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QSC AMP I'VE NEVER SEEN BEFORE
- Thread starter lowphatbass
- Start date
what you have there, my friend is a "QSC Power Amplifier 3.7" 
sorry, i had to say it. Must be fun to find new toys!
sorry, i had to say it. Must be fun to find new toys!
what you have there, my friend is a "QSC Power Amplifier 3.7"
I guess I set myself up for that one!
Bob Lee (QSC)
In case you missed it, I work for QSC Audio!
- Jul 3, 2001
- 12,668
- 2,036
- 67
- Disclosures
- Former Technical Communications Developer, QSC Audio
That's pretty old for a power amp. Those were made from about the late 70s to mid 80s.
Cool, thanks Bob, as always.
I guess this amp made the rounds as a slave to drive bass cabs on a some reggae circuits back in the day. I didn't get a chance to use it at all, I just thought it was pretty interesting to see a piece of gear I've never seen before.
That amp held a place in my band's rack driving (2) 2-12" midrange (upper bass) cabs. They were very solid hard working amps. We had started off with even older smaller versions in our very first PA with even the older series before this generation. We had the 2 space Crossover 1.1 50W amp included for highs married with QSC 3.5 mono 100W amp. They too were incredibly solid performers.
I got an amp that looked very much like that (QSC A-41 model) back in 1988 and used it for my home stereo until about 2015, when I gave it away to someone.
It was soooooooooooo heavy.
It was soooooooooooo heavy.
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I have a herd of PLX I use for sound reinforcement.
These are rock solid work horses.
My very first was an MX-3000a, a real lead sled at 69 pounds bare.
It was 100% dependable, but simply to heavy for portable use, sold it off.
These are rock solid work horses.
My very first was an MX-3000a, a real lead sled at 69 pounds bare.
It was 100% dependable, but simply to heavy for portable use, sold it off.
- Feb 12, 2006
- 61,070
- 5
- 221,138
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
The A-42 was an early (maybe the earliest) grounded collector topology amp that I am aware of. I serviced a few back in the day, but mostly the follow up series 1 models based on the same topology.
Jibes with my experience, I had a bandmate buy one of these kind of QSC's around 1979.
I was away that Summer working and bought a Tascam Model 3 since he had a four track Teac 2340-S.
To fund the Tascam I traded in a Peavey PA-400 head, so we had no power for the columns I still had.
So we went down to Orlando and bought a power amp, I think it was a 1.7 but memories are fuzzy on that.
We used it out live to drive the old Peavey columns and it was much cleaner (the Tascam helped a lot in this regard) and louder than the PA-400 was.
I recall it as not being all that heavy, just lopsided in weight because of the transformer, it was two rack spaces.
You would know better than me but I believe QSC went to the "Series I" amps in the early to mid 1980's, I have a 1400 series one I bought in 1988. Still have it, great amp.
The Series I/One came in four space 1700, three space 1400, three space 1200 and I believe a single rack space one called the 1000. I think there was also a mono version of the 1200 called the 1,100.
The single space one is very identifiable by the giant heat sinks on the side. The 1100/1200 were passively cooled but the 1400 and 1700 had fans.
I actually started out with a 1200 (this was for my bass rig) but I would just clip it constantly so I went back to the store and gave it back, getting the 1400. The salesman (a guy who had sold me a lot of gear) laughed and said "I told you that you would be back for the 1400!".
It was more a money thing, I paid $555 for the 1400, that would be a $1,400 amp today.
To put the price into perspective, in 1988 you could buy new Peavey CS-400's all day for around $400.
Analogeezer
I had one of those around 1980-81 that I used with an IVP preamp and later an Alembic F2-B (which I still have). It had a built in limiter which worked in a very musical way for bass. I moved on to a power amp with more wattage and more flexibility as far as bridging, but the 3.1 sounded great and served me well at the time. A bit later I had a QSC 1400, which was a beast - looking back on it I think it was maybe the best power amp for bass I've owned, with very solid and authoritative low end. It wasn't bridgeable into less than 8 ohms, which was a bit impractical though.
I got to visit the Quilter amp facility a few years ago when I was participating in R&D on the Quilter amps. Pat (Quilter) had a room that was basically a "museum" of QSC and Quilter products from various eras, and they had a couple of the 3 and 4 series power amps in the pile.
I got to visit the Quilter amp facility a few years ago when I was participating in R&D on the Quilter amps. Pat (Quilter) had a room that was basically a "museum" of QSC and Quilter products from various eras, and they had a couple of the 3 and 4 series power amps in the pile.
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Yeah when I got my 1400 I used it with a rackmount preamp (a Peavey ProBass 1000, which frankly sucked) and ran it into four separate cabinets; two single 15" cabs and two folded horn cabinets (copies of the original EV Eliminator PA cabinets from 1969). All loaded with JBL's.
This gave me 600 watts (4 ohms per side) into four cabinets and finally allowed me to compete with the maniac guitar player who used two 100 watt Marshall stacks (as in full stacks, four cabs).
A lot of gear to haul but this was in the 1980's when hauling a lot of gear was just the way it was. Our drummer had so many drums (double bass, four racks, two floors, a set of Octabons, and a Tama two pad E-drum setup) and cymbals he used TWO Trap cases to hold all the crap.
Thank god we had four roadies and a good friend of mine who acted as stage manager. The thing with dumb guys you use as roadies....they just kinda stand around not knowing what to do, they need direction.
One of our roadies was great, a huge, 300 pound guy (named Leroy) back when nobody weighed 300 pounds, he just needed direction
Leroy could carry one each of my large single 15" cabs in each arm, dude was STRONG!
So John was kind of the director of moving and setting up gear, he would bark out orders to the roadies and this greatly facilitated load in and load out.
GREAT guy, I am still very good friends with him to this day. Weird thing he never went to college or anything but is one of the most intelligent people I know. His dad had an engineering degree from Cornell and the family was large (like four or five kids). Somehow John is the only one who got the brains, his siblings are kinda simple but somehow he got the engineering brain.
Analogeezer
Back around 1980, our sound guy Carl Taylor (who later was head honcho at Crystal Taylor Sound….now CTS) showed up at gig with a rack setup and told me my bass amp (a Lab Series L4) sucked and I needed to buy this rig. It was a Roland SIP-301 preamp and a QSC 1401 power amp. I gigged that rig for probably 20 years until I sold (the still working )1401 and replaced it with a RMX850. I ran that rig for another 10 + years. Its still sitting in my garage. For the occasional gig that requires an amp these days I mostly use a PF-500.
Wow, the last time I saw one of those was around 1982. A friend had one in his rack system. I had a Bryston 4B in mine. If you'd told us forty years down the road those racks would become 6lb 800w bass heads the size of a Steven King paperback we'd probably have thought "Awesome!" figuring you were high and might have a joint.
Believe it or not, this was one of the "newer" series in the late '70s and early '80s. My high school band had the earlier set of Series One mono amps.
This 3.7 power amp was the one we used in our college years to initially drive our JBL 4550 bass bins, but we moved it over to drive our 2-12 midrange boxes after we upgraded to a BGW amp. This amp was warm, efficient, and just excellent all around. Our band manager stole our gear from us when we broke up in our last year of college.
- Feb 12, 2006
- 61,070
- 5
- 221,138
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
I don't think so.
The Series 1 amps were newer, after the 3.7. The Series 1 included the 1100 (rare), 1200, 1400 and 1700, all were stereo, bridgable and used a grounded bridge topology.
Many years ago, I had a contract to service the electronics for a mid size chain of movie theatres, several thousand of these amps. Ironically, I first encountered Bob Lee (from QSC) during this time.
