Amplified Music Products SL-1 Bass Preamp

Don't remember the exact year (early-mid 80's), but my SL-1 came directly from the manufacturer as no Wisconsin AMP dealer was established. Called them...they agreed to sell me one. Listed for $400---they sold it wholesale for $250. This is one elaborate preamp---the predecessor to many of today's current models. I looked around for a decent Bass pre but couldn't find anything close to this. Saw an ad in the original GIG Magazine and called the company. The rest is history. Front panel, left to right: Normal & Low(padded -10db)inputs, Input Gain w/"Clip" LED, Limiter pot w/"Active" LED, Flat/Enhance switch, Bass control(shelving type), four band semi-parametric EQ, Treble control (shelving-type), Tone Balance (similar to a tone contol), Volume control, Variable 100-1khz Xover, obligatory Power switch w/indicator. Rear Panel: Xover High and Low outputs, Parallel Full range outputs, Ground lift barrier strip, Balanced XLR output(switchable Direct or Line), Effects loop in & out. Again, this was so far ahead of anything else for bass. I wanted something similar to a guitar preamp. I played many years without ANY malfunctions. (wish my playing was the same!!!) Couldn't ask for a better preamp---and way ahead of it's time. There isn't, in my opinion, a sound that can't be achieved with all the controls available. I modified my unit by wiring in an AC outlet on the back to turn my effects on and off when I used the preamp on/off switch. Also wired in a footswitch jack to operate the Flat/Enhance function. One thing I would have and thought of adding is a headphone jack. It wouldn't be difficult to do. Years ago this pre was used with an Alesis Quadraverb for effects and a Carver PM-1.5 power amp thru many speaker cabs...dual 15's, 18, 18 w/2x10 bi-amped, etc. One drawback; this preamp measures 2-1/4" high...1/2" taller than the 1-3/4" standard rack dimension. I caught this before I designed my rack so it really didn't matter, but it could have been trouble fitting it in a regular rack. Overall, what a great piece of gear!!!

My first and current bass-a '68 Fender P w/DiMarzio's. I've had a dozen or so others thru the years and all sounded good to me thru the SL-1. I've played many musical styles and never found this unit to be wanting. The SL-1 is not only versatile sound wise, but ultra quiet to boot. The built-in compression and gain plus volume cotrols allow clean to distorted sounds.

Dependability was not a concern. In fact, I never carried a backup preamp but did haul an extra Carver around as I powered my PA with 3 Carvers and sometimes 4. I've never had to do anything to this unit as far as maintenance, not even spraying the pots, switches or jacks. If every piece of gear was as good, what a wonderful world it would be. (Sounds like a line from a song!!!)

Other than them selling me the unit at wholesale direct, I never needed there help. One thing; not only did they include the owner's manual, but also a schematic and operational block diagram. All companies should be so thorough.

My years playing started at 14, continuing to 2006. I'm 63 now. As mentioned earlier, I've had a dozen or so basses, played Peavey, Fender, Ampeg, Carvin, Lab-Series amps plus others I can't remember anymore. But the workhorse has been my custom rig with the AMP, Alesis and Carver. That's traveled the whole Midwest and been stored continuously, winter and summer, in station wagons, vans and trailers. How about reliability and then some!! One thing about the innovation of Amplified Musical Products-they designed and built a single 15" cab that stored in it's own road case. But, the cab sat on top of the case wherein the whole stack combined to double the internal cabinet volume. What a great concept. I've never seen that before or since. I was always looking for one of those, couldn't locate one and seriously thought of building my own. I was just too busy building custom racks, cabinets and complete PA's for everyone else. One last comment, the headphone jack would have been great, especially after my marriage!!

This is a late 80's model designed by Steve Rabe of SWR fame, along with some of the top engineers from the Acoustic amp company.
The SL-1 Preamp is similar to the pre used in the famous A.M.P. BH-420 that Jaco used in his later years, but the SL-1 has even more eq bands.
Features: single rack space, both active and passive inputs, input gain e/w led, input limiter e/w led, enhancer, crossover, (6) band semi-parametric eq., effects loop, balanced DI out (direct or line), master tone, master vol.

Full and super clean. No noise. Very SWR-esque. I can make any style (slap, fingers, pick) come alive with this unit.

A friend had it from new, and I've owned it for 5 years, and there has never been a problem with it in 20 years.

The company no longer exists. Thank God it's so reliable. However, I would imagine any tech worth their snuff would have access to schematics if it ever needed servicing.

I've played pro for 25 years, and have owned about everything worth owning. Typically having several excellent rigs at the same time. This unit ranks at the top of the heap. It is in the league with SWR, Eden, Gallien Krueger, EBS, etc. Very top knotch tone, and extremely reliable.