Hello everyone,
I am looking into building a DIY 300B power amp.
I was considering the idea of buying this "DIY AUDIO NOTE MEI SHU AN 300B Tube Single-Ended Amplifier PCB With Power Supply Board" PCB, which is basically a clone of the power section of the AN Meishu, and assemble it with high end components: AN/Tango/Tamura OPT (whichever I can find used at a decent price), Duelund coupling caps, carbon film resistors and all the good stuff)
Do you think it's worth or it'd be a waste of good components?
Thanks,
Marco
I am looking into building a DIY 300B power amp.
I was considering the idea of buying this "DIY AUDIO NOTE MEI SHU AN 300B Tube Single-Ended Amplifier PCB With Power Supply Board" PCB, which is basically a clone of the power section of the AN Meishu, and assemble it with high end components: AN/Tango/Tamura OPT (whichever I can find used at a decent price), Duelund coupling caps, carbon film resistors and all the good stuff)
Do you think it's worth or it'd be a waste of good components?
Thanks,
Marco
If you use a PCB, get ready for a very difficult time if you want to modify the circuit, after it is built and listened to.
"Cheap is Not Good, Good is Not Cheap" - Frank Reps, Baby Ongaku, Sound Practices.
"Easy is Not Good, Good is Not Easy" - Me . . . I just thought of it.
Just my opinion
"Cheap is Not Good, Good is Not Cheap" - Frank Reps, Baby Ongaku, Sound Practices.
"Easy is Not Good, Good is Not Easy" - Me . . . I just thought of it.
Just my opinion
I recently had fellow member v4lvelover design a stock Williamson PCB for me, with room to adjust the compensation networks based on the output transformer. The PCB version measures better than my point-to-point builds and makes it incredibly easy to build a classic Williamson amp. So PCBs can be a plus.
It is P2P . PCB is only a base for components. It is very labor intensive and yes , it can be difficult to repair.
Prepare to spend at least $2000 for AN output transformers. Some say it's the best AN amp in the old lineup. Only a special order now. You can buy all the parts from AN parts retailers . I have a pair of P4 monos which is the same circuit in PSE variant ,still to be refurbished. Skimping on spending that $1000 for few caps and handful of resistors...That's how much it costs to play Audio Note game ..
Prepare to spend at least $2000 for AN output transformers. Some say it's the best AN amp in the old lineup. Only a special order now. You can buy all the parts from AN parts retailers . I have a pair of P4 monos which is the same circuit in PSE variant ,still to be refurbished. Skimping on spending that $1000 for few caps and handful of resistors...That's how much it costs to play Audio Note game ..
I don't understand the logic behind buying the cheapest circuit on the market and then stuffing it with the most expensive parts. How about buying a good circuit and then stuffing it with good parts?
I have yet to see a boutique part outperform an off-the-shelf part on any measured parameter. And, frankly, the charcoal-stuffed cardboard tubes that Duelund sells as "power resistors" frighten me.
Tom
I have yet to see a boutique part outperform an off-the-shelf part on any measured parameter. And, frankly, the charcoal-stuffed cardboard tubes that Duelund sells as "power resistors" frighten me.
Tom
@tomchr which schematic would you suggest for a good 300B SET?
Everybody will have an opinion on 300B. Building Audio Note amp circuit only makes sense if you get genuine AN output transformers . Level 3 Audio Note which still sells for thousands or tens of thousands of $$$ does not have any exotic parts except their PIO (they are not PIOs actually since there is no oil in them to be found ) capacitors. To get exotics you have to have really deep pockets. Only few people can build truly great sounding amps with exotic parts They are usually not on DIY forums. Everybody is happy with the amps they built until they get trounced by fairly ordinary factory amps. The reality of DIY...
Everybody will have an opinion on 300B. Building Audio Note amp circuit only makes sense if you get genuine AN output transformers . Level 3 Audio Note which still sells for thousands or tens of thousands of $$$ does not have any exotic parts except their PIO (they are not PIOs actually since there is no oil in them to be found ) capacitors. To get exotics you have to have really deep pockets. Only few people can build truly great sounding amps with exotic parts They are usually not on DIY forums. Everybody is happy with the amps they built until they get trounced by fairly ordinary factory amps. The reality of DIY...
grovergardner, Michael C and limono,
At least PCBs have made it possible for some to have the courage to build a tube amplifier that they otherwise would not have attempted.
I do have to say that over the years I built some electronics that used PCBs.
Mostly radios and such.
The only two audio amplifiers with PCBs I had was a low power solid state Heathkit; and an already built Dyna ST-70.
The ST-70 had the PCB taken out soon after I got it. The amplifier became a test bed for many different topologies and different parts (only the power transformer and chassis remain on the amplifier.
The A470 output transformers were taken off of the amplifier; one has the E's and I's re-stacked with a Kapton spacer 'air gap' for single ended use, including 20%, 50%, and 80% UL taps.
Which 300B amplifier is a good question. There are lots of good ones.
But that reminds me of a writer in "Sound Practices" who once said: "I never met a 2A3 amplifier that I did not like".
I built a few 300B SE amplifiers and a 300B push pull amplifier too.
I still have a pair of 300B tubes if I get the urge.
At least PCBs have made it possible for some to have the courage to build a tube amplifier that they otherwise would not have attempted.
I do have to say that over the years I built some electronics that used PCBs.
Mostly radios and such.
The only two audio amplifiers with PCBs I had was a low power solid state Heathkit; and an already built Dyna ST-70.
The ST-70 had the PCB taken out soon after I got it. The amplifier became a test bed for many different topologies and different parts (only the power transformer and chassis remain on the amplifier.
