guitarleeman's TS808 Mod information

[guitarleeman]

Hey,this is guitar leeman. Ive heard one of the best mods for TS808 builds or TS-9 toTS808 mods is to use carbon composition resistors for the resistors that are changed to get to TS808 original specs.Also the dual op amp supposed to be a Texas Instruments JRC4558 with the Texas logo.Tell me if anyone has tried this. The resistors are 1/4 Watt.

[5150]

A bit late, but I'll try.

I modded a TS7 (same circuit as TS9, two resistors off from a TS808) to original TS808 specs about...three hours ago (not counting debugging time).  I had just read this post as I was checking the last of my solderjoints and decided that while I still had the holes open I might as well give it a try - I wired up a DPDT to switch back and forth between the two carbon comp resistors and two identical values from a Radio Shack value pack, and plugged in.  I went through my normal setup: two guitars - a Dean ML with a Dimarzio Super Distortion and a Schecter Blackjack 7-string (tuned D-G-C-F-A-D and Bb-Eb-Ab-Db-Gb-Bb-Eb, respectively, with GHS steels) into the TS, then to a heavily modded DS-1, then a Rocktron Silver Dragon, into a Roland Cube 30 (did not try and see how it reacted with my wah pedal, but that may come later).  I honestly couldn't tell the difference on the normal mode of the TS7 (although the 'Turbo' mode, which if I remember right adds a bit of gain, a bit of buzz, and not a whole lot of use, made them sound a little less 'open' and a bit harsher) on its own (trying just about every bit of the range on all 3 knobs), or as a boost for either the DS-1 or the Silver Dragon (the way I normally use the box - not much for subtle drive in most situations; Drive and Level dimed, tone between 10 and 2, depending on the pedal I'm boosting).  I didn't leave them in there - weren't too easy to come by - but if needed I can certainly try and put together a sound sample going between the two.  I think if there were more of them used, it might make a slight difference, but I wouldn't guess that the TS has quite enough gain in most parts of the circuit to give that nice sparkle some carbon comps might give.  Just to make sure we're talking about the same resistor values (I'm going with what I found in a few places here and a few external mod pages), surrounding an electrolytic cap are a 470 and a 100k, which were replaced by a 100 and a 10k, respectively.  I've been told that these are the only two differences if the opamp is the same, so I just left it at those two and will play around with other stuff later.

As far as the IC, I haven't been able to try the TI - mine came with a JRC - but will do so if I can get my hands on one anytime soon (hard to do when you can't order online).

If you guys can think of anything else I could goof around with, let me know.

jeff

[cd]

The real question should be, who has NOT tried this?

For your reading pleasure:

First and last stop for everything and everything TS:

http://geofex.com/Article_Folders/TStech/tsxfram.htm (from 1998)

Why CCs make not one whit of difference, with the numbers (not mojo hearsay mumbo jumbo) to back it up:

http://geofex.com/Article_Folders/carbon_comp/carboncomp.htm (from 2002)

[bwanasonic]

I went through my normal setup: two guitars - a Dean ML with a Dimarzio Super Distortion and a Schecter Blackjack 7-string (tuned D-G-C-F-A-D and Bb-Eb-Ab-Db-Gb-Bb-Eb, respectively, with GHS steels) into the TS, then to a heavily modded DS-1, then a Rocktron Silver Dragon, into a Roland Cube 30

No offense, but that is not what I'd call the ideal rig for this listening test. I'd leave anything other than the pedal being tested out of the equation for one thing. The other issue is, the resistor swap relies on the input stage of a tube amp for it's effect. It's a subtle difference at best, but vintage style pickups and tube amps are better to highlight it. I found it to be more of a slight change in response, rather than a change in tone. I refer only to the change in resistor values - I don't subscribe to CC mojo in 9v pedals.

