Thanks, mate. The correct spelling is one problem foreigners have with this language. Its just not that you read and speak it anyday, so errors occur.I assume that is what you are talking about, there have been many types discussed in this threadBTW there is no h in wimpy
sure, because he never knew how to use them....
Sakuma is long gone, he can not make tube amps ever again...
i am more of a PRR fan, i learned a lot from him...
energy is but the consumption of power over time, they are inextricably intertwined......how do you frame tones? this is subjective...
what may sound good to you may sound awful to me, so where does that leave us?
if you are not a native American or English language speaker, that is understandable, context is more important than spelling..
That is why Owen (of Dark Lantern) described him as a bit eccentric.
However, I do think Sakuma san would respect your inductor loaded DC coupled implementation.
He said "I think an amplifier builder should consult with himself and his amplifier before asking the reference books and authorities."
and
"I opened the reference books every day. And then, that old interstage transformer asked me:
'Sakuma, who do you build this amplifier for? Do you make the amplifier to get praise from electronics teachers?'
Since that day, I have made amplifiers for my own pleasure as an amateur".
A low loss transmission of the driving amplitudes is just as desirable and the input impedance of the 300B is not very high.
A plate inductor implies a rapidly rising inductive reactance with frequency - a thin and bright sound. The Japanese predilection (shikō) dictates the traditional musical instruments to be reproduced with a high degree of brightness.
A plate inductor implies a rapidly rising inductive reactance with frequency - a thin and bright sound. The Japanese predilection (shikō) dictates the traditional musical instruments to be reproduced with a high degree of brightness.
Well, I've been through a lot of changes in the last year to my main amplifier. It went something like this....
- 300b with a DHT driver. I started a thread on this, which gave me a lot of ideas. I focussed on the 10Y as driver, also tried an 01A but that required a cathode/source follower which I never got round to constructing. So I needed a step-up input transformer or some other kind of gain stage. I tried several op-amps, particularly the NE5534 which sounded quite good. Ultimately I wasn't satisfied, though. Ale Moglia is using a 1:8 step-up with a Lundahl LL7903 which is the transformer Per Lundahl himself recommends for this.
- 300b with an IDHT driver. I came across quite a few nice drivers with mu around 20 - KT61, EL84 in triode etc. Still needed an extra gain stage
- Took out the 300b and put in higher gain output tubes, mu of around 15-18. At this point the IDHT drivers worked fine and gave enough gain. The IDHT output tubes, however, were not as smooth as the 300b, even though they were better than I expected and I found the EL12n pretty good. Stayed with this for a while and will keep it as a possibility. I could put the 10Y back again with no need for extra gain on the input.
- Came back to the 300b with a driver like KT61 in triode with mu of around 20. This required a step-up transformer again, so back to trying some. The LL1540 was disappointingly flat sounding even though it's mumetal. The Hammond 124b (49% nickel) was better. Larger transformer, more details. This remains a possibility given a good step-up transformer
- And finally back to 300b with an IDHT driver like C3g or C3m. This may be where I'll end up, when I find a driver I like. I have both of these coming and will try them out. I've been disappointed with the tubes I tried such as EF180, 6e6p and 6N1P but I'm ready to believe that there does exist a good enough sounding IDHT. It needs a driver with come current capability and a mu of 30 or over, so not a typical wimpy driver unless I go for a cathode/source follower which I'm reluctant to do. But I'm also reluctant to spend money on an amorphous or finemet input step-up. So I'll see if the C3g or C3m does the trick. Many fans think so.
So that's been my journey. I've tried and eliminated a lot of options and gained a lot of knowledge along the way, and I'm left with two or three viable choices. It's been a lot of work, but I've been stuck at home for a year and counting so not too much else to do!
- 300b with a DHT driver. I started a thread on this, which gave me a lot of ideas. I focussed on the 10Y as driver, also tried an 01A but that required a cathode/source follower which I never got round to constructing. So I needed a step-up input transformer or some other kind of gain stage. I tried several op-amps, particularly the NE5534 which sounded quite good. Ultimately I wasn't satisfied, though. Ale Moglia is using a 1:8 step-up with a Lundahl LL7903 which is the transformer Per Lundahl himself recommends for this.
- 300b with an IDHT driver. I came across quite a few nice drivers with mu around 20 - KT61, EL84 in triode etc. Still needed an extra gain stage
- Took out the 300b and put in higher gain output tubes, mu of around 15-18. At this point the IDHT drivers worked fine and gave enough gain. The IDHT output tubes, however, were not as smooth as the 300b, even though they were better than I expected and I found the EL12n pretty good. Stayed with this for a while and will keep it as a possibility. I could put the 10Y back again with no need for extra gain on the input.
