The most expensive parts of a DIY tube amp is always the OP transformers unless your using something like NOS Western Electric 300B tubes.
If you think making really high quality transformers is that simple than I suggest you buy a winder and start a business. Many have tried........
BillWojo
If you think making really high quality transformers is that simple than I suggest you buy a winder and start a business. Many have tried........
BillWojo
It sounds like the secret is always in the transformers and that's what most on here aren't comfortable with, but some say they can do it... why shouldn't I just hire someone who says they can do it?
You tell me? How should I verify that it's a real unity coupled or 8b transformer?
I thought you might be a young kid, no offense. I think I would be accurate to say that your relatively new to tube amp design. I couldn't design an amp but I know enough to put a kit together or follow a schematic. An awful lot of the folks on here that have replied are light years ahead of me and I have the utmost respect for them.
They know what it takes to design a superior OP transformer or know enough to know that it is a very specialized field and few have the knowledge to do it right. If it was easy company's like Hammond would have Mac clone transformers in their catalog but they don't. And those Mac transformers really won't do you any good without the supporting circuitry to make them work correctly. The engineers behind the Mac's and the other legendary amps were the best engineers that tube audio has ever seen. They had to figure out how to build unconventional transformers so that what they designed could be realized.
Your best bet to build an amp that you want to copy is to find one that is in rough shape but with working OP transformers and build from there. It will be way cheaper than having someone try and build clone transformers and as tsmith1315 said, how will you know that you got what you paid for.
Really rough Mac amps can be found on ebay if you keep your eyes open. If they are not restorable due to rusted out chassis or damage you may find a good set of iron. If I was on the same mission as you that's where I would be looking. Or place adds, this forum would be a good place to start.
BillWojo
They know what it takes to design a superior OP transformer or know enough to know that it is a very specialized field and few have the knowledge to do it right. If it was easy company's like Hammond would have Mac clone transformers in their catalog but they don't. And those Mac transformers really won't do you any good without the supporting circuitry to make them work correctly. The engineers behind the Mac's and the other legendary amps were the best engineers that tube audio has ever seen. They had to figure out how to build unconventional transformers so that what they designed could be realized.
Your best bet to build an amp that you want to copy is to find one that is in rough shape but with working OP transformers and build from there. It will be way cheaper than having someone try and build clone transformers and as tsmith1315 said, how will you know that you got what you paid for.
Really rough Mac amps can be found on ebay if you keep your eyes open. If they are not restorable due to rusted out chassis or damage you may find a good set of iron. If I was on the same mission as you that's where I would be looking. Or place adds, this forum would be a good place to start.
BillWojo
So what's the hardest part about building these unity coupled and 8b transformers? Is it the cost of the wire and cores?
Or is it just knowing how?
Or is it just knowing how?
Yes, it's Wolfgang 'Funker's' Story. He lives next to Hamburg, far away from me. We've had extensive correspondece and telephone callson exactly this subject.
He used quadruple C cores and dual chamber bobbins for his OT's. I'd prefer dual C's and two bobbins per OT, though.
Best regards!
Did he documented the process so we can call make a MC3500? How much did 1 core cost him, not including the winder, not including his time?
It takes about a minute to find this one. The guy says he never wound a transformer before.
Looking forward to your build thread.
Just saying that, everything you have said up there... well, nothing can't be replicated. It is just a matter of time, money, and effort. The laminations are nothing special as with modern materials sciences, you can get the same or pretty damned as close as you want in terms of composition and the shape and colour. The same goes for the wire composition and gauge of the wire and coatings used in those wires. The windings I am sure can be copied from originals.
Not everyone is trying to clone the proven classics. The article expanded on that specifically in that it was a re-design to copy a "clone" (look it up, there are many copies on the internet with just vague search terms), and each iteration was an improvement on the prior design using available components. He got 18 watts in triode mode and 35 watts in UL mode per side at 1% distortion.
8b < 8b clone < 8b copy of the clone
And that this was proven with the better gain, lower distortion numbers, and tonal range all through the use of toroidal transformers, subtracting what was not needed, and using better components. So basically the author didn't recreate the classic 8b was because he could get much better results with what he had available to him. The last line of the article says, "I dare say that this replica amplifier exceeds the overall performance of the original Marantz 8b."
You can improve upon the prior art either by re-designing it using the prior art as a foundation for improvement. That example can go for cars (modern cars are a result of better use of materials making them less polluting and more efficient and safer than those of the 1960's... a new Shelby Mustang or a Challenger would blow the doors off their 1960's brethren) and the vacuum tubes amplifiers (which for the most part have been replaced by transistors in amplifiers).
The Marantz 8b output can be found on the internet.
Thanks for the info.
What is the hardest part of that makes these classic transformers impossible?
Did the guy who wound his own MC3500 transformers document his process so others can do it? Did he get it done right with +/- .1 db or less type specs?
Are you saying that a well known toroidal transformer is better than a vintage unity coupled mc transformer?
How can I make the known and simpler 8b design and make it a 300w mono bloc? Difficult? Possible?
What's the most powerful single stage amp that I can DIY? Can I get common modern wattage like 75-100watts from a single stage tube amp?
been looking at this for ages now, i wonder if Alvin Lockheart is still around, and if the core material me mentioned are still available...
or maybe cores from other sources can be used...
it is not, i wind my own power traffos and OPT's, i understand the article as a whole...
that's how to do it, understand the concepts then you can tweak it...
and rocket science isn't really that complex either, just takes time
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