The Sound-O-Mat

The DOD FX90 Delay Pedal

Out of all the companies or subdivisions that have made guitar effects pedals, esp. those with a long list of them as a main product, by far the the worst constructed are made by DOD (although the new Berhinger knock-offs seem to be vying for this title).

But like any company that makes a product line, there's often at least one or two gems that somehow manage to get by. In the case of DOD, one is most certainly the DOD FX90 Analog Delay pedal, usually selling for anywhere from $20-$40 (although some times as much as $70) used these days, which is a great price for an Analog Delay of this quality.

It's got the usual downsides of DOD gear:

• The battery cover tends to eventually break and you have to Duct Tape the battery inside.
• It's hard to find a non-DOD power adapter for it since it needs 10VAC DC with negative tip.
• Although this particular one has both a perfect cover and pedal, the pedal switch itself is junk - even when playing at home, much less out at a gig, in a dark, loud, stinking club, pedals that have a nice, definitive "click" to the on/off switch is definitely what you want.
• Some pedals actually sound "better" when the batteries are going dead - so much so, a company has created a power supply for them that will reproduce this "problem".
• DOD pedals, esp. the analog ones, are known to "eat batteries", so you always need a box of 9-volts about if you don't get wall-warts for them all or a DOD Pedal Board
• The LED is supposed to be "bright when battery power is good, and weak as the battery dies" as if that's a feature, and not just bad design as to how the LED/light is powered and often they just don't work at all.

So how does one live with a DOD pedal, esp. the ones like this that sound really good for the price, give a decent analog sound, and we can modify to really make them even better, as good as anything even 5x the price, or as good or better than Boss pedals (which tend to set the high-bar)?

We contacted the company about buying battery covers wholesale so we could replace our own and our friends' and offer them at local music shops, but all we got was a couple of emails saying either (1) they looked into having them made but it was too expensive (huh? they're still making 4-5 pedals that use those covers) or (2) the covers are made in China where the pedals are also made, and they just come shipped as one unit. We asked why the Chinese company couldn't just make an extra 100,000 covers and ship those to DOD who would easily resell them, and we didn't get a reply. They're obviously not a well-run company.

As far as the switches, those just stink when you're looking for a nice click: you just have to step on it and hope. And those are hard to replace, although getting the LED properly modified and set up helps a lot. But in this case, the DOD FX90, since delay isn't something one tends to turn on/off much if at all (say, vs. distortion) it's not really too much of an issue with this pedal, which you tend to just get dialed in to the settings you want, and then leave it alone.

Oh, and yes, it eats batteries, in part because DOD pedals just seem to suck power, and being analog as well, it's a bad combo. Definitely a pedal you want to find a "wall wart" power supply for if you're going to gig or just don't like piling up landfills with batteries, and if you own three or more, it's worth getting a DOD Pedal Board, which they don't make any more, but also show up on eBay pretty cheap.

All that aside about DOD crap pedals in general, let me go on about the wonderfulness that is this particular one.

First off, it's analog, and having heard at least 4x types of digital delays, rack mount, pedals, you name it... there's just something that even the Line-6 DL-4 "Delay Modeler" pedal, which does OK to pretty good, can't do in comparison to even this cheaply made thing. The schematics are rather simple, being analog, and you can
view them in PDF format.

What's worth noting is that you can open up this pedal, and with some time, parts, and skill, modify this pedal from a decent one (esp. for the price) into a great pedal into one that you'll never part with.

We have started modifying ("modding" or "mod'ing") these and Boss pedals ourselves, and it's been fun and interesting, esp. when you can make them do strange things, or in the case of the DOD FX90, radically improve it, easily doubling its worth but still being a bargain at even twice the price.

Mics and Phantom Power (48V)

Here's a question we answered today about someone trying to use a condenser mic that has an XLR connection (a balanced, powered, shielded type of connection, the best you can use in a studio) and required phantom power, as most good mics do. Here's what we wrote, about the Digidesign Mbox 2 and the really impressive "WE WANT ONE" MXL 990 mic he has:

Just to be complete, the "Digidesign® Mbox® 2 Pro" - assuming you got the pro model, not the original, is an "audio/MIDI production system ... packing an impressive variety of connection options into a compact interface". I'd read about it before and it sounds like a great box for a lot less than other similar products.

The MXL 990 mic is a condenser, shock mount mic I've read good things about in Tape-Op Magazine, cardioid pattern with 30Hz-20KHz range (claimed) that requires a shock-mount. Similar to my Audio-Technica 4033 but with more on the bass end. A great mic from what I've read.

