Sunday, March 10, 2013

I Heart Pedal Trading; or Quieting the EH Holy Grail Reverb

Yesterday I traded a DiMarzio "Very Metal" pedal for an Electro Harmonix Holy Grail Reverb pedal, the EH power supply included. It's the original "wide" model (and has Rev A on the PCB). I'm excited to have a compact reverb, for use with those amps that don't have it. My Lafayette "Echo-Verb" is cool, but it's big and needs maintenance (bypass get's muddy when the effect is set over halfway--probably needs new caps, or just a relay-driven bypass).

I love trading gear. Everyone wins--you clean out unused and unwanted stuff, and replace it with (hopefully) stuff you want, and might actually use. I never used the Very Metal pedal; it's really not my sound. Plus the non-true bypass wasn't very transparent. Yeah, it looked ironically cool, and probably will continue to be collectable, but that's mostly based on the famous "knobs that go to 11." But I generally only keep things I use; if it sits, let someone else enjoy it.

I crack open the Grail to check the type of bypass--and find it's a true-bypass version. Some of the first versions didn't have it. I don't know if it was home modded or factory, but I'm happy... 

True bypass

Oh the Noise Noise Noise!


Plug in the Electro Harmonix power supply, and the Holy Grail works fine. However, it's noisy, especially set above halfway. Overall, I'm somewhat disappointed with the noise floor at such a noticeable level. I half expected this from online comments. 

What do we suspect first with noisy digital pedals? --the power supply. The original EH power supply is a standard step-down transformer/rectifier type, a likely culprit.

So I try the Holy Grail with a 1Spot switching supply, daisy-chained with other pedals. Cool! It's much quieter! But when the Cry Baby wah is engaged there's a very noticeable high-pitched whine as the treadle is pushed down toward the treble position. Not good.

Next option: use a second 1Spot, dedicated to the Holy Grail alone. I keep a second 1Spot on hand to use with effect loops. Success! The Holy Grail is whisper-quiet, and now some of the subtleties of the effect can finally be heard.

You may take this as gospel ;-) -- always use a separate, dedicated switching power supply for the EH Holy Grail Reverb pedal.

Using a 1Spot with the Holy Grail requires an adapter cable to fit the 3.5mm jack. FYI, the polarity is fairly standard--shaft negative, tip positive, +9V. Ironically, I had the adapter already, for the Very Metal.

Overall Impression of the Electro Harmonix Holy Grail Reverb

I like it a lot. It's smaller than an external spring reverb. It does a decent job of simulating reverb for amplifiers that don't have the option. I can't say I LOVE it, but then I'm spoiled by the real thing...

The Hall setting is particularly good, if not something that I'd use often, or use live. But it's very cool. 

And the Flerb setting? (Flanger/reverb)--it's great fun! Again, maybe not a "live" effect, but cool anyways.

Goodbye "Very Metal"

Here's portrait of the DiMarzio pedal. Very Metal, I hope you've found a home, but I won't miss you...(except for your knobs that go to 11).

I got you in a previous trade for the equivalent of $25, and I traded you for something I wanted...more. Pedal love is fickle...

After further testing, a tiny amount of high frequency noise is still present with the dedicated 1Spot. But it's very small compared to the hiss and whine of the other options...


  1. hi there,
    dig the blog, just saw this and as I am working on a busted holy grail rev A for a friend, i was wondering if you could snap a photo of the other side of the board for me? there is a green wire coming out of a pad marked "J" that i cannot tell where it is supposed to go. I couldn't see it in your photos and if you could snap a quick one I would greatly appreciate it!

    1. Hey, Cliff,

      Yeah, I can do that. Give me a few days to disassemble and photograph the pedal--it's a busy time. The board is fixed in place, probably soldered directly to the POT.


    2. Those photos are up in a new post: