Category: Repair

Some people are simply amazing. And by amazing, I mean amazingly thick.

Here’s the story: Impaled drummer Raul called me from his work, Guitar Center. They were moving locations in the East Bay. They had a used Ampeg 1540HE cabinet they had sold and had been returned. Why? Because whomever sold this used item to Guitar Center did a real cracker-jacked job to fix it. Apparently, Guitar Center employees had never bothered to take off the grill before they bought it. One 10″ speaker and the 15″ speaker were replaced with car stereo sub woofers. WTF? They wanted it gone before they opened the store and let me have it for $50. What a mess. But I got it roaring again and looking okay.

The 1540HE is a fairly specialized cabinet. It’s designed to be paired with an Ampeg 400T rack mount amplifier or any amp that can do bi-amping (Ampeg 200T is another). What’s bi-amping you say? Basically, here you’ve got two cabs in one. The 400T is capable of running like two amps in one and splitting your signal between highs and lows. The theoretical use of the 1540HE is to send highs to the 10″ speakers, lows to the 15″ speakers, then blend and adjust until you get one bad-assed tone.

That’s the theory, anyway, so long as you know how to adjust one of these:

These cabs don’t have a lot of fans online and they weren’t produced for very long. Most numbnutted bass players just stuck an amp on top and plugged in, not accounting for bi-amping. It just doesn’t work as well, as the four 10″ speakers and the one 15″ speaker will not have the same presence from a single signal (say that three times fast). One can end up with weird phase cancellation of the actual sound coming out or just not get the full effect from the top or the bottom.

What really doesn’t make it sound good is when some dickbag puts in subwoofers meant for a car.

That is what I extracted from the cabinet. Speakerotomy. Luckily, I had a 15″ and a 10″ lying around that were perfect replacements. The 15″ I’d actually salvaged from a weird, fancy Hammond PR40 oak enclosure that someone had dumped in Oakland. I nabbed the only speaker left in it, and lo and behold, my pack-ratting paid off. The cab fired up fine and the speakers were all blaring.

A really bad design flaw on the 1540HE is the placement of a high frequency attenuator knob on the jack plate. It sticks out. Now, how many people do you know that load these refrigerator sized enclosures with grace? The damn shaft of the potentiometer had snapped in half. I pulled out the circuit board from the inside and went about figuring a solution.

I used a 1/4″ thick nylon bolt to extend the shaft of the pot. I got a nice set-screw knob from Al Lasher’s and the back plate was fixed. And ready to be broken again due to piss poor design!

The wood of the cabinet had itself taken a bit of beating. The majority of SLM made Ampeg cabs are comprised of particle board. That’s a far cry from the sturdy baltic birch the originals were constructed of. As soon as the cab starts taking hits from being loaded and unloaded, the edges start to fall apart. There’s really no excuse for this, other than planned obsolescence. I did my best to patch up some nasty wear on the corners where the metal plates had fallen off.

First, I filled in the original screw holes with some toothpicks covered in wood glue. Break these off, and you have a tight fit for a new screw where the old one have stripped out.

I mixed up some wood putty epoxy and molded myself new corners. It’s not as good as wood, but it’ll have to do for a patch up job.

The tolex had a lot of rips. I put some more glue on these and then just taped it down and hoped for the best. Tolex is awesome and sucks all at the same time. It protects the wood, but when it rips, it’s over. The best is to just try and keep up with the rips as they happen. Cut off small pieces before they become big ones or glue ’em back down.

The casters also had to be replaced with correctly sized ones, not available at any store I’ve found. My only source is Fliptops. The ones the dildo before me had used lifted the cabinet a good 2″ off the ground. His solution? Nail a 2×4 board to the front of the cab. I had a salvaged (again) pair of casters that were Ampeg replacements. I bolted them in, ripped off the 2×4, and added a pair of the large rubber feet that are on all modern Ampeg bass cabs. Finally, I replaced the grill fasteners with some I had ordered awhile back, also from Fliptops. Put it all back together, and it ain’t too shabby.

The first problem was the actual effect. It was doing something, but it was all wrong. The wah effected half way, then went silent, then effected opposite as the foot treadle was moved on its axis. I suspected immediately that it was the curtain that rolled over the light dependent resistor inside the pedal. These things were taped in place originally… thirty years ago. When I opened it up, it sure as shit was flapping about. I removed the flap.

You can see it’s just masking tape that’s supposed to be holding it all together. I marked where it was and simply taped the curtain back in place. Easy, peasy, nice and squeezy.

If you have everything in place, the foot pedal will roll the curtain over the LDR and block the light from the power indicator as it’s pressed towards the heel. You can adjust the LDR slightly to allow more light on it, carefully so as to not break the leads. The curtain can also be adjusted with the nut attaching it to the foot pedal. 

The wah was working well now. In fact, really well. I like the PWO wah sound a lot more than the already incredible wah sweep on the Power Wah Fuzz. It has a richer body to it, allowing a more full range of frequency to come through. I also like the fact that this is one of the rarer Morley pedals that doesn’t double as a volume pedal, like the Wah-Volume WVO. On the PWO, the treadle can be left at any angle and engaged into wah mode. On the WVO, you’re subject to where the treadle is set for volume when you want to engage the wah.

Next up, I tackled the aesthetics. Hey, if you’re gonna have a huge, chrome box taking up stage real estate, it better look sharp. This guy had a lot of dimpling in the chrome finish that led to big rust spots. The spots look worse than they are as oxidization spreads. The best thing to do is get rid of as much as you can with a fine 000 grade steel wool pad rub down.

The bottom of the pedal was pretty fucked. The rubber feet were gone and it had velcro from being on someone’s pedal board. Nasty masking tape was also on there. It all had to go. This is where A.D.D. is a blessing and curse… does the bottom of the pedal really matter?

I had to get a little more aggressive on this part. The bottom is made of sheet metal and not chrome plated. It requires sandpaper to polish. I started with a 320 grit and moved up to 600 and ended with 1200 for as fine a polish as I could get. I replaced the feet with some generic sticky-backed rubber feet available at Radio Shack. They are really close to the originals.

For once, the 387 power indicator bulb was actually in-tact and working. This is usually blown and folks think their pedal is dead. As a matter of course, I like to tape in a spare bulb for future generations. I believe the children are our future. Hey, that’s got a nice ring to it. I should write that down, or something.

Something about these old guys made in the ’70s… sure they take a little more massaging, but they are able to keep on ticking and kickin’ ass. Oh, and the pedals from that era keep working, too.