Nah. I say let it stand. After all, without it none of the more productive dialog that followed would have taken place, right?
A "problem" with toroidal power trafos is their extended frequency response. Trash can "ride" on the AC mains. Ferrite beads on the primary side connections deal with the issue.
Kodabmx has cleverly taken advantage of a characteristic that could be a liability and turned into an asset. I'd appreciate it if he'd discuss the feasibility of using that method in the O/P "iron" role of an "El Cheapo". Obviously, the only mode choices for the "finals" are full pentode and triode. His previous low impedance remark suggests pentode is a bad idea. Could toroidal O/P "iron" be more cost effective than the Edcor GXPP15-8K?
Kodabmx has cleverly taken advantage of a characteristic that could be a liability and turned into an asset. I'd appreciate it if he'd discuss the feasibility of using that method in the O/P "iron" role of an "El Cheapo". Obviously, the only mode choices for the "finals" are full pentode and triode. His previous low impedance remark suggests pentode is a bad idea. Could toroidal O/P "iron" be more cost effective than the Edcor GXPP15-8K?
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Is a forum only good for making compliments and give a five star rating to everything shown as it is good practise on Facebook to indulge the ego of his creator? Is that what a DIY forum is about nowadays?
Why not saying the truth, that it's not good design practise to staple toroids?
Because it may hurt the original builder and his ego became scratches?
I don't think so. The rule, better to say nothing than to say something criticising can be applied in small talk where thematics are always superficial and nobody is really interested in real opinions.
And no, I'm not generally of controverse opinion. When something is build fine then I will say its been build fine. But when something is build like a misleaded amateur idea has come to reality, than it should be able to critisize those faults and not always say the usual bla bla fine, great build, super duper design and so on. But I think the reality is, I'm not the generation Facebook who needs in a repetative style to become smiles and stars and "great, that you have done this" ratings. I'm about reality and only this can help to improve.
Its way too much bushit thats been shown on the internet in terms of design and engineering. The most amateur amp designers choose a walnut frame, put an aluminum plate on it and underneath it looks like in a garbage can. Thats the reality and that happens, because those builders like this guy has never been shown how to do it right. They have no clue of how to do electrical things the right way, they are foreigners in the land of the electrons and have not the practical experience to do things the way it should be.
The truth is fine, but what I read was unsubstantiated opinion, your objections were not based on a technical analysis or experimentation, and bluntly it was dismissive, disrespectful and mean, maybe that's not what you intended but that is what many of us read into it.. 😀
We know you don't like toroids, but several highly capable members here have demonstrated that they can be employed in novel and imaginative ways to get good results at low cost. I don't use them in my own designs but would consider them in a budget constrained PP amplifier with something like the 6C41...
Low source impedance and good circuit DC balance as well as careful testing and evaluation of candidate transformers is required. Koda spent a lot of time figuring this out, and it is very evident in the electrical design. It's clever and innovative even if it doesn't fit the conventional tube design dogma.
Would you have had a different reaction if the toroids were hidden in nice looking cans? I know from experience that appearance does play a role in a lot of people's perceptions of quality. (I know this because I have made some pretty ugly looking junk in the past and I noticed that appearance influenced perception a lot..)
I have the same opinion about a lot of creations, but I try to guide people to doing things better, not everyone is open to constructive criticism either, but you have to try and in a respectful way. I am obsessive about the way I build stuff (I am an EE and earn my living designing consumer electronics) and even I get criticism from people who have not seen something done a certain way before.
We know you don't like toroids, but several highly capable members here have demonstrated that they can be employed in novel and imaginative ways to get good results at low cost. I don't use them in my own designs but would consider them in a budget constrained PP amplifier with something like the 6C41...
Low source impedance and good circuit DC balance as well as careful testing and evaluation of candidate transformers is required. Koda spent a lot of time figuring this out, and it is very evident in the electrical design. It's clever and innovative even if it doesn't fit the conventional tube design dogma.
Would you have had a different reaction if the toroids were hidden in nice looking cans? I know from experience that appearance does play a role in a lot of people's perceptions of quality. (I know this because I have made some pretty ugly looking junk in the past and I noticed that appearance influenced perception a lot..)
I have the same opinion about a lot of creations, but I try to guide people to doing things better, not everyone is open to constructive criticism either, but you have to try and in a respectful way. I am obsessive about the way I build stuff (I am an EE and earn my living designing consumer electronics) and even I get criticism from people who have not seen something done a certain way before.
I think you should mount your second toroid on a screw thread a bit above the first with a gap in between. It would look well eccentric.
Hi Eli.
I think this setup would work fine for El Cheapo in either triode or pentode, using 2 VPT12-2080 with interleaved primaries shown, except the secondaries connected in series parallel. Think 480:12. Connect each coils' secondaries in parallel, and then connect those together in series minding the phase otherwise you will have a very quiet amplifier 😀). This will give you ~9k6:6R which is a little higher than the Edcor, but passable, especially if you ditch the tube rectifier and use the extra voltage to counteract the higher Z OPT.