Anyway, it's mono, of course, and has what's called an XLR connection, and most importantly, requires "48V Phantom Power (+/- 4V)", so it's a phantom-powered mic.

So you'll need an XLR cable for the mic, and something that supplies phantom power. I plug my phantom powered mics directly into my Mackie mixer, which provides 6 phantom-powered XLR jacks for mics (you can turn the phantom power on/off.)

So the question is, does the Mbox 2 have XLR inputs, and looking at the photos it does, let's see... specs say "4 analog inputs (2 XLR/1/4” TRS combo jacks & 2 1/4” TRS jacks)" so you have 2 XLR jacks, so all you need, cable-wise, is a standard, shielded (!!) XLR-to-XLR cable.

Checking the specs further, the Mbox 2 offers "48V phantom power for condenser microphones", so you're good to go, you just need the XLR-to-XLR cable and if the phantom power is something that needs to be turned on, turn it on. As for output, the Mbox 2 offers 8 audio outputs, but they all look to be line-level outputs, so you'd need to run the output either to powered speakers, or to a pre-amp.

This Mbox 2 even offers a phono pre-amp with RCA hookups so you can hook up a turntable to it. Quite the unit, it covers everything.

My guess would be that if you have the right cable and the phantom power turned on, that your output needs to go to powered speakers/monitors (ones that have their own amps built-in, and provide better sound since the amps are designed specifically for the speakers/monitors) or you need to go to some kind of pre-amp from the output in the Mbox 2 and then plug your speakers into the pre-amp.

Should all work just fine. Bad cable is something to check for too, as always!

The two key things here are that many people don't understand that some mics can generate enough output to make line-level signals which usually don't need to be boosted, but really good mics, regardless of whether they're condenser, ribbon, PZM (piezo-electric), transducer, etc. usually need what's called "phantom power". The best analogy is the output from a turntable, which requires a "phono pre-amp" just to boost it to line-level output. Phantom power mics need a 48V boost to get them to line-level, and either you need a soundcard, mixing board, or some other pre-amp to supply that phantom power to boost the system.

The other thing is to make sure you have good cables, as many times people can waste a lot of effort when a bad cable is involved. Phantom mics are also very easy to fry so a bad cable can ruin it, and they should come with an "off" switch, and one should always turn off the mic before turning on the phantom power, except for PZM mics, or you can literally burn out the mic if there's a power spike when the phantom power is turned on.

Good mics are delicate things - learning to use them correct is very important. If there's anything to be understood about mics, that's Rule #1.

White Noise and Radio Sound on Stereo Speakers

This seems like a somewhat obvious question, but it's really not. Most people don't realize just how much "signal noise" there is going through the airwaves around their home: cell/mobile phones, CRTs and anything with an unshielded power supply, AM/FM radio signals, and a laundry list of others. Recently someone asked:

"Hoping you have an idea of what's going on here. I am getting background white noise along with a very low volume radio sound through my stereo speakers. This happens regardless of what component is selected,e.g. AUX, CD, Phono."

The only idea as to why the Bose system is picking up radio signals as well as white noise, likely from the wiring or radio signal interference, or perhaps internally generated, is the design of the Bose system. It could be that the Bose speakers aren't properly designed or shielded and are picking this stuff up. The other possibility is that the cables you're using are sensitive enough to pick up such signals and aren't shielded.

You don't mention the resistance of the JVCs vs. the Bose (8 ohms?) but my guess, without having that info, is that the Bose run at a lower resistance (4 or even 2 ohms instead of 8 ohms) which makes them more suseptible to picking up radio interfere, and a good set of shielded cables from your receiver to the speakers would help. To save yourself $$$, find the Bose unit that is the "noisiest" and try buying enough shielded speaker cable to plug that one in, and see if it goes away. If it does, and you want to keep the Bose system, then you can then go buy enough shielded cable for all of them.

That's about the best I can do with limited information. Do remember that it could be a problem with the Bose system itself, so if it's new you might want to return them and try another, as it might be a manufacturing defect, so get them back while they're still under warranty if you can.

Amps, Power, Speakers and Resistance (ohms) Explained

Ohms are a measurement of the amount of electrical resistance that the cables and circuitry of any electric signal carrying audio gear (or any electronics for that matter) produces. The lower the number, the more resistance, and the more overall power (watts) that the gear can support and is required.

You can't tell what an amp is running, since it switches automatically. It is dictated by the speakers you hook up. You need to check the rating on those, and if they're 8 ohms rated (most common) then that's what your amp will be powered at, if they're 4 ohms, it will be more wattage, etc.

