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Thanks for viewing my guestbook! It is a place for your quick comments or suggestions about AMZ.
Name: amz-fx     ()  
Posted: Wed May 23 05:36:06 2007
This guestbook has been made obsolete by my new fx pedal blog. There will not be any new updates here so be sure to bookmark the new blog page. Thanks!

AMZ Guitar Effects Blog
Name: amz-fx     ()  
Posted: Tue Apr 24 04:25:32 2007
If you were into building synths back in the late 1970s or early 1980s, you probably remember Electronotes, a journal of synthesizer related circuitry and design. It is still around and there are new articles being published. Check it out:
Electronotes Free Issues
Name: amz-fx     ()  
Posted: Thu Apr 19 14:01:33 2007
Do you find that the basic Eagle CAD libraries are missing a lot of parts that you need? Then download the Spark Fun Electronics parts footprint file:
SFE Eagle Library
Name: amz-fx     ()  
Posted: Tue Apr 17 13:38:50 2007
Here is a nice article on converting an old scanner to become a pcb exposure system:
LED scanner system
Name: amz-fx     ()  
Posted: Mon Apr 16 20:05:32 2007
Ever wonder what the alloy composition was of the Hammond 1590 cast aluminum boxes? Here you go:


Name: amz-fx     ()  
Posted: Fri Mar 30 06:44:36 2007
A free ezine for the frugal audio enthusiasts who enjoy finding great value:
Affordable Audio Ezine
Name: amz-fx     ()  
Posted: Mon Mar 26 12:21:07 2007
A good paper on oscillator design:
TI Opamp Oscillators
Name: amz-fx     ()  
Posted: Mon Mar 26 06:48:47 2007
Need a filter in a hurry? Check out this appnote from TI:
Filters in 30 seconds
Name: amz-fx     ()  
Posted: Thu Mar 22 17:26:23 2007
Make a pcb by the electroless salt water etching process:
How to Etch with Salt Water
Name: amx-fx     ()  
Posted: Wed Mar 7 13:53:40 2007
What happened to the electronics hobbyists? See this article in Electronic Design:
What happened to the Electronics Hobbyist?
Name: amz-fx     ()  
Posted: Wed Feb 7 15:06:42 2007
Want to talk about pedals and related items? The Pedal post has a nice forum with knowledgeable guys:
Pedal Post Forum
Name: amz-fx     ()  
Posted: Tue Feb 6 11:32:27 2007
You need a Chimp... which is a distortion, fuzzy, amp-sim kind of plugin, very responsive to the input gain. Designed mainly for the guitar, although can be used on about any sound you want crapped-up.

Did I mention that it is FREE!

Chimp Amp-Sim v1.1
Name: amz-fx     ()  
Posted: Thu Feb 1 13:45:59 2007
Here is a nice paper on mixing, compression and EQ:
The Book of Dar
Name: amz-fx     ()  
Posted: Sun Dec 31 06:21:11 2006
A last entry to get us started for the New Year... here is a vst plugin that does amp simulation. Free!!!
Tube Driver VST
Name: amz-fx     ()  
Posted: Sun Dec 17 05:12:06 2006
Ecasound is a software package designed for multitrack audio processing. It can be used for simple tasks like audio playback, recording and format conversions, as well as for multitrack effect processing, mixing, recording and signal recycling.
Ecasound Homepage
Name: amz-fx     ()  
Posted: Wed Nov 15 11:35:45 2006
Are you interested in Spice simulations of circuits? Then you need this collection:
MicroSim Application Notes
Name: amz-fx     ()  
Posted: Wed Nov 15 11:27:40 2006
Another useful ebook from Texas Instruments:
"Handbook of Operational Amplifier Applications"
Name: amz-fx     ()  
Posted: Sun Nov 12 05:29:46 2006
The sale is back on at Harbor Freight so if you missed the cheap stepped drill bits or the $2.95 multimeter, now is your chance.

Next, here is something I found yesterday which is very useful. A white LED flashlight for only a buck! I've already used it when reconnecting the wiring on the back of my TV and it works great with no real hot spots. Can't beat it for one dollar! The unit is available in several different body colors and I bought it at The Dollar Tree.

What do you do first when you buy something new and cool? You take it apart, of course! It appears to be merely 3 AAA batteries in series driving the white LEDs which are in parallel... just about the worst configuration possible. I expect that at some point the LED which is drawing the most current will burn out!