Considering a pair of VPT12-2080 are under 40$ US, it's a bargain. Especially if you're not in the USA as shipping is _expensive_!
And when you get into larger amps using big sweep tubes, the bigger ones make even more power because of the lower primary DCR of the toroids. Plus, I've never had open from a bad tube arcing over 😀
I want to mention again, that MaxHifi was the member who originally suggested I try this since the design he commented on used two coils, but in simple parallel connection.
Try it, you'll like it. And if you don't? You now have filament transformers 🙂
Haha Kind of like this? Sorry about the angle, it's hanging on a wall.
Originally, I had wanted to mount one coil on top, and the other underneath but I couldn't spare the real estate. This was my take on El Cheapo. It uses 6P15P as pentodes biased with LM317s bypassed by 1000uF, and the frone end is a 6N3 VA into cathodyne PI. It's powered by a 12V 10A brick and a 280V boost converter. Total cost was under 100$ CAD since I built it in a 4$ cake pan.
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BLAHAHAHA. Thanks. I needed a good laugh. Please feel free to post your award winning manufacturing skills and designs 🙄
The way YOU think it should be isn't the only way of doing things, but that's obvious to most people.
Once again, please grace us with your design skills. School me. Show us all how amateur we all are. I expect you to hand built everything and wire it all point to point though. From scratch. Without SPICE for the designing. Enlighten us all!
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I think Schmitz didn't want to argue against the use of two toroids as a single OT (I think he's capable of reading the schematics…), but he doesn't like stacking those instead of mounting them side by side.
Anyway, I won't judge it. But I'd also cover all toroids with cans for safety reasons.
Best regards!
Edit: kodabmx, your design in #28 looks awful crazy! I really like it and will keep mounting toroids on round coil formers in mind 🙂!
Anyway, I won't judge it. But I'd also cover all toroids with cans for safety reasons.
Best regards!
Edit: kodabmx, your design in #28 looks awful crazy! I really like it and will keep mounting toroids on round coil formers in mind 🙂!
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There is a cover for it. My dad just didn't want to pay 100$ for a cover for a 150$ amplifier. The transformer primary leads are in a robber sleeve, and the chassis has a rubber grommet. What's the safety issue?
https://www.newark.com/hammond/1451-30bk3/chassis-cover-1441-1444-series/dp/50H5755
https://www.newark.com/hammond/1451-30bk3/chassis-cover-1441-1444-series/dp/50H5755
The safety issue covers the toroids themselves. A cover, for instance a soup can ;-), will protect them against accidentally hurting them.
Best regards!
Best regards!
Yes, exactly. By own bad experience it never can be excluded that bare toroids (or other trannies) can be damaged by spiked, edged and/or acute things contacting them.
Best regards!
Best regards!
In germany, this piece of bad DIY would never make it pass to sell officially by the VDE regulations. And for a good reason.
Buy three of those Campbells soup cans and put them over the toroids. Andy Warhol would say then it's some kind of electric art.
Maybe Banksy will spray tag it and you can sell for one million cash.
At last, it did find a reason to exist.
Buy three of those Campbells soup cans and put them over the toroids. Andy Warhol would say then it's some kind of electric art.
Maybe Banksy will spray tag it and you can sell for one million cash.
At last, it did find a reason to exist.
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As Mimi Eisenhower used to say, "If you can't say anything nice, come sit next to me"
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John: 😀 😀
Schmitz, almost no DIY would meet VDE requirements, including I would guess stuff built by most German DIYers. I build to a high level of quality, but I suspect even in my case that remediation would be required.
DIY tube audio gear should never be left running unattended, and that probably goes for most inexpensive products sold on Amazon and eBay as well.
I agree with the suggestion that the toroids should be covered for safety. i.e. to prevent physical damage that could make them hazardous.
Metal cases need to be connected to safety earth and that connection needs to conform to recommended UL/CSA/VDE practices.
Schmitz, almost no DIY would meet VDE requirements, including I would guess stuff built by most German DIYers. I build to a high level of quality, but I suspect even in my case that remediation would be required.
DIY tube audio gear should never be left running unattended, and that probably goes for most inexpensive products sold on Amazon and eBay as well.
I agree with the suggestion that the toroids should be covered for safety. i.e. to prevent physical damage that could make them hazardous.
Metal cases need to be connected to safety earth and that connection needs to conform to recommended UL/CSA/VDE practices.
Gentlemen. Stick the subject, which is a tube amp. The subject is not each other.Disrespect of other members will earn you time in the sin bin.
Hey fabei,
Getting back to the original post (hope he is still around)...
I have the PCB (I think it is partially populated) for the Baby Huey EL34 (not EL84)...most of the difficulty in wiring is done on this PCB, so just add trannies, case, connectors and tube sockets, and that should be it... pm me if any interest...
Getting back to the original post (hope he is still around)...
I have the PCB (I think it is partially populated) for the Baby Huey EL34 (not EL84)...most of the difficulty in wiring is done on this PCB, so just add trannies, case, connectors and tube sockets, and that should be it... pm me if any interest...