1993 Infinity DPA 275 - Class D Before It Was Cool [4K]

[@HifiVega]

I was always curious about these amps! That 4ohm stereo efficiency was insane for 1992!!! Great video as always

[@wal2]

Yeah I was expecting maybe 80% but I was like "whaaaaaat?"

[@tharealmrinvincible6386]

Tell Doc and Marty to keep going back in time and bring more of these old school amps. Show these youngsters how we did it before they were born.

[@bigdogbrodavepresents6178]

I own (3) A/D/S/ 2001 amplifiers, the very first true audiophile amplifiers ever made. Designed in 1973, these amplifiers are TRUE AUDIOPHILE CONSTRUCTS. Bi Amp, 160 watts and these came with their own speaker system the A/D/S/ 2001 bi amp speaker system. Possibly the most RARE of all A/D/S/ produced speaker systems. Perhaps theres interest in these. OLDEST SCHOOL HI FI... from the daze. BDBD/2022

[@SteveSega]

I installed a DPA 2300 and DPA 275 in a Mercedes for a customer when I was at Ramstein AB back in '97. The DPA was powering 2 Kicker Solobaric 12" and the DPA 275 was powering MB Quart 3-ways (6.5"/3"/tweeters). It was very difficult because of the fuel tank location in the Mercedes, but once I worked around that, it sounded awesome!

[@wal2]

👌😬👍

[@danrogers9945]

Cool to see this amp tested!i had one (think in 93-94) it ran 2 pioneer 6x9s in my Chevy chevelle (1973).it did pretty good with my alpine cassette deck!omg were old buddy

[@wal2]

Thanks for watching and commenting!

[@CriticalThinking88]

Holy shit! You continue to blow my mind with the old school amps you get your hands on. Yeah, they were massive and not very efficient but so many memories.

[@americanjoe7679]

Love seeing you review old school classic amps!

[@Choralone422]

I remember seeing this amp in the Crutchfield catalogs and the write up about it in Car Stereo Review. It seemed really cool but was out of my price range as a teenager back then. Very cool video!

[@wal2]

Yes I was curious as well. Thanks for watching and commenting!

[@MickeyMishra]

If it sounds good to Big D? It's good for me! Thank you for being one of the few that listen to the amps instead of just giving us numbers. Numbers are nice and all. But they just don't tell the whole story or when used in real world applications and speakers. I did however notice the high end was a bit boosted for my ear in the pants seat. But nothing bad as far as I can tell from the short demo in the video. Amazing how this Car amp still works after all these years. Its not often things last as long as they did back then when your talking about consumer grade electronics in general. Excellent work as always!

[@wal2]

Yeah the sound demo over KZbin isn’t a great way to show SQ, but if I didn’t so it then people would ask so I do it anyway

[@lupillos7404]

No way, I had one of this amps back in the days 90’s bought it from a technician that worked on amps that work for Jbl in northridge ca and found out then they also make Infinity and Harmon kardon and of course jbl all made there, I had this amp running with two 10’s was picking them up really good was looking for one last time see if I can find one and you come up with the amp video 😂 good to see this amps are still out there very very rare amps, good videos like always. 👍🏻

[@wal2]

Thanks for watching and commenting!

[@stereomc3954]

Sounds good. I also remember these back in the 90s

[@wal2]

Thanks for watching and commenting!

[@freeair7292]

Beautiful amp and the build quality looks solid!

[@MrFARTSANDWICH]

That build quality is excellent

[@wal2]

Cool design I just hate I broke that connection off the RCA jack

[@calvinevans8305]

Wow, that's so unique. I've never seen that before. Awesome video.

[@wal2]

Thanks for watching and commenting!

[@alanstant9356]

I have heard of infinity but not an amp like that. I was pretty impressed with it overall.

[@dankomartek2145]

I have one of these. Great little amp.

[@wal2]

👌😬👍

[@scottphillips471]

Awesome video!! I have three of these amps, (one is still a virgin). Also have a Nucleus with the optional fader. Thanks for doing what you do!!