- Came back to the 300b with a driver like KT61 in triode with mu of around 20. This required a step-up transformer again, so back to trying some. The LL1540 was disappointingly flat sounding even though it's mumetal. The Hammond 124b (49% nickel) was better. Larger transformer, more details. This remains a possibility given a good step-up transformer
- And finally back to 300b with an IDHT driver like C3g or C3m. This may be where I'll end up, when I find a driver I like. I have both of these coming and will try them out. I've been disappointed with the tubes I tried such as EF180, 6e6p and 6N1P but I'm ready to believe that there does exist a good enough sounding IDHT. It needs a driver with come current capability and a mu of 30 or over, so not a typical wimpy driver unless I go for a cathode/source follower which I'm reluctant to do. But I'm also reluctant to spend money on an amorphous or finemet input step-up. So I'll see if the C3g or C3m does the trick. Many fans think so.
So that's been my journey. I've tried and eliminated a lot of options and gained a lot of knowledge along the way, and I'm left with two or three viable choices. It's been a lot of work, but I've been stuck at home for a year and counting so not too much else to do!
Hammond and Lundahl are cheap, middle class audio transformers. Don't expect world class performance from middle class equipment. That won't happen. Its like always in life, if you don't pay the price for premium parts in DIY, no premium performance will happen.
To build a 300B amp has been done since decades. WE came up with their cult design in the 1930s. There isn't any problem to drive this tube and there are so many ways to do so.
To build a good amp has NOTHING to do with a special concept that means one stage to drive the tube, is has ANYTHING to do with creating a perfect working environment for the tubes. Dogmas don't help here. If you could go out of your dogmas, then you will find a very simple way to establish a working circuit. And that doesn't need months of twerking and experimenting, it just needs data sheets and the will to build an amp.
Nothing new here, and I don't expect that you found out something new with your project.
Just repeating and always repearing the same story here. Maybe with some exotic tube types this time.
To build a 300B amp has been done since decades. WE came up with their cult design in the 1930s. There isn't any problem to drive this tube and there are so many ways to do so.
To build a good amp has NOTHING to do with a special concept that means one stage to drive the tube, is has ANYTHING to do with creating a perfect working environment for the tubes. Dogmas don't help here. If you could go out of your dogmas, then you will find a very simple way to establish a working circuit. And that doesn't need months of twerking and experimenting, it just needs data sheets and the will to build an amp.
Nothing new here, and I don't expect that you found out something new with your project.
Just repeating and always repearing the same story here. Maybe with some exotic tube types this time.
Andyjevans,
Thanks for sharing your explorations and conclusions. I enjoyed them and learned a lot.
I think it's pretty obvious from the amount of experimenting I've done that I found out a lot of new things, and that the process started out with no dogmas whatsoever except the desire to use a one stage driver tube, if that's what you're referring to. I'm not pretending anything is new to the world, but I did explore a number of options that were new to me.
I am indeed using some exotic tubes as well......... some of the tubes that time forgot. You're right there!
<Under a dogma (old Gr. Δόγμα, dógma, "opinion, doctrine; decision, ordinance" [1]) one understands a fixed definition or a fundamental, normative doctrinal statement, the truth of which is established as irrefutable.>
Exactly thats your dogma, but you deny to have a dogma.
Your not able to see what you do, building restrictions on the construction of an amps topology.
You simply don't understand that tube amp design is about other construction principles than your simplified world.
Always when people start building amps with those dogmas in mind, its an endless story because they are not open to search for a perfect solution, just want a testimonial for whatever concept they have in their heads for whatever reason (most often they think, only this concept is the best, of course).
B. Oring.
Exactly thats your dogma, but you deny to have a dogma.
Your not able to see what you do, building restrictions on the construction of an amps topology.
You simply don't understand that tube amp design is about other construction principles than your simplified world.
Always when people start building amps with those dogmas in mind, its an endless story because they are not open to search for a perfect solution, just want a testimonial for whatever concept they have in their heads for whatever reason (most often they think, only this concept is the best, of course).
B. Oring.
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I can design an extremely good 300B amp in five minutes, because thats the time to draw the concept. What is special about a 300B amp is to source the parts which are being needed to build such an amp. And I doubt that you even don't have the budget to fund such an amp.
