Noob's 1st baby step: Need help with Holy Grail rehouse

[jubal81]

Found this place thanks to a member posting on TDPRI. Great community!
Anyway, I've got the serious bug to do some tinkering/pedal building, but I've never worked with electronics before.
One thing I've always wanted to do was rehouse/upgrade my HG, as it has some really weak components and is put together pretty shabbily. I think this would be a good first foray into getting familiar with circuits, soldering, etc. before I move on to a kit - and hopefully my own designs some day.

However, before I get started, I have a few questions.
1. Which parts should I replace?
I know I want a new LED and a toggle switch instead of the sliding one. Is there anything else I should swap out? The 1/4" jacks look pretty weak in there.

2. I want to mount the PCB instead of having it dangle from the POT. What's the best way to do this?

3. Which type of toggle switch do I need to buy? The slider has 2 rows of 3 connectors (for whatever that's worth). Mini-sized or fat?

4. I'd like to buy predrilled if I can. It has 1 Pot, 1 switch, 1 LED and 1 footswitch. Are all 4 of those holes the same size? Do I need to ask for custom drilling?

Also, any other tips/suggestions are very welcome.

I've scoured Google looking for this very project and I found a few, but the details are scarce and the threads are very old.
Here's a picture of what I'm going for:

[phector2004]

1. How old is it? Usually, people change the electrolytic caps on older effects as they tend to go bad. Your's looks quite new, so I probably wouldn't bother!
Most other parts won't change much at all, so you're probably better off leaving it as is. What is it, exactly, that you'd like to change about them?

2. There are many options for this. The most common ones are small plastic standoffs, but you can also use the metal hexagonal standoffs. You might need to use some JB Weld if you don't want to drill holes in your enclosure.

3. A standard DPDT should work fine. Dual Pole (2 columns) Dual Throw (2 positions to switch the middle lug to, so 3 rows). I don't know how big "standard" is but I think the ones I've used so far are "mini". Watch out for short lever arms, though (Unless you're into that kind of thing   )

4. Haven't tried them myself, but I think pedalpartsplus.com has pre-drilled enclosures. They should have a 3-knob pedal drill template, but I'm not sure if the holes will be too big for a toggle. They also do custom.
Have you considered just buying a painted enclosure and drilling on your own? As long as you have bits up to 1/2" (stomp switch, DC jack-size), you can do it. Unibits are very useful for this kind of stuff.

Good luck!

EDIT:
You might like to get a set of Switchcraft jacks. They seem to be the most sturdy ones around. Make sure to get the open kind, and if you want your input cable to switch the power to the effect on, a stereo jack for that side.

As for the LED, the one in the pic has a bezel. Any 5mm or 3mm ultrabright does the trick, but note that you'll need to bump up the LED resistor value. 1k Ohm on a blue ultrabright lights up a dark room and leaves spots on your eyes for a few minutes. Not fun. 4.7k Ohm is just about right for me. The bezel is optional, but makes mounting a breeze.

[jubal81]

Thanks for the reply.

That's not my HG. That's a photo I found on the internet from someone else who did just what I want to do.

I bought mine used a while back and it looks rough enough to have been abused at plenty of bars.

Here are some pics of mine:

[LucifersTrip]

One thing I've always wanted to do was rehouse/upgrade my HG, as it has some really weak components and is put together pretty shabbily. I think this would be a good first foray into getting familiar with circuits, soldering, etc.

...just a quick suggestion. I really think building a 5-15 part distortion or fuzz would be the best way to get familiar with circuits & soldering. Why take a chance ruining a $50-100 pedal when you haven't gotten soldering down yet...

When you build from scratch, you will be able to hear what changing each part in the circuit does.

Also, with the amount of upgrading you want to do, it'd probably be tougher than building a simple distortion/fuzz from scratch.



good luck

[jubal81]

One thing I've always wanted to do was rehouse/upgrade my HG, as it has some really weak components and is put together pretty shabbily. I think this would be a good first foray into getting familiar with circuits, soldering, etc.

...just a quick suggestion. I really think building a 5-15 part distortion or fuzz would be the best way to get familiar with circuits & soldering. Why take a chance ruining a $50-100 pedal when you haven't gotten soldering down yet...

When you build from scratch, you will be able to hear what changing each part in the circuit does.

Also, with the amount of upgrading you want to do, it'd probably be tougher than building a simple distortion/fuzz from scratch.



good luck

Well, I'm not terribly attached to the HG as I got it super cheap and I imagined rehousing it would only require soldering 2 components - the POT and the LED.

Building a simple fuzz or modifying my DS-1 was going to be my next step.

As for the toggle switch, do I just need to get one with the same 3X2 layout with an ON-ON-ON configuration? And will swapping out he LED - probably from a 3mm to 5 mm affect anything other than the color of the light?

[phector2004]

The color is of your own choosing. The 5mm is physically bigger, but it looks like EHX already uses 5mm LEDs. I mentioned this before, a regular LED resistor won't do if you get an ultrabright LED (well... it becomes irritating). If you buy a regular LED, then you can swap it in without increasing the resistor value.

I don't know if ON-ON-ON is what they've used, as the middle setting could just be open (ON-OFF-ON)
Got a schematic?

[jubal81]

OK, upon further research:

Couldn't find a schematic of the Holy Grail, but I found one for the GGG D-Verb here: http://www.generalguitargadgets.com/pdf/ggg_verb_lo.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a.