[@vasquez3769]

Great videos man. Can't wait on the JP83 dyno

[@nexiabiamp]

I’m just so amazed at how fast you can press the buttons on the Dyno, all while speaking perfectly. ❤

[@isaakwelch3451]

It's a voiceover

[@wal2]

Skillz!

[@bigdogbrodavepresents6178]

Nice... I always thought MMATS and BLADE came out with the first Class D jobs... Never considered the Infinity offering... RARE... 1991 was a year of advancement in car audio. BDBD/2022

[@wal2]

Full range D was Infinity

[@bigdogbrodavepresents6178]

@@wal2 ahhhhhh "Full Range".... I get ya. BDBD/2022

[@bigkou_916]

Love these old school equipment from my Era. 👍

[@orangejjay]

I'm not sure why/how I wasn't subbed to this channel but I am now. Thanks for the cool stuff, as usual, man.

[@wal2]

I use this one for the stuff I don’t think will be very popular and stuff other than car amp tests too

[@chris.o]

That’s got to be a rare amp!

[@jimsellers6911]

Love the old school amps !!!

[@wal2]

Me too!

[@scuff433]

Love it, imma big Infinity fan 😍

[@wal2]

👌😬👍

[@1rexrex]

I remember this small boutique in N. Alabama had these and some Focal speakers on the wall. Looked so nice.

[@wal2]

👌😬👍

[@brianfernandes2382]

I had a couple of the DPA-275 units. The were great little amps, not huge power, but sweet & efficient. Great for a mid-tweeter combination. They were not recommended for lower impedance loads as the frequency response rolls off.

[@wal2]

👌😬👍

[@hoopdyhop76]

I had a system with 4 of these. A 3way setup in the front with one DPA running the tweeters, another running 3 1/2 mids and two bridged powering 7 inch midbasses. All controlled by a PIoneer ODR system. Bass was two infinity self powered 10inch subs. Everything class d and it sounded great, anyone who says other wise doesn’t know what they’re talking about. These replaced a McIntosh MC440M and I didn’t miss the McIntosh at all.

[@isaakwelch3451]

On the topic of class D, I replaced a newer a/b phoenix gold amp in my car with a phoenix gold class d for higher rated power and noticed the sq drop when I did. I wouldn't run class d this old, but it's still super cool

[@raymo6795]

...still would not use class d for anything but sub ....i just bought new Mmats class d 6 channel, does not sound as good as 30 year old Soundstream...going back to SS

[@marvinclarke9082]

Wow, I'm literally looking at a DPA-275 on my desk right now!

[@wal2]

Wow, that's cool!!

[@ehrenkrause9861]

Always cool to see something different 😁👍

[@wal2]

Like erry week!

[@TheDudeRc]

I LOVE that generation of Infinity speakers, the Betas are simply amazing speakers. To this day I still run a 30 year old pair of EMIT-Ns in my car. Installed a lot of their stuff in the 90s but was never a fan of those amps. They just sounded weird and muted while also being sharp if that makes any sense. lol

[@wal2]

👌😬👍

[@dyslectische]

Not that strange . Old stereo for home with class-d are not that great . Its kill dead sound. Even today you have not that great class-d.

[@60NXNP09]

"Stereo Review magazine was definitely for car audio enthusiasts.

[@KARR]

Never seen this amp before pretty cool

[@OldManBadly]

The funny part being that you can wander onto Amazon and get that power in a class D for about pennies now.... time flies.

[@nearchd504]

That's so interesting to see this amp

[@TheTruthTeller1111]

I used to have that amp! I also had the 250. I also had a couple of Carver amplifiers, a PPI 2150AM, and a pair of Orion HCCA 225s. I'm old...

[@wal2]

👌😬👍

[@TheTruthTeller1111]

@@wal2 I traded both Infinity amps and a pair of 8" Infinity subs and separates for a used XR250 dirt bike. I thought I made out like a bandit. I got a lot of good deals on audio when I sold audio and video at hhGregg. Some of the best sales people made almost twice what the sales managers made. We always had the best equipment in our cars.

