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!

Make sure you are subscribed to my channel so you'll receive notifications when I upload the next exciting video! Thanks for your support and remember to keep it Old School!


Subscribe to my channel: http://www.youtube.com/BigDWiz
Visit My Website: http://www.oldschoolstereo.com
Follow me on Twitter: http://www.twitter.com/oldschoolstereo
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Check out these other cool car audio channels:
http://www.youtube.com/CarAudioFabrication
http://www.youtube.com/meade916
http://www.youtube.com/SoundManCarAudio
http://www.youtube.com/DAmoreEngineering

1993 Rockford Fosgate 200 DSM vs SMD AD-1 Amp Dyno - Impressive!

1993 Rockford Fosgate Punch 200 DSM Amplifier

The 1993 Rockford Fosgate Punch 200 DSM was one of the most well regarded amps of it's time. Here's a quote from a May/June 1993 Car Stereo Review test of the Punch 200 DSM, "In terms of design, construction, aesthetics, and sonic purity, Rockford's Punch 200 easily stands among the best power amplifiers on the market today...If you're driving your system with something else, chances are you're listening to something inferior." (Ken C. Pohlmann)

We knew based on the previous tests of the Punch 200 this amp was powerful and dynamic, however we were unaware of the hidden "dynamic power" within this amp. Back in 1993, this amplifier retailed for around $600 US and replaced a legend, the Punch 150HD. It was no small feat for Rockford engineers to create a superior amp to the tried and true Punch 150, but trust me...they were successful! 

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 = 4 ohms stereo x 2
8 ohms - Amp is rated at 200W at 12V (or 100W x 2 at 4 ohms)
8 ohms - Certified 1% THD - 258W at 12.85V
8 ohms - Uncertified - 262W at 12.87V
8 ohms - Dynamic RMS - 262W at 12.83V

4 ohms mono = 2 ohms stereo x 2
4 ohms - Amp is rated 400W at 12V (or 200W x 2 at 2 ohms)
4 ohms - Certified 1% THD - 421W at 12.53V
4 ohms - Uncertified - 423W at 12.51V
4 ohms - Dynamic RMS - 459W at 12.93V

2 ohms mono = 1 ohm stereo x 2
2 ohms - Amp is not rated at 2 ohms mono or 1 ohm stereo
2 ohms - Certified 1% THD - 573W at 13.06V
2 ohms - Uncertified - 856W at 11.87V
2 ohms - Dynamic RMS - 890W at 12.97V

All tests above were at 40Hz. We re-ran the tests at 1kHz and the only notable differentiation in results was the 2 ohms Dynamic RMS test where we obtained 920W at 12.79V. We have determined the difference was related to voltage and believe provided the proper voltage (14.4V), the amp would have measured over 1000W Dynamic RMS at 40Hz also. Not bad from a 200W amp!

Watch the video in full 1080P HD Here >>

Or embedded below:


More Amp Dyno AD-1 tests coming!

Make sure you are subscribed to my channel so you'll receive notifications when I upload the next exciting video! Thanks for your support and remember to keep it Old School!


Subscribe to my channel: http://www.youtube.com/BigDWiz
Visit My Website: http://www.oldschoolstereo.com
Follow me on Twitter: http://www.twitter.com/oldschoolstereo
See us on Facebook: http://www.facebook.com/oldschoolstereo


Check out these other cool car audio channels:
http://www.youtube.com/CarAudioFabrication
http://www.youtube.com/meade916
http://www.youtube.com/SoundManCarAudio
http://www.youtube.com/DAmoreEngineering

For more information about Rockford Fosgate equipment, please visit:
http://www.rockfordfosgate.com

3840W Custom Power Resistor Bank for Testing Amplifier Power

Yes, I know, if you guys watch my YouTube videos, then you've probably seen my old resistor bank (aka "Fred Sanford" - Big Dummy). This resistor bank was comprised of (16) 50W resistors for a resulting load of 800W at either 2 ohms or 8 ohms. It was a great starter resistor bank, but in testing amps such as the Orion XTR-2250 and Rockford Fosgate Power 1000 Mosfet, I needed not only more power capability, but also configurations for 4 channel loads at 2 ohms.

