Phoenix Gold MS-275 Update and More

I have had many comments on the Phoenix Gold MS-275 vs. Rockford Fosgate Punch 150HD and many want to know the results of my test. Well, I may actually be able to get those results online sooner than expected. The MS-275 is in the hands of an expert technician right now and should be back in action within a couple of weeks. I had originally planned on testing the amps with subs only, but now I think I'll use the Phoenix Gold XV4 tri-mode crossover to fully test the amp's capabilities with the full music spectrum. Are you excited to see the results? I know I am...


Also, please check the comments posted on YouTube as I've had some well though out responses to my overview, including some technical corrections. The comments about music power versus test tones made me reconsider using the output tests as my main deciding factor on the winner. Even Zed Audio warns test tones are not a good indicator of an amp's true musical output and actually put severe stress on the amp. See the 2011 Zed Audio amp lineup's manual for an extremely well written technical description of amp operation.


Please send all comments, questions and suggestions to oldschoolstereo at gmail. I hope to have a submission form shortly....


-D

Rockford Fosgate Punch 150HD vs. Phoenix Gold MS-275 - Old School Amp Shootout!

Let's take a trip back in time, 20 years to be exact. You are in the market for a new amplifier for your system and you've narrowed the decision to two popular choices...The Rockford Fosgate Punch 150HD or Phoenix Gold MS-275. Both can be had for about $500 US (remember, 1991 folks) so you grab your Car Audio & Electronics April 1991 "Buyer's Guide" issue and review the specs. Both amps appear to be rated the same in 4ohms stereo at 75 watts/ch at 4 ohms bridged at 180 watts. How can you decide between the two? You really like the Phoenix Gold's 24 carat gold plated circuit board and terminal strip connectors. You are also intrigued by Rockford's reputation of overbuilding and underrating their amps. Again, a tough decision, but how do you choose only one?


Step forward to 2011...


Although in 1991, I could not afford either of these amps, I thought it would be a great way to relive those days as if I could choose between them. Now with the capability to bench test each amp in addition to some real-world tests with speakers, this could be a better experience than the car stereo shops of days past.

Rockford Fosgate Punch 150HD , Phoenix Gold MS-275 propped up by a Kicker Solobaric S10c

I've been fortunate in finding near MINT examples of each amplifier. My MS-275 is the rare gray color (most are the white color which are later models), while the Punch 150HD is the classic black. The original MSRP of the MS-275 was $479 US, while the Punch 150HD was a little higher at $515. See my video overview below as I'll go into further details of each amplifier. Power output and subwoofer tests coming soon in another video, so stay tuned...

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Edit: 6/25/11 


Unfortunately, it may be some time before the power output test is complete for the Phoenix Gold MS-275 as the output capacitors are showing signs of leaking (common problem for most 90's PG amps). The capacitor swap is a relatively complex task, at least one I don't want to chance with such a nice amp. I'll send the amp off in a few months to have the caps changed out, so it may be a while before I post another video in this series. I may, however, go ahead and show a video testing the Punch 150HD and its output test...we'll see.




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HiFonics Vulcan and Thor VII - Old School Classics!

I'm SO glad there are other people out there who take good care of their old school amps! I recently ran across a local Craigslist ad where a person was selling a couple of classic early 90's HiFonics amps...the Vulcan and Thor (both VII series). I met the seller and ended up buying the amps...simply amazing to see these amps in such great condition to be 20 years old!

Early 90's HiFonics Thor VII and Vulcan VII in near MINT condition!

A friend of mine back around 1991 had a Thor VII, exactly like the one I picked up, and I always recall the amp being very powerful. Back then, his Thor powered (2) 15" subwoofers from a local speaker manufacturing shop. The speakers were 8ohm each wired in parallel and the amp was bridged mono putting out a rated 400 watts. This was a BIG power back then and to my ears still plenty of power for the right subs.