[@davidtappe5337]

Great seeing amps I couldn’t afford back then. Made do with home speakers and and autozone eqs

[@wal2]

Thanks for watching and commenting!

[@thomasbradian6367]

In 92, I bought a kenwood 921(75wattsx2) the thing was the size of 2 of those, and it came with a fan for a 200watt amp. Sherwood BP amps didn't recommend 2ohm stereo either

[@RJSDZNS]

Them be some white legs D😂😂 Great content as always. The efficiency at 4 ohms blew me away!

[@wal2]

Homie needs some Sun!

[@RJSDZNS]

@@wal2 😂😂 your a stud man! I love your channels!

[@djsnocone378]

Great stuff, keep ‘em coming. Would love to see some old Sherwood, deltasonic, alphasonic, and proline

[@wal2]

Yeah boi!

[@halidaymichael2899]

I installed some of these back in the day. Was expensive in NZ and was kind of harsh sounding. We were an Alpine and Rockford dealer as well.

[@dlcarburetor]

Nice. Funny how that works, use the amplifier as the manufacturer intended and it will sound just fine. I've always been a fan of most things from the Harman Kardon group including Infinity.

[@audiophile6475]

Yeah I get the feeling people where using it with 8-ohm or possibly 2-ohm speakers and getting either super harsh highs or very muddy highs and just decided that "class d can't do SQ like class A/B) when it comes down to the filters used need 4-ohms specifically to work as intended.

[@ccroson7935]

I really love infinity products especially their speakers I have a set of infinity overture three speakers with self powered amplifiers in them Amazing it’s too bad they don’t make stuff anymore I don’t really understand why

[@carlosmaple162]

I see a lot of new Infinity car audio items on ebay for sale.

[@johnviera3884]

Tripath filed a patent to make a Pulse Width Modulation (PWM) Class D amplifier in 1996. That’s the modern Class D design we all know today.

[@mullinperformanceaudio5902]

I can't imagine the assembly process of that amp from the factory.

[@scottiffanimccord1509]

Way cool amp D thank you!

[@wal2]

Thanks for watching and commenting!

[@msh6865]

What's funny is that amp is probably older than many subscribers of this channel. Lol. I remember the DPA amps but, never saw one in a install back in the day. In 1993 the bigger names like RF,, Orion, LP, etc. we're the gear everyone wanted to run. Infinity was considered ultra high SQ.

[@wal2]

IDK a lot of y’all old like me 😝

[@jstrahn]

Infinity for the win! I might be a tad biased. You need to test the Infinity Beta 300 I have.

[@wal2]

Yessir we need to work that out 🤙

[@bassntruck]

I have a bit of an Infinity Beta Amp collection. Bought most of them new. Used the heck out of them. I sent D and some of the other guys messages years ago if they wanted some to test but they never got back to me. And this was when they were new channels. Oh well.

[@wal]

@@bassntruck it’s nothing personal bro. I get around 5 offers a day to test amps. It’s appreciated but I can’t do them all

[@csj9619]

Sorta reminds me of the "Nucleus" crossover that Infinity made around the same time.

[@wal2]

I have one of those and was gonna show in this video but decided to give it its own

[@josephlandrum9269]

I have always been any Harmon product fan. I am running Infinity Kappas in my Benz. New-old....Infinity has always made great products. Great content. If you have the opportunity to test an Xtant 403 amp, Xtant 1044dvc sub, or Boston Acoustics GT22 amps, I would love to see your results. Just some of the old school stuff I have. Thank you

[@wal2]

I tested a Boston GT42 I believe…

[@greggarner4477]

Infinity Capa has always been very good, but not overly popular. They've always been kind of a mystery at a high price. At least in my area.. Maybe that is different elsewhere..

[@stevefox3763]

I like infinity but you struggle to find anything in the UK these days. Had various infinity sub's back some 20 years ago and loved my perfect 12's and I still have a pair of kappa 50cs components that refuse to die or even show signs of degradation after 20 years, well the main drivers, the tweeters have been replaced many times over lol.

[@paulgood2218]

Great video

[@wal2]

Thanks for watching and commenting!

