Mods for Ibanez TS7??

[siaoguitar]

Hi, got a TS7 tube screamer recently, but find that it is rather warm, got to turn the tone all the way up to get a clear tone, do we have any mods for this ? To make it clearer and yet not too bassy?

I will start by putting an IC socket on the board and play around with different OpAmp.......

[moro]

Hi, got a TS7 tube screamer recently, but find that it is rather warm, got to turn the tone all the way up to get a clear tone, do we have any mods for this ? To make it clearer and yet not too bassy?

I think that's the first time I've heard the Tube Screamer described as having too *much* bass.

Assuming the guts are the same as the TS-9 / 808, maybe you could play around with the 0.047uF cap? Reduce it to 0.022uF?

[wampcat1]

Hi, got a TS7 tube screamer recently, but find that it is rather warm, got to turn the tone all the way up to get a clear tone, do we have any mods for this ? To make it clearer and yet not too bassy?

I will start by putting an IC socket on the board and play around with different OpAmp.......

http://www.indyguitarist.com/schematics/ibanez/TS7-01.pdf

R30, c31. change these values. current rolloff is about 723hz. Try changing c31 to a .15uf or a .1uf.

bw

[siaoguitar]

Hi, got a TS7 tube screamer recently, but find that it is rather warm, got to turn the tone all the way up to get a clear tone, do we have any mods for this ? To make it clearer and yet not too bassy?

I will start by putting an IC socket on the board and play around with different OpAmp.......

http://www.indyguitarist.com/schematics/ibanez/TS7-01.pdf

R30, c31. change these values. current rolloff is about 723hz. Try changing c31 to a .15uf or a .1uf.

bw

Hi, thanks, appreciate it, will try it out.

[mjones99]

TS-7 Tone Lok Mods

There are several interesting things about the TS7.  First of all the circuit is nearly identical to the TS9.  Why do I say nearly?  The circuit has a  Hot mode and the parts are 1/8 watt in general instead of the 1/4 watt used in the TS9.  There should be little argument that the wattage of the resistor affects tone.  The Hot mode switched can be set to the TS9 mode and *puff* you have a TS9.  At about 1/2 the cost!  Here are some other interesting things.  The new TS7 comes with the re-issue JRC4558D chip.  So if someone is charging you to install a JRC4558D chip in the pedal BEWARE!!!!  Now this JRC4558D chip is not the good old one.  It is a new chip relabeled to meet the demand for a JRC chip on the market.  I still recommend the Texas Instruments chip.  It is sweeter sounding and all of my customers like it.  I have had some that had a TS9 modded by me with a JRC chip and then sent it back to get a TI chip when they got their second T.I.808 mod pedal from me.  They were obviously pleased with the TI tone!  So am I!!!

So here's what to do to make a TS7 a real  --|:|-- Screamer!!!

Change R85 to a value between 2.2kohm and 3.5kohm for More Drive.  The lower the value the higher the distortion.  The top end of your drive control now has an extended range!  It will be a resistor one the main board that is marked yellow, violet red gold.  Note I had a typo here before.  I hope this hasn't caused anyone problems! :-)

Change C34 to fix the darn bass response!  The Tone Cap mod.  Change it to a value between 0.68uF and 0.1uF.  Use a good film capacitor. The 0.1uF is a more common value.  Changing it to either value will not affect the singing midrange tone of this pedal.  Changing this value is not a bass boost, it is a frequency response fix.  The roll off is not designed to take into effect the fact that guitar players tune down, there are 7 string guitars with a low B string, etc.  The 0.68uF will barely fix the problem if are worried.  I wouldn't be though.  Out of hundreds of mods only 2 people have said that it was to much bass.  That is probably a 0.5% chance that the 0.1uF would be too much.

Change R27 to a value between 22kohm and 27kohm.  The lower the value the Less Drive you have when the overdrive knob is turned down.  This is a very important mod if you want a clean boost or to drive the input of a tube amp into saturation without the effect of the TS7.

Change R58 to a 10kohm and change R55 to a 100 ohm.  This is the old standard TS808 mod.  It changes the output impedance of the circuit.  It was designed to drive a tube input.  The engineer that designed the TS808 said that he changed it to its current value to eliminate some static electricity effects.  Has anyone experienced some sporadic ticks or pops with a TS808?  Email me if you have.  He says it doesn't affect the tone of the circuit.  I can tell you that a change of impedance will affect how it works with other effects or amps and that of course will make a change in volume, tone, or both.

Change D3 or D4 for some More 2nd Order Harmonic Content.  Just change one of them in my opinion.  I like the sound of asymmetrical clipping.  These diodes are in the negative feedback loop of the op-amp.  It takes a certain amount of voltage to get them to forward conduct (turn on).  If the two diodes are different the top or the bottom of the sine wave will clip sooner or later depending on the voltage needed to turn on the diode and how sharp the knee is.  I like the sound of the standard Ibanez diode in one position and the 1N4002 in the other.

Change that itsy bitsy tiny weenie red led to a BLUE LED.  Drill out the hole to 5mm or a little larger than 3/16ths .  Use the red led's stand off for support. For a blue LED you need to change the 10k resistor to a 4.7k ohm.  The 10k you need to remove is marked brown black orange gold and it very close to the red LED and stand off.

 

Robert Keeley BSEE

Last updated 03/29/02