I recall each local stereo shop trying to best each other by saying how underrated the particular brand of amp they sold was. It was pretty evident to me, Autotek, Orion and Rockford Fosgate were underrated, but what about HiFonics? These amps were well regarded and were actually priced reasonable versus their power output ratings. For comparison, the Rockford Fosgate Punch 45 retailed for $275 US and was rated to deliver 22.5x2 or 70x1 at 4ohms. The HiFonics Vulcan VII was priced at $330 US and was rated 50x2 or 180x1 at 4ohms. A feature missing on the Vulcan causing me to decide on the Punch 45? Built-in Bass and Treble EQ's. I know it seems silly to think this would be a deciding factor, but it actually swayed my decision. The only "remote" bass controls we had back then was something like the Audio Control Epicenter (and they were pricey around $180 US).

With that said, let's work forward to 2011 and seeing how the 1991'ish HiFonics amps perform on the OldSchoolStereo.com test bench. Since I have the privilege of previously testing Zed Audio built amps, I had a preconceived expectation of the results....and I was pretty spot on!

Here are the results:

Vulcan VII
RMS Output Power:

4ohms stereo = (rated): 50w/ch / (actual): 59.44w/ch
2ohms stereo = (rated): 90w/ch / (actual): 104.4w/ch
4ohms bridged = (rated): 180w / (actual): 208.8w

***Max Output Power:
Max Output (hard clip) = (actual) 370.5w/ bridged at 4ohms

1991 HiFonics Vulcan VII

Thor VII
RMS Output Power:
4ohms stereo = (rated) 125w/ch / (actual) 157.0w/ch
2ohms stereo = (rated) 200w/ch / (actual) 252.6w/ch
4ohms bridged = (rated) 400w / (actual) 462.2w

***Max Output Power:
Max Output (hard clip) = 475.5w/ x 2 at 2ohms!!! (over 950w total!!)

***This MAX number is what most of the mfg's use today when rating amps

1991 HiFonics Thor VII

I did some basic SQ testing with some separates and a 10" Kicker Solobaric S10c sub and was VERY impressed by the power, clarity and control both amps offered up. I'm even considering using these two amps in my Old School Stealth Install until my RF Power 650 gets it's facelift.

Stay tuned in for more updates...

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Old School Stealth Install - Part 1 - The Subwoofer

I must admit, I've been contemplating swapping out the cheapo EFX sub which came stock in the Scosche SCXB04 for quite a while. I've had this "stealthbox" like sub for the past 3 years and it has handled the rear channels of the Rockford Fosgate Power 550x very well. I've not bench tested the 550x for 4 ohm mono loads, but I'd estimate around 325-350w. The SCXB04 houses a 10" EFX sub in an approx. 0.75cu/ft injected molded plastic enclosure and is custom fit for 2004-2007 Scion xB's. Yeah, it's a funny looking car, but I laugh at other people when I fill up after averaging 35mpg.


My favorite feature of the SCXB04 is it's stealthy nature. I can have a decent amount of bass without sacrificing ANY usable interior space. Now, on to the question of what sub to use to replace the 10" stock sub? Well, I have only a few 10" subs to choose from; MTX Blue Thunder BTW-1044, JL Audio 10W3-D4 or some recently acquired Kicker Solobaric S10c's. After some online research, I found the box can support a 10" sub with up to 5" depth. Right away, the JL 10W3 was out (too bad, this is a NICE sub!). What about the Blue Thunder 10? Well, it is an early 90's sub and wants a minimum of 1 cu/ft of airspace and it would probably not perform optimally in th slightly smaller enclosure. Turns out, the decision was kind of a "no brainer"....The Kicker S10c it is!


I pulled the SCXB04 out of the car and noticed Scosche's attempt to be slick in using some strange star-headed screws...why would they do this? Not sure, but it was easy to locate a proper sized tool in my stash for removing these screws. Once I got the EFX sub removed, it was pretty apparent the EFX sub was somewhat smaller than the S10c. No fear, Dremel tool is here! After marking the box with an estimated cutout based on the S10c, I began the process of removing plastic. I used the cut off wheel on my Dremel and about 30 minutes later and a ton of black plastic shavings on my arm and leg....the box was ready for the Kicker sub. While performing the sub swap, I thought it would be a good idea to trade out the stock 16ga speaker wire for some high-quality 10ga wire. I actually used power and ground cable from an old amplifier install kit I had. This was to ensure there was no power loss due to wiring inside the box. Honestly, the 16ga factory wire was probably more than sufficient for up to 400w, but I didn't want to take any chances.


