Holy Grail or other nice reverb schem?

[TryingToDo613]

Hi guys. I love that pedal and would love to try to inline it into one of my amp builds but I can't find the circuit. I'd really take any nice ss reverb that doesn't need a tank. -ph

[ninoman123]

Reverbs arent really a DIY thing. Ive never seen a schematic for a ss reverb. The Holy Grails are digital and not very possible for DIY. Maybe someone knows of some other, but I doubt you will get any DIY reverb that will sound good.

[nelson]

any good at programming?


the holy grail is digital..........unless you get the code from EH program it into dsp etc it is not going to happen.....

you could always  buy the holy grail and somehow stuff the circuit into your amp.....but then again thats what an effects loop is for.....


peter snowberg is developing some sort of diy dsp project.........I personally cant wait......

[Mark Hammer]

This question has come up a few times since the release of the HG, and the answer hasn't changed.  The pedal relies on the Crystal Semiconductor CS4811 from Cirrus (both companies are known for their computer sound cards, among other things), and some custom programming, as noted.

The obstacles to building your own are:
1) Getting hold of the chip in the first place in quantities of one.
2) Doing the programming yourself.
3) Making a board with suitably fine traces.

Given these constraints, you'd probably have to give up playing your instrument for the next year just to find the time to meet these challenges. :x   Not what you'd hoped for.

The Matsushita MN3011 multi-tapped delay chip, which seemed to come and go in a matter of 2 years over two decades ago, was initially developed to mimic the multiple reflections inherent in a natural reverberant environment.  The 6 taps in the chip allow the user to have multiple reflections that are not multiples of each other (as they would be in a standard delay line).

There are varying opinions about how decent a job this chip can do at mimicking reverb.  Several commercial products from both Rockman and Gallien-Krueger have used the MN3011 for reverb, but personally I have never seen a circuit using one that went the limit in terms of either optimising the circuit for "best" reverb, or in terms of providing some degree of user control.  

There is a project posted around for a solid-state reverb that appeared in Electronics Today ( http://www.synthdiy.com/show/getfile.asp?get=873 ).  The PCB mask is given but needs some digital touching up if one wanted to use it to print out a PnP-type mask.  Our patron saint (chief rabbi?), Steve Daniels at Small Bear Electronics has a modest stash of MN3011s at a respectable price.

Another avenue to consider is the Femto-verb (a play on Alesis' Microverb, Nanoverb, and Picoverb) from Dave Stockett and Peter Snowberg.  This uses some chips from Wavefront Semiconductors that appear to have been developed largely for the Alesis line, though they show up in a lot of moderate-priced guitar amps that include the standard set of 16 digital effects to be selected from by a knob on the far right of the amp's control panel.  These chips *are* available, require no programming, there is the posted circuit, and there are more reverb programs to choose from than provided by the HG (the Holier and Holiest Grail exploit all the possibilities of the CS4811).  The downside is that the chips are surface mount type, so you will need to get hold of a product called "surf-boards" which are essentially small printed circuit boards that allow builders to adapt surface-mount devices to standard 1/10" PC/perf spacing.  There is another recent thread ( http://www.diystompboxes.com/sboxforum/viewtopic.php?t=36096 ) on this.

[Mark Hammer]

I justed posted a retouched PCB mask for the ETI article here: http://img.photobucket.com/albums/v474/mhammer/ETI-3011-Reverb-PCB.gif

Since it is just a retouched screen capture from the PDF, I have absolutely no idea of the scaling.  Users will have to resize to arrive at proper size for a PnP print.  I have, however, flipped the image so that it is oriented for PnP.  The image itself is also oriented to match the parts layout diagram in the article.

Enjoy.

[TryingToDo613]

Thanks very much for your posts Mark.  I thought maybe it was using a pt2399 chip like the digital delay kit I got from buildyourownclone.com.  I'm actually a big fan of proprietary American engineering and will just put effects loops in my amps for that wonderful reverb unit. I think this stuff is a little over my head still. I am going to try the one in this article and thanks again for the retouched pcb.  -ph

[Mark Hammer]

You're welcome.

