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Willsenton R300B SE Integrated Amp

ThoFi said:
Hi.
In my case the Gold Lion 300Bs had red plating.
No issues with the rectifier tubes.
Regarding rectifier tubes. My unit was shipped with 274Bs.
I changed to EH5U4GBs.
About delay board I know in my unit it is not installed.

I did email china hifi about the red plating.
Waiting for reply….
Click to expand...
I have used Linlai Global 7300B-D going on 150+hrs.
 
Mopardave said:
Did you like the Raytheon 5u4g rectifier tubes? Just ordered a pair of Sophia Electric 274b to try and looking for other rectifiers and power tubes to try. How are the Lanlai 7300 power tubes working out?
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Does your R300 has any modifications?
Does it have the delay board?
I assume it’s not a good idea to use 274Bs in the R300…
Cheap and robust 5U4GB might be better?
 
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Mopardave said:
Sophia Electric Princess mesh plate 274B and rigid plate 274B tubes have been widely praised as the best sounding rectifier tubes ever made. However there is a catch - the first capacitor after the rectifier tube needs to be small. The max value allowed for the Princess 274B mesh plate is 4uf, or 8uf for the Princess 274B rigid plate. But for a typical 300B single ended amplifier, it is usually larger than 8uf. To overcome this limitation, Sophia Electric came out with a newly designed Aqua 274B rectifier tube to raise the limitation from 8uf to 47uf. This Aqua 274B can directly replace 5U4G in most amplifiers with great sonic improvement.

Aqua and WE 274B tubes would deliver 150ma-160ma of current at 430vDC per 274B tube.

Stereo 300B tube amplifier needs to have one 274B rectifier tube per channel, two 274B rectifier tubes for two channels. If the amp was designed to have only one rectifier tube for both channels, then 5U4G is more suitable.
I am yet to pull the cover and take a peak. Maybe Steph knows whats in it. My plan for this is to install the soft start and the 3 caps as well as sockets. Waiting for Steph and corhibajoe to finish and let us know what works best. The Sophia 274b looks to be a tough tube.
Click to expand...
do they sell those anymore?
 
Mopardave said:
Sophia Electric Princess mesh plate 274B and rigid plate 274B tubes have been widely praised as the best sounding rectifier tubes ever made. However there is a catch - the first capacitor after the rectifier tube needs to be small. The max value allowed for the Princess 274B mesh plate is 4uf, or 8uf for the Princess 274B rigid plate. But for a typical 300B single ended amplifier, it is usually larger than 8uf. To overcome this limitation, Sophia Electric came out with a newly designed Aqua 274B rectifier tube to raise the limitation from 8uf to 47uf. This Aqua 274B can directly replace 5U4G in most amplifiers with great sonic improvement.

Aqua and WE 274B tubes would deliver 150ma-160ma of current at 430vDC per 274B tube.

Stereo 300B tube amplifier needs to have one 274B rectifier tube per channel, two 274B rectifier tubes for two channels. If the amp was designed to have only one rectifier tube for both channels, then 5U4G is more suitable.
I am yet to pull the cover and take a peak. Maybe Steph knows whats in it. My plan for this is to install the soft start and the 3 caps as well as sockets. Waiting for Steph and corhibajoe to finish and let us know what works best. The Sophia 274b looks to be a tough tube.
Click to expand...

thank you for your answer.
Yes let’s see what Stephe gonna find out.
But the first information and pics do not look promising.
Far too large caps and only one choke…
And the delay board for soft start….
 
ThoFi said:
thank you for your answer.
Yes let’s see what Stephe gonna find out.
But the first information and pics do not look promising.
Far too large caps and only one choke…
And the delay board for soft start….
Click to expand...

