GCX LED Mods

[evolu]

Hi all,

Does anybody know what voltage LED's are used for loop / activity status on the GCX units?
I currently have 2 x GCX's, with failing eyesight and the unfortunate habit of playing live whilst being drunk I get confused as to which unit I am looking at / controlling, I figured changing the LED's in one of the GCX units would help.

If it makes any difference, both of my units are the older Digital Music Corp versions.

Also, I have read that the Burr Brown OPA2134 is a good mod for the buffer stage. Are these IC's soldered or plug in? How many of these will I need per unit.

All advice is mucho appreciated.

E

[JohnClark]

The LEDs in the GCX are T-1 3mm. Anything around 20mA at 2.1V should work just fine. Superbright LEDs will likely draw too much current. The resistors directly behind the LEDs can be changed to set the desired brightness... but you will have to experiment to find the correct value for the LEDs you use.

The BB OPA2134 is what we currently use in the GCX and is a great op-amp for the buffer. There have been some running changes to the GCX over the years so it may not be a drop in replacement in all GCX units. Some of the earlier GCX units had a single rather than a dual op-amp. Your best bet is to look inside first and see what you have to begin with.

Let us know how you do on this project!

[Steven Latch]

and the unfortunate habit of playing live whilst being drunk

You've just made my day!!! I guess nobody in the Voodoo lab R&D and marketing department ever thought during the design process of a new product: "That's great but what about people who play drunk?" Food for thought...

[JohnClark]

Are you kidding!?



This is in the R&D Man Cave!

[evolu]

and the unfortunate habit of playing live whilst being drunk

You've just made my day!!! I guess nobody in the Voodoo lab R&D and marketing department ever thought during the design process of a new product: "That's great but what about people who play drunk?" Food for thought...

Sadly no.
After all these years playing live I Still get nervous, that hanging around bit between soundcheck and playing is not good for my nerves, however, a drink is.

[evolu]

I goy around to swapping the LED's and buffer out today. I left one of the GCX units with the original TLE7072 so I could do the Pepsi challenge.
In my opinion the BB OP2134 sounds 41% better, clearer less grainy, I now seem to have better control over unwanted top end frequencies.

I also swapped the LED's out with some T1 blue LED's, 10ma @ 2.4V forward current, they look nice (why don't Voodoo Lab make them all with blue LED's...much nicer looking).
I may have to fit a higher value load resistor as they are quite bright with the original 220R.
Can anyone (John) suggest are more suitable value or is it just down to personal preference?

Thank you, everyone, for your help.

One other thing: I have a GCP, very nice it is too, but I have a problem. I often need more than 4 presets per song but would like to keep the instant access function. Is there a work around?

[kiwihamma]

Hi to any electronics whizzes,

(That might be just John Clark who knows, I hope you see this, although you must be a busy busy man. )

Can you please help me with LED specs?

I don't post on forums much, so I wasn't sure whether to start a new thread, but hopefully this is relevant as I only found the one thread for replacing LEDs, so the info might be better contained in one place? The FAQs don't say.

I too have 2 GCX's (and loads more VL gear ), but have a slightly different reason for swapping LEDs:

I want to have a spectrum of colour for the 8 loops e.g. white,yellow,amber,orange,red,green,blue,purple.

The reason is I have my GCP in 10-preset mode. If I want to know what pedals are engaged in a preset, I have to either enter edit mode, or walk up close to see.
I would love it if I could glance over and see "ah - white and red are on meaning I'm going through the preamp of Amp B, etc"

Here's the thing though: Every LED provider has literally thousands of values to select: Even just selecting T1 3mm, diffused, 2.1 or 2.2V, 20ma means there's not much results returned.

So my question is - hopefully for John: What are the tolerances of the LED parameters I can mess with (voltage, current, type), and what can't I change, so that I have better luck sourcing some LEDs?

I'm pretty handy with a soldering iron, built circuit boards etc, plus I'm fairly happy to go research if given a start.

Thanks a million!

PS: Both GCX's are less than 4 years old.