Carver PM-1.5 PA amplifier rescued from the dump
Вставка
- Опубліковано 26 сер 2024
- This is another piece of audio gear that was headed to the recyclers. Let's see if it will work again or if it is good for parts.
Patreon www.patreon.co...
Email: johnaudiotech@gmail.com
Thank You!
it is amazing what the people throw away
Truly!
Not really, serving a past life as an audio service technician, had I the opportunity to take every Carver Magnetic Field amplifier ever made and toss it into a metal shredder at a landfill, I would. These amps are terribly unreliable, they don't really sound that good and they are a pain to fix. If I were the OP, I would have put that thing right back where it came from and not waste my time. The only thing Carver ever produced that was good, were the tube amplifiers. Now THOSE are worth saving.
that is gold... one man's trash is another man's treasure, truly
Bob Carver has been one of my Hero's from when I was just 10 years old. I still remember reading the article in Stereo REview magazine. And his Coffee can Amp he brought to a Audio show. And how it sucked so much power it blew the fuse for the room and out went the lights.
Bob Carver is on my list of people to see one day. If anything? I want to get one of his car amps. Maybe one of his old soldering Irons. :-)
The other story I remember is that he is a GREAT Inventor, not a very great Business person. Hence why his companies kept getting bought out and then they kicked him out shortly after.
I think he still owns and Runs Sunfire. Really, if I had to do Home Audio? I think that I would be running all Carver stuff. (or stuff made by him or tweaked by him at the very least)
His from the old skool. And I like that. One day, I have to catch an Audio show with him showcasing some stuff. I know he made some Line Array speakers a while back. Still... I think I would rather have his Amazing Loudspeakers. They just look great!
This is the first time I am seeing brushed DC motor fan (hair dryer fan) in an amplifier... Interesting.
Also this video really reminds me of Maxxarcade. He used to work with a lot of PA equipment but unfortunately most of his videos are gone because of copyright issues. I really like watching people repair PA equipment for some reason.
Rock Bands like Pink Floyd, Led Zeppelin, ect, ect. Loved to used these amps for their rock concerts. And stack like between 6 and 10 of these things on top of each other. This is what the " Sequencer " button is for. You turn the power on the one main amp. Once it is fired up you hit that Sequencer button. And it will turn on the other amps that are stacked.instead of turning on ever single Carver. You use one to turn on the rest you have stacked. I have had my Carver pm-1.5 sense 1990 it is still going strong. shakes my and my neighbors house's. It is just unreal. God Bless Bob Carver.
That's 2 things Carver was notorious for - flawless designs with 3 voltage rails when others struggled to get 2 working together, and overheating problems.
Gotta love that inrush current.
What a beast ! can't believe it was gonna be landfill ....cheers.
What a find! I had a similar story back in 07 with a Kenwood KA-127 destined for landfill.
Fix the lot, eBay them and buy that audio distortion analyser you were after !
I was just wondering what you could get for something like that on ebay. Tested works as is. Gotta sell for something. I mean it is a 1,200 Watt amp. At only ten cents a Watt that's still $120. Which is not bad for just pick it up and carry it away.
BTW, how about using something like REW for distortions test. If the sound card is good it could run on 96kHz or whatever the max capabilities of the software/hardware..
@@pliedtka There's a freeware audio spectrum analyser I use ... but it's only 'good' for an 'indicated' -120dB signal to noise and there's a bit of noise pick up from wherever at the low end as well.
I think the one John was talking about getting would go down to -140dB with low distortion measurements to match - certainly better than the 'average' PC sound card.
That's the problem with his amps - they're better than his (current) test equipment !!
I worked with a sound company, in the early 1980's. We ran this exact amp, I think. Yep, 600 watts @ 4 Ohms, or you could bridge it. They were awesome amps. Sounded great, a bit lighter to carry, and reliable. The fan is not running loud; that's just the way that particular fan sounds. I can remember that their fans had a unique sound. You can easily throw a block party with it!
I bought two Carver PM-1201's in 1993, they have been driven to the limit at countless events for 29 years without any failure or overheating, great amp.
Many dont like to service these amps because they fear what they dont understand. I have serviced my share of carver pm series gear and personally use the pm 1.5 amps in bi-amp setup for my home audio setup.and I love the sound and understanding how they work I feel that they are easy to service. If those say Carver is junk then they must say they are just scared of the pm /pt series. or they just use cheap speakers and not want to hook up A big amp to them.
Hello, I've got two carver pm1200 amps. Both have humming / starting transformers and then the fuse blows out. There was a transistor in the powerstage that was shortened. It stil doesnt work. Do you know how to repair?
I own both the 1.0 & 1.5t and they are mint condition. I still use them today to drive my subs and the Sunfire 5 channel amp by Carver for the remainder of my system. These amps I will not part with. When you match output to dollars they are hands down the best value against amps costing thousands more.
ohh it's a fan!! Let's stick some fingers in it 😜
I remember fixing these things. Full of dry joints on the molex connectors which snot the output stage. It's only a little puppy and used mostly for top end amps. Driving the compression driver or any mids.
My job is fixing PA amps and pro audio gear so, know them quite although, not seen one 9ver the bench in a long time.
