I use older transformers from battery chargers and you will also find that a lot of these transformers are center tapped at your 6.3 volts you need for tube radio 6 volt filament. for 5 volt filament I use old VCR transformer. This is why I take old unwanted electronics from friends at work. You never know what reusable parts you will find inside them.
@dhpbear29 ай бұрын
I'm old enough to remember when JAMECO was 'James Electronics"!
@prophetsnake9 ай бұрын
Another alternative would be an Antek toroidal transformer. For $29 you can get a transformer with a range of secondary voltages plus two 6.3V secondaries as well. For not a lot more you can get a 100Va unitgood for something around 20W output. I've used these transofrmers on a half a dozen projects. they also have transformers with a 5 volt winding as well.
@magnetus269 ай бұрын
how about the output is it just 160v on the high voltage side? is it that too low??
@Traci_S_Aaron9 ай бұрын
This is probably one of your better videos
@d-labelectronics9 ай бұрын
Thank you, doing my best
@DetroitWrecker6669 ай бұрын
Really good to see someone finally do this and not sell all the snake oil.
@giulioluzzardi76329 ай бұрын
Simple and Stylish in its 2-tone Green and white housing with a sound that will definitely please the neighbours...I bet it would sound "Cosmic" with an Alnico P10r type speaker...in a matching 2-tone green and white cabinet, like a Sci-fi mini stack!
@danrussell93579 ай бұрын
The video was practical and specific. Thanks for the tube amp content!
@petedavis79709 ай бұрын
Here's a 2-birds with one stone solution for getting both high voltage and getting your filament voltage: You get 2 transformers: 120V-12V (this is your filament supply). You then connect the secondary of a 120V-6V transformer to the secondary of the first transformer. So it goes kind of like this: 120V -> 12V -> 6V (12V) -> 120V (240V). Does that makes sense? So you're putting 120V in one side, you're getting 12V after the first transformer and then you're getting 240V after the second transformer.. You can use different secondary voltages on the second transformer to get different voltages. You can use a 120V to 9V, for example, to get 180V after the second transformer. I used to get old tube stuff off of craigslist. I think maybe it got more popular since I was doing that, but I was getting old Hammond organs (and Conn and Baldwin) for peanuts, sometimes free. I'd strip them for parts. But you'd get a complete tube amp. The Hammonds are particularly excellent for making making guitar amps. I had both L100 series and M3 series amps. Anyway, if you can find that stuff on Craigslist, it's a great way to get free parts. The only down side is getting rid of the organ body. My cousin owned a restaurant at the time and he'd let me dump them in his restaurant's dumpster.
@nomadicnerd8189 ай бұрын
I've used the N68X for a couple amp designs using series filament tubes (fused wall power for filaments and the N68X for B+). It works great and 240V will rectify to about 330V, depending on the current draw. Another alternative for filaments is a 12V center tapped transformer,, not uncommon on solid state electronics. Your 12A*7 tubes can use the full transformer voltage swing, and 6V output tubes can each take a leg and the center tap.
@rimmersbryggeri9 ай бұрын
If you are in a 240v country can you just use an equivalent isolation transformer as the power transformer?
@Bleats_Sinodai9 ай бұрын
Another good option is something like what the peeps from the Brazilian forum Handmades did with their Camine HB-1, HB-2, and other such projects, where they use a 30v+30v transformer to get 60vAC, and run that through a voltage doubler to get 145v DC. It also powers the filaments from the 30vAC center tap (where they're wired in series). There's also many projects from the website OzValves where they use voltage multipliers to get B+ voltages.
@n8iws4849 ай бұрын
Nice budget build and recycled Regency cabinet. It will look great on someone's shelf.
@davidwhitson45589 ай бұрын
Win/Win/Win. Thanks Terry
@jerryking24189 ай бұрын
Good advice on sourcing inexpensive parts.
@p_mouse86769 ай бұрын
I often use those Meanwell DC power supplies for the heaters/filaments. They are pretty cheap plus have the advantage of not introducing any humm.
@RobynTapps9 ай бұрын
Keep it up Terry ❤️, as a canadian I will always use a hammond. but will for sure check these out!
@Wizardofgosz9 ай бұрын
Triad makes nice stuff. I used their toroidal transformers in all sorts of my builds. I'm surprised they don't have a more direct equivalent.
@edwardhannigan63249 ай бұрын
Great job Terry.. Now, a small amp project that is affordable.😊 Ed..uk.
@kennethc24669 ай бұрын
Thank you fine sir, for all your great help and knowledge...let alone entertaining videos. A great trifecta!
@garp329 ай бұрын
Good info there Terry. Thanks for the tips! Those are very affordable! And honestly, this is one of the reasons I haven't made a homebrew amp yet. Transformer costs. Also good tip on the preamp tubes! I figured there was a comparable single triode to the 12AX7. =) Awesome.
@amberyooper9 ай бұрын
I would probably turn the output transformer 90 degrees from the power transformer to reduce the possibility of magnetic coupling, but other than that, a nice build.
