They should come with a data sheet - if not it can be downloaded. I don't have mine handy at the moment.
The primary is normal - two wires, one for plate, one for B+.
The secondary has five or six leads, one is the common. Select the other lead for the desired combination of plate load and speaker impedance according to the data sheet.
I do not use new manufacture power transformers, so I can't help you there.
Win W5JAG
When I first built my TSE, I ran 45's and used the 158M as the L in an LC power supply configuration. It worked satisfactorily in this configuration for both 45 and 2A3W (5930). It will have more inductance at less than it's rated current, and slightly less at more than it's rated current. Seems like I've run mine up to 130ma or so in my SSE.
I am neither a Hammond fan nor hater. One of the more useful things about Hammond chokes and transformers is that they publish the dimensions for their chokes and transformers and there are always several current/inductance/voltage combinations within a given dimensional specification, making it easy to swap parts without drilling new holes. Sometimes two parts can share the same set of chassis holes - one part above the chassis, one part below.
Things like this may or may not be important to you.
Win W5JAG
Thanks for the reply fellas. Upgrade's down the road for sure. I'm patient but not 6 weeks worth so I will go with Hammond iron to get this going. I found more testing procedure hook ups under the setting bias area or Tube Lab's web site.
Close up. Kind of relaxing. This is my 4th electrical component build and I'm finally learning to take my time. The testing part scares me a bit.
Close up. Kind of relaxing. This is my 4th electrical component build and I'm finally learning to take my time. The testing part scares me a bit.
An externally hosted image should be here but it was not working when we last tested it.
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Another option if you want off the shelf:
https://www.tubesandmore.com/products/transformer-one-electron-output-4800-1684
4.8k Ohm primary impedance, 4/8/16 Ohm secondaries
https://www.tubesandmore.com/products/transformer-one-electron-output-4800-1684
4.8k Ohm primary impedance, 4/8/16 Ohm secondaries
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According to tracking my tube sockets are at the post office. Headed to town. Should be able to just about finish loading the pcb.
Couple more pics. And as I site here listening to my 2a3 amp I'm wondering if I might want to make this a Universal unit instead of a pure 45. Anyway.
Couple more pics. And as I site here listening to my 2a3 amp I'm wondering if I might want to make this a Universal unit instead of a pure 45. Anyway.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
You're most welcome.
Heat sink ideas for Q1, Q2 and U2, U3:
http://www.mouser.com/ds/2/303/sink_csm-959214.pdf
Hmm... options, options...
The 2A3 will require 3-3.5k primaries, while the 45 recommended is 5k. So you will need an OPT with dual primaries. Among off the shelf choices the James 6113HS comes to mind.
2A3's work fine at 5K. You might lose a little power, not enough to worry about, imo. IIRC, when I was playing with the 5930's on the SSE board, I was seeing at least 3 watts with a 5K Transcendar as the OPT. That's about all a 2A3 is ever going to do unless they can be driven into A2, which I do not know.
If you are using one of the Hammond 125 series OPT's, use 2.5K or 5K for 2A3, and 5K for 45. It's as easy as moving one lead.
Win W5JAG
from that other thread re: 5930 (2A3W) : " I didn't take any notes so this is from memory:
With a 5K Transcendar as the OPT, 12BH7, 1 Khz sine wave tone, and an 8 ohm resistive load, I saw 3.25 watts at the first indication of sine wave distortion. "
If you are using one of the Hammond 125 series OPT's, use 2.5K or 5K for 2A3, and 5K for 45. It's as easy as moving one lead.
Win W5JAG
from that other thread re: 5930 (2A3W) : " I didn't take any notes so this is from memory:
With a 5K Transcendar as the OPT, 12BH7, 1 Khz sine wave tone, and an 8 ohm resistive load, I saw 3.25 watts at the first indication of sine wave distortion. "
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These will work fine.
The 270FX will put the B+ in the 320 to 330 volt range which is slightly over the max spec for a 45, but I have seen no issues at this voltage and still have the same pair of tubes in my amp that I pulled out of a dead radio about 12 years ago.....with 1929 dates on the "tested" stickers.
45's want about 30 mA each + 10 each for the drivers, and maybe 10 more for the mosfets. A 100 mA choke is OK here, and the extra resistance will help keep the B+ down. I'm using a choke that I took out of a dead HP audio oscillator. I'm guessing it's good for maybe 100 mA. It works fine and doesn't get warm. There is zero hum on 106 db speakers, with powered subwoofers.
I tested my initial build with several different OPT's including the Hammond 125CSE, the Edcor XSE15-5K and several more expensive OPT's. I preferred the Edcors over the Hammonds, but the difference was slight.
If I did it over today I would choose the Edcors because of the price difference. I went with Electra Print's in my initial TSE build after hearing a pair that a friend bought.
The Edcors wound up in a SSE that runs 6V6GT's in triode and sounds almost as good as the 45 based TSE, for less than half the money. Both amps used the Allied electronics 6K56VG power transformer, which is a smaller version of the Hammond 270FX. It is made by Hammond.
The 2A3 has a hungry filament. It wants at least 2.5 amps per tube, and some of the new production tubes want more. This requires a power transformer with a 6 amp 6.3 volt winding, not common. I resorted to a second transformer for the filament. The 2A3 also wants a 2.5 to 3K load impedance, and 50 mA or more of plate current. It is possible with the transformers you have except for the filament current.
Can I mount these like this. Can these be oriented wrong. Just a mock up and I need fasteners and some mylar.
An externally hosted image should be here but it was not working when we last tested it.
My choke selection changed to the Triad cx14. Orders in for the rest of the pieces. Top plate design next.
I have 4 of these heatsinks I might try and use.
I have 4 of these heatsinks I might try and use.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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