Before I get too deep in the discussion of the new resistor bank, let me digress and explain my use of the resistor bank. In this case, I use the wirewound power resistors for testing audio amplifiers power output (in watts). Many people use speakers when attempting to calculate amplifier wattage output, but fail to account for the fact a speaker is a reactive load and other factors must be calculated to obtain wattage. When using resistors, the wattage calculation can be more easily obtained using Ohm's Law. We use a Velleman HPS-50 o'scope/True RMS Volt meter, Fluke 85III True RMS Volt meter, Steve Meade Designs/ D'Amore Engineering DD-1 (aka SMD DD-1) along with our resistor bank to calculate continuous (RMS) power output from the amplifiers we test. For more information on how I test my amplifiers, see this video (to be updated soon).

I recently invested in (32) 120W 16 ohm wirewound resistors so I could test a wider variety of amplifiers. See the result below:

Custom 3840W Resistor Bank made from PC Tower

The OldSchoolStereo.com 3840W Power Resistor Bank has the following features:

- Custom PC Gaming Tower
- (8) Separate 480W 4 ohm loads
- Supports 8 channel amps down to 1 channel monoblocks
- (3) Internal 12V fans in push/pull configuration for maximum air flow
- 12VDC 600mA AC Adapter for powering the fans
- capable of testing 4 channel amps with all channels driven at 2 ohms (960W each)
- configurations for high-current amps at 1/2 ohm mono (3840W)
- multiple configurations for 1 ohm and 2 ohm loads (both stereo and mono)
- safely test amplifiers silently at various test tone frequencies
- Acrylic window showing off my lackluster wiring skills

Rear view of the 3840W Power Resistor Bank

Stay tuned for an upcoming video overview of the 3840W Air-Cooled Power Resistor bank.  We also have MANY amplifiers to test in the upcoming months, so stay tuned for updates, tests, overviews and more!



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

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!***

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

Lepai LP-168HA Mini Amp Tested and Reviewed

Lepai LP-168HA "Super Bass" 2.1 Mini Power Amplifier

The Chinese mini amp invasion continues! This time we will show off the Lepai LP-168HA, a 2.1 channel mini amp. It is called a 2.1 amp, because it offers 2 stereo channels as well as a single "bass" channel. Sounds very promising at the rated 40x2, plus 68x1 power output. Now, as we've seen before, the manufacturer's ratings for these amps means nothing...Actual RMS output means everything!

The Lepai LP-168HA offers 3 inputs, all in parallel (non switchable). On the front, there is a 3.5mm stereo input jack, while the back offers left and right RCA input jacks as well as a USB port. The USB port will play back MP3 files on a compatible thumb drive, MP3 player, cell phone, etc. This feature wasn't tested other than for charging and it failed on 2 out of 3 devices tested. The 1st generation iPod Nano was the only device accepting a charge from the LP-168HA...neither the iPhone 3G nor the iPhone 4 would receive charge from the USB port.

Lepai LP-168HA's Rear Connections

The LP-168HA also offers a separate volume (and TINY knob) for the bass channel as well as the stereo channels. Unlike most amps offering a bass channel, there is no "master" volume controlling all outputs. You must adjust the bass channel and stereo channels independently. What a horrible design! Furthermore, the bass channel reaches full power at just a slight turn of the bass volume adjustment. There is no input gain control for the channels, just the volume knobs.

Speaking of input gain, there is a VERY important note here...I was unable to drive the front channels to clipping with an iPod Nano 1st gen or iPhone 4. It appears the LP-168HA wants an input of around 2-3V to reach max volume, and most portable devices don't have enough juice! I had to use my Yamaha home theater receiver with approx. 3V pre-outs to drive the LP-168HA to it's maximum volume. I didn't mention this in the video review, but feel it is a BIG deal.