The PT2399 is a decent chip, and excellent value for the money.  The problem is that there are more kinds of reverb in the world than what happens in a long narrow cinder-block corridor or a high school washroom with cement floors.  Single-reflection emulators (i.e., one delay time with many repeats) like the PT2399 do a great job mimicking those sorts of environments.  What they can't do is mimick the way it sounds when you walk into a new house, stand in the living room, away from the middle, and your voice bounces off the hardwood floors, the walls of the dining room, off the kitchen cupboards, and patio door.  All those sounds arrive back at your ears at staggered unrelated intervals, and with different degrees of treble content.  To simulate that, you need to have a means of producing multiple arrival times.  That's what the MN3011 was intended to do with its multiple taps.

Spring reverbs and plate reverbs are also capable transmitting multiple reflection times simultaneously.  They may be bigger than a chip, but they're a helluva lot smaller than an empty house, and a lot easier to carry around, too!  :lol:

Ultimately, if a spring reverb is too bulky, and an MN3011-based circuit too complicated, the smart money says just buy one of the many current or on-the-horizon digital solutions.  When it comes to mimicking multiple arrival times, digital just plain does it better and easier.

[Arn C.]

And let us not forget - Was it Ansil that had the FISH TANK REVERB?

Peace!
Arn C.

[ninoman123]

There is a beer tank reverb on guitargeek.com

[barret77]

I vote Mark Hammer as the "digital R.G." of the forum  

[amz-fx]

Coming soon:

http://209.124.248.167/media/misc/tc47.jpg

affordable and a great sound!

regards, Jack

[Mark Hammer]

the smart money says just buy one of the many current or on-the-horizon digital solutions

:wink:

[rocket]

Is there any change that Steve/Smallbear makes available the Cirrus or Wavefront chip?

[Mark Hammer]

Don't bank onit  Keep in mind that Steve often has to field questions from newbies about transistors, for heaven's sake.  Beyond simply supplying the chips, being able to provide the needed level of servicemakes these things a bit too problematic to carry.

Besides, you can simply go to the Wavefront site and get the chips from them.  I am very reluctant to mention it, since the guy was so generous with me and I do not wish to exploit that, but when I tried to actually BUY one set of chips, they insisted on sending me a couple of sets....free of charge.  You can make the same request yourself.  They MAY charge you (the price, even in singles, is pretty damn competitive), but they MAY decide to treat you like they treated me.

[theplastictoy]

Coming soon:

http://209.124.248.167/media/misc/tc47.jpg

affordable and a great sound!

regards, Jack

How soon? I've been wishing for a line 6 reverb stomp for ages!
Any idea of release date?

[Mark Hammer]

How soon? I've been wishing for a line 6 reverb stomp for ages!  Any idea of release date?

My guess is that you'll have to do what the rest of us do, cruise the Line 6 website or attend NAMM.  I'm as in the loop about this as Jack is, and the first I heard about an impending release date for the Liqui-Flange and two of the other pedals in the second wave of the Tonecore series was from someone else's posting here about news on the Harmony Central site.  Even though you can now find demo videos on the Line 6 website for these things, all that says is that its close enough to release time now that they feel comfortable talking about it.  I've heard nothing about a release date, and I doubt anyone else has, either.

If it means anything, though, beta testing for the first 6 pedals in the line was completed this time last year, and they were released in September.  On the other hand, there are a couple of other pedals in the line not yet disclosed, and I suspect Line 6, like any other company in such a position, plans to launch them all at once.  

That could be soon, but that's simply idle speculation on my part.  I don't speak for Line 6.  Still, I don't know why anyone besides some software companies would tantalize the public with a product well before they had some sense it was ready for release, so I guess you can at least start getting your Christmas wish list ready now.

