Linear Power 8002SW Amplifier Amplifier Dyno Test Old School AD-1

Early 90's Linear Power 8002SW 800W Mono Amplifier

The Linear Power 8002 was an 800 Watt single channel amplifier optimized for 8 and 4 ohm loads. It was available from 1991-1997 and sold at a MSRP of $1599. Unlike most of the mono amplifiers of today, this 8002 is capable of reproducing the entire 20Hz - 20kHz frequency range. 

We initially ran all of the tests using the 4 ohm power supply taps, which lowered rail voltage and increased current. Amp is less efficient in this mode and also produced less power. After a call with Linear Power, it was suggested I set the amp to the 8 ohm taps to run the 8 and 4 ohm Dyno tests. If you read the original Linear Power manual, they caution against running the amp in 8 ohm mode powering 4 ohm speakers. It is quite evident these amps are overbuilt and are more than capable of handling the additional load without breaking a sweat!

Linear Power 8002SW's Guts - TO-3 Transistors

Specifications according to the 1991 Car Stereo Review Directory (July/Aug 1991):

"1 channel. 800 W x 1. Features biwired output terminals for feedback loop, which keeps speaker wire DC resistance from reducing damping factor; defeatable subsonic filter; soft turn-on/off; fan cooling; metal shroud. FR 19-20,000 Hz. 17 x 3 x 9.5 in - $1,600" (CSR Jul/Aug 1991)

The Linear Power 8002 was also in a battle of "monster" amplifiers in the October 1991 Car Audio & Electronics magazine. Other challengers were the Rockford Fosgate Power 1000 Mosfet, Precision Power 2350DM, Orion GS500 and HiFonics Colossus VII...quite a group of large, powerful, Class AB amplifiers! Since the 8002SW is a mono amplifier, the tester used 2 of these amps in the comparison. It may or may not surprise you, but the Linear Power came out on top. Quite an impressive feat, considering the competition!

Watch the video and see the results obtained from this 20yr old car audio amplifier. Nothing short of spectacular!

Here are the results from my test with the SMD/D'Amore Engineering AD-1 Amp Dyno:

8 ohms mono - 8 ohms - Amp is rated at 800W at 12V
8 ohms - Certified 1% THD - 818W at 13.99V
8 ohms - Uncertified - 819W at 14.05V
8 ohms - Dynamic RMS - 1029W at 14.31V

4 ohms mono - 4 ohms - Amp is rated 800W at 12V
4 ohms - Certified 1% THD - 824W at 13.5V
4 ohms - Uncertified - 855W at 13.48V
4 ohms - Dynamic RMS - 1407W at 14.5V
4 ohms - Dynamic RMS - 1606W at 15.17V



All tests above were at 40Hz. As you can see by the results, this amp is well suited for subwoofers or mid-basses as it has a nice amount of dynamic headroom for those transient peaks. 

Watch the video in full 1080P HD Here >>

Or embedded below:


More Amp Dyno AD-1 tests coming!

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http://www.youtube.com/meade916
http://www.youtube.com/SoundManCarAudio
http://www.youtube.com/DAmoreEngineering

Possibly the Ultimate 50 Watt Cheater Amp from the 90's?

Yes, I know, if you guys watch my YouTube videos, then you've probably seen the Lanzar Opti 50c. But wait, is it possible another "50 watt" amp may give the Lanzar a challenge for king of the 25x2 amps? Well, yes, specifically the U.S. Amps VLX-50. I recently came across a near MINT 1996 model in the "Mirror Polish" finish which looks nearly chrome. See the pics below:

1996-1998 U.S. Amps VLX-50 Ultra-High Current Cheater Amp

The VLX-50 has the following ratings:


2 x 25W at 4 ohms (12V)
2 x 31W at 4 ohms (14.4V)
2 x 62W at 2 ohms (14.4V)
2 x 125W at 1 ohm (14.4V)
2 x 250W at 0.5ohm (14.4V)
2 x 500W at 0.25ohm (14.4V)
1 x 1000W at 0.5 ohm bridged (14.4V)
THD: less than 0.006%
External 120A Fuse Required

VLX-50 Inputs and "Vari-Loud" controls

The U.S. Amps logo is laser etched on the heatsink and it surprisingly took me several days to prove this was actually a VLX-50. For some reason, U.S. Amps didn't put any markings on the end plates or even on the circuit board indicating the model of some of their amps (this one included). I was able to get confirmation from U.S. Amps this was indeed a VLX-50, based on the serial number. I even posted a thread over on DIYMA to get some info and got some great info in the archaeological dig.


