Tube Tape Xfmr Amp Conversions Akai, Magnecord, Ampex, Bogen

[xfmr]

I have begun a new blog that will have extensive details of my tube amp conversions for my new internet radio station at xfmr.org (so new there is nothing there yet!). These preamps, amps, mixers and fx units are mostly made from vintage tape machine amps that have lost their transports. I tear them down to bare parts, redesign, and reassemble using new wiring and other new parts where needed. Consider it creative recycling of a sort. Also, while tube devices are the easiest to convert and will take up the bulk of discussion, there will also be some solid state stuff from the likes of Yamaha, Grommes, and Shure. Come on by and see what I've got started. As folks interact and ask questions I will add details to the projects while they progress. Eventually I will do some recordings with all this stuff and that is where the radio station comes in, to broadcast the fruits of this rig. Here is the link.
http://xfmr.blogspot.com/

[xfmr]

Lots of new stuff is being added all the time. I finally got a scanner and am getting some hand drawn schematics up. First two are my original tube preamp and low watt instrument amp designs. My 8 watt Plexi should be up soon. Please feel free to leave comments.

[Snarl 12/8]

A looooong time ago you said you'd post some schematics/tips/howtos on how to modify the HeathKit Signal Tracer into a better guitar amp. Not that you owe me jack shit, but I wanted to let you know I could really still use that knowledge. My signal tracer died a while back, but I don't really have a clue about how to dive in there and fix things. Do you (or anyone else, for that matter) have any clue how to replace those multicaps? (That's what I call those capacitor cans that have more than one capacitor in them, not sure if that's the technical term for them though.)

Edit: I gotta say, btw, that the stuff on your site looks really thoughtful and beautiful. Thanks for sharing.
_________________
Carl Keil

[xfmr]

I did do a few signal tracers a few years back. Is it the Heathkit IT-12 that you are talking about? I may have a hand drawn schematic somewhere I can scan. From what I remember it was basically the same preamp and driver as the Jekyll & Hyde amp I posted the schematic to on my blog today. The power section used the stock power tube just as it came. I rewired the heaters and replaced all the caps as well as added a headphone, line out jack. NOthing earth-moving as far as mods go.

[kslight]

Looks cool, I've been following your stuff for a long time. Never made an RCA patch bay SK 1, but I have made some pretty crazy stuff out of them. One of mine is all body contacts...(there are dozens!).

One question...why did you create a new user id on TOMB instead of renaming your old one?

[xfmr]

[Snarl 12/8]

[xfmr]

[xfmr]

Here it is, as promised... just years later. Today's xfmr blog is about the Heathkit IT-12, as best as I can remember it. If anyone wants to donate one of these to me so I can verify the mods in action that would be super. http://xfmr.blogspot.com/2012/06/signal-tracers-as-recording-amps.html

[Snarl 12/8]

You rock.
_________________
Carl Keil

[xfmr]

[xfmr]

I have some sound samples of the Pre+Amp up now for those interested. Same preamp circuit as the 2xPre as well. LOTS more samples to come! GO here: http://xfmr.blogspot.com/2012/07/preamp-sound-samples-1.html

[xfmr]

Stuff has slowed down at the blog for now, but that is because I am working on art and samples for the forthcoming xfmr site. In the mean time feel free to stop by and leave some comments on the projects. The posts that get the most interest from the public will be the ones I am most likely to update with new info, so vote with your comments!

[xfmr]

The new page on the bog has a time lapse teardown,desolder, and cleanup videos of one of the Akai, Roberts Monoblock amps:
http://xfmr.blogspot.com/2012/07/time-lapse-footage-of-akai-roberts-tube.html