A suggested mod: add a 56 ohm resistor in series with one of the wires going to the back of the LED circuit board... doesn't matter which wire. The LEDs will not be as bright but they will not be in danger of burning out either.

regards, Jack

Click Here for Photo of Flashlight
Name: amz-fx     ()  
Posted: Tue Nov 7 05:02:56 2006
This is an online newsletter that occasionally has some useful information that could apply to pedalbuilding:
Analog Dialog
Name: donald stringer     (usa)   troublerat_AT_alltel_DOT_net
Posted: Sat Oct 21 07:36:21 2006
I know you are a very busy man but a welcome tutorial in the future would be something along the lines of low frequency oscilators and how to impliment them into effects. I have been on a lfo splurge trying to find one that works in tremolos and more or less trying to learn about them in general and I am not getting to far. For me the tutorial may read lfos for dummys.
Name: amz-fx     ()  
Posted: Fri Oct 20 16:47:46 2006
Looking for some great reading on guitar effects pedals? Check out the Pedal Power articles by Robert Keeley:

Musician's Hotline
Name: John Kennedy/Steeel Woool     (U.S.A.)   jmxkennedy_AT_aol_DOT_com
Posted: Wed Oct 18 02:09:14 2006
I wanted to thank you for your writings. Especially about web sites/ the thing u have on disc makers. very helpful.

I'm making a web site/music store and I gotta learn how to do much. thanx for your free really helps...

Visit my Page
Name: amz-fx     ()  
Posted: Mon Oct 16 17:02:58 2006
Electronic Design's Guide To New International Environmental Laws
RoHS Guide
Name: amz-fx     ()  
Posted: Mon Oct 9 16:49:19 2006
I found a good page of cabinet-speaker sim schematics. Not in English but you can find them if you are persistent:
Cab Sim Schematics
Name: amz-fx     ()  
Posted: Thu Sep 28 17:15:53 2006
Fabric that shields from electromagnetic fields? Should be good for lining the inside of wooden effects boxes:
NaturaShield Fabric
Name: amz-fx     ()  
Posted: Fri Sep 8 07:54:46 2006
If you are designing FX circuits, this is a pdf eBook that you need:

Opamps for Everyone
Name: amz-fx     ()  
Posted: Mon Sep 4 20:02:51 2006
There is an interesting web site on how-to-build things that just linked to my site- thanks!. They have some interesting links! Check it out:
Name: amz-fx     ()  
Posted: Mon Sep 4 09:43:45 2006
Why do people come to this web site, get the information they want and then when they build the circuit and it doesn't work, they post questions about it on another forum. I just don't get it. Nor can I be on a dozen different forums answering questions and the answer you receive from someone else may not be entirely correct. Just a mystery...

regards, Jack

Name: Mike     (USA)  
Posted: Tue Aug 22 11:16:04 2006
Is there any mod that can me done to the Gnatt to get more sustain from the pedal? Thanks

If you are talking about the Fat Gnat pedal, it should have PLENTY of gain. regards, Jack

Name: Mike     (USA)  
Posted: Wed Aug 16 09:52:14 2006
I have the AMZ CD. Does the Big Muff $ RAT ebook contain mod information not on the CD? Are the RAT mods valid for the RAT 2 model? Also, finally is it possible to convert the +9v adaptor input to take the Boss type? Thanks

1. The ebook does have a small amount of info that is not on the CD.
2. The Rat mods apply to the Rat 2 or vintage Rat, and some of them to all models.
3. The Rat is easy to convert to a standard power plug but you have to drill the hole larger and the Rat enclosure is steel and fairly hard. If that doesn't bother you then it is merely a matter of drilling the hole and installing the new plug in place of the old.

Name: amz-fx     ()  
Posted: Wed Aug 2 20:28:06 2006
My page at has been copied word-for-word at NOT COOL!

Check it out!

Name: amz-fx     ()  
Posted: Fri Jul 21 09:25:36 2006
John Broskie's tube circuit blog has an interesting soft-clipper circuit. I've seen similar circuits before but never got around to trying them out. It would take some mods to get this one to work with 9v power.
Soft Clipper
Name: amz-fx     ()  
Posted: Sun Jul 9 21:33:09 2006
Wow! Here is a great find... if you are a fan of the Beatles music... Alan W. Pollack's notes on the musical context of the Beatles recordings. Tbis will keep me occupied and reading for a long time!
The Beatle's songs analyzed
Name: amz-fx     ()  
Posted: Thu Jun 29 08:37:28 2006
Okay, I've got to have some of this.... magnetic viewing film:
Wonder Magnet Film
Name: Jim R.     ()  
Posted: Tue Jun 27 06:49:30 2006
This is cool, a tone that is so high pitched that adults cannot hear it but young people can. Load it on a cellphone and get calls in class and the teacher can't hear your phone ring! Free download.