So, the best part about having an amp rated at 50 watts total put out 1000 watts is the "cheater" factor. Back in the 90's, you could have two of these and still compete in the 100 watt and under competition class (as they rated amps by their 4 ohm output power). Thus the "cheater" status as you could have up to 2000 watts if these amps were properly loaded down. Orion really started the cheater amp category with the 225 HCCA, which was introduced in the late 1980's. Also, as a response to ultra-cheater amps like the VLX-25 and VLX-50, Orion developed the "1-watt" Concept 97.3 back around 1997. The cheater amp era basically ended around the early 2000's as most manufacturers were competing to see how high they could rate their amps (by using MAX power) instead of underrating amps. Another reason why I prefer the car amplifiers from the 80's and 90's...

VLX-50 Power / Ground / Speaker Terminals

Get ready for the long awaited 25x2 cheater amp shootout. As soon as the temps cool and I complete my additional resistor loads, we'll see how the VLX-50 competes against the monster Lanzar 50c. I don't believe the Orion 225 HCCA, Rockford Power 50x2, MTA 225HO or Audio Art 50HC have a chance against the VLX-50 or 50c, but who knows? We all may be surprised!




See my video overview of the U.S. Amps VLX-50 below.




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Watch the video on YouTube in 1080P or embedded below:

Old School Monster Car Audio Amplifiers

Some Old School Monster Amps from the OldSchoolStereo Collection...no Class D here!

Anyone who was in the car audio scene during the 90's probably recognizes names like "The Beast" and "Power 1000c". Old school monster amps were unlike the big mono block amps of today...they were Class A/B, much less efficient and some would say, much better sounding than the amps of today. I'm not getting in a battle of what's better, just confirming there are two sides here. Since you are visiting OldSchoolStereo.com, you are more than likely a fan of the older amps. Many of the amps you see in the picture above are almost legendary in the history of car audio. Let's talk a little about each amp and it's impact on car audio.


First off, you'll notice a trio of Orion amps, all bearing the same heatsink design. The "big red" Orion 2100 HCCA is well known to be a monster cheater amp. The "Digital Reference" model displayed above was rated to handle 2 ohm mono or 1 ohm stereo loads and put out in excess of 800 watts loaded down. Efficiency? Well, not so much. All of these big Orion's require a 2nd battery and an electrical upgrade on most vehicles. Why, might you ask? Well, these amps can pull over 100A of current and most stock electrical systems would not be able to handle this massive load. Speaking of massive, the XTR-2250 was so well known as "The Beast", Orion even engraved this saying on the amp. It is rated at 250 watts per channel at 4 ohms stereo, 500 watts per channel at 2 ohms stereo or 1000 watts bridged at 4 ohms. What you say? No one ohm bridged like a Sundown? No sir, this amp would and will fry if pushed too hard.

Orion Monster Amp Art by BigDWiz

Speaking of being pushed too hard, the Orion Concept 97.3 is an amp of almost legendary status. A quick search on the Internet will give you dozens upon dozens of different pages attempting to explain this amp. Orion introduced the amp in 1997 as a bold statement to IASCA and dBDrag for the wattage classes. The 97.3 was rated at 0.5 watts per channel at 4 ohms...yes, I said 1/2 watt per channel! What's up with that? Well, Orion was trying to show the "cheater amp" had gone too far when companies such as US Amps and their VLX-25 had ratings of 12.5 watts per channel at 4 ohms but put out over 1000 watts loaded down to 1/2 ohm. Orion, an originator of cheater amps with the 225 HCCA back in the 1980's, decided it was time for this to stop. What did they accomplish in their effort to change the rules? Well, they ticked off many competitors who attempted to use these amps at low ohm loads (and fried the amps) and even got the amp banned by IASCA in 1998 (source - Orion dealer). Why would the amp cause this much controversy? Check out these ridiculous ratings, it may help (ratings pulled from the Concept 97.3 manual):




