Realistic AF-15

[John_H]

I've been wanting to build a little 1X12 guitar combo. My search for a donor amp ended with this. circa '60 or so. MIJ
tube compliment; (1)EZ81, (1)12AU7, (2)12AX7, (2)EL84.

Even though the USPS aparently dribbled it across North America it arrived in running condition. This gives proof that you can throw this old gear across the street, or a continent without killing it. It's not without problems, so rather than repairing it I'm thinking about reincarnating it as the illegitimate oriental child of a Marshall 18.

For anyone that has built/modded a Marshall 18 your input would be great. TIA

[John_H]

Most of my parts arrived, so I was able to get busy on this thing over the weekend. After gutting all of the switches, and related circuitry that are at home in a hi-fi, but don't belong in a guitar amp I replaced a large fistful of various capacitors. (I'm still waiting on a couple)

When I first powered it up it sounded allright. There was a slight hum, but otherwise it seemed fine. After running for just a couple minutes it made some noise then went dead silent. Fearing that what I heard was the last dying gasp of the output transformer I quickly checked some voltages. Everything looked good. It was at this time I resorted to my diagnostic secret weapon. The Sacred Chopstick came to the rescue once again. After poking around for a minute or so I located the culprit resistor.

This thing sounds pretty good. I ran it on the bench for a few hours, and then swapped tubes. This definatly made the amp happy. The next hour or so was spent with it turned up loud annoying the neighbors.(priceless)

I bought two different vintage alnico 12's on ebay. Neither has arrived yet. I need to decide on a speaker before I experiment anymore with the tone. I think I'm going to like this amp.

[stokes]

These are great experimental platforms,cheap but usually have decent iron,not like you have to worry about ruining something.Sounds like you have things well in hand with this project,if this is your first build you will have a great time tweaking it.Enjoy.

[John_H]

These are great experimental platforms,cheap but usually have decent iron,not like you have to worry about ruining something.Sounds like you have things well in hand with this project,if this is your first build you will have a great time tweaking it.Enjoy.

My amplifier skills are pretty limited, but I have fun fumbling my way through things. Keeping it cheap is what it's all about. If it was an expensive hobby for me I probably wouldn't enjoy it nearly as much. I bought this one for twenty bucks+freight.

The speakers that I bought arrived. The one that I'm going to use is a Magnavox. I like the sound of it. Even with a 6db L-pad which throttles it down to around 3.5w it blows me out of the room. I can't wait to hear it in a cabinet. The amp is pretty much done. I'll tweak on it more probably after I build the box for it.