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Willsenton R300B SE Integrated Amp

StepheK said:
I'm looking at the schematic from Wilsenton, it says 5AR4 over the rectifier tube on their schematic. They list in the manual a 5AR4 as a sub for the rectifier. And as I point out in the video, it's running about 20V higher, but it's under the max rating for the caps. Yes it's pushing it but I feel the slow voltage ramp up is much easier on the cap than slamming them with 400V on startup. Any upgrade, I would have the first cap be 500V rated for sure.

And yes this is also pushing the voltage a 300B tube is rated for, but in my experience if you expect to get anywhere near the rated power in a SE amp, you have to really push the output tubes.
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Can you share a copy of the schematics? China HiFi refuses to send me the schematics due to copyright concerns. I’d be very appreciative as my R300 keeps blowing fuses and is now dead. My service tech needs the schematics to diagnose.
 
Capricho72 said:
Can you share a copy of the schematics? China HiFi refuses to send me the schematics due to copyright concerns. I’d be very appreciative as my R300 keeps blowing fuses and is now dead. My service tech needs the schematics to diagnose.
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From StepheK Thread #152..."They did supply me with a schematic for the R300, that at this point they asked me not to share and I am going to honor their request. I do plan to dive into this stuff in a future video soon, and feel I can share the power supply details in the as built amp."

Maybe at a later date or release some as in this case the Power Supply details?
 
Capricho72 said:
Can you share a copy of the schematics? China HiFi refuses to send me the schematics due to copyright concerns. I’d be very appreciative as my R300 keeps blowing fuses and is now dead. My service tech needs the schematics to diagnose.
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I think you have a early version, the amp I have is a later version with a different PS layout. In a couple of weeks I plan to have an early version here to dive into and can create a PS schematic then.
 
Mopardave said:
Yes, i have the TAD's in my amp now. Not many hrs on them yet, but they sound pretty good. Not much different from the 5u4g Linlai they replaced. I am always looking for more detail in the music whether it be from tubes, cables, wire, or the 45 speed LP's i use. So, i will be doing the mods that others here have done and hope to see another vid from StepheK with the early version of this amp.
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what version of the R300 do you have?
how did you set the bias?
 
Mopardave said:
Yes, i have the TAD's in my amp now. Not many hrs on them yet, but they sound pretty good. Not much different from the 5u4g Linlai they replaced. I am always looking for more detail in the music whether it be from tubes, cables, wire, or the 45 speed LP's i use. So, i will be doing the mods that others here have done and hope to see another vid from StepheK with the early version of this amp.
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May I ask if you did tube rolling the 6SL7 and 6SN7s?
what are your findings?
As far as I know the 6SN7s should have the most impact to SQ?
what about the 6SL7, the 300Bs?
thanx
 
Mopardave said:
The original 6SL7 is very good, but i am using a tung sol 6SL7 right now. The original 6SN7 are not so good. I currently have metal base chineese tube, I think 6n8p? They are very nice and i just received a pair of the PSVANE 6sn7 coke bottles white base. The 300B is Gold Lion and best you can do for the money. I had some ked-rad 5u4g in it and they were ok rectifiers, just butt ugly.
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maybe the 6sl7 do not impact SQ?
Psvane, very interesting. Maybe you could share your experiences.
Im jealous about your Gold Lion. My pair died after 2h…red plating.
Do the 300Bs or 6sn7s have more impact on SQ.
what’s your experience…

i tried different 6sn7.
EH, TungSol, TAD and 12au7+adapter (rcs, mullard, full music), cheap NOS GEs
The TAD is interesting because different to the others. Cleaner, clear dynamic sound…
 
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Mopardave said:
I have only used the 5u4G Linlai rectifier. I like them. Cohebajoe has used a few Linlai, might want to ask his opinion.
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Sorry for not updating the thread. I have moved out of NJ and in Sarasota, FL and will be unpacking the R300 later in the week. Need to go over Stephe mods before I turn-on the Amp. Still would like to use the 274B tubes.
 
Well I got the power supply under control, this resolved the noise I measured in the THD+noise testing. The square wave is still wonky but it looks a little better with some GNFB tuning. The huge dip at 10K is still there but then I discovered this amp is HYPER sensitive to the tubes installed in it. Just moving the same tubes from the left to the right channel does crazy stuff. More work to do...

 
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