STEREO (watts @ ohm load)


0.5x2 @4
1x2 @2
2x2 @1
4x2 @0.5
8x2 @0.25
16x2 @0.125
32x2 @0.0625
64x2 @0.03125
128x2 @0.015625
256x2 @0.0078125
512x2 @0.00390625


 MONO (watts @ ohm load)


2Wx1 @4
4wx1 @2
8WX1 @1
16WX1 @0.5
32WX1 @.25
64WX1 @.125
128WX1 @.0625
256WX1 @.03125
512WX1 @.015625
1024WX1 @.0078125




Next we'll talk about the monster Rockford Fosgate amps, the Power 1000c Mosfet "Terminator Edition" and Power 650 Mosfet. Back in the early 90's the 1000c sold for $2650, while the 650 was around $1800. Again, these amps were WAY out of the reach of most car audio fanatics including me. These Power Series amps all had model numbers based on their output at 2 ohms stereo or 4 ohms bridged. For example, the 1000c was rated at 150x4 at 4 ohms, 250x4 at 2 ohms or 500x2 at 4 ohms. Similarly, the Power 650 Mosfet was rated at 125x2 at 4 ohms, 167.5x2 at 2 ohms or 325x2 at 4 ohms bridged. Unlike the Punch series amps at the time, these Power series are not known to be underrated more than 10-15%. Both amps have a temperature controlled cooling fan and the 1000c includes an ultra cool LED meter for each channel.

1991-1993 Rockford Fosgate Power 1000c Mosfet Amplifier

Next up, we'll discuss the Precision Power ProMOS 450. This amp preceded PPI's "Power Class" line and the models in the ProMOS family were made from the late 80's until the mid 90's. The 450 was the most expensive ProMOS amp and incorporated two separate ProMOS 50's into one chassis. When the first ProMOS amp, the PPI ProMOS 2050 hit the market in 1989, it went for around $800. By the early/mid 90's, the four channel 450 could be picked up for around $900 US. All of the ProMOS amps were rated to handle 1 ohm stereo or 2 ohm bridged loads. The 450 had the following ratings; 50x4 at 4 ohms, 100x4 at 2 ohms, 200x4 at 1 ohm, 200x2 at 4 ohms or 400x2 at 2 ohms. The heat sink used by these older PPI amps are in my opinion, some of the most classy designs of all time. Very simple, yet elegant and powerful. Too bad PPI used the hateful proprietary Molex plug for speaker connections and straight 8ga wiring for the positive and ground connections. As you can see from the picture below, the ProMOS 450 is even longer than the Orion 2100 HCCA!

PPI ProMOS 450 "Art Series" vs. Orion 2100 HCCA "Digital Reference"

The Earthquake PA-2300 is another very powerful Class A/B amp from the 90's. It is rated at 380x2 at 4 ohms, 575x2 at 2 ohms or 1150x1 at 4 ohms. Based on ratings alone, this is the most powerful old school amp in the bunch. The newer Dragster DH-1804 edges out the PA-2300 in power ratings, but just slightly. The Dragster is another four channel amp rated at 180x4 at 4 ohms, 300x4 at 2 ohms or 600x2 bridged at 4 ohms. Although I haven't confirmed by testing, I believe the Earthquake PA-2300 may be the most powerful amp in this group. What do you think?


See my video overview of each amp below.