Another area of interest is the crossover for the bass channel. I just verified my tests in the video using a 2nd example of this LP-168HA and both exhibit the same issue. The bass channel's crossover is cutting out some of the highs, but not fully until 2kHz or higher. I tested using a 1kHz test tone and was still able to hear it quite clear, even setting the crossover at 50Hz! Needless to say, you'll want to add a passive choke to keep your "subwoofer" from getting frequencies too high. Speaking of this, I'm not sure which "subwoofer" you'd use with this amp, but it better be a small and efficient one!

Lepai LP-168HA Controls

Watch as I verify RMS power output using the Velleman HPS50 and SMD DD-1 Distortion Detector. How close can we get to the manufacturers claim of 40x2 and 68x1? Well, you're gonna have to watch and see....

If you haven't seen the intro article to the "Chinese Mini Amp Invasion" check it out now. Also, I've made a video playlist of all the mini amps I've tested, see it HERE.

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

See the Lepai LP-168HA in HD on YouTube

or embedded below:

700 Watt Mini Amp? Lepai LP-V3 Tested and Reviewed

Lepai LP-V3 Mini Amp

The Chinese Mini Amp Invasion continues!! Next up is the Lepai LP-V3. This mini amp touts use of a BOSE power IC. In fact, the non-grammar corrected text "This Amplifier is use BOSE Power IC" is silk-screened on the amp. You'll also see "700 W Max Music Power" labeled on the amp. The LP-V3 uses the exact same enclosure as the LP-2020A+, I reviewed earlier.

See a size comparison w/ the LP-2020A+ below:

Lepai LP-2020A+ and LP-V3 Mini Amplifiers

In addition to touting a BOSE IC, the LP-V3 promises an RMS Power Output of 25 Watts. No clarification if this 25 Watts is per channel or total watts...

The next two pictures below show both ends of the amp...one for the controls, the other for the connections. Here again, the LP-V3 is a clone to the LP-2020A+:

Lepai LP-V3 Controls; Power, Tone/Direct, Bass, Treble & Volume

Lepai LP-V3 Connections; RCA, 1/8" inputs, Spring-Loaded Speaker Terminals and 12v5A DC  Power Input

Well, enough about the connections and controls, how does the LP-V3 sound? Well, in a nutshell, weak. I was expecting much more dynamic and punchy sound as delivered by the LP-2020A+. The LP-V3 appeared to run out of steam quickly and obviously didn't put out anywhere near the power of the 2020A+. In fact, the LP-V3, reminded me greatly of the tiny and unimpressive Kinter MA-150 I tested earlier. Very disappointing, especially considering the supposed "Real" RMS output of 25 watts. I was beginning to seriously doubt the validity of this claim. Fortunately, I have an easy way to determine the actual RMS output of this amp...

Results? Not impressive and not even close to the 700 Watt, or the 25 Watt RMS ratings. Using a 12V 35Ah Sealed Lead-Acid battery showing 13.0V of charge, I was able to obtain:

Output Test Results:

• 4.43V RMS of Unloaded Output at the speaker terminals
• 2.0 Watts RMS / channel at 8 ohms
• 3.6 Watts RMS / channel at 4 ohms
• 5.1 Watts RMS / channel at 2 ohms
• 11.9 Watts MAX / channel at 2 ohms

(tests above were conducted using a 1kHz 0dB Sine Wave Test Tone from the SMD DD-1 test disk and output was verified by the DD-1, which detects distortion at 1%. The resistive loads of 8, 4 and 2 were conducted with BOTH channels loaded)

Stay tuned for more tests of these mini amps and see which one (if any) you should buy. Check out my video review of the Lepai LP-V3 below. Make sure to Subscribe to my YouTube Channel to stay updated of my latest videos. You can also follow me on Twitter @oldschoolstereo.


See the video on YouTube in 720p HD or embedded below:

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500 Watts in Your Pocket? Kinter MA-150 Mini Amp

Kinter MA-150 vs. CD: Size Comparison

The promise of 500 Watts in a palm-sized amplifier is appealing to many people. The Kinter MA-150 is another contender in my Chinese Mini Amp Invasion shootout and is the smallest amp in the bunch. Although technology such as "Boosted Rail" has enabled Rockford Fosgate to make the PBR300x1 just slightly larger, it "only" promises 300 Watts of power at 1 ohm. Not to mention, the PBR300x1 costs around 10x as much as the Kinter MA-150...

