Amplifier Bench Tests Rare Amps and More

Once again, I've slacked off posting on the blog here. My apologies, I've been focusing on creating more content for my YouTube channel. Make sure you subscribe so you can stay updated and notified when I upload new content. My goal is to upload at least one video a week and for the past few weeks I've been doing 3 videos per week! See some of my recent video uploads below.

Wow, check a MINT copy of a mid-1970's Fosgate PR-235 amplifier. These amps are ULTRA-RARE and finding one in this condition is almost unheard of. Big thanks to Mike for sending this one my way!




Next up, a patiently awaited power output demo of a MINT Lanzar Opti Drive 50c ultra-cheater amplifier from the mid-1990's. Can it meet or beat it's 800w rating at 1/2 ohm mono? Watch the video to find out!






What about a purple beauty? Say what? The mid-1990's rare special edition Orion NT 200 arrives to the OldSchoolStereo.com labs for testing. This amplifier is a dual-mono design and was built to the strictest standards to ensure the best sound quality possible. Watch me un-box and show off this beauty! 

Now, here's another very interesting power output demo. We test the Orion XTR-2250 "The Beast" amplifier to see if it can stand up to it's name. Well, do you think it can match or exceed it's rated 1000w output at 4 ohms bridged? No spoilers here, watch the video to find out! 

Orion XTR-2250 RMS Power Output Video

***Amp output tests coming soon. We also have lots of cool overviews of some fantastic Old School Car Audio Thanks for your patience!***

Rare Old School Rockford Fosgate Power 1000 Mosfet Terminator Edition Amplifier

est. 1990 Rockford Fosgate Power 1000 Mosfet "Terminator Edition" Amplifier designed by Wayne Harris

Let us take a journey back to the year 1989...Car audio had been around for a while, but with amplifiers such as the HiFonics Colossus, Linear Power 8002 and Rockford Fosgate Power 1000, things were really getting serious. Wayne Harris, one of the pioneers of modern car stereos, was hired by Rockford Corporation and was given the task of swapping out his amps in the "Terminator Hearse" with the Power 1000 Mosfets. Wayne was kind enough to send an email describing the beginnings of the 1000C:

"If I recall correctly, I went to work for Rockford in July of 1989. One of my first tasks was to upgrade the equipment I was using in the Terminator. Rockford gave me 6 each Power 1000 amplifiers. Unfortunately, they were too long to fit in my car. I took the sheet metal for each amp to a machine shop and had them cut off the “caboose”. This made the amp about 6 inches shorter. (Now the amps would fit in my amp rack.) I then designed an LED bargraph meter display and installed these displays within the MAIN housing of the amplifiers. The final step was to chrome plate the amp shroud and then apply custom silkscreen.

The VP of marketing (Jerry Cave) saw the amps in my car prior to the 1990 CES show in Las Vegas. He like the amps in my car so much that he decided to make all Power 1000 amps look the same."

As many of you old schooler's know, Wayne Harris' Terminator Hearse is a legend in car audio. If you haven't seen it, take the time to view the video of this beast from 1985 from dBDragUSA's YouTube channel...can you say 30" subwoofer?

Sorry for the side track, I'll try to stay on subject here. The Rockford Fosgate Power 1000 Mosfet "Terminator Edition" (from now on we'll refer to as the 1000C) was a step forward in design from the original Power 1000 Mosfet, which was introduced around 1987. The internals were identical except for the LED meter and removal of the "caboose". The 1000C's chrome appearance and $2650 US MSRP meant this amp was not for your average 16 year old getting a new stereo....it was for serious competitors and those who got had the means to buy such an expensive amplifier. Many Rockford dealers had one or more of these amps in their demo vehicles and most of us could only dream of owning such an amp.

RF T1000 vs. Orion Concept 97.3

The 1000C is a four-channel, class A/B amplifier with no internal crossovers. See detailed specs below:

• Power Ratings 2 Channels (Bridged): 500 watts x 2 channels from 20-20,000Hz with less than 0.1% THD
• Power Ratings 4 Channels: 4 Ohms: 150 watts x 4 channels from 20-20,000Hz with less than 0.05% THD; 2 Ohms: 250 watts x 4 channels from 20-20,000Hz with less than 0.1% THD
• Frequency Response: 20-100,000Hz +0.5dB, -3.0dB
• Damping Factor: At circuit board: Over 200 (referred to 4 ohms); At speaker fuse: Over 50 (referred to 4 ohms)
• Signal to Noise Ratio: Over 80dB Unweighted
• Instantaneous Peak Output Current: Over 100 Amperers 
• Protection: The Power 1000 is protected by analog computer output protection circuitry and a 100A fuse. A thermal sensor shuts down the amplifier in case of overheating
• Dimensions: 22.75" L x 7.4" W x 3.75" H
• Weight: 21lbs
• MSRP: $2650 US (1991)

Here is an informational email I received directly from Rockford Fosgate when I inquired about the 1000c Terminator Edition amp:

“The T1000’s went from the black painted and silkscreened ones with the caboose (that covered the 6ga B+ & Gnd terminal block), then to the black painted and silkscreened ones that no longer had the caboose and just had the one B+ and two GND cables hanging out of it.  Then it migrated into a chrome fan shroud.  That’s about the time that Wayne Harris came on board with designing the LED output meter for the T1000’s.  Then probably in ’92-’93* is when the Terminator Edition hit the market with the special screening and LED display.  It was a very limited run….I think maybe only 100pcs or so.  I think Wayne had 10 of them for himself.”

(* I think the year range was '90-91 - BigDWiz)

See the unboxing and overview video below. More information coming as soon as I get the amp repaired and fully functional...

Make sure to Subscribe to my YouTube Channel to stay updated of my latest videos. You can also follow me on Twitter @oldschoolstereo.


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





Make sure to Subscribe to my YouTube Channel to stay updated of my latest videos. You can also follow me on Twitter @oldschoolstereo.

-BigDWiz