[@scottnimblett7735]

Love the videos!! Especially the old school stuff. Can you acquire a Blade Digital amp from the 90s? Would love to see a Dyno on one.

[@wal2]

Thanks for watching and commenting! And the suggestion!!

[@olcjoedaddy]

Those early digital amps where voodoo stuff. Honestly I never gave it a chance back then but ironically it's all I run nowadays.

[@wal2]

👌😬👍

[@randomtube8226]

Infinity makes good home audio and has good vintage stuff. Not saprised at how well this amp did.

[@wal2]

👌😬👍

[@bobdodge3171]

I remember when that amp came out

[@wuerzburgkids4evernever795]

It sounds better than that critical mass you tested.

[@gabec6522]

Still love the mtx blue thunder the best.

[@92hbhbhybrid88]

I remember this amp from the Crutchfield catalogs.. oh my..

[@wal2]

Yea I show a clip of one in this video 👍

[@markeithcash]

Harmon one of my favorite manufacturers just because always price friendly and do rated if not more. I'm still disappointed in myself for selling my 611a for like 30 bucks 😔

[@wal2]

😬👍

[@Loudkona]

hey big d i got a question how did they get rms numbers back in the 80 and 90s without an amp dyno.

[@dameon2170]

In 1995 I seen speakers that could take more power than today amps too

[@davidtashman8217]

All class D amplifiers are designed with a low pass filter on the outputs and most are designed for a 4-ohm load. Similar to the Infinity graph, if you use a 2-ohm load, the low pass filter will shift to a lower frequency when it comes into effect. If the low pass filter is in an audible area of the frequency range, then you will notice a diminished high-frequency response. It is unfortunate that this information is no longer passed onto the end consumer to educate them. On a side note, looks like that used a great OP-Amp at the time, the tl084cn which is still used on the Ti label today on many amplifiers. That was ahead of its time, kudos to Infinity.

[@Grommet2007]

With today's well-designed Class-D amps, that rolloff at high frequencies is not enough to be noticeable.

[@davidtashman8217]

@@Grommet2007 you are correct that some of the higher-end, and well thought class d amplifiers won't make a difference because of their higher roll-off frequency outside of the audible hearing range, but surprisingly there are still a lot on the market which are audible.

[@wal2]

I thought all of the Class D’s today use high enough switching frequencies so this is no longer a concern? 🤷‍♂️

[@davidtashman8217]

@@wal2 I'll post the info, but that is not the case for all. There are several which have been measured by some German and Russian hifi magazines which still have a drop off when using a 2 ohm load.

[@Grommet2007]

@@wal2 Yup...! Well, almost all of them... :-)

[@alexkay1874]

Picked up a Phoenix Gold M25 Yesterday at the thrift store . went back in time 2015 when you did a dyno drag race with a Fosgate .BOOYEE That was hard to watch you doing your AM radio DJ voice .

[@wal2]

Oh wow that bad 🤣

[@waltkosch]

I have yet to see any Sherwood amps yet. Wonder if a Sherwood could bump the Phoenix Gold 🌀 Cyclone ??

[@wal2]

I don’t have one in possession, but I rotate things often so I’m sure I’ll come across one

[@MrBarkley76]

That 2 volt RCA input 🤣

[@brentb5303]

These things have so much in common with the Blade SE series. Especially how it slides into the heat sinc. I wonder if this isn’t even a BASH amplifier. It would account for it sounding good because the output is A/B with a class D power supply. I’m really curious now because class D, even in the late 90’s, did not sound good.

[@wal2]

I don’t believe this one is BASH

[@steveo5174]

On the same uncommon subject as this old class D amp, I'd love to see an old Blaupunkt class T amplifier get tested. Something like a PA2150.

[@wal2]

Thanks for the suggestion

[@HamiltonMechanical]

Thanks big D! :) i like the design of that one! neat little package. Back when infinity was still their own! Bought an infinity/jbl a while back and man, it was SUPER disappointing, wound up shipping it back to crutchfield and getting an alpine, much better choice!