If you have subwoofers that are 4 ohms, then that's what the amp will run them at, 600 watts RMS, probably around 1000 watts peak. You cannot "switch" or "change" the resistance: it is dictated by the design of the sub-woofer itself.

You're also working under a misconception - just because something is rated as requiring less ohms, which means your amp can use less power to run it. It will not give you "more power". The amp simply runs at whatever wattage is necessary to drive the speakers or woofers, and changing them will make no difference. If you want louder, all you can do is buy a more powerful amp, and make sure your speakers and woofer can handle that power without blowing out.

Hooking Up Turntables to Various Things

I recently wrote an answer on AllExperts.com where someone was asking about hooking up a turntable, aka a phonograph or grammophone player (technical names) to some kind of amp or box I'd never heard of (an "Mbox 1".) Here's what I wrote that's important info for anyone who wants to set up a turntable because they've realized that contrary to popular belief, vinyl is not dead:

There's an important thing (or three) to know about turntables. Aside from magnetic vs. other carts, the main one is that the signal from phonograph players, as they're technically called, is very, very low, even lower than line level. It's also been recorded with a freq. transformation known as the "RIAA Equalization Curve"; you can read more about that here:

The Sound-O-Mat: RIAA Equalization Curve

So what you're getting out a turntable needs to be heavily boosted as as signal (which is why pops, clicks and vinyl hiss is so noticeable, although the curve does help remove the hiss) and also the amp you're plugging into, in this case an Mbox 1, needs to have what's known as a "phono hookup" which boost the signal as well as applies the reverse transformation for the effects of the RIAA Equalization Curve.

It also needs to be grounded, if it's not grounded you're in bad shape, sound-wise. I haven't looked up the specs on the Mbox 1 but if it doesn't have at least one "phono (line) in" pair of red/white plugs and a place to hook up the ground line from the turntable, then the only way you can make it work is to buy what's known as a "phono preamp", which is basically a, well, pre-amp that corrects the RIAA equalization and boosts the signal to what's called "line level". If you do a Web search you'll find lots of them; the cheap ones will sound bad, so it's worth spending money to buy a decent one, but no need, unless you want, to go crazy on the audiophile ones, although I have to admit some of the tube/valve-based phono preamps out there, while expensive (we're talking US $1000 and up) sound pretty damned great.

Subwoofer for Home Theaters

Here's a question we recently answered about adding a sub-woofer (aka a "sub") to a modern TV system:

"My 50" rear projection Sony Hi Def TV has 2 RCA red/white ports labeled "Audio out". Can I just buy a subwoofer and plug it in to the output jacks on the TV. Why do I need an amplifier? I'm happy with the midrange/treble. I can't tell for sure, but I think Sony does what some of the other companies do: the bottom of the TV set has 5 speakers or so, angled different directions, to give some illusion of surround sound. Whatever they do, it sounds pretty good, seems like it could just use some bass." -- David

Hi David,

If you have RCA-style red/white output jacks on the TV, you can hook it up to a sub-woofer, but the sub will have to be separately powered, and must have what's called a "low-pass filter" built into it so it only plays the lowest frequencies. You don't need a separate amp but the sub needs to be powered, which means it has an internal amp.

If you shop around carefully at subs before you buy you shouldn't have a problem. Good luck!

The Boss (Roland) CE-300 Super ChorusRack Mount Processor

Ah, nothing like getting your hands on a piece of classic, almost "retro" music processing gear. We recently found a Boss... er, Roland, who owns and makes all Boss gear, which is just another brand that their brilliant founder came up with... anyway, a Boss CE-300 "Super Chorus".

It's a classic piece of kit that was probably used on 80% of the albums produced in the 1980's and early 1990's before it fell out of favour, which is too bad, because it's like most Roland gear: you can use it very subtly as a processor to just barely tweak something, or you can set it to "11" and it becomes almost a musical instrument, given the kinds of crazy sounds it can produce.

For starters, if you're interested in one, best to read up on it on the best place to find out about audio gear, because all the reviews are written by end-users like ourselves, not paid reviewers: Harmony-Central. Bookmark this site if you're a musician, producer, audio engineer, or in any way ever need to know anything about music gear, it's the place to go. Here's the entry for the Boss CE-300 Super Chorus.

So we've been playing with this thing, and for such a simple interface, there's so much you can do with it, it's astounding. First off, it's got the mono input and stereo output 1/4" jacks in front as well as back, so you get a free patch-panel as part of the deal. The power switch is obvious, and ours came with a busted LED that took 2 seconds to fix. The controls are very simple: input levels, and you can push it to +3dB at least without really overloading, although you can also overload it to get some interesting effects.