It calls for a 10K linear pot. Is that what I should get for the HG? How much does the value matter? Should I get a 16 or 24 mm size? And I prefer audio taper pots in my guitar, should I go audio with the pedal or does that only matter for volume control?

I also scoured the EH forum about the switch. If I understood correctly, the slider style and toggle style are different and the toggle wiring (On-On-On) should look like this pic I photoshopped:


I also found this thread with a video and explanation of the same project done by Bjorn Juhl: http://www.bjfe.org/viewtopic.php?f=4&t=657&p=2947&hilit=holy+grail#p2947

Excerpt:
"Hm, well the construction has a couple of weak points that one could address:
Potentiometer holds the pcb.
Power is brought with an AC adapter that leaves unregulated voltage and can at start up break a 47R resistor with it removing power from the reverb circuit.
Input- and output- and DC jacks make the contact to ground but none of those have locking washers and metal sides of the case is a bit to thin to hold the jacks firmly without locking washers.

Now measuring the pcb it would fit into a small hammond box with the regulator and crystal facing the top of the case if pot is removed and connected via wires, which then ofcourse removes the weak point of the pot. I choose an Alps RK-09 and mounted that with a locking washer
and found a tooggle switch that would fit next to the pot and have a height over pedal surface the same as the pot with a knob mounted and finally DC jack replaced with a 2,1 mm Marushin chassis mount jack

The 47R resistor was replaced with a 1N4002 diode giving about the same voltage drop but now protecting against false polarity. "

It looks like he changed out the weird DC jack for a standard Boss style. I'm not bent on doing this, but it would be a nice touch. Any ideas?

[Taylor]

Couldn't find a schematic of the Holy Grail, but I found one for the GGG D-Verb here:
It calls for a 10K linear pot. Is that what I should get for the HG? How much does the value matter? Should I get a 16 or 24 mm size? And I prefer audio taper pots in my guitar, should I go audio with the pedal or does that only matter for volume control?

You're confusing a lot of things here. The D-verb and the HG have nothing to do with each other, other than that they are both reverbs. The pot in the HG is controlling a DSP chip, in a circuit completely different from the GGG one, so the pot value of the D-verb will not tell us anything about the HG. Forget about that D-verb completely.

If you really feel you need to have the board not be mounted to the pot, then clip the pot off the board and attach that same pot to the board with wires. Don't use a different pot. Normally I would say that you should desolder the pot, but that could easily damage the board, and if you're a total beginner this is probably a bad idea.

[phector2004]

Honestly, if I were in your shoes, I'd leave it as is!

Aside from having the EHX cool-factor, it's fully functional. And until you've got some experience doing this stuff, you're very likely to mess up. Sure, it might work all right in the beginning, but after some wear and tear, it'll die when you least expect it.

There's nothing wrong with the pot being soldered to the PCB, the "AC adapter that leaves unregulated voltage" is most likely regulated and won't "break up" the resistor  , and you won't need a protection diode unless you start mixing your adapter polarities (most pedal adapters are pin negative, so it shouldn't be a problem). I don't really understand that switch wiring, and it's probably best not to touch the pots on a digital circuit.

My suggestion is maybe to try out the beginner project here at the forum (See forum section), or a simple booster (LPB-1), or distortion (Electra distortion), or a simple fuzz (Bazz Fuzz? Silicon fuzz face?). When you're more comfortable with soldering and get a better understanding of the components you're dealing with, you'll be able to mod your DS-1 (see Wampler mods) or tackle other builds. Not much you can change on a digital circuit, anyways!

[LucifersTrip]

One thing I've always wanted to do was rehouse/upgrade my HG, as it has some really weak components and is put together pretty shabbily. I think this would be a good first foray into getting familiar with circuits, soldering, etc.

...just a quick suggestion. I really think building a 5-15 part distortion or fuzz would be the best way to get familiar with circuits & soldering. Why take a chance ruining a $50-100 pedal when you haven't gotten soldering down yet...

When you build from scratch, you will be able to hear what changing each part in the circuit does.

Also, with the amount of upgrading you want to do, it'd probably be tougher than building a simple distortion/fuzz from scratch.



good luck

Well, I'm not terribly attached to the HG as I got it super cheap and I imagined rehousing it would only require soldering 2 components - the POT and the LED.

You said you wanted to rehouse it...that's much more work. You also mentioned "the 1/4" jacks look pretty weak" and the toggle switch...

And will swapping out he LED - probably from a 3mm to 5 mm affect anything other than the color of the light?

If you are indeed going from a 3mm to 5mm, then you will most likely have to reduce the led resistor to get the same brightness 

After reading all your questions in the last post,
http://www.diystompboxes.com/smfforum/index.php?topic=90678.msg771801#msg771801,
do you still think rehousing/upgrading is easier than building a 10 part distortion from scratch?

[jubal81]

You guys make really good points, so I'm going to defer to your wisdom and let this project wait until I know a little more.

The tools I ordered are on the way so I think I'll order the parts today for the 'beginner boost' project. The directions here are great and I really think I can knock it out.

Thanks for the help!

[jubal81]

Well, I went and did it anyway and aside from a few problems with part quality it was a total success. Sturdier and sounds better with a 5K pot.

[ode2no1]

and now the question is: what would it take to get that empty holy grail enclosure into my hands?