Korg - TBN-1 Tonebooster [schematic]
- gigelmargel
- Resistor Ronker
Hello all,
I have an old Yamaha Tone Booster TB-1 and it sounds pretty good.
The main problem is the very low efficiency of the tone pots: the bass pot has almost no effect, while the treble pot has a little more one.
The schematic is here: Anyone has some mods for it?
Thank you very much!
I have an old Yamaha Tone Booster TB-1 and it sounds pretty good.
The main problem is the very low efficiency of the tone pots: the bass pot has almost no effect, while the treble pot has a little more one.
The schematic is here: Anyone has some mods for it?
Thank you very much!
- Attachments
-
- korg tone booster tnb-10.pdf
- Korg Tone Booster TNB-1
- (527.74 KiB) Downloaded 127 times
- gigelmargel
- Resistor Ronker
No ideea?
- dai h.
- Solder Soldier
(I'm assuming this something a couple of decades old) have you tried fresh aluminum electrolytics? They can age and lower in value which would lessen bass(my understanding is this is to do with evaporation of the liquid inside--not sure if wholly or partly due to). Specifically the power supply ones (100uF,10uF), the gain cap(1uF), output coupling (10uF).
- gigelmargel
- Resistor Ronker
Thx dai! I will try to change all the caps, but other people seems to have the same problem.dai h. wrote:(I'm assuming this something a couple of decades old) have you tried fresh aluminum electrolytics? They can age and lower in value which would lessen bass(my understanding is this is to do with evaporation of the liquid inside--not sure if wholly or partly due to). Specifically the power supply ones (100uF,10uF), the gain cap(1uF), output coupling (10uF).
- dai h.
- Solder Soldier
well if you need more sophisticated suggestions (unfortunately) I'm not knowledgable enough to give you much more than my suggestion to change to new caps, but FWIW in this demo of the Korg version of the same pedal:
I am hearing (through my so-so PC speakers) an increase and decrease in bass. Have you tried new caps yet?
From what I see, the tone control section looks very much like that found in many guitar amps (which AFAIK only reduce from a maximum point of least loss--if that makes sense), and the op amp after gives a bit of gain (about a 5:1 ratio of the feedback resistors). Perhaps a tone circuit that adds gain is more suitable? Maybe an EQ pedal (to give more control instead of what sounds like a general bass boost)?
I am hearing (through my so-so PC speakers) an increase and decrease in bass. Have you tried new caps yet?
From what I see, the tone control section looks very much like that found in many guitar amps (which AFAIK only reduce from a maximum point of least loss--if that makes sense), and the op amp after gives a bit of gain (about a 5:1 ratio of the feedback resistors). Perhaps a tone circuit that adds gain is more suitable? Maybe an EQ pedal (to give more control instead of what sounds like a general bass boost)?
- modman
- a d m i n
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Service manual
- Attachments
-
- korg tone booster tnb-10.pdf
- Korg Tone Booster TNB-10 service manual
- (527.74 KiB) Downloaded 177 times
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