TS 808 Output Impedance Question

[Khas Evets]

R.G.'s article on the Tube Screamer mentions that the main difference between the TS-9 and 808 is the change of the output impedance from roughly 10K to 5K. Since both of those are small compared to the 1M amp input impedance it's looking at, does this really have an audible effect? If it does, could you describe the difference in tone?

[Strat Cat]

A device with a high output impedance tends to lose some of the highs due to the capacitance of the cables used. Not to mention the loading effect on your signal from the pedal's bypass buffer. If the cable from the Tube Screamer to the next pedal is short there is little loss of highs due to the minimal cable capacitance. If the cable is a long run to your amp then you may lose some of your tone's highs. An easy way to check is by swapping between a long cable run and a short one to see if you can hear an audible difference. Some people, like Warren Haynes for example, like this loss of highs in their signal.

[TheBigMan]

R.G.'s article on the Tube Screamer mentions that the main difference between the TS-9 and 808 is the change of the output impedance from roughly 10K to 5K. Since both of those are small compared to the 1M amp input impedance it's looking at, does this really have an audible effect? If it does, could you describe the difference in tone?

IIRC the change was made by Ibanez to reflect the increase in popularity of solid state amps, and the output section of the TS-9 was a better complement to their inputs.  However, the point of tailoring a pedal called a Tube Screamer to SS amps is completely lost on me.

I don't know for certain that this is true either, but I have read it in more than one place.

[bwanasonic]

When I performed this mod on my vintage TS9, I remember thinking "sounds more open, throatier, and less constricted", but since I had no practical way of quickly A/B ing the change, I can't say what percentage of this perception was *all in my mind*.

Kerry M

[Khas Evets]

I might try switching in a parallel 10K resistor with the 100K to see if there's any difference.

[Khas Evets]

Just tried it (on an SD-1). I'm not sure if I actually heard a difference or wanted to hear a difference, but it's *very* subtile. I think bwanasonic's comments are good. The upper mids may have been slightly tamed.

Has anyone else done an A/B test on this?

[cab42]

I build a TS clone with a 808/9-switch (I call it TS-817 as it is both types in one). I can't hear much difference, other than one of them is a bit louder and "open" than the other.

Unfortunately I forgot to label the switch and i can't remember which position is which :oops:

I have only used it on a couple of SS amps, as my tube amp is down at the moment, but it could be fun to test settings vs. amp type.

Regards

Carsten

[Johan]

..what is important to remember, and noone ever seem to do just that, is that the outputbuffer sits after the switching and will affect ( or not affect? ) the bypassed sound too...

johan

[formerMember1]

i just did the 2 resistor mods to my TS9DX.  I also changed out one tantalum cap to a boxed metal film cap,(i couldn't fit a box metal film cap, in place of the other tantalum cap since the IC chip is in the way).  I also changed the NP caps to boxed metal film.

If i use the modded TS9DX w/ everything on full, on a JCM2000 high gain channel, reverb maxed, with my strat tuned down a half step, it nails the early EVH tone.  (think eruption,devil,panama,cradle,ain't...love) (minus the phasing,) (and that is with a strat too!!)

If i use the modded TS9DX on a clean tube amp it sounds  more throaty and thick, more bassy and more natural sounding, sounds closer to a overdriven warm tube amp than a pedal.   But I am not sure i like the modded sound.  I tried a few stock original Ts808 and they didn't sound as good as a stock new TS9 reissue.(IMHO)  I even tried a reissue ts808 and didn't like it as much as my stock ts9DX.  

BUT, i am not sure if it was the cap change, or the resistor swapping that made the sound change that much.  I will fiddle with that another time, and figure out which mods made the difference.   Another thing is, some people say modding the TS9 this way, doesn't make a big noticable difference, but i don't agree.  I could hear a Huge difference.  But again, i don't think i am gonna keep it this way, probably mod it back to stock. :wink:

Use a copper braid and don't damage the orignal stock parts, you might want to change them back.  It is worth modding to learn though.

[bwanasonic]

BUT, i am not sure if it was the cap change, or the resistor swapping that made the sound change that much.

I tried swapping out the tantalum caps and didn't like it. I would only recommend it to people who hate tube screamers, as it ceases to sound like one after that mod. Actually my favorite TS mod is to swap out the entire pedal for a Nobels ODR1  :lol:

Kerry M