how close they perform takes any doubt out. Maybe even do some fine tube tuning. As for the other issue don't give it any power your energy is much more deserved with the ones here that truly appreciate the effort and meticulous detail you put into your work.
Reviewers rarely state anything negative - Why? - So they can keep reviewing other products. Nice video. I remember a company named Solo Electronics that made tube amps which received great reviews. Their amps were breaking after a few months of use.. Within 2 years the company quietly closed their doors with no support.
It turns out that the R300 has many design issues. And on top there are different versions around. Unbelievable! I hope you are able to determine all these faults for this version and the others.
Amazing work. Many thanks for that!
Greatly improved and its looking great step by step.
Great video Stephe. The analysis and solutions found thus far has been really great to observe,
Keep it up!
Keep up these great videos they are hugely informative to owners out there don’t let the minority detract your passion and will to share your knowledge and experience with us
I got swept up in the TH-cam praise for the Wilsenton praise. I'm really appreciating your criticism here. I wouldn't have known otherwise. Also I'm finally able to differentiate between the R300 and the r800i...
Much appreciate this series.
You keep doing you!
Thank You for your job! 300B amps remain something I never heard but believe to be audio heaven. I'd be disappointed a lot with these flaws, if I bought one. So I remember the words of an early dealer 30 years ago. They pointed into that direction, that things may not come out as I expected them, if buy this sort of amps.
Pretty amazing how you were able to get the channels to match up nearly identical. Frustrating but also interesting in analytical way and what person doesn't like solving puzzles. You are doing a great job.👍
Yet more proof that when you get a cheap deal the reason is that the product hasn't had sufficient time and effort put into getting the best performance and reliability out of it. Also there is a temptation to just put whatever components in that are the cheapest and available at a given moment in production. Reliability, performance and consistency are what costs money....
try conrad johnson than
I was considering buying a Willsenton amp until I watched your vids. Thanks for your honest feedback on all the design flaws.
You doing great. Please dont stop, no need to be frustrated. I LOVE your channel!
Maybe the electronic parts have been calibrated around these chineses tubes or there sommething whit the preamp section. Anyway I've listened to some demo of this amp on youtube and do not like it at all; no precition on the sound in general. Hope you have better luck with you're one. Thank to you're video, I found theme instrutive.
Thanks for all you do. Following along.
So helpful video
😢 thank you so much for all you do!
Thank You for the truth !
Ms. Stephe, the hell with the critics. My unit came with the 5U4G so “maybe” I don’t have the issues you described but I’m wondering if I should replace those with the 5AR4’s as a precaution. I’ve already replaced the preamp tubes with high quality Psvane-UK models.
transconductance in vacuum is not the same in one batch , this is true even for transistor. BUT with right biasing circuit you can decrease these variation. As I see it you don't have feedback too. So this is even get worse with THD .
I usually match my transistor in my amplifier to get lowest feedback . You can build circuits to match these tubes for highest transconductance for vacuum tube too.
It does have GNFB but what I am finding is not typical of normal tube amps. This issue isn't related to transconductance directly, that in itself is not going to double the THD.
It could be output transformer , what if you disconnect output transformer and just load bias it with resistor then make THD measurement. It would give you some idea if it is output transformer .
Great video thank you
As usual great info and out standing detective work
Back to the driver stage. You shouldn't have more work to do, Willsenton should!
Yup, I honestly just don't understand how nobody caught any of this. The issues with the R8 weren't anything like this one.
It's horrible made. Had one in for service. Horrible unstable design. Bit with power supply and the driver stage is a complete mess.
I may have asked You that before. But then I forgot: Can You please build a Bottlehead 300B power amp kit? They advertise with a special circuitry and I want to know Your opinion about it. Thx.
Happy to build one for someone if they wanna send me the kit!
Why does a power amp need a cascade at the front end? Seems superfluous to me. I would think that a 6SL7 has sufficient gain.
It likely is. Part of this may be their desire to design an amp with insanely high input sensitivity, as this makes many users believe it has more power than it actually does. "I never turn it up past 1/4 volume it has so much output power!" I see this in most made in China amps.
Very interesting. Question, how long are you letting the tubes warm up before you’re running the tests? I’ve found tubes sound very different after 30 mins of being powered up. I would think if they sound different after 30 mins, they would measure differently after 30 mins?
That's why there are jump cuts in the video, there is at least 20 minutes of warm up time. And I have tested that, I haven't measured any major difference between a 5 minute warmup and a 30 minute one. We are talking 10ths of a % and this is seem mostly in the frequency response, not power vs THD.
@@SkunkieDesignsElectronics Thanks! Tubes are not “fast audio” :) Swapping out tubes and listening is a slow process. I would have thought the differences in distortion from cold to hot would have been greater, thanks for sharing your findings!
What did you find out about that ugly deep on frequency response after 10khz?
Nothing yet, I'm pretty sure it's in the front end. Or else REALLY bad output transformers
The plate load or cathode resistor is significantly different on 1 channel versus the other?
They are exact same.
@@SkunkieDesignsElectronicsOK. Filament voltage identical on both sides? Tube sockets have no cold joints? Sorry, just throwing up ideas as this is quite weird.
@@el_arte Electricity in and of itself is weird. 😕
Steph I love that most of the mods you do are easily done and require cheap parts only. Gives people a chance to buy these China amps and get them working better.
@@lysippus agree these amps should leave the factory in a functional state, but I think it is great that she tries to get the most out of these amps by avoiding more expensive mods like OPT swaps etc. Great news for anyone that has already bought one and has the oppotunity to get it up to scratch for as little as possible. I get the feel that steph would be fine dling these videos for us if it wasn't for the unfortunate abuse.
Skunkie I just love when I see you and your show great info beautiful host