Once the box was rewired with the 10ga wire, I dropped in the S10c sub and pre-drilled new mounting holes. I was very careful to ensure I had the Kicker emblem lined up properly for mounting (at least I thought!). After securing the 8 screws, I was ready to mount the SCXB04 back in the car. Once I began to recall how the box fits in the car, I realized I mounted the S10c sideways! Doh! Due to the fact the sub will be  mostly hidden, I decided to leave as is for now.


View the video below for the entire process:


View the video in 1080p HD

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Now, after using the Kicker S10c for the past 3 weeks in my daily driver and testing it out with various genres of music from jazz, rock, country, pop and rock, I must say it is a HUGE improvement from the EFX sub. Bass notes are noticeably deeper and tighter with the S10c. Although the EFX sub was no slouch in the SPL department, the Kicker S10c easily knocks the EFX sub out of the ring. I'm extremely happy with the sub swap and can't wait to upgrade the front stage from the 6.5 and 4" coaxials to 6.5" separates. I've been searching for some Boston Pro 6.4 or 6.5 separates, but so far have only been able to locate some Boston Acoustics Rally RC61 separates. 


I'm also getting my Rockford Fosgate Power 650 re-powdercoated and re-silkscreened so it can replace the tried and true 2002 model Power 550x. My biggest hurdle will be deciding the mounting location of the Power 650, while keeping the install as stealth as possible. Unfortunately, the Power 650 is too large to fit under the driver's seat, which is the current location of the Power 550x. I doubt in real world numbers if the 650 is more powerful than the 550x and also requires an extra feature I require....remote bass control. Luckily, I have an early gen Audio Control Epicenter, which will fit the bill as a bass level controller.


Also, one last note about the old school install; I am planning on using a new head unit, capable of iPod/iPhone control and maybe Bluetooth. I'm not going for NAV or DVD, but have some models in mind to replace the "Premium" Pioneer Scion head unit (T1809) I'm currently using. I actually purchased this head unit a few years ago and have been impressed with it's operation and sound quality. It even has 3 sets of pre-amp outputs, VERY unusual for a factory head unit. Unfortunately, the lack of support for my iPod means the T1809 has served it's purpose, but its time to move on to another unit.


Stay tuned for upcoming updates to the "Old School Stealth Install" project...


-D




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Old School Crunch Amp - CR100

Over the years, brand names are sometimes passed along from one owner to another. Remember Polaroid instant cameras? It was only a few years ago when you may have noticed DVD players branded with the Polaroid name. Well, unfortunately in most cases, the same passing along of name brands happens in the car audio world. I myself, dropped out of the car audio industry for nearly 10 years and when I returned, the brands I knew once as high quality, "Made in the USA" were well....not what they used to be. Some people may argue the Internet forced many car audio companies out of business and although I'm not sure it is 100% the case, I'm sure it had an affect on the industry.

Now, why must I bore you with history of car audio brand names? Well, because the next amplifier I'm going to talk about is the Crunch CR100 from approx. 1992. This amp was one of several made by Zed Audio, regarded by many as some of the better old school amps. Other brands, such as HiFonics and Autotek (among others), had models of amplifiers made by Zed Audio. If you happen to visit or search eBay, you'll notice the Zed-built amps usually go for a premium.

