November 10, 2010 at 8:34 am #5169AndyKeymaster
Have built 3 now. Love them,November 17, 2010 at 12:39 pm #5203M FowlerParticipant
I actually haven’t build one yet but have built a lot of other amps. Perhaps this is one I could build for one of my kids.
MarkDecember 3, 2010 at 2:11 am #5214clevedaleParticipant
I have Hunters book and the updated notes as well. Has anyone got the latest layout and or BOM for the amp? Drill plan for a Hammond Enclosure? Should I just use Webers Maggie Layout and Schematic? I only want the ability to use one power tube instead of the two.
Thanks in advanceDecember 3, 2010 at 2:26 am #5215AndyKeymaster
I would use the Maggie stuff, its pretty accurate to the Two Stroke. The only difference is outlined in another topic here. The Negative Feedback Loop (NFB) is wired a bit differently on the Maggie. I haven’t tried it in Weber’s arrangement, but the Hunter arrangement works well.
They have the chassis drawings too if you are looking to punch your own:
http://www.webervst.com/chassis/December 3, 2010 at 2:37 am #5216clevedaleParticipant
I may be blind,lol but I don’t see the Maggie Chassis?
I am thinking the 5F2?
Are these the right Magnetic transformers for the two stroke?
Fender Single Ended Champ Style Upgrade 15W Output Transformer 4/8/16 Ohm
Fender Champ, Princeton, Bronco Style 5W / 15W Power Transformer 120/240V
ThanksDecember 3, 2010 at 3:30 am #5217RobinParticipant
The 5F2 chassis works great. It requires very little in the way of modification to work with the 2Stroke design (with the Hammond or Weber transformers at least). The Magnetic Components PT (40-18027) looks like it would work, there is only 2A available for the rectifier and heater circuits, 3.5-4A would be more versatile if you decide to add something later. The MC OT specs primary taps at 5k & 8k, the original 2Stroke spec calls for 2-2.5k so you might want to consider that. I did not check around the MC website for other possible single ended OT’s. Triode Electronics is helpful about what Magnetic Components products are available. Their phone: 773-427-8823December 3, 2010 at 4:53 am #5218soundguyParticipant
I used the Weber WSE15 OT, which was in Dave’s build notes. It has a primary impedance of 5k so I think the Magnetics Components spec should be OK in that regard. I’ll have to consult my Hunter book, but the lower impedance specs may have been his original design that used two output tubes. However, as Robin pointed out, the amperage available for the heater and rectifier is less than the WSE15, which is spec’d at 4A. I don’t know if that would be a problem or not. That rises above my knowledge level. Anyone have an idea about that?
The multiple output impedance are important if you’re going to swap between different output tubes, as there will be primary OT impedance mismatches, depending on which tube type you’re using. Changing the secondary OT impedance helps to fool the transformer for load matching.
Also, I used the Weber 5F2 chassis for my build.
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