I picked up the Kinter MA-150 from an eBay seller for around $15 US shipped from China. Now, logic will tell us we shouldn't expect much from an amp only costing a few dollars, right? Yes, this is a rational thought. "You get what you pay for" comes to mind. So, what does the $15 get you? Continue reading...

The Kinter MA-150 has a slightly different design than the other amps in this shootout as it requires molex-style plugs for the speakers and power. The other amps in this comparison have spring-loaded speaker terminals and a 5.5mm x 2.1mm center positive power plug.

Kinter MA-150 Speaker Output and Power Inputs

The opposite side of the MA-150 has a USB port for charging external devices, RCA L/R jacks, Volume knob and crossover switch. See picture below:

Kinter MA-150's USB, RCA, X-over and Volume adjustments

For more details on the technical specifications, please see the Chinese Mini Amp Invasion article for a spreadsheet comparing each amplifier in the shootout.

The Kinter MA-150 is heavily marketed on eBay as a motorcycle or scooter amplifier. Obviously, the main reason is the small size, low power consumption and "rated" high-power output. Now, logic and science will tell us, based on the MA-150's 12v 0.5A power requirement, you can use the equation Watts = Volts x Amps to get 12 x 0.5 = 6. Taking into account 100% efficiency, the amp should put out 6 watts, based on the power going in. Well, unfortunately, the amp is NOT 100% efficient, so even the 6 watts may be a stretch.

Power ratings vs. actual output aside, I decided to run the sound quality test first. I tested several tracks, including one of my favorite "Chelsea's Day" by Sam Cardon. It was readily appearant to me the MA-150 didn't have the power, clarity or dynamics of the Lepai LP-2020A+ . My reference speakers, the Athena Point 5 MKII bookshelf speakers are extremely transparent and it was obvious the MA-150 was struggling to push them to room-filling level. Again, based on the output I was expecting, this wasn't a surprise to me. After a few minutes demoing my reference tracks, I decided to put the MA-150 on the OldSchoolStereo.com test bench and get some actual numbers.

Results? Not impressive and not even close to the 500 Watt rating. Using a 12V 35Ah Sealed Lead-Acid battery showing 13.0V of charge, I was able to obtain:

Output Test Results:

• 4.56V RMS of Unloaded Output at the speaker terminals
• 2.1 Watts RMS / channel at 8 ohms
• 3.4 Watts RMS / channel at 4 ohms
• 5.3 Watts RMS / channel at 2 ohms
• 15.6 Watts MAX / channel at 2 ohms

(tests above were conducted using a 1kHz 0dB Sine Wave Test Tone from the SMD DD-1 test disk and output was verified by the DD-1, which detects distortion at 1%. The resistive loads of 8, 4 and 2 were conducted with BOTH channels loaded)

Stay tuned for more tests of these mini amps and see which one (if any) you should buy. Check out my video review of the Kinter MA-150 below. Make sure to Subscribe to my YouTube Channel to stay updated of my latest videos. You can also follow me on Twitter @oldschoolstereo.

See my video review / bench test of the Kinter MA-150 and decide for yourself if this is the amp for you...


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SMD's DD-1 - New School Tool for Old School Amp Testing

SMD's DD-1 "Distortion Detector" vs. Velleman HPS50 Oscilloscope

Many of you who follow my blog and videos, know I've had a Velleman HPS50 oscilloscope for a while now and keep adding components to enhance the capabilities of my test bench. My primary focus now is testing amplifiers for maximum continuous RMS wattage output. We all know most of the ratings we see on amps today are not RMS, but MAX output. This is a marketing ploy, not useful at all in determining the actual output of an amplifier. I'll soon get one of these amps on the bench and show you actual RMS wattage output vs. the value claimed on the amp. You may be amazed and not laugh so much at the old school amps and their low wattage ratings...

