Wednesday, February 4, 2009

Mo' Fun With Mods

Here's another example of me finally getting around to doing something that Stephen S suggested that I might find useful at some point. He brought it up again recently, so I decided that I would revisit the sites where the modification was best explained. I've had both of these bookmarked for years. One of the sites has some of the best Kalamazoo amplifier information on the 'net provide by Miles O'Neal and the other was shared with harp players by Don DeStefano, who was THE go-to guy for amp mods for harp guys back when I burned my first resistor. Stephen referred me to him more that once.

The mod is simply constructing a type of "line-out jack" for my smaller Kalamazoo so I can make it bigger by going into a p.a. system or even a larger amp. Nothing new here with this slave/master amp scenario and some smaller amps come complete with a line-out feature. I'm not going to go into a lot of detail here, because it is explained better by Don or Miles. Keep in mind that both make it plain that this is not a pre-amp line-out modification, but simply a matter of taking the signal off the Kalamazoo speaker, padding it with resistors and sending it into whatever larger sound source deemed necessary.

I'll be honest here and say up front that I really didn't understand what the heck they were talking about back in the day and really didn't understand schematics and it was a bit of Greek to me. It's dirt simple, though, and those of you that know of such things, well, you know that already. Both links describe a method of constructing a non-invasive outboard box that can then be hooked up to the speakers and both mention that it can be a more permanent mod by mounting the jack in the amp. I chose the cheapest method of sticking it all into a plastic film canister (mentioned on Miles' pages) with alligator clips on the wires protruding from the can. I chose Don's resistor values of 2.2k/100ohm, which he's says should be used with the Kalamazoo's 8ohm speaker output. Miles mentioned that he went with 4.7k/470ohm after finding some Gibson amps from the same era having those values. I think Gerald Weber is given credit for the former values. I may make another can with Miles' numbers and see it sounds.

My taste tests involved using the Ol' Smoky 3725 Bell and the Silvertone 1483 as the Mother or slave amps and I ran both into my DIY Python 4x10 Cab (with 2 Weber Vintage alnicos and 2 Weber Signature ceramics-discussed previously). The Bell seemed to have issues with a bit of hum and some static (the hum was ground loop, which was solved with a suggestion from Stephen to use a two prong AC adaptor on one amp--the static I'll deal with later), but it boomed the Kalamazoo through the Python quite substantially with really great tones. After unhooking the two from each other and blowing just through the Bell, it is plain that I need to open her up and see if dirty pots, crappy resistor soldering or what needs to be addressed.

Since most folks feed the overdriven tone of the small amp into a bigger wattage clean amp (which I don't own), I did choose to plug the Kalamazoo into the cleaner channel of the 1483. Voila! The Kalamazoo One on steroids. Big ol' dirty, fat sound getting down. So, it works as promised. Now, I doubt that I would ever take the Kalamazoo and the 1483 out at the same time because the 1483 can do that stuff on its own when plugged into my grid leak input with my crystal mic. I might consider the Ol' Smoky, which actually sounds much better in tandem with the 'Zoo. When the need arises to travel light, then I'll have a better option that just plugging my mic through a p.a. or playing through a vocal mic and the same and without having to mic the amp. I can think of a few times that I could have used this method. This is what Stephen's recent reminder was all about. Anyway--Got to go dive into the Ol' Smoky.

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