Line6 Dl4 mod to fix volume and tone drop?

[John Egerton]

Hey guys...

I was wondering if any of you can help me fix a plroblem thats been annoying me for ages...

do you know if there's a Line6 Dl4 mod to fix volume and tone drop problems?

I understand keely does one but does anyone know how he does it? or a method I could use?

Thanks

John

[MartyMart]

A friend has asked me to do the same thing.
It may well all be SMD inside, but the basic vol drop should be a simple
correction on the output opamp.
That should be just an increase in 1 or 2 resistors, the "tone" may need
some more investigation !

MM.

[John Egerton]

Is there anyone that can talk me through this? maybe provide me a picture of something to replace...

The thing has been annoying me for a long time now...

I've realised that its not really 'all' the models that the volume drop happens in... I believe its the delays that are more agressive, the ones that really colour the sound... Such things as the multihead delay or the sweep echo...

Thanks

John

[Johan]

I've realised that its not really 'all' the models that the volume drop happens in... I believe its the delays that are more agressive, the ones that really colour the sound... Such things as the multihead delay or the sweep echo...

Thanks

John

..if its not on ALL models, then it is in the modeling( programing/software), so the original models are probably like that too...and doing a hardware-mod will then change the ones that you are happy with too...
..its an ongoing dilemma among people who do replicas of all sorts..if you builld a clone of a 1959 fender bassman, do you builld it like they sounded new or the way they sound 45years later?. if the original has an easy-to-fix flaw, do you builld in the flaw or do you fix it?

I can probably locate the two or so resistors needed to change to get the FX-sound up a little, but it will affact ALL non-bypassed sounds. without exeptions...is that what you want?..

johan

[Johan]

..ok..found the schem..R36 and R37 is the easiest thing to do. they are both 36kOhm. reduse them to get more output ( I'd try something like 20K ). It's all smd, so be carefull, or ask someone who is better than yourself with the iron ( if you're unsure, that is..)
they are the resitor going to the inverting input on one of the last stages before the output. the feedbackloop has compansation to attenuate the highs a little, so dont mess with the feedback. this all hapens around IC U17...good luck..
johan

[dubs]

Thanks for the tips.
George Tripps ( Way huge fame) modded a line 6  dl-4 for charity ebay auctions(Tsunami?) . I saw a small pic of the guts.
Apart from fixing the volume drop (couldn't see what he did) he replaced them two tl072 smd opamps with burr brown opa2134 and some smd caps with wima caps for better fidelity.
Luckily I got some smd opa2134 samples before TI stopped giving samples.
I'll post a pic when I get home.

[dubs]

O.k modded my dl-4. Looking at way huge picture I removed c4 and c8  1uf electro replaced with panasonic metal film or wima caps.
Changed U22 and U3 (tl072) to  burr brown 2134UA.
Lowered value of r36 r37 to 22k. Improved output alittle but I think still could go alittle  lower (maybe 15-18k??). But I'm not changing it since some of the tracks lifted off in soldering.
Also the way huge mods looks like they replace R43 & R1 with normal sized components which looks to me like WIMA caps(??)

Anyway I think the fidelity is improved - a little more clarity overall.

Removing SMD on these boards- you need to be VERY VERY VERY careful! I used a 15watt iron with very fine tip for smd and I still lifted some tracks and almost screwed up my board- they are much more delicate than even the boss pedal boards. I only recommend people with very good soldering experience to attempt this.

[sam24]

hi everybody...i wanted to do the mod for the volume drop...so i changed the r36 with a 22k and everything went right, then i did the same with the r37 but unforunally i made a s...t and now i have a dl4 WHITOUT the r37 resistor....BUT IT WORKS! can i know what the r37 is for? why my dl4 still works!?!?!?

[wavley]

I accidentally ran into this the other day during a google search for something unrelated apparently Keeley mods these... http://www.robertkeeley.com/product.php?id=40

[ayayay!]

R36 & R37 are going to their respective outputs. So if you move that cable over to the non-mono side, it probably won't work.  For what it's worth, I had to put trimpots in mine, then I sold it.  Couldn't wait to get rid of that thing.  What I hated about the DL4 was that the only modeler I used (I think it was the DMM) had a built-in volume drop, "just like the original Memory Man."  Whatever.

So when I boosted the DMM volume up to where it should have been, all the other models were ABOVE unity gain.  Irked me to no end, so off to evilbay it went.  

Here's my thread if you're interested.  (I'm diggum12)   http://indyguitarist.com/forum/index.php?PHPSESSID=ec8b36c2850a0070071d2e5dc57045f7&topic=1067.0

And I think I settled on 22k's in series w/ 10k trimpots.   You'll probably find the tone isn't bad at all once you get your volume boosted.