[@wal2]

Oh wow I’ve always had good luck with both Brands

[@wayneslain9444]

This is not only the first full range class D, but probably one of the first class D, period. Not too long before this they transitioned from vacuum tube to transistor.

[@lasskinn474]

Yea look they had been using transistors for decades before this, its 90s

[@wal2]

That tube comment? Are you back from the past?

[@v12alpine]

Maybe the 1st class-D for car audio but they've been around since the 50's and commercially available since the 60's

[@wayneslain9444]

@@lasskinn474 well, we're saying widely commercially available for car audio. I'd have to look it up but I think they started using transistors in car audio in the late 70s, and they weren't fully transitioned to transistors from tube until the 90s. It was still pretty common to see tubes for car audio in the 80s. So this amp came out in 93, so not too long before that, about a decade or so was when you started seeing the move to transistors. I stand corrected good Sir.

[@lasskinn474]

@@wayneslain9444 you could look it up and find that transistors were in wide use in all consumer audio in 70s. You'd have to do real digging to find any tube based car audio at all from cassette or 8 track era. Tubes aren't very good for environment of the car and car audio in general got wide use with transistors and you wont find any 80s car amps with tubes basically.

[@martinlopezkush]

Hi I’m a big fan of all ur videos and appreciate all the hard work u put in all the things u do. I just got one question well just I have been wondering what u do for a living just curious thanks man 🙏🙏

[@wal2]

I play with Fosgates

[@martinlopezkush]

Nice what city are they from?? 🧐

[@johndilauro3462]

If you remember Blade Technologies had BASH amplifiers BASH is a form of AB and Class D Technology Back in the 1990’s .They had big amplifiers Power wise That were thin and 1/2 the size of regular amplifier Do you remember Blade Technologies ? They were black amplifier with a red light that was down the front .

[@wal2]

Yessir!

[@johndilauro3462]

@@wal2 I didn’t know it but Hifi Vega did test a BLADE SE 2250 It was a dual mono .250x2 amplifier That was about the same size as a RF Punch 75 .It actually exceeded its power ratings That’s crazy A lot of companies thought BLADE Technologies was full or Crap Because their amplifiers were so small and so thin .They we’re so thin . I highly doubt they did well in NV,AZ or Cali There is no where for the air to circulate Who would have thought class D and BASH Technology would be the future of car audio

[@N7-alpha]

They sounded different when they came out because every body was use to ab amps, in this age of blue tooth and mp3 it sounds fine.

[@wal2]

We’ll that’s a good point!

[@minenachos]

Did you notice the voltage was different with the wattage on the stereo test

[@wal2]

Yes that’s normal too

[@Van1018s]

Very cool amp review, but am I missing something? Shouldn’t 4 ohm mono be equal to 2 ohm stereo, which the amp protected in? How do both channels continue to see 4 ohm with the amp bridged at 4 ohm?

[@wal2]

Great point! Either (1) the amp lowers rail voltage when switching to mono or (2) the amp does way less at 40Hz than 1kHz. I have a feeling it’s #1

[@Van1018s]

@@wal2 yes. Probably works as a full bridge and cuts rail voltage in half.

[@or8106]

Is this maybe they first clases D car audio amp in they history of the car audio?

[@wal2]

The Infinity DPA250 was the first “full range” Class D amp to hit the market.

[@stevel.2759]

Installers love Infinity

[@wal2]

👌😬👍

[@mike.hunt420]

Can you find any imfornation on the first infinity basslink t, i seen one and by the time i bought it it was blown

[@wal2]

Check with Infinity

[@kencreten7308]

Very cool.

[@wal2]

👌😬👍

[@FATHERSOFBASS]

Growing up I always loved alll there equiptment it was always like fancy and expensive like more then alpine lol I’m 46 @10:46 imm outta herrrrrr

[@wal2]

👌😬👍

[@the_dark_defender]

What's in the box? What's in the box? Awww what's in the boxxxxx??! What's in the Fing box?!