Unlike most modern car audio amps, the CR100 has a harness for speaker connections. I'm not sure why companies continued to use these harnesses instead of barrier strips into the mid 90's?. As most of you know, these harnesses are usually lost over the years or have been cut so many times, the wires are too short! Luckily, the Crunch CR100 I picked up had about 8 inches of speaker wire and even more power/ground wiring length. An immediate problem I had was identifying the speaker and remote turn on wiring colors. Some old school amps used red for remote turn on, others used blue...this amp has both! I opened the amp to reveal the guts and it appeared the blue was the turn on, however I wanted to be 100% sure, so I confided in one of my favorite resources - diymobileaudio.com. Within a few minutes, a member posted the wiring diagram and even a link to the owner's manual. Wow, this is great!

Zed Built Crunch CR100 Guts

The CR100 also allows plug-in modules for crossover/EQ and the one on this particular unit has an M30 module - selectable high/low pass crossover, adjustable frequency and bass boost at 45hz. At the time this amp was new to the market, Crunch offered several different modules so you could customize the amp to your liking.

Crunch CR100 with M30 Module

Now that I have the wiring guide, let's hook this baby up and see what she'll do! Since I was unsure if the amp would handle realistic 1ohm loads, I kept my testing loads to 2ohms minimum (2ohms stereo or 4ohms bridged mono). I connected up the amp to my Audio Authority 100A 13.8v power supply to guarantee I had plenty of juice for the test. The manual suggests a 15A fuse, yet strangely enough says it will consume 14A at full power into 4ohms...what about 2ohms? 15A sounds a little small to me. This amp just has to be more powerful than a Rockford Fosgate Punch 45HD....doesn't it?

Crunch CR100 Wiring Harness

If you read some of the enthusiast forums online, you'll hear rhetoric like "extremely underrated" and "highly underrated" when referring to these old school amps. As my test have shown, in some cases this is accurate, but in most cases the old school amps are only slightly underrated.

Here are the ratings obtained from the Owner's Manual:

• 50w/ch @ 4ohms stereo
• 90w/ch @ 2ohms stereo
• 180w bridged @ 4ohms

And here are the official OldSchoolStereo.com test results for the Crunch CR100:

• 61.93w/ch @ 4ohms stereo
• 88.84w/ch @ 2ohms stereo
• 198.8w bridged @ 4ohms

For additional information on my testing methods, see my previous post: Testing Output Power from Old School Amps. 

In addition to the power output tests, I hooked up the amp to a few speakers including a JL Audio 8W1 and a 12" Rockford Fosgate Punch classic sub. I set the CR100's M30 module to low pass at approx. 120Hz. The Crunch CR100 delivered all the power the JL 8W1 wanted and kept great control of the sub during testing. I demo'd several songs including; Jazz, Pop, Rock and Rap samples from my BigD demo CD. The nearly 200 watts at 4ohms mono was ample power to shake items on the wall of the OldSchoolStereo labs (aka "my garage"). Not only impressive from a 200 watt amp, but also from a 8" subwoofer!

The Rockford Fosgate PCH-812 subwoofer is 8 ohms, so it was only seeing around 100 watts. It is a mid-90's subwoofer and only needs 100-200 watts for ample output. Again, the Crunch CR100 provided clean, accurate power allowing the Punch sub to stand up to it's name!

I'm not sure how good the Crunch CR100 would prove pushing late model, heavy magnet, inefficient subwoofers...but it does a great job powering similar age (mid 90's) subwoofers and would be a great amp for a modest system. I guess one day I'll have to get some newer subwoofers to use testing these old school amps. Yep, I'll do that just as soon as the donations help pay for some...

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Update: 6/26/11


I just located some Crunch amplifier ads from 1992 and 1993 Auto Sound & Security magazines. These ads show off the CR series amps and plug-in modules. With this information, I updated the post to note the amps were from the 1992 timeframe (not 1994) as originally stated. See a couple of the ads below:

Crunch Amp Ad from May 1993 - Auto Sound & Security

Crunch Amp Ad - November 1992 - Auto Sound & Security

A Rare 1982 Rockford Fosgate Amplifier - Punch Power 360

My earliest recollections of aftermarket car audio amplifiers was the mid to late 1980's. Rockford Fosgate, along with a few others (Orion, Precision Power, Soundstream, etc) ruled the car audio aftermarket at this time. But, what about the early 80's? I know companies like A/D/S and Nakamichi were around, but why would manufacturers produce high output car audio amplifiers when 6x9's were high tech at the time? 