Incidentally, many of these pedals are stereo, and sound positively wonderful in stereo - something that doesn't come across all that well in the largely mono demo videos.  So, if you wanted to add a Z-Vex stereo micro-tube-amp to your Xmas wish list, that'd be a nice combo.  :wink:

I have to confess, I feel a little awkward flogging this stuff, though it's hard NOT to be enthusiastic about it.  It'd be nice, though, if there was somebody here from time to time who might put in a plug for other companies as well, just to add more balance.  Certainly Zach, Ton, and more recently R.G. were not shy about doing so, but it would be nice to have broader representation.  I mean, why NOT have someone from DOD staff, or one of those Japanese companies we never know enough about, or Dunlop, hipping the rest of us to stuff on the horizon?

[casey]

how about a new project using a smaller spring reverb - but like in a coil or zig zag pattern and put it in a slightley larger box?

[Mark Hammer]

I've had something like that "on its way" since last summer, using springs from Home Depot, small speakers from a Macintosh, a crystal/piezo mic cartridge from a phone, and a 386.  It should actually fit into a chassis smaller than the one Danelectro uses.  Unfortunately, I'm so far behind on projects, it'll be awhile.

[casey]

I've had something like that "on its way" since last summer, using springs from Home Depot, small speakers from a Macintosh, a crystal/piezo mic cartridge from a phone, and a 386.  It should actually fit into a chassis smaller than the one Danelectro uses.  Unfortunately, I'm so far behind on projects, it'll be awhile.

supercool...well there ya go folks!  how do think it'll sound mark?

[Mark Hammer]

Initial tests indicated it would sound like reverb, but the fact remains that spring reverb quality generally increases with spring length.

Ever try to bend a steel bar?  Hard to do, eh?  Make it a whole lot longer, and a bar of the same gauge steel can seem positively floppy by comparison.  The thing with springs is they have to be stiff enough to conserve whatever energy is being transmitted through them and bring it to the other end, yet compliant enough that they can vibrate easily and flexibly enough to transmit at least *some* upper mids and treble, and accommodate multiple simultaneous "copies" of the original waveform.  Remember that springs are used to mimic the multiple reflections of an asymmetrical room/space, so the same signal that has travelled down the spring and been bounced back in the other direction like a wave in the bathtub is making the spring wiggle at the same time as another completely different waveform is travelling in the opposite direction down that same spring.  That spring needs to be supple to do that.

If the spring is too short and stiff, it resists the vibration and severely limits the bandwidth (anyone for reverb bandwidth of 10hz-200hz?).  If it's too floppy, by virtue of length or "softness" of the spring, the waveform quickly dissipates in the spring and nothing is received at the other end.

Consequently, the ideal is to have longer springs possessing the relative stiffness to be efficient transmitters, and also to have several parallel springs of slightly different tension (and simple differences within tolerance can easily accomplish that) to mimic multiple reflections a little better.  What I had on the workbench used readily available springs (I paid a little over a buck each) that, when stretched to about 5-6 inches, had a decent balance between stiffness and compliance.  I soldered a trio of them together into a Y configuration, so that the "driver" side would end up transmitting through two angled springs to the piezo receiver end (springs can be soldered directly to piezo discs).  The Y configuration would accommodate a greater length of travel in a smaller rectangular space as well.  Still, expect the tone to be more like a high school bathroom than a Lexicon digital reverb or even a decent Fender.  When I get back to it, I think the smart thing will be to build in some type of strategic low midscoop into the electronics of the receiver end to make the resonances less obvious and make the treble some more abundant.

Sound-wise, you'd be better off with an accutronics reverb pan.  My own goal was to be able to make something from locally available parts that would fit in a small battery-powered (an octet of C-cells) practice amp with a 6-8" speaker.  In my case, quality was NOT going to be "job #1".  Of course, the quality of digital reverb available these days for budget price, makes it foolish to waste effort on %^&*amamie spring solutions like mine unless there is some specific challenge to be overcome, or some specific "I wonder if..." goal in mind.