I recently decided to pick up a SMD DD-1 "Distortion Detector". This device was developed by the brains at D'Amore Engineering in conjunction with the KING of car audio on the Internet, Steve Meade (www.stevemeadedesigns.com). Steve Meade (meade916 on YouTube) is famous for his 30,000 watt custom Chevy Tahoe and has several hundred videos. Steve is also the largest car audio channel on Youtube with over 100,000 subscribers and over 100 MILLION video views. Impressive to say the least, but this DD-1 is not hype, it is a truly powerful and affordable tool for everyone from electronics enthusiasts to car audio shop installers and many in between.

So, what's the deal with this DD-1 and why might you want one? The SMD DD-1 is marketed as an amplifier gain matching tool. Matching your car audio head unit and amplifier has been a black art for many years. Without an oscilloscope and test tone, setting gains was really just a guess for most folks. The DD-1 costs only a fraction of most oscilloscopes and offers simplicity in setting/matching gains for your car audio equipment.

Here's what's included in the package:

• The Distortion Detector (DD-1)
• Protective silicon rubber boot
• Calibrated Test Tone CD
• Harness
• Printed owner's manual

According to the manual, the DD-1 has the following specs:

• The DD-1's circuitry is 100% analog
• Distortion Detection trigger level > 1.0% Harmonic Distortion
• Guaranteed operating range of input signal is 1.2Vrms - 125Vrms (15,000 Watts at 1 ohm) Autoranging
• Signal Present LED trigger voltage 750mVrms
• Low Battery LED trigger battery voltage < 5.6Vdc
• Auto shut-off timer 8-10 minutes after on button is pressed

Now, I must be honest. The unit's ability to match gains is a great feature, but I've had this ability with my Velleman HPS50 portable o'scope for a while. A recent video on Steve's channel about the upcoming AD-1 "amp dyno" got the wheels spinning in my old school head. This DD-1 can be used for more than just matching gains...it can be used to assist in amplifier output testing! This feature in a sub $200 device is unheard of. A bench version of a THD analyzer can cost MANY thousands of dollars. I've been watching eBay for a year or more hoping to find a deal on one of these THD analyzers so I could verify distortion during my amplifier tests. After seeing the AD-1 demo, I was convinced to buy the DD-1 to use as a tool in my RMS output tests.

The DD-1 has proved to be an invaluable tool and will ensure accuracy in my amplifier tests. I have MANY old school amps I plan on testing in the upcoming months. The DD-1 will ensure < 1% distortion in my results which is great. As I mentioned above, not only do many manufacturers rate amps by "Max" output, they also sometimes use distortion numbers up to 10% for their ratings. I think it's important to keep the distortion less than 1%, which should be inaudible for most people.

I have done some initial tests with the DD-1 and have been impressed with it's ease of use and ability to detect low levels of distortion. See some videos below and be sure to subscribe to my YouTube channel to stay updated with the latest amplifier and car audio tests and demos.

Buy the DD-1 Direct at wccaraudio.com

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Can The Orion Take The Punch?

Rockford Fosgate Punch 45HD and Orion 222 SX

The Rockford Fosgate Punch 45HD and Orion 222 SX....by today's terms would be called "tweeter amps". Go back 20 years to 1991 and people were using these amps not only to power subwoofers, but in some cases entire systems! Since both amps were rated at 45 watts or less at 4 ohms (both channels), people either had really efficient speakers or didn't require high volumes, right?

Well, many people were told and believe the old school amps are always "very" or "highly" underrated. Read on to find out if this is the case with either or both of these mini powerhouses.