A 300B amp is such an expensive thing, if its done real good but technically its no rocket science, basically its just 1930s technology.
For those, who aren't able to fund for a real good 300B amp, my advise is: get another amp with different tubes. Because real 300B tubes (I'm talking WESTERN tubes, no asia scam) are the kings of audio tubes and its a sport for the kings to build such an amp.
If your able to only affort Hammond and Lundahl, forget about that kind of quality which could be possible.
Btw, I will blow your two stage concept away with a real three way concept. because it uses specialised tubes where you never be able to find a tube which could combine the function of a delicate input and a thunderfull driver tube.
A 300B amp is such an expensive thing, if its done real good but technically its no rocket science, basically its just 1930s technology.
For those, who aren't able to fund for a real good 300B amp, my advise is: get another amp with different tubes. Because real 300B tubes (I'm talking WESTERN tubes, no asia scam) are the kings of audio tubes and its a sport for the kings to build such an amp.
If your able to only affort Hammond and Lundahl, forget about that kind of quality which could be possible.
Btw, I will blow your two stage concept away with a real three way concept. because it uses specialised tubes where you never be able to find a tube which could combine the function of a delicate input and a thunderfull driver tube.
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Schmitz77 - thanks for your comments. I leave you in your own world to design and build your own concepts and good luck with that. I don't share your views on a lot of aspects of the 300b amp, from tubes to OPTs to design, though I believe we agree on some things like a driver with plenty of current capability. I'm not interested in a 3 stage amp - I've built two or three already, and 2 stages sounded cleaner. But of course, you're welcome to your own interpretations of design.
I think forum members would be interested in some of your personal designs if you'd like to publish them?
Thanks for the support from members who have found my year long journey of some interest. I do try and document my experiments and post design concepts. This is a great forum.
.
I think forum members would be interested in some of your personal designs if you'd like to publish them?
Thanks for the support from members who have found my year long journey of some interest. I do try and document my experiments and post design concepts. This is a great forum.
.
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We all knew the difference between a "good" amp and an excellent one. Its like the distance from earth to moon.
I did build my first 300B amp after studying the sybject many years with other tube amp designs. It used Lundahl iron. Later, I used much better iron, but I understand people in an audio forum are not all the same, don't share the same visions and don't have the same experiences.
Kinda understand this "two stages sound cleaner to me" design goal.
Never wanted a "clean sounding amp", just wanted a good sounding amp.
The best clean sounding component is in the end a straight wire- we all know that this isn't possible, at least if iron comes into the game. I heard many SET irons, Lundahl was not bad, but not excellent sounding. There are much cheaper, more bad sounding designs. But there are far better designs, too. I doubt that your experience has shown you better transformers, because better 300B transformers are not only far superior, but far more expensive, too.
If you have ever that opportunity to audition one, my advise is to do so.
When a "clean sounding" amp is the goal of a design, a 300B tube is close to the worst candidate for this. Literally there are many other tubes that sound far more "cleaner" than a 300B tube.
So to design a 300B amp with the design goal of a "clean sounding amp", is a paradox in itself and robbs this king of triode tubes off its virtues completely. The highest virtue what can be achieved with a real 300B tube to let its virtues shine in a special way, and that always doesn't mean a clean sounding amp.
So good luck with your project from my side!
I did build my first 300B amp after studying the sybject many years with other tube amp designs. It used Lundahl iron. Later, I used much better iron, but I understand people in an audio forum are not all the same, don't share the same visions and don't have the same experiences.
Kinda understand this "two stages sound cleaner to me" design goal.
Never wanted a "clean sounding amp", just wanted a good sounding amp.
The best clean sounding component is in the end a straight wire- we all know that this isn't possible, at least if iron comes into the game. I heard many SET irons, Lundahl was not bad, but not excellent sounding. There are much cheaper, more bad sounding designs. But there are far better designs, too. I doubt that your experience has shown you better transformers, because better 300B transformers are not only far superior, but far more expensive, too.
If you have ever that opportunity to audition one, my advise is to do so.
When a "clean sounding" amp is the goal of a design, a 300B tube is close to the worst candidate for this. Literally there are many other tubes that sound far more "cleaner" than a 300B tube.
So to design a 300B amp with the design goal of a "clean sounding amp", is a paradox in itself and robbs this king of triode tubes off its virtues completely. The highest virtue what can be achieved with a real 300B tube to let its virtues shine in a special way, and that always doesn't mean a clean sounding amp.
So good luck with your project from my side!
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