Another bit of advice to avoid melting banana plugs when soldering the OT wires to them. Solder the Out trans wires to open hole tab lugs and mount that lug through the hole to the banana plug end,... I think that is why they include two brass hex nuts on that banana plug. Old bake light plugs could stand the heat of soldering but they don't make banana plugs that way anymore.
Hi, Thanks for the great video series on the MKIII build. What gauge wire did you use for your connection runs? What gauge wire comes off the transformers? Cheers.
Your new in box stripper may not be totally dead. If you open the case, I think you'll find a big D size ni-cad battery. Ni-cad provides large current but is hard to find a replacement for. Nice job on these amps.
I was thinking the same. Most of the old transformers have a few layers of fish paper under the bells, that may easily be removed, and then there is a heavier piece of fiber board with some lugs crimped to that, and the enameled coil wire from the transformer windings come out to those lug terminals and the outgoing cloth or plastic insulated wires are soldered to those lugs as well. So without compromising the transformer at all, You can, with a little care attach new out going wires if the insulation is frayed or cracked. Do be careful to put some kind of insulating hi temp plastic or paper insulation back over the terminal strip You don't want a bare wire touching the end bell metal surface and short to ground, unless the end bell is well insulated on its inside surface, and the primary wires can instantaneously have more than the supply voltage on them. Many of the newer transformers are not so nicely put together as the old ones, though often times guitar amp trannys have thermal fuses buried under layers of tape, and open up but the transformer is still perfectly good, once You remove the dead fuse.
A great video series ! ! ! A word of CAUTION though !!! on teflon insulated wire. I would say never use it. Luckily I was warned by a top tech who had been poisoned by breathing the fumes and had persistent health problems, back about 50 years ago. Fluorinated hydrocarbons in general have been linked to serious forms of cancer. I always use computer grade oxygen free multi-stranded wire. It is easy to work with and very high quality. Another caution on painting transformer laminations,... also not a good idea as the accelerants for drying them may contain nitrates, and cause the laminations to conduct between, and eddy currents can cause the transformers to over heat. This is particularly true of clear nitrated lacquer. High temperature black may be better, but the pigment in black is usually either carbon or black iron oxide. So better just to brush them off, and turn which ever face You are brushing toward the floor, as metallic dust getting between laminations or eventually finding its way into speaker voice coil gaps is also bad. Slightly rusty plates do no harm at all. If you want them to stay shiney, I would suggest old fashioned purely oil based varnish, with no drying agents. Not polyurethane either, as various forms of mold and mildew seem to love it, if the transformer ever gets damp, for a couple days. Love the video series, and great general guidance and advice, on this great classic Amp ! I didn't realize these Old Classics are so well supported by various kit and part suppliers. Thanks for all the valuable information ! ! !
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Another bit of advice to avoid melting banana plugs when soldering the OT wires to them. Solder the Out trans wires to open hole tab lugs and mount that lug through the hole to the banana plug end,... I think that is why they include two brass hex nuts on that banana plug. Old bake light plugs could stand the heat of soldering but they don't make banana plugs that way anymore.
Always happy to watch very informative videos to learn from. Thanks again. :0)
Hi,
Thanks for the great video series on the MKIII build. What gauge wire did you use for your connection runs? What gauge wire comes off the transformers? Cheers.
You can use standoffs to extend the bolts. You don't need to change the bolts.
Thanks for the solder walk through! There are some solder videos but not the advanced technique stuff.
Your new in box stripper may not be totally dead. If you open the case, I think you'll find a big D size ni-cad battery. Ni-cad provides large current but is hard to find a replacement for. Nice job on these amps.
Couldn't you replace and splice the wires under the bells to keep it cleaner in the amp?
I was thinking the same. Most of the old transformers have a few layers of fish paper under the bells, that may easily be removed, and then there is a heavier piece of fiber board with some lugs crimped to that, and the enameled coil wire from the transformer windings come out to those lug terminals and the outgoing cloth or plastic insulated wires are soldered to those lugs as well.
So without compromising the transformer at all, You can, with a little care attach new out going wires if the insulation is frayed or cracked. Do be careful to put some kind of insulating hi temp plastic or paper insulation back over the terminal strip You don't want a bare wire touching the end bell metal surface and short to ground, unless the end bell is well insulated on its inside surface, and the primary wires can instantaneously have more than the supply voltage on them.
Many of the newer transformers are not so nicely put together as the old ones, though often times guitar amp trannys have thermal fuses buried under layers of tape, and open up but the transformer is still perfectly good, once You remove the dead fuse.
It would have been a good idea to have some sort of grommets on the chassis holes where the transformer leads pass through.
Whats the song you use in your introduction?
A great video series ! ! ! A word of CAUTION though !!! on teflon insulated wire. I would say never use it. Luckily I was warned by a top tech who had been poisoned by breathing the fumes and had persistent health problems, back about 50 years ago. Fluorinated hydrocarbons in general have been linked to serious forms of cancer. I always use computer grade oxygen free multi-stranded wire. It is easy to work with and very high quality.
Another caution on painting transformer laminations,... also not a good idea as the accelerants for drying them may contain nitrates, and cause the laminations to conduct between, and eddy currents can cause the transformers to over heat. This is particularly true of clear nitrated lacquer. High temperature black may be better, but the pigment in black is usually either carbon or black iron oxide. So better just to brush them off, and turn which ever face You are brushing toward the floor, as metallic dust getting between laminations or eventually finding its way into speaker voice coil gaps is also bad. Slightly rusty plates do no harm at all. If you want them to stay shiney, I would suggest old fashioned purely oil based varnish, with no drying agents. Not polyurethane either, as various forms of mold and mildew seem to love it, if the transformer ever gets damp, for a couple days.
Love the video series, and great general guidance and advice, on this great classic Amp ! I didn't realize these Old Classics are so well supported by various kit and part suppliers. Thanks for all the valuable information ! ! !
I guess the client choose not to have the old capacitors in place... such a pity... I would have had them shained and baffle to mirror finish...
1/2 aluminum srand offs.
Enjoyed this series immensely. One point though. PLEASE, there is no such word as “eXcetera”. It is eTcetera. Otherwise keep up the good work!
Yeah , that "word" kept on cropping up. I guess I'm another word grump !
please help I want to buy a radio, but I do not know models
But I have a picture of him and unclear
please help