Well, if you know the culture of Rockford Fosgate, then you know why they produced an amp like the Punch Power 360 back in 1982. This amp was rated at 90 watts x 4 channels into 4ohm loads and although bridgeable, was not designed for loads less than 4ohms in stereo and 8ohms in mono. The Power 360 retailed for around $900 and from the research I've done, less than 50 were produced. Can you imagine the market for a $900 car audio amplifier back in 1982? All assembled and soldered by hand in the Rockford headquarters in Arizona. Unlike later Rockford amps, the Power 360 used bi-polar output devices as opposed to mosfet. You'll notice in later amps (late 80's - early 90's), Rockford is VERY proud of the mosfet outputs as nearly every amp has "Mosfet" listed in it's title.

Now, nearly 30 years later, what's the chance I'd come across a 1982 Punch Power 360 amplifier in ANY condition, much less near mint? Well, I wouldn't have placed any bets on it, that's for sure! I've seen a few on eBay over the years, a few from serious collectors, but unlike a Punch 45 or 150, this is an amp you just don't see very often. Not only was I fortunate enough to acquire this rare beast, I was also given some literature from another Rockford Fosgate collector.

1982 Rockford Fosgate Punch Power 360 Literature

And the "Pre-Z" pre-amps that matched up with the Power 360:

1982 Rockford Fosgate Punch Power 360 Pre-Amps - 250, Z & ZX

Now, on to the actual amp I picked up as I'm sure you are intrigued, right? I'm sure there are some people with their $100 2000-watt amps, who don't really get the excitement here....I can understand as old school and vintage stereo equipment is not everyone's cup of tea. However, this is Old School Stereo, so I'm not too concerned, as my audience should enjoy the vintage gear.

First up is a top picture of the Rockford Fosgate Punch Power 360's heat sink. Notice the "Rockford Fosgate" emblem on the amp plate. Other 360's I've seen up for sale were missing this cosmetic piece. Also, this amp is not missing a fan shroud...the Punch Power 360 and bipolar Power 650 amplifiers did not come equipped with a fan shroud.

1982 Rockford Fosgate Punch Power 360 Top View

Next up is the bottom of the amp. As with most of the Power series models, there is quite a bit of information silk-screened on the bottom of the amp. Some of this information includes wiring color codes for speakers, DIN connector and power wires. There is also access to the gain controls for each left and right channel from the "high" and "low" channels (most amps would denote these channels as "front" and "rear"). See more details below:

1982 Rockford Fosgate Punch Power 360 bottom view

Although this amp was introduced in 1982, it still had a full 2-way active crossover built-in. The "high" channels could be set either "flat" or at selectable frequencies with a 12dB/octave high-pass slope. The "low" channels offered the same crossover slope for low pass signals. Although the amp was designed to work with line-level inputs, the "high" channels were only accessible if the DIN connector was used. You could use RCA inputs only for the low channels. I'm guessing Rockford thought if you could afford a $900 amp back in 1982, you could also drop a few more hundred on a "Pre-Z" pre-amp (see pictures from literature). Luckily, these days, we have DIN to RCA adapters, so you don't have to own one of the super rare Pre-Z pre-amps to utilize the high channels of this amp.

Rockford Fosgate Punch Power 360 Speaker Harness and Inputs

Keep watching for an upcoming bench test of this amplifier where I'll give actual output power results. Also, if anyone has any additional information on this amp or has any corrections to what I believe are facts above, please contact me oldschoolstereo at gmail.

-BigD

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MASSIVE Old School Car Audio Picture Gallery

To all of the old school fans who haven't seen this, get your coffee and a comfortable chair and enjoy going through 10,000 old school car audio pics!

Old School Audio's Picasa Gallery

Wow, what a collection! Great work by the guy who set this up. Enjoy the trip down memory lane.

-BigD

Old School Car Audio Literature Wanted!