Mosquito Ringtone
Name: amz-fx     ()  
Posted: Thu Jun 22 04:48:43 2006
Don't you think it is odd that the UK/EU has several hobby electronics magazines, including Elektor Electronics and Everyday Practical Electronics, while the USA has none? Even Australia has a nice electronics publication: Silicon Chip. It's good that the Internet makes international electronic subscriptions simple and affordable. The American publications Radio-Electronics and Popular Electronics were great magazines for decades and I know all hobby project builders mourn their demise.
Name: amz-fx     ()  
Posted: Thu Jun 15 05:28:35 2006
Free audio editing software for Windows

Wavepad by NCH
Name: amz-fx     ()  
Posted: Sun Jun 4 18:58:42 2006
Build a simple direct box for guitar:
Jfet Direct Box
Name: amz-fx     ()  
Posted: Mon May 8 18:19:39 2006
I wrote an article for the Disc Makers e-zine:

Webmaster Tips for Filmmakers
Name: amz-fx     ()  
Posted: Mon May 8 17:57:22 2006
A pessimist thinks that everybody is as nasty as himself, and hates them for it.
- George Bernard Shaw
Name: amz-fx     ()  
Posted: Sun Apr 23 13:40:56 2006
An interesting article about capacitor performance from the Best of Bob Pease:
Capacitor Soakage

Name: amz-fx     ()   amzfx_AT_email_DOT_com
Posted: Tue Apr 11 04:14:13 2006
Thinking outside the box requires different attributes that include:

* Willingness to take new perspectives to day-to-day work.
* Openness to do different things and to do things differently.
* Focusing on the value of finding new ideas and acting on them.
* Striving to create value in new ways.
* Listening to others.
* Supporting and respecting others when they come up with new ideas.

Out-of-the box thinking requires an openness to new ways of seeing the world and a willingness to explore. Out-of-the box thinkers know that new ideas need nurturing and support. They also know that having an idea is good but acting on it is more important. Results are what count.

-Ed Bernacki

Name: amz-fx     ()  
Posted: Sat Apr 8 07:39:20 2006
Interested in circuit bending? Check this guy out:

Table Hooters
Name: amz-fx     ()  
Posted: Sun Apr 2 07:43:54 2006
I was looking at some old data on my AMZ CD-ROM earlier today for a project I'm working on and got lost in browsing through some of the old projects... I did not even remember the improved jfet buffer or jfet coloration articles that are in the Lab Notebook! I need to re-read the whole thing...

Order the AMZ-CD
Name: amz-fx     (USA)  
Posted: Wed Mar 22 16:11:30 2006
"Prouver que j'ai raison serait accorder que je puis avoir tort." - Pierre Augustin Caron de Beaumarchais, Le Mariage de Figaro (Proving that I am right would be admitting that I could be wrong.)

IF anyone thinks that my opinion carries more weight than the average bozo, then you are spending entirely too much time on this forum. I assure you that in other parts of the stompbox internet world, the mojo-epistles of any local boutique guru are weighed with greater reverence than my more scientifically oriented "rants".

I am anti-mojo... I make no excuses for that. Where is the state-of-the-art advanced by mojo-claims that have no substantiating data? Unsubstantiated claims should always be open for debate. I had rather educate than obfuscate.

Let's look at the typical pedal mods -- Most recommendations are made on the basis of very unscientific tests. A mod is made to a pedal and then the sound is compared to what the person *thinks* the pedal sounded like before the mod! That is very subjective at best and open to a broad interpretation and the vagaries of the human memory.

Are we a subjective community or an objective one? Do subjective opinions without a shred of supporting evidence carry the same weight as a scientific look at the same idea? Do we allow pedal builders to continue to make claims without challenging them?

I am certainly not against mods because many may have a clear audible effect. MAY have, but not always. Substituting opamps can change the sound of a pedal... it's possible but not guaranteed in every circuit.

At the same time, if someone (such as myself) does objective scientific testing and reports those results, the claim is usually made that "just because you cannot measure the effects of a mod, it does not mean that the ear cannot detect it"... this is a view antithetical to traditional scientific method and the existence of any ultimate scientific validation. While there are no absolute truths (only relative truths), in the context of our hobby, scientism rules as the truth.