@christophervillanti14179 ай бұрын
You can very easily add a standby switch to this setup.
@scottysledshed9 ай бұрын
Now thats freaking cool. Now I need to dig through the shop and see what I could put one of those in. Maybe a Benton Harbor, Mi 1960's green thing??Hmmm....
@Tony770jr9 ай бұрын
Hi Terry, wow nice cost reduction!
@skullheadwater98399 ай бұрын
Another option is control transformers. They are usually used to step down 480 or 240 to 120 but you can reverse feed then and they are cheap, I got a bunch free working as an electrician.
@richardgale90059 ай бұрын
HI Terry , Im in the Uk, i built an amp Standel 25L15 years ago, but now got problems, its the transformer 350-350, etc..... But its the 6.3V with the Center Tap connected and its a dead short to ground, (both 6.3v wires) unground Center Tap, no short to both 6.3v wires. Many thanks Richard
@electrolytics9 ай бұрын
Rock and Roll D-Lab.
@bevinmodrak49979 ай бұрын
Awesome amp Terry.
@richardbrobeck23849 ай бұрын
Nice Job Terry !
@brentnearhood88749 ай бұрын
Thanks! Terry 🔉
@jimgiordano82189 ай бұрын
Another awesome project.
@juliochingaling58249 ай бұрын
Thank you Sir, great video and very helpful. Blessings.
@rockitlikeawolf9 ай бұрын
This is awesome, man.
@luizfernandolessa18899 ай бұрын
Beleza. Meu sonho é fazer um para contra-baixo. Saudações do Brasil 🇧🇷.
@huddyskiba19 ай бұрын
No Antek toroidal love?
@thylordsatan6669 ай бұрын
Midnight Rider Allman Brother's.
@thesjkexperience6 ай бұрын
I wind pickups. Transformers don't look that difficult to make. Like I need another rabbit hole lol!
@rb0326829 ай бұрын
Very cool!
@alfonsogomez47259 ай бұрын
Hola amigo, vi en otro video que enseñas a probar transformadores para single ended para determinar la corriente de trabajo bajo carga, mi pregunta es siempre se prueban con carga de 10k 10w? O depende de la valvula? Quiero probar un pentodo de salida en single ended EL34, muy buenos y educativos tus videos, saludos desde Chile.
@davidsimpson33807 ай бұрын
Very interesting! The Princeton reverb puts out 12 watts and it's original power transformer was only about 70mA ..... Will this alternative power push pull 6v6s with 4 12ax7s if you bump up the filament transformer to 2.2 amps? With the lower supply voltage(240 vs 320) and a SS rectifier will it make 10 watts?
@lego404049 ай бұрын
Thank you So much Terry for that information. I took a break from building for a little while and in that short time I can’t believe how much transformers went up. Our options in HIFI Outputs are nearly none. A pair of Edocrs I bought for under 30 a few years back are over 60 now. The last small wattage amp I built for my garage using 6DN7s(Mike Frieda’s schematic) I wound up using those PT-31’s. Inexpensive but sound great to my 55 year old ears. Any thoughts on output manufacturers out there for alternatives?
@d-labelectronics9 ай бұрын
I am using the P-T31 on this build also. Other than that one, I use the Hammonds or Classictone if I can find them
@jackstevens7489 ай бұрын
Hi terry from down under . I watch you KZfaq channel all the time and its a very cool channel . I have a Johnson Viking 2 with the 122 vfo. Would it be possible to give me some advise ? When I load up the JV2 with vfo on the 160,80,40 band switch I get harmonics on 20 meters and 10 All other band allocations are fine no harmonics for example if I load the JV2 up on 40meter on the 40,20,15,10 allocation no issue with harmonics at all, This is the same with the 40 and 80 fix crystals no harmonics In your experience have you seen this behavior before? . and if so would you give me a clue onto were to start looking in the vfo .? Thank you for your time. Below is a photo of my Johnson Viking 2 Andrew
@vfrfoxtrott64309 ай бұрын
👍👍
@andrefiset35699 ай бұрын
I met a guy who used 70v distribution transformers for output transformers, he put a capacitor somewhere if I remember well.
@d-labelectronics9 ай бұрын
Yes, I have tried them in the past. They seem to lack in response, but are useable
@andrefiset35699 ай бұрын
@@d-labelectronics Maybe a travel, step up step down transformer can work too for a H.V. power transformer.
@defh2o9 ай бұрын
Pacific Audio Magnetics - great units maybe2/3 the cost for a spec transformer. I used them in my first 5E3 build. Check them out!
