Tuesday, May 31, 2011

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...


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

Sunday, May 15, 2011

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.



Wednesday, May 11, 2011

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!

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


Sunday, May 1, 2011

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!