First up, the Orion 222 SX appears to have a heat sink surface area advantage at 8.5 x 8.5 x 2.25 inches. It carried an MSRP of $329 US back in 1991 (reference - Car Stereo Review, July/August 1991) and included the following specifications from Orion:

222 SX Ratings at 12 VDC (both channels driven):

4 ohms stereo - 22 watts RMS
2 ohms stereo - 44 watts RMS
4 ohms mono - 88 watts RMS
(not rated to handle 1 ohm stereo or 2 ohm mono loads)


More Specifications:

• Requires external 15A Fuse, 20A provided by Orion (according to the manual)
• Stereo, Mono or Mixed-Mono operation
• Left and Right Peak Power LED's
• 0.005% THD at rated power
• Damping Factor - Greater than 500

On one side of the 222 SX are the power/ground wires (10 gauge), plus the 9-pin molex connector for speaker and turn on connections (See my Youtube Video on how to make these yourself!). The opposite end of the amp has input connections from both RCA and DIN connections. The DIN connection supports Orion EQ's and crossovers and provides phantom power for these devices as well. There are also two buttons, one for "EQ", providing a +15dB boost at 40Hz, -4dB at 200Hz and +6dB at 10kHz, in addition to a "Mono" button for bridging the amplifier. The 222 SX also has Peak/Power LED's and a single input gain control. See the connections below:

Orion 222 SX input connections, Peak/Power LED's, Gain control, EQ and Mono buttons

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Next up may be Rockford Fosgate's most well known amp from the mid-80's to early 90's, the Punch 45. In 1991, Rockford updated their vulnerable Punch 45 to the Punch 45HD, aka "Hybrid Design". Again, many competitors in the late 80's/early 90's used a single Punch 45 to compete in the 50-watt and under class.

The 45HD required spade connectors for the power and ground inputs. The opposite side includes; speaker/remote connections via 6-pin Molex plug, Bass/Treble knobs, Left/Right RCA Inputs and gain controls for both channels.

(Top) Rockford Fosgate Punch 45HD's 6-pin molex connector, bass/treble controls, left and right RCA Inputs and Gains

The slightly smaller heat sink of the 45HD measures 6.6" long  x 8.6" wide x 2.2" high and carried an MSRP of $275 back in 1991 (reference - Car Stereo Review, July/August 1991).


Punch 45HD Ratings at 12.5 VDC (both channels driven):

4 ohms stereo - 22.5 watts RMS
2 ohms stereo - 35 watts RMS
4 ohms mono - 70 watts RMS
(not rated to handle 1 ohm stereo or 2 ohm mono loads)



More Specifications:

• Requires external 15A Fuse, 20A can be substituted for "extreme" loads
• Stereo, Mono or Mixed-Mono operation
• 0-18dB Bass Boost at 45Hz, 0-12dB Treble Boost at 20kHz
• 0.05% THD at rated power
• Damping Factor - Greater than 200 at circuit board, greater than 50 at speaker leads

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Now you've read about the ratings and specifications, do you have a choice between the two for powering a single 8" subwoofer? I realize these amps may not be well suited to drive subwoofers, but this is OldSchoolStereo and I'm taking the test back to the old school!! Luckily, I have an early 90's JL Audio 8W1 (4 ohm) which will be the perfect test sub for these amps. In addition to the subwoofer test, I'll also test resistive RMS wattage output from both amps at several ohm loads.

Now, the question I'm sure many of you are asking....did I have a favorite before the tests? Well, I must admit I've tested the Punch 45HD before and knew what to expect from this little "punch". That said, I had high hopes for the 222 SX based on how well the Orion 275 SX fared against the Punch 150HD and Phoenix Gold MS-275. This is a CLASSIC shootout as I expected the results to be very close. I can't go without saying I broke the rule of my YouTube channel saying I wouldn't do "woofer flex" tests. I just couldn't resist seeing how these baby amps pushed the JL 8W1. I also used my Zoom H4 audio recorder for GREAT quality bass without distortion. Just make sure you use your headphones while watching the YouTube video to get the best experience (well, unless you are watching this on your home theater with an 18" powered sub...)

I put the Orion 222 SX on the bench first and connected up the resistor bank, 1000Hz test tone and Velleman HPS50 oscilloscope/true RMS Volt meter. Results are:

Recent Arrivals to the OldSchoolStereo.com Labs

I've recently done several unboxings on my YouTube channel. I'll have more articles and tests in the near future, but for now, enjoy the videos!