In addition to the Car Audio Magazines, I'm also searching for some Old School Car Audio literature, brochures and other training manuals. I'm particularly interested in Rockford Fosgate (1984-1995) literature and especially some of the RTTI training manuals. I'm also looking for Orion, PPI and Phoenix Gold literature up to 1995.

I've posted some of the Rockford literature I've been able to find over at the Rockford Fosgate Vintage Forum. Let me know what you have. I'd also be interested in copies if you want to keep the originals. Remember, oldschoolstereo.com is only a hobby currently and I've already spent a ton outfitting my test bench so I could measure amplifiers actual output power...

Contact me at oldschoolstereo at gmail or via comment below if you have anything to offer up. Thanks!

-BigD

Old School US Amps 50HCA vs. USA-50

I recently put a couple of US Amps amplifiers (1992'ish US-50HCA and 1999'ish USA-50) on the OldSchoolStereo.com test bench. The outcome was not quite what I expected. Both amplifiers are rated at 25 watts x 2 into 4ohms.

First up is the 1992'ish US-50HCA, which is finished in a beautiful blue color and is in AMAZING condition to be a nearly 20 year old amp. As with most of the late 80's and early 90's car amplifiers, the 50HCA has direct wiring, no terminal strips for the wiring connections. The 50HCA requires a 30A fuse and is stable to 1ohm mono or 0.5ohms stereo, according to the manual. Later models of this amp, known as the USA-50HC, require a 75A fuse, and are likely to be MUCH more underrated than this model. US Amps denoted their "competition" amps as either HCA,  HC or VLX series.

Proceed forward a few years to approximately 1999 and you could pick up a US Amps USA-50 in your choice of several colors. My sample is purple in color and has terminal strip connections for speakers and power. It also has a clear acrylic cover on the bottom of the amp to show off the "guts". The standard USA model amplifiers were rated for 1ohm stability in contrast to the HCA, HC or VLX series' 0.5ohm stability. The USA-50 requires a 25A fuse and also includes a 100Hz high pass or low pass crossover.

I was expecting the US-50HCA to be a beast, but not so much. Here are the results (RMS unless otherwise stated):

4ohms stereo - 33.4w/ch
2ohms stereo - 59.6w/ch
4ohms bridged - 126.3w
2ohms bridged - 198.2w
Max Output at 2ohms mono - 282.5w (hard clipping)

(The US-50HCA, like the Orion 225HCCA is rated to handle 1ohm mono and 0.5ohms stereo and I don't have the resistor bank loads to test these configurations yet.)

And the USA-50:

4ohms stereo - 38w/ch
2ohms stereo - 65w/ch
4ohms bridged - 133.7w
2ohms bridged - 167.6w
Max Output at 2ohms mono - 274.9w (hard clipping)

Surprised with the test results? I was. I guess the real test will be the 1 ohm mono test for the US-50HCA to see how much power it's really capable of. Now, let's see if I can sell a few amps to fund the needed resistors for the additional 800W 2ohm load.

Stay tuned, more coming soon...



See both amps pictured below; 50HCA in blue and USA-50 in purple...

US Amps US-50HCA on top and USA-50 on bottom

US Amps US-50HCA on top and USA-50 on bottom

US Amps US-50HCA Guts

Testing Power Output from Old School Amps - Part 2 - Video Demo

I recently did a video review showing the details on how I measure output power on my old school amps. I've had a ton of questions with people wanting me to explain further the process. If you want to do this yourself, you'll most likely need to invest some money in the tools. At a minimum, you'll need the following:

• 12v Automotive starter or Marine Deep Cycle battery or 12-14.4v Power Supply with enough output to handle your amp's load
• True RMS Volt Meter
• Oscilloscope (My Velleman HPS-50 has a built-in RMS Volt Meter)
• Speakers or Resistors for "loading" the amp

Watch the video to see the components I use for my tests. 


Click the link if you prefer to see the video in HD (720 or 1080p):

Old School Amp Output Test Demo in 1080p HD!

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