Wait till you guys see the 10K square wave output... O.O
 
Can’t wait:oops:
but my first question is safe use / reliability :rolleyes:
besides measurements it will be interesting how you like how it sounds
 
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Mopardave said:
Thank you StepheK for another great vid. Yes, the tubes that come with that amp belong in the trash except the single 6SL7. It seems fine to my ears, but im using a Tung-sol gold pin 6SL7 in its place anyway. My 60 year old ears are not earing what the scope is showing, but that may be because i am using very efficient Klipsch design speakers(CornScala) and 9 oclock on the dial is about 90db and as high as i listen. The dip on the scope at 12K may be beyond my hearing. I think the Gold Lion 300b is the best inexpensive tube. The EH dont rate very high, but i have never tried them. Very interested in what you find and repair as i would like to update the problem areas. Using chinese 6n8p metal base and Linlai 5u4g rec tubes and would like to try the Sophia Electric 274B when they get here. Great thread. Can't wait to see what it takes to fit the flaws.
Click to expand...

I bought a pair of new Gold Lion 300Bs.
After 2h running with my R300 both Gold Lions started red plating!
price €400/pair
 
Mopardave said:
Thank you StepheK for another great vid. Yes, the tubes that come with that amp belong in the trash except the single 6SL7. It seems fine to my ears, but im using a Tung-sol gold pin 6SL7 in its place anyway. My 60 year old ears are not earing what the scope is showing, but that may be because i am using very efficient Klipsch design speakers(CornScala) and 9 oclock on the dial is about 90db and as high as i listen. The dip on the scope at 12K may be beyond my hearing. I think the Gold Lion 300b is the best inexpensive tube. The EH dont rate very high, but i have never tried them. Very interested in what you find and repair as i would like to update the problem areas. Using chinese 6n8p metal base and Linlai 5u4g rec tubes and would like to try the Sophia Electric 274B when they get here. Great thread. Can't wait to see what it takes to fit the flaws.
Click to expand...

Just remember, even if your ears don't hear this mess, those signals are still being fed to your nice speakers. That kind of distortion can kill tweeters and clouds the whole spectrum they transmit. It's probably safe if you don't turn the amp past 9:00.

And you are right on the EH300B, they aren't great, but I'm not going to put a pair of my 300B-Z treasure tubes into this amp until I know it's not going to fry them. I still don't understand why they didn't just make this amp cathode biased.
 
StepheK said:
Just remember, even if your ears don't hear this mess, those signals are still being fed to your nice speakers. That kind of distortion can kill tweeters and clouds the whole spectrum they transmit. It's probably safe if you don't turn the amp past 9:00.

And you are right on the EH300B, they aren't great, but I'm not going to put a pair of my 300B-Z treasure tubes into this amp until I know it's not going to fry them. I still don't understand why they didn't just make this amp cathode biased.
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but the volume knob position depends on the input level of the source…???
how did you define max 9:00?
I don’t understand

I do set the R300 at 11:00 and adjust the volume with my source.
average 70dB
 
ThoFi said:
but the volume knob position depends on the input level of the source…???
how did you define max 9:00?
I don’t understand

I do set the R300 at 11:00 and adjust the volume with my source.
average 70dB
Click to expand...

Very true, the output is what matters. I did say 'probably' and assumed he is using something like a CD deck with no source volume control. I personally will not run speakers that I care about for very long with this amp until some of these issues are resolved.
 
StepheK said:
Very true, the output is what matters. I did say 'probably' and assumed he is using something like a CD deck with no source volume control. I personally will not run speakers that I care about for very long with this amp until some of these issues are resolved.
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Stephe, I followed your advice and disconnected my expensive speaker and hooked on my Klipsch RP600m. (4Ohm taps)
Cant help but it sounds beautiful.
Did you some listening with your Klipsch and the R300?
 
I agree with @StepheK , even though you like the sound it is not working as a good amp should. Get what you pay for I guess. The 10kHz square wave is a total mess and the frequency response plot is a total disaster. Already rolling off by 10k with a huge dip before 20k. I would guess it is lousy output transformers. I have a pair of Edcor SE transformers that have a dip like this but at a higher frequency. The Willsenton packaging is nice but it reminds me of the old adage about putting lipstick on a pig. Maybe Stephe can do something with it.
 
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