Amps that Rumble...Earthquake PA-2040c and PA-2300

Earthquake PA-2040c and PA-2300 Amplifiers from 1995. Photo (c) OldSchoolStereo.com

One of the "sleeper" Car Audio brands back in the mid-90's was Earthquake. Competing against established brands such as Rockford Fosgate, Orion, Precision Power, Soundstream, etc. proved to be a difficult task. Everyone had a favorite brand, but how did the lesser known brands survive? Well, building quality products was one way and another was to test well in the Car Audio magazines. Earthquake accomplished both of these tasks and although never became as popular as the brands listed above, they did create a place for themselves in old school car audio history!

I recently acquired two Earthquake amplifiers and will briefly overview them below.

First up is the Earthquake PA-2040c. The PA-2040c is a two-channel amplifier with a built-in crossover. The crossover is non-adjustable and either 80Hz low-pass or 200Hz high-pass at 12dB/octave. You could also bypass the crossover to use the amp full range. In addition, the amp also included rotary bass and treble controls at 45Hz and 12kHz. Going by the model number, one might assume the amp is rated at 40w x 2, however specs in the included manual state 52w x 2 @ 4 ohms. I'm still unsure of the "250 watts at 2 ohms" silk-screened on the amp. I don't see any specs referring to this power at 2 ohms? Maybe Earthquake was following lesser brands with "max" output claims? Well, only the bench test for RMS output power will tell us....

Earthquake PA-2040c Amplifier Controls

Earthquake PA-2040c Amplifier Top View

Earthquake PA-2040c Amplifier Speaker Outputs and Power Connections

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Earthquake also produced larger amplifiers, such as the PA-2300. Again, going by the model number, one might assume 2 x 300 watts, right? According to the manual, 2 x 380 watts RMS at 4 ohms and a mind-boggling 1150 watts RMS at 4 ohms bridged. In the mid-90's there were few car audio amplifiers claiming 1000 watts plus. The PA-2300 had no internal crossover, but had a counterpart, the PA-2300c, which did. A rather unusual feature of the PA-2300 was the dual bass controls. One centered at 30Hz and the other at 45Hz. Why two bass controls? I'm not certain, but maybe a tuning choice for those using sealed vs. ported subwoofer enclosures?

Earthquake PA-2300 Amplifier

Earthquake PA-2300 Bass Controls and Inputs

Although these amplifiers look very similar to amps made by Zed Audio (HiFonics VII, VII, Autotek BTS series, Crunch CR series, etc.), Earthquake amps were NOT made by Zed Audio. Although this is the case, rest assured the Earthquake PA series amps were built like a tank. The amps you see above were originally purchased in 1995 and variants of the PA series went back to the early 1990's.

Stay tuned for upcoming power output tests of these amps. Make sure to SUBSCRIBE to my YouTube Channel to stay notified of my latest video uploads.

See the mystery "unboxing" of these Old School Gems below:

Video in 720p HD

or embedded below:



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Orion 275 SX - Old School 75x2 Powerhouse!

Old School Early to Mid-1990's 75x2 (150 watt) RMS Amps from Rockford, Phoenix Gold, Soundstream and Orion

So, you may have already seen some of my earlier amp output tests on the Rockford Fosgate Punch 150HD vs. Phoenix Gold MS-275 and the Soundstream Reference 300....but what about the Orion 275 SX? Well, wait no longer, my friends. I finally got the Orion 275 SX on the OldSchoolStereo.com test bench for some RMS watt output tests. How do you think it compared to the others? Well, keep reading to find out.

Now, first of all, I think it is important to mention a comparison of the 275 SX....in many ways, it is very similar to the 225 HCCA. Both share the same sized heatsink and require a 35A fuse. I've done some preliminary tests with Orion's 225 HCCA "digital reference" amp a while back and I must say the amp was VERY impressive! The 275 SX is only rated to handle 4 ohm mono or 2 ohm stereo loads. As with many of the old school amps, it can handle lower ohm loads, but not designed to handle the 1/2 ohm loads as the 225 HCCA does without a sweat!

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Orion 275 SX vs. 225 HCCA vs. Messy Test Bench!

