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onboard midboost for strat

3/14/1997 12:47 PM
chris stone
onboard midboost for strat
I am intereted in putting an active mid boost (similar to the one in the eric clapton sig.strat) in my strat. Does anybody have the schematics for this or a similar beast? Any replies would be greatly appreciated!
3/16/1997 5:30 PM
Mark Hammer

As usual, Craig Anderton has a schematic for just  
such a device in his most recent book of projects  
for guitarists. It offers some gain, output  
buffering (so you can keep those slinky highs  
from switch position 2 & 4), fairly low battery  
drain, operation off one 9v battery, and a choice  
of mid-boost points. PAIA sells the very same  
circuit as a floor stomp-box, with 6 selectable  
boost points. They call it the "Mid-ranger",  
and sell it for around $40 the last time I looked.  
The schematic originally appeared in Guitar  
Player, some time in the early to mid-80's (1983?).  
I've got one and it works fine. Low noise.  
Good sound. Engaged by a SPST switch, which  
means you can use a 10k pot w/switch to boost the  
mids, and bypass the effect when switched. In the  
off-position, the effect still provides buffering  
and draws battery current.
4/24/1997 9:47 PM
You CANNOT play a strat without a John McIntyre Musitech MidBooster! One tone control becomes variable gain (15db); other tone is low-mid-boost to high-mid-boost. Various versions are available, inc. low noise version for transmitter use and bass version. I picked up one in a bargain bin for $25! Retail about $100. Runs off one 9v - push-pull switches back to passive operation when the battery fails (after about 18 months of being on 24hrs/day!!!)  
Try Musitech in Calgary, AB Canada.
6/1/1997 12:44 AM
Eric C.

do you use the mid/booster with american standart pickup or Lace?  
I think try to put Musitech with gold lace.  
Eric C.
5/20/1997 12:34 PM
Scott Davey

Dan Torres, the amp repair / mod guy in San Mateo, CA sells a mid kit much cheaper than the other options mentioned here. Many bad reports on his amp service, but I heard the installed mid mod, and it really sounds good. One direction on the pot cuts the mids, giving a sort of "glassy" tone, sorta surfish, and the other boosts the mids. Sounded good to me. It's not active electronics, though.
9/12/1997 4:37 AM
Steve Ahola

I've been using Dan Torres midrange kits for a few years and put them on practically all of my guitars. Last September I decided to resurrect a 1965 Pro Reverb I had butchered up in the early 80's with countless magazine projects by getting the stuffed circuit board for his Super Texan kit. I knew zilch about tube amp theory so I bought his tube amp book as well along with some of the other add-ons.  
To make a long story short, the stuffed circuit had a few mistakes on it, with one lead missing and a few caps having the wrong value. I'm not complaining, because in dealing with those problems I learned a lot about tube amps. As an added bonus, a few of those "mistakes" led to mods I added which actually improved the amp design. (In one part of the circuit, they put in an 0.47uf electrolytic cap instead of a 4.7uf cap, which resulted in a thinner sound like vintage Roy Buchanan. I liked that unplanned sound so much that I added a mini-toggle switch so that I can choose between either value!)  
Judging from your remarks about his amp service, maybe I wasn't the only one to get a board that was assembled wrong. Another observation- his amps seem to be a bit on the bright side, with not a lot of bass. Maybe he has hearing loss from playing next to loud amps on stage, and he makes his amps a bit too bright because that's what sounds best to him.  
Getting back to his midrange kits, what you describe is his Super Midrange control which works great with single coil pickups. He also makes a regular Midrange control which just cuts the mids and I like to use that with humbuckers (since they usually have plenty of midrange to begin with). Some complaints I've heard about his Super Midrange control are that there is no center detent position (like a TBX), there is no setting which effectively disables it and that there is a noticeable signal loss in any of the settings.  
To get around all of that, I'll rebuild his control on a push-pull pot with the down position being his regular mid-cut midrange control and the up position being the Super midrange control. In the down position with the knob set to 10 the control is effectively taken out of the circuit. If I wish to clean up the sound by removing some of the mids, I can turn down the control. If I want to dirty up the sound a bit and remove some of the highs, I'll pull out the knob and set it between maybe 7 and 10.  
With those mods, I consider it to be the ultimate mid control. However, if you don't want to go to all of that trouble, just stick the Super Midrange control in your guitar and replace your volume control with a push-pull pot (or mini-toggle switch) that can bypass the midrange control for stock sounds.  
As for active controls, I feel that they can interfere with the almost magical interaction between a good pickup and the tube input stage in your amp. (My idea of the "Perfect Guitar Sound" is Albert King and SRV's version of that sound...)
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