The A470 output transformers were taken off of the amplifier; one has the E's and I's re-stacked with a Kapton spacer 'air gap' for single ended use, including 20%, 50%, and 80% UL taps.
Which 300B amplifier is a good question. There are lots of good ones.
But that reminds me of a writer in "Sound Practices" who once said: "I never met a 2A3 amplifier that I did not like".
I built a few 300B SE amplifiers and a 300B push pull amplifier too.
I still have a pair of 300B tubes if I get the urge.
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If you are not looking to save money then lets work with a parts budget of $4000US plus then ok?
Let's also work under the assumption that to be truly high performance (what does that mean in the context of 1% THD) it will have to be all DHT.
So very likely a 3 stage design, unless you can get the requisite gain on the input via a high output DAC (on the order of pro level 18-24dBu).
Each DHT (there will be 3 per channel) will require is own CLC power supply with proper regulation (Rod Coleman pcb) for the filaments. Design power supply each driver section to supply 20-100mA of current depending on tube choice. DC filaments of 300B is going to be a few amps as well.
High performance means dual mono. By my count that is 2-4 power transformers for filaments, 4-6 chokes. Could get by with a shared power transformer for all your driver tube B+.
Pick your operating point and determine how much inductance and resistance you want to load the 300B with. Find a great not just good transformer, it won't be cheap.
Two chassis, one dedicated to power with umbilical leads to your driver/power tube chassis.
300B lives and dies by the tube that's driving it. And that as mentioned is either via another two DHT tubes in front of it or some other creative solution.
Hopefully other experienced 300B builders will chime in and confirm that without honing in on your design goals you are bound for disappointment.
The Audio Note Kit Mentor 300B with their highest rated output transformer would be the way to go if you are not prepared for the exponential cost of a "state of the art" 300B build beyond $5000.
See Ale Moglia's site Bartola Valves for what many consider the edge of the art of modern tube design. Some like the hybrid approach to using solid state parts in classic tube circuits. Others prefer a more purist approach.
Let's also work under the assumption that to be truly high performance (what does that mean in the context of 1% THD) it will have to be all DHT.
So very likely a 3 stage design, unless you can get the requisite gain on the input via a high output DAC (on the order of pro level 18-24dBu).
Each DHT (there will be 3 per channel) will require is own CLC power supply with proper regulation (Rod Coleman pcb) for the filaments. Design power supply each driver section to supply 20-100mA of current depending on tube choice. DC filaments of 300B is going to be a few amps as well.
High performance means dual mono. By my count that is 2-4 power transformers for filaments, 4-6 chokes. Could get by with a shared power transformer for all your driver tube B+.
Pick your operating point and determine how much inductance and resistance you want to load the 300B with. Find a great not just good transformer, it won't be cheap.
Two chassis, one dedicated to power with umbilical leads to your driver/power tube chassis.
300B lives and dies by the tube that's driving it. And that as mentioned is either via another two DHT tubes in front of it or some other creative solution.
Hopefully other experienced 300B builders will chime in and confirm that without honing in on your design goals you are bound for disappointment.
The Audio Note Kit Mentor 300B with their highest rated output transformer would be the way to go if you are not prepared for the exponential cost of a "state of the art" 300B build beyond $5000.
See Ale Moglia's site Bartola Valves for what many consider the edge of the art of modern tube design. Some like the hybrid approach to using solid state parts in classic tube circuits. Others prefer a more purist approach.
6A3 , they are silver wired point to point circuits. Chinese versions have filament supply on PCB boards as a simplification. The original AN boards don't but the rest has to be wired P2P. Here is mine phono clone.
This one with those abysmal V-caps which I happened to to have on hand and because I already built one with AN coppers.
I happen to like AN and I think they have the best systemic approach to get decent sound in Euro flats.
The opinions you will hear are " yeah , I didn't think it will matter so I substituted beaf with chicken and I will tell you the dish is not worth the troubles , plain vanilla and lacking in flavor" It's not only with AN. Whichever amp you will choose to make stick with designer's choice of parts and move on to next if not your flavor. Well if you're Andy Grove , Shindo or Kondo like majority designers here disregard and proceed to make your world beating amp.
First I would suggest successful cloning of Proac 2.5 ...AND that perennial favorite Gainclone where everybody is skimping on most important part - cut core transformer
Those deadbeats old Naim aficionados chasing clunkers with Fisher-Holden trans in them when Antek provides all the quality one needs ..
This one with those abysmal V-caps which I happened to to have on hand and because I already built one with AN coppers.
I happen to like AN and I think they have the best systemic approach to get decent sound in Euro flats.
The opinions you will hear are " yeah , I didn't think it will matter so I substituted beaf with chicken and I will tell you the dish is not worth the troubles , plain vanilla and lacking in flavor" It's not only with AN. Whichever amp you will choose to make stick with designer's choice of parts and move on to next if not your flavor. Well if you're Andy Grove , Shindo or Kondo like majority designers here disregard and proceed to make your world beating amp.
First I would suggest successful cloning of Proac 2.5 ...AND that perennial favorite Gainclone where everybody is skimping on most important part - cut core transformer
Those deadbeats old Naim aficionados chasing clunkers with Fisher-Holden trans in them when Antek provides all the quality one needs ..Attachments
If I had lots of money to spend on 300B SE output transformers, I would purchase the Monolith Magnetics models.
With DHT output tubes, I do not like global negative feedback around the output transformer, and no negative feedback from the primary either.
Under those restrictions, I consider the output transformer to be the Heart of the amplifier.
Just my opinions.
With DHT output tubes, I do not like global negative feedback around the output transformer, and no negative feedback from the primary either.
Under those restrictions, I consider the output transformer to be the Heart of the amplifier.
Just my opinions.