Instead of spending so much time comparing the 275 SX to the 225 HCCA, let's move on to the comparison against the other 150 watt amps I've mentioned before. Here are the specs of the 275 SX:

Specs: rated @ 12.5 volts*
2 x 75W @ 4 ohms
2 x 150W @ 2 ohms
1 x 300W @ 4 ohms bridged
THD: 0.03%
S/N: 110dB
Freq. Response: 6Hz 20kHz (±0.5dB)
Fuse: 35A
Dimensions: 11" x 8.5" x 2.25" (28cm x 21.6cm x 5.7cm)

*note: The Orion 275 SX uses an unregulated power supply, so more volts = more power! Also, my power supply is non-adjustable at 13.8v, nearly a volt and a half more than Orion's 12.5v rating, so take this into consideration.

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Orion's 2nd Gen HCCA and SX Spec Sheet / Manual

Ok, enough specs and talk about the amp, let's see how it performed.

Watch the video in 1080p HD

or embedded below:

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Make sure you subscribe to my YouTube channel to stay notified of the latest "old school" car audio videos. Much more exciting tests, demos and information coming up soon...

-BigD

Soundstream Reference 300 Power Output Test

Soundstream Reference 300 on the OldSchoolStereo.com Test Bench

I recall back in the early 90's patiently awaiting my monthly Car Audio magazines so I could see amp tests. It was very rare to come across a test I actually cared about, but maybe once a year or so. I drooled over the Phoenix Gold MS series, Rockford Fosgate HD series, Soundstream Reference series, just to mention a few. Well, these days, I spend some of my free time bench testing some of these amps I always wanted back in the day.

I recently picked up a Soundstream Reference 300 and couldn't wait to add it to my old school 150 watt (75x2 RMS) amp tests. If you've missed it, I've already done an overview and RMS watt output test of the Phoenix Gold MS-275 and Rockford Fosgate Punch 150HD.

The Reference 300 is a no-frills old school amp. It has no internal crossover and as with earlier Soundstream amps, all connections are made on one side. There are also two openings on the bottom of the amp with switches. One switch controls high power or high current mode, while the other allows switching between mono / coherent stereo / mixed-mono modes. The Reference 300 is rated to handle 1/2 ohm loads in stereo or 1ohm modes in mono, while in the high-current mode. High power modes are designed for loads down to 1 ohm stereo or 2 ohms mono.

See power output specs from the manual below:

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Soundstream Reference 200/300/500 Power Ratings at 12v

Also, here are some of the design specs of the Soundstream Reference Series amplifiers:

Soundstream Reference Series Design Features

The ability to drive 1/2 ohm loads was a rarity back in the early 90's. Only a handful of amps were rated to handle these loads. Orion HCCA models come to mind, but there were others from US Amps and Phoenix Gold, to mention a few.

As for the power output test, I was anticipating Soundstream to rate the Reference 300 conservatively. As you may have seen already, the Rockford Fosgate Punch 150HD was rated at the same 75x2 at 4 ohms and delivered nearly 120x2 at 4 ohms on the OldSchoolStereo.com test bench. Many manufacturers during this time rated their amps based on 12v, not the 14.4v you see today.

150 Watt Old School Amps from Phoenix Gold, Rockford Fosgate, Orion & Soundstream

So, enough talk already, how did the Soundstream Reference 300 perform on the bench? Well, now that you asked, here are the measurements (All taken based on 100Hz test tone and 13.8v input).

Continuous RMS Wattage Output: 

• 4 ohms Stereo - 105.6 watts/ch (both channels driven)
• 2 ohms Stereo - 134.1 watts/ch (both channels driven)
• 4 ohms Mono - 267.3* watts (in high-power mode)
• 2 ohms Mono - 224.7 watts (in high-current mode**)

*See the update video below for the updated 4 ohm mono test
**The Reference 300 popped it's 30A fuse when I attempted 2 ohm mono testing in the high-power mode.

See the power output test in in 720p HD or embedded below:



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UPDATE: One more demo to see if the 4 ohm bridged mono mode would yield the rated 300 watts:


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Keep watching and subscribe to my YouTube channel to stay updated with my latest Old School Car Audio tests and demos.

-BigD