[@wal2]

Sorry I learned how to tease by watching network TV 😝

[@the_dark_defender]

@@wal2 You want me to become vengeance. You want me to become… wrath?

[@bassmansl9596]

Nice bro 👌

[@luke144]

Not a fan of D Class but this one doesn't sound too bad. It has some clear headroom issues but it works. AB for me.

[@wal2]

😬👍

[@mr.jojomunoz6561]

ive been wanting a infinity amp for awhile now, they just dont come with a bass knob so its alil inconvenience for some genres of music

[@israeljarvis8086]

Cool! Whats the most efficient amp you've come across?

[@wal2]

Some of the Korean half bridge amps have measured in the mid 90’s at 4 ohms (Crescendo, DC, D4S)

[@mrworldwide6770]

Why do some amps have more wattage on one channel then the other

[@joshuawheeler4404]

People saying it sounds bad I would put money that some have never even listened to the amp also that is a great example of conformation bias people reading something and believing it so much it affects their perception of something

[@wal2]

So true!

[@quintonlitton6779]

At one time had the dpa 250 on two mtx road thunder 12s

[@wal2]

Oh wow how did that work?

[@quintonlitton6779]

@@wal2 honestly it was kinda perfect for the mtx 12s. Not super loud like spl but it sounded great and got loud enough.

[@gilbertw5370]

Big D. You keep up with any social platforms

[@wal2]

I prefer anti social media 🤣

[@gilbertw5370]

@@wal2 I had sent a link to a ultra rare RF amp

[@stormyyoung6344]

Wounding what amp had the first clip indicater/light and how accurate it was? Btw cool looking amp.

[@wal2]

😬👍

[@matthewlawson5634]

Not sure who was first,but I had both coustic 360 and 460 amps back around 94 95ish they both had clip lights

[@bebe1979]

This was before the Harmon take over if i'm not mistaken?

[@wal2]

Maybe a couple of years before? 1994 I believe was when Harman bought Infinity but if I’m wrong someone will surely correct me

[@stevemccauley5734]

Harmon took over Infinity in 1983. Sadly Samsung took over Harmon a few years ago.

[@devnull182]

Nows the time to start doing electrical Frequency response measurements and graphs for us. At 4 down to the stable ohm load. Let’s find out if they Lyin to us!!

[@wal2]

That’s getting a little deep in the weeds for what I like to show, but maybe 🤔

[@matthewramsaroop3814]

Hey where you'd get the specs for it??

[@wal2]

Manual and magazine. Both literally in the video 🤷‍♂️

[@MuvoTX]

Weren't these sold at crutchfield?

[@wal2]

Yes it’s in the video

[@robsorgdrager8477]

Tell me thing wasn't designed to be mounted under a seat. As for sound quality I think it sounds ok but soooo many variables involved. It might be a little bright but it didn't seem muddy or incapable of driving the speakers. Digital will always suffer from square waves but it can sound very warm with good drivers.

[@wal2]

It surprised me, I was expecting bad SQ based on what I was told

[@robsorgdrager8477]

@@wal2 never go off what your told 😎 , make your own opinion.

[@girthquake9655]

I can smell that box from here...

[@wal2]

Smellovision!

[@killernukem5914]

Nice

[@wal2]

😬👍

[@craig1474]

Sweet

[@wal2]

yeah boi!

[@wal2]

See the 1993 Car Stereo Review Article: bit.ly/3lV9wER *Shop (affiliate links):* ELAC Debut 2.0 B6.2 Speakers: amzn.to/3gcZHiC SMD / D'Amore Engineering Amp Dyno: goo.gl/sJTcf7 XS Power D1400 Batteries - amzn.to/2BPFCKW XS Power PSC60 Charger - amzn.to/2CHGcfs Fluke 1000A AC/DC Clamp Meter: amzn.to/2Rw5WDA Handheld Dyno: amzn.to/2u2EgKV My Favorite Screwdriver Kit: amzn.to/2x0VzcE _DISCLAIMER: This video and description contains affiliate links, which means that if you purchase from one of the product links, I may receive a small commission. As an Amazon Associate I earn from qualifying purchases_