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Watch the video on YouTube in 1080P or embedded below:

Some Really Powerful Mini Amps? The Rockford Fosgate Punch Boosted Rail Amplifiers PBR300x1 PBR300x2 PBR300x4

Rockford Fosgate Punch "Boosted Rail Amps" - From left to right; PBR300x1, PBR300x2 and PBR300x4

I get questioned all the time as to why I do tests and reviews of new amps on OldSchoolStereo.com. Isn't this website for stereo gear from the 80's and 90's? Well, yes, but I also like to test new products that stand out from the rest. As you may have seen on my YouTube channel, I like to make portable boomboxes and tiny amps such as the Rockford Fosgate PBR series intrigue me. Also, let me make it clear...these Punch PBR series amps pack a big power "punch" and are not to be confused with the other Chinese Mini Amps I've tested in the past. Those amps from Lepai, Kinter and others will brag about "500 Watts" or more and must have misplaced the decimal point when converting from Chinese to English or something...

The Rockford PBR series I'm talking about here are the 300 watt versions; Specifically the monoblock PBR300x1, stereo PBR300x2 and four-channel PBR300x4. Each amp is identical in size, but vastly different in output configuration.

• The Punch PBR300x1 is a mono block amp, designed for subwoofer duty only. It is rated at 75x1 at 4 ohms, 150x1 at 2 ohms and 300x1 at 1 ohm. The PBR300x1 is also unique in that it relies on the three 15,000uf 25V caps to keep the rail boosted during high power operation. The PBR300x1 has no switching power supply toroid, whereas both the PBR300x2 and PBR300x4 do
• The Punch PBR300x2 is the most flexible amp in this series as it is suitable for stereo, mono or tri-mode operation and has built in low-pass and high-pass crossovers. The PBR300x2 is rated at 100x2 at 4 ohms, 150x2 at 2 ohms or 300x1 at 4 ohms bridged mono. Before I purchased the amp, I contacted Rockford Fosgate to find out if the amp could be used in "tri-mode" operation (stereo and mono simultaneously) and the answer was yes. This intrigued me as it would allow me to test the amp using an old school tri-mode crossover, and possibly a good candidate for a boombox project.
• Lastly, the Punch PBR300x4 is a four channel model rated only to handle 4 ohm loads at 75x4. You can choose Low Pass, High Pass or bypass for crossover duties. Unfortunately, no Punch Bass port is provided and the PBR300x4 is not bridgeable. This amp seems well suited for powering front and rear full range speakers.
• All of the PBR300 series measure  6-15/16"W x 1-9/16"H x 4-5/16"D
• Street price for the PBR300 series is around $250 US each

Not mentioned above is the recently introduced Punch PBR500x1. The 500x1 is not only larger in size, but also much larger in power output delivering 500 watts at 1 ohm. We may get one of these amps soon to run through the test bench, so stay tuned.

PBR300 series internal components, left to right; PBR300x1, PBR300x2 & PBR300x4

Over the past few months, we've had a chance to put two of the PBR300 amps on the OldSchoolStereo test bench and also run through some real world tests with speakers and subwoofers.

First to test was the original "Boosted Rail" amp offered by Rockford Fosgate, the PBR300x1. After seeing Steve Meade's video about this amp at the 2011 Consumer Electronics Show, I was eager to get my hands on one. PASNATION also has an excellent video explaining the technology in these amps. I also created a couple of videos showing off the PBR300x1. See them below:


Part 1: Unboxing and Overview - See on YouTube in 1080P HD or embedded below

Part 2: RMS Power Output Test - See on YouTube in 1080P HD or embedded below

After the apparent success of the PBR300x1, Rockford expanded the line of "boosted rail" amps with the PBR300x4 and most recently the PBR300x2. I purchased both amps, most recently the PBR300x2. With this amp's ability to work in stereo, mono, or both (using passive crossovers), I decided this might be the perfect amp for a high powered portable boombox. Also, to add some flair of old school, I decided to test the amp using a Phoenix Gold XVR4 tri-mode crossover network. The XVR4 provides 80Hz low-pass filtering at 12dB/octave and 120Hz high-pass at 6dB/octave. I thought this would be a perfect match for my recently created Rockford Fosgate AUDIOphile Bookshelf Speakers and a trio of old school JL Audio 8W6 subwoofers. It turned out to be a great combination indeed! See the full test and demo below:


Rockford Fosgate PBR300x2 Bench Tested and Demo'd - on YouTube in 1080P HD or embedded below





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-BigDWiz