Next there's the modulation of the chorus, which you can choose the speed of, and the "depeth", which is basically how much of the original signal/sound comes through vs. the altered, better known as the "wet/dry" ratio. If you want the full effects, you just dial it all the way over.

The chorus control itself has a "Tone" control, which is rather arbitrary, but on top of the unit is the entire circuitry layout, showing the signal path from input all the way to output and all of the possible effects that you can use on the way. The "Tone" seems to just drive the chorus units to stronger levels, but we haven't studied the diagram closely enough yet. It does do as it says, and next to it is the "Level" dial, which is how much of this chorus you want, from "Min" to "Max".

Add a "bypass" switch to skip the processing so you can compare it to the original source, and a "mute" switch which just turns off everything, and that's it. The "mute" might seem odd but we've already made this thing scream and crank out some loud, gnarly noises: even through it's a purely digital effect box, it seems that if you really turn things up, you can overdrive circuits and/or get them to feedback, so it's actually nice to be able to hit the button should things get out of hand.

Right now we're amazed at how much these are selling for on Ebay, and despite owning over a dozen (possibly closer to two dozen) software-based chorus plug-in effects here at The Sound -O-Mat Studio, within a minute we knew it was a great purchase, because we've never heard anything like this.

To sum it up, it's a 10/10 and if you're at all interested in chorus as an effect in your studio or as a musician, you'd be wise to check this out. Oh, and for the guitarists out there, although it's a rack unit, it has a plug in back for an on/off foot-switch and is the same circuitry and algoritms as the classic but expensive Boss CE-1, CE-2, & CE-3 guitar pedals. In fact, we'll probably sell off our Boss CE-1 for twice as much as we paid for this. It's built like a tank, so you can tour it without worry, and if you have any rack units at all, we'd say you can probably get rid of any chorus git-peds you've got and go with this one and get them all in one neat package.

Cleaning & Repairing the Roland Space Echo (Chorus Echo, Tape Echo)

Our studio owns a couple of different versions of the famous Roland Space Echo tape echo/reverb/delay/chorus unit. They started with the "RE100" and "RE200" in 1973, but both of these seem to have disappeared without trace. It was also launched alongside the RE-101, but this lacked six of the modes, the EQ and the all-important reverb, so it was the RE-201 that became the Space Echo. Oddly enough, we like our RE-101 and RE-301 better.

They are built like a tank and look superb. Later came the RE-301 "Chorus Echo" which added the all-important "sound-on-sound" effect (basically, a switch to turn off the tape erase head) and a really great analog chorus circuit, and then the RE-501and the rare rackmount SRE-555 which added chorus, sound-on-sound, a fourth echo head and a balanced (XLR) input.

There was even a cut-down model, the RE-150, but this was really just a reissue of the RE-101 without reverb nor EQ, and only had two playback tape heads instead of three like the original. Most of these remained in production until 1990, having been first released between 1973-1976. That's quite a long run for audio equipment, second only to guitar pedals.

A digital version, the RE-3, was launched in 1988, and, although it was an OK unit that didn't really sound like real tape echo but has its own unique sound in its own right, but it was not a great success. So people like the Roland SP-808 for its tape echo effects, which are identical to the RE-3, and easier and cheaper to find.

Of course, there's other brands, the Korg Tape Echo, the Ace Tone EC1 which is a dead ringer for the RE-101, with the same three-channel input configuration and prominent VU meter. Sure, the Ace's controls are different, with buttons rather than the rotary knobs of the Space Echoes, but the family resemblance is unmistakable.

These amazing analog wonders often need a good cleaning, adjustment or repair. We've gotten quite good at it, although when they start to get dirty and act funky, we'll often leave it that way for awhile to see what kind of weird sounds we can get out of this thing.

And even in the most basic use, we've run electronic digital recordings through one of the units with all the effects turned off just to get the sound of a real, high-end tube amp sound.

If you're in the Portland, OR metro area and own any kind of tape echo unit, we can happily clean, adjust and repair your unit for you for a lot less than what the local shops cost. We can also provide information, so if you've been looking for a repair manual and/or the operation info card/sheet that's supposed to be on the inside cover, we can probably help you out with that too. Having operating info and/or the repair manual can make your life so much easier.

Heck, we even run this blog through Space Echo before we allow anything to be posted! So if you've got a Roland Space Echo and need any help or have any questions, please drop us a line!