@wklinger799 ай бұрын
What about a solution for modulation transformers? If I'm looking to build a mid-to-high power plate modulated transmitter, there's a definite shortage of modulation iron aside from cannibalizing a radio to get the iron out of it
@MrMarkar19599 ай бұрын
if i could build an amp,,i wouldnt have two crying for a doctor
@ljpotential2ba1st9 ай бұрын
I'm a 56yr young gentleman from Ohio & I have an old JVC receiver that pops the fuse just like the Realistic receiver you repaired 4yrs ago. I'd like to have it repaired 😢 would you please accept the task? I look forward to your reply🙏🏼
@patprop749 ай бұрын
You clearly demonstrated that it works which is fantastic, however, I am just wondering something, you said the 120v Red wires are the line, but looking at the Datasheet it clearly says that the black, yellow/black, Green/black/red/ and the black are the power in and the Reds and white are the outputs, do you forsee any long term use issues? are both sides the same wire gauges and or ohms turn ratio?
@d-labelectronics9 ай бұрын
Hello, In this application it works great, Thats why I made sure to test & show a demo. I have built these for years, Never a complaint or report of failure.
@patprop749 ай бұрын
@@d-labelectronics Sweet! Thank you Terry for this and everything else you do for the DIY Small Tube Amps community. We all appreciate you man. Thumbs up!
@broberts18714 ай бұрын
Both the PT and the filament transformer are connected to the incoming wall AC?
@Hipyon9 ай бұрын
What do you think of the AliExpress smp 250v 100mA 6.3v 3.5A at 26€ they also have higher voltages and Centre tap
@marsmediapro9 ай бұрын
What looper pedal are you using, Terry?
@AiMR9 ай бұрын
Great video! Hey, wouldn't it be just as easy and a lot cheaper to buy an old tube radio at a flea market and repurpose it?
@d-labelectronics9 ай бұрын
Yes, if the transformer lines up with the high voltage required. You can use the main power tranny in the Regency MR-10 receiver. It is around 400vac CT. Then use the cabinet for the retro look!
@alanpecherer57059 ай бұрын
It's all a question of volts and amps. So, assume you're looking at an old tube radio at the swap meet and wondering whether the trannies will work for you, and of course, all you can do is to make an educated guess. That is, if it HAS trannies...many AM radios do not, they fetch their B+ direct from the AC line. No goodsky. But you will find that it's often the case that an old radio will not make more then 200-225 volts. And yes, you can make a low-power 2-3 watt amp with that with a solid state bridge rectifier, but not even a genuine Fender Champ which wants 325 or so volts despite the low power rating. Probably the radio output transformer is a piddly little thing designed to drive a 4" cheesy speaker, or maybe it's even the field coil on the speaker! Yikes! Not that great. The snarls come in when you try to make a push-pull 10-20-50 watt amp. For that, you are gonna need 350+ or even 450 volts on your 6V6 or 6L6 plates and that you won't find that in a radio receiver. In an old TV set, yes, you definitely can. The truly useless (except for the cabinetry and/or chassis) flea market stuff is in old tube VIDEO equipment. Wideband amplifiers, distribution amplifiers. It usually looks pretty good and is generally well built, but remember, the old NTSC video signal was a 1-volt peak-to-peak affair and did not have to drive any appreciable current. So you take the trannies out of that gear and you will find that the power supply makes only 100 or so volts, the tubes run at 80-90 plate volts and the trannies are completely useless. That's because the thing only has to swing 1 volt on the output! Oh, and by the way, on that kind of old tube video gear, you may not even be able to physically fit a 6V6 or a 5Y3 inside the thing because it was built to be slim and trim and the cage for the chassis isn't tall enough to fit an octal tube! Ask me how I know!!
@soapboxearth29 ай бұрын
You probably already covered this, but is there a cheap ot out there that would be good for these amps ?
@PaulinTaegu9 ай бұрын
These are harder to come by. You must know what you want specifically and look for something near that as surplus. I found a deal on these rather small transformers, about 1/2 the size of a Hammond 125 and I got like 20 of them for around $3 a piece including shipping! They work fantastic for little 6AQ5/6V6/EL84/EL86 PP Output transformers. Around 10W Output is the max you can run on 1 of these. I've still got a number of them lying around in my shop waiting for me to start tinkering around again.
@soapboxearth29 ай бұрын
@@PaulinTaegu what a great find that would be. I'd love to find some at that price.
@Barracuda480828 ай бұрын
Sweet work you do. What wattage would say this kit is..10, 15 ? 73, Kb8qlz
@jamesberlo42986 ай бұрын
Why the 3 Transformers?
@d-labelectronics6 ай бұрын
That is this design rather than using expensive production transformers
@waynegram89079 ай бұрын
D labs the Hammond 269EX Transformer specs says the secondary max voltage can be 380VAC but the max secondary current is 0.71mA?
@Joetechlincolns9 ай бұрын
71mA not .71mA. Straight from Hammond site.
@waynegram89079 ай бұрын
@@Joetechlincolns 71mA can't supply enough current for Preamp tubes and Power Tubes
@d-labelectronics9 ай бұрын
Its more than enough. The amp featured runs around 35ma on the 6V6, Preamp tubes draw maybe 1ma each
@gingercat7779 ай бұрын
But but...if I use anything else but Mercury trans my tone will suffer 😅