Kerry M

[5150]

I really don't think that any part of my rig is going to suck the life out of carbon comps, and I don't think there's any good reason to believe there was any in the first place.  I think this fascination is more like the 'alternative medicine' nonsense (magnet therapy, hypnotism, psychic surgery, 'faith healing') than anything else - lots of hype, no results but whatever the power of suggestion might bring about.  First, I had true bypass over everything else and had put the other effects in there because I was testing it not only on its own, but in conjunction with other effects.  The first thing I always do (to make sure I didn't do anything wrong on it) is make sure everything checks out on its own, make sure all switches are active and nothing got bumped when I put it back together, etc.  Second, the Silver Dragon is tube (I didn't use the built-in SS driver) to see if the 'tube mojo' brought out any difference between the carbon comps - it isn't a tube amp, but it gets a better overdrive and distortion than many tube amps I've played through (including, but not limited to, the school jazz band's Blues Jr and a borrowed Peavey Classic 30).  Finally, the Blackjack has a Seymour Duncan JB in the bridge, with a split coil mode, which gets a very good vintage-y bridge single coil sound, and a 59 classic, for a 'vintage' neck humbucker sound.  There are more rigs than that out there; I was going for as much range as I could when I found that I couldn't find anything that set the two apart, and seeing as how I have two guitars, one amp, and a few other pedals, I'm a bit short on variety.  Anyway, there was still no difference, and if the magic and sparkle are that hard to find, I don't think anyone will notice in the average Joe's rig.  Also, I don't really know too many people who are into DIY because they have too many 59 Strats and first-run Bassman heads.  Unless someone has a TSL half-stack they're willing to let me borrow, I'll have to leave my comments as they are and the carbon-comp for the people who spend big bucks on vintage pickups and tube amps to highlight 59 cents worth of extra resistors.

Jeff

[bwanasonic]

I was thinking you were testing the difference in resistor values. I'm not surprised then that you found no difference!

Kerry M

[R.G.]

Also the dual op amp supposed to be a Texas Instruments JRC4558 with the Texas logo.

I think it's going to be remarkably hard to find a TI-logoed JRC4558, given that the JRC4558 is and always has been made by NJR.

[Mark Hammer]

Stuck a 330R resistor in series with one of the diodes the other night (not both).  Gotta say, I kinda like it!

[George Giblet]

> TI-logoed JRC4558

but TI did make RC4558's (without the J).

National made LM4558's but these appear to be different to the others.

[R.G.]

but TI did make RC4558's (without the J).

Yes, they did. The RC4558 was originally a Ratheon device, if my memory doesn't play tricks.

[5150]

I was thinking you were testing the difference in resistor values. I'm not surprised then that you found no difference!

Kerry M

No, there was a subtle difference - less harsh and tighter when pumping other high-gain devices, so I was able to crank the gain more and use more treble on all my boxes and not have to worry about harshness or sizzle.  I'm very surprised at how well this turned out, and am now searching for any reason why people would seek out $500 original-spec 808s for the same circuit - or, even better, shell out $99 for a new TS9 to mod themselves and feel like they got one hell of a bargain, completely failing to notice (or condemning) the lowly TS7 with its less-repulsive paint job and frightfully amusing locking knobs.  People are silly sometimes.

Jeff

[Dai H.]

Also the dual op amp supposed to be a Texas Instruments JRC4558 with the Texas logo.

I think it's going to be remarkably hard to find a TI-logoed JRC4558, given that the JRC4558 is and always has been made by NJR.

I think this bit of mythology was supposed to be "Texas Instruments RC4558 made in Malaysia (with the TI Texas state logo)", lol... (I've got one of those!  )

The mods that wouldn't die!  The Tube Screamer mod orgy!!!  

[johngreene]

but TI did make RC4558's (without the J).

Yes, they did. The RC4558 was originally a Ratheon device, if my memory doesn't play tricks.

Considering Ratheon and JRC merged in 1959 to form NJR, I'd say they are probably the same thing! I don't think either was making 4558's in 1959.

--john