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DIY Stompboxes => Building your own stompbox => Topic started by: nero1985 on August 13, 2004, 11:10:13 PM

Title: onboard preamps!
Post by: nero1985 on August 13, 2004, 11:10:13 PM
does anybody know anything about onboard preamps for guitar that can give me boost or cut of MIDS????
Title: onboard preamps!
Post by: Alpha579 on August 13, 2004, 11:39:17 PM
for mid boost, you could try the Eric Clapton mid boost preamp...
Title: .
Post by: petemoore on August 14, 2004, 02:11:41 AM
Small EQ and distortion changes in early stages can have large influences on later stages.
 Tune the Booster to the Chain, this includes Guitar, effects, amp.
 Depending on the circuit and the transistor used, many different boost tones are available
 I use:
 Fetzer Valve  Jfet
 Stratoblaster  Jfet
 Mini-booster  Jfet
 Mosfet Boost  
 Dual Clean Mosfet Booster
 Rangemaster Ge PNP
 Vox reble Booster Ge PNP
 Brian May Treble Booster Si NPN
 Micro Amp JRC 4558
 ???????????? All have at least one sockketed cap and transistor.
 J201 Smooth can be clean-ish / high end sparkle
 Mosfet Big CLean Loud
 Ge transistors impart tonal characteristics including EQ and Distortion, probly a bit 'bias finicky' for onboard guitar use  
 ...Current consumption?...
 ...Bypass?..
 For mids cut: Notch Filter or Tone Control...[   ]
 For mids boost: Smaller input cap or cap in signal path cuts bass [LP filter], cap from signal path to ground [HP filter], cuts highs..tune for desired midrange boost response
Title: Re: .
Post by: onboard on August 14, 2004, 04:22:26 PM
Quote from: petemooreSmaller input cap or cap in signal path cuts bass [LP filter], cap from signal path to ground [HP filter], cuts highs

Wouldn't the filter flavors be named the other way 'round?
Cap in signal path cuts bass (HP filter)
Cap to ground cuts highs (LP filter)

Maybe I'm all mixed up.....just trying to understand high and low pass....

High pass cuts lows, low pass cuts highs, right?
Title: .
Post by: petemoore on August 14, 2004, 05:02:32 PM
Nope you got it right...typo sorry
 anyway ''socket' when in doubt... :oops:  8)   Dohh...lotta help I am sometimes...
Title: onboard preamps!
Post by: onboard on August 15, 2004, 12:32:28 AM
I'm curious what this                                                                               Musitech (http://www.stewmac.com/shop/Electronics,_pickups/Preamps:_For_magnetic_pickups/Musitech_Preamps.html) preamp circuit is...gotta love that shrink wrap job. :wink: For $80 I won't be buying one to trace anytime soon, though it's gotta be a good circuit for StewMac to carry it.