Pedal builders should spend more time creating something new and different, and less time hyping the latest marketing trend, whether it is germanium devices, stacked metal film caps, CC resistors or exotic opamps.

I bought a couple of boutique pedals from a builder who is very highly regarded on another forum... praised by many for his "ear for great tone". One of the pedals that had been lauded for being so fat and rich sounding, was actually quite thin and nasal through my system. I tried numerous amps and guitars with the same result. I did some tests on the pedal and they confirmed what my ears had heard. So I opened it up, chipped off the special mojo epoxy and traced the circuit... which further confirmed what I had heard and measured. Yet forumites continued with their praise: "What a marvelous tone! And the fidelity! The sustain of that beautiful tone! I have never heard anything like it in my life!" It's all subjective, isn't it?

One of my favorite magazines is Stereophile, because I love looking at the reviews of equipment that I will never buy, even if I could afford them. The staff of the magazine go to great lengths to downplay the fact that many of the extremely expensive tweaks, accessories and components that are advertised in their magazine have absolutely no audible effect on the sound of music. They even contrive a convoluted logic that blind listening tests are somehow flawed because the test itself is "an interfering variable". Huh?

John Atkinson, Editor of Stereophile, wrote in a feature article: "But when you have taken part in a number of these blind tests and experienced how two amplifiers you know from personal experience to sound extremely different can still fail to be identified under blind conditions, then perhaps an alternative hypothesis is called for: that the very procedure of a blind listening test can conceal small but real subjective differences."

I suggest that the alternate hypothesis is horsepuckey. The blind listening tests are not at fault but instead the amplifiers that you "you know from personal experience to sound extremely different", are in fact so similar that you cannot tell them apart unless you are looking at them and allowing your mind to have a subconscious influence on your auditory decisions.

This type of audiofoolery is similar to the arguments for homeopathy and alternative medicines, which is "I have seen it work, so the process is valid". Bloodletting made lots of people feel better in the 1700s but it killed George Washington!

Penn & Teller had a program on Showtime where they did taste tests in a fancy restaurant comparing expensive bottled water. The customers claimed to be able to tell the difference in the waters and explained the subtle variations in the taste... EXCEPT, all of the bottles actually contained ordinary tap water. Just say No to H2O. The name of their program explains it all...

But I digress...

Why do people buy (or make) expensive mods to pedals?

  • They are exclusionary. I have something out of the ordinary and you don't.
  • The mods look cool. Big fat 630v caps in a stompbox look really neat. They look good so they must sound good.
  • Crowd mentality. This psychological phenomenon suppresses a person's willingness to think for himself and increases suggestibility.
  • Peer pressure. People are unlikely to break from the group-think unless they have a strong ally or some other compelling reason.
I made a custom pedal for a player in Australia not long ago... it had NOS germanium transistors and stacked metal-film box capacitors... but it was an original design that required the use of those components.

Why is the subject of subjective listening tests vs. lab measurements such a hot topic? Voodoo, hoodoo, mojo, you know.

ZVex uses ceramic and tantalum capacitors in his pedals but you never seen any "hi-fi" mods offered for them. Why is that? I have my theory.

The bottom line is, if you want to make mods, whether of the mojo-type or not, then by all means do it! Give it a try. You might like it, or you might not be able to tell the difference but you can have fun trying, and that's what it is all about. I will be glad to help anyone wanting to try any of these mods, even if I don't agree with them...

Best regards, Jack

ps: If you want to recap a vintage pro-audio mixer I will certainly agree that the cap upgrades will be audible... but switching electrolytic capacitors for film capacitors in a new stompbox will have no effect on the sound. The bandwidth is too restricted, there are too many other non-linearities with greater influence on the sound, and normal component variations will nullify the impossibly small differences in the signal from one modified pedal to another.


An Audiophile Sounds Off
Penn & Teller
The Paradox of Choice : Why More Is Less
John Edward or More Penn & Teller

Name: Christian     ()  
Posted: Mon Mar 6 20:38:27 2006
Just saying hi, great site.

Name: amz-fx     ()  
Posted: Sat Jan 7 17:27:06 2006
I like the quote from this boutique pedal page, "NOT based on the Jack Orman AMZ booster, like the majority of boutique boosters on the market"

Killer Guitar Boost
Name: amz-fx     ()  
Posted: Mon Jan 2 19:02:56 2006
If you like pictures of hand-wired amps, check out this site:
Amp Chassis Pix


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