They punch hard for an old class H linear amp of their size
I had a Carver M-0.5T
Best amp I ever had
Cool, it looks like a well built, serviceable unit
I had a PM 1.5 for my PA setup. It's a 600 watt per channel amp at 4 ohms. A phenomenal unit for its era with better output than any other available amp in a 2U space (obviously before class D amps became prominent).
The way that amp is built might want to use another 2U under it just for air flow. Or even mount it upside down.
An audio file would be very happy to have that amplifier he would probably pair it with a nice tube preamp and be very happy
Carver stuff was the best. Great engineering. Bob Carver's Sonic Holography technology was/is magic.
Carver Amps are great! Lots of people would be happy with this one. It sounds like you have a buyer in the comments here…
I’ve used these and similar models quite a lot i live sound systems, both permanent installed and portable touring rigs. I’ve got a video somewhere, of a rack of about 12 of these in a rack, all doing their thing, driving different elements of a large speaker system. Some drive tweeters, some drive midranges, some drive subwoofers.
Great amps, even though I consider carver to be a little gimmicky at times with their designs. Their PA amps were pretty good. Nothing too unusual on those. These benefit from new caps sometimes.
These amps always seemed to do their power respectively and were pretty reliable as far as things go. These don’t like to be stacked closely in a rack though. Minimum spacing between these amps must be one rack unit on top and bottom, between multiple units, for cooling purposes.
Seems to me, Carver amps always had noisy transformers.
These ran pretty hot when we used them.
I have the very same amp haven’t used it for more then 15 years now so it could use a complete service and possible upgrade ❤❤
Do you want to sell it?
Bob Carver said in an interview that this low feedback amplifiers some better at higher feedback, it was done at the time to keep distortion figures low for marketing make it 0.1 thd
Smokin' hot amp! Hope it holds...
It's new experience to hear John comment on these real famous equipment, and told us how they work and why it's efficient. People did throw out things that cost some cash, back 30 years ago I heard Carver (may not the same model) in show room with some real punch.
I have one of these that I use as my daily driver. 450 watts /channel or 1200 in mono bridged mode. With my 500 watt rated Polk towers I set some serious SPL.
We have a carver pm-300 and it has been used in a home studio and also as a party amp. It has a pretty nice sound a good clipping function when it's driven hard and it'a passive cooling design. It gives around 150 watt rms per channel at 4ohm load.
1 height unit and 19inch standard.
Thin design low weight but good power. I think it's class g is/was the early era before class d design became more common.
That amp is worth a lot of money, I'd do what you can to fix it cosmetically, probably could still get a $/W for it!
Nice job getting that up and running, not that there was much to do. That must be the most power you've had on the bench, isn't it? I remember that the three rail voltages were something Carver touted in their advertising copy, only they used flowery, marketing-speak to sell it to the non-engineer types.
I have 2 Carver M-400t amps, 200 w/c at 8 ohms, 400 watt bridged. Incredibly strong and powerful amps. I have Klipsch Forte speakers I bought new, and powered them with the bridged Carvers. I had to have the woofers replaced under warranty because I pushed them too far and ripped some of the woofer surround from making them overtravel their normal excursion limit. I was lucky they replaced them under warranty. Carver made some top quality gear back in the day.
I forget exactly what happened to Carver but I think Bob Carver was voted out by his executives and they destroyed the company trying to make the same amps everyone else was making.
Love carver stuff
Snickers has his priorities straight!
These Carver amplifiers have a reference voltage for the fan and if the line voltage is too low that reference voltage is out of whack and causes a comparative to turn the fan on to full power.
Sure it will work, just get the service manual, to tune it, clean the pots, switches. I would change the fan for PC type. 114V on rails - holly s..t, that thing can push some serious bunch electrons, but I wouldn't go below 4ohm load.
When I load test an amp, I also parallel output from the resistive load a loudspeaker thru a... 100-200 omh resistor just to "hear" what's goin on, on a studio scale...
Luv my Carver equipment! Got several systems. - Great video too. Thanks.
Glad to see Snickers looks fine and in good spirit, though a bit thin.
Nice new scientific calculator. Sneaker as always a trademark & constant value 😁
What a find !!! :-)
Wow thats Some cool title for an Amp..! Who Loves Ya Mang" Peace ,,, from Dunedin New Zealand.!
Great little amplifier
Thats the special Carver design
One just like this on eBay right now. 250.00. I’m sure you’d have no problem selling it.
CAN YOU DISCUSS THE TYPES OF CONSTANT CURRENT SOURE ?
Carver's been pre-loved for sure, it's seen some $hit man.
man I've found truckloads of working equipment / gear in the recycling. Around here they drop them in bins by the roadside.. if you can get to them before it rains, you are winning. Found a whole late 70s pro recording studio (no mixer - all the 'goodies' like dbx compressors, eq's , reverb, echo ) pulled out of someones closet and tossed in the recycling. the guy around here literally gets pennies per pound for it - he doesn't 'upcycle' it or resell it.
When I worked in a board assembly house we ran all of the boards we made through a dishwasher. So what's rain do to stuff? Solid state means it is hermetically sealed. So pretty much air and water tight. The trick is to let it dry completely out before powering it up.
@ things left wet can corrode. There were parts we couldn't wash too. Things we'd add as final assembly items.
Its a bit too big for a headphone amp.. but I'm thinking it could boost a tube amp input into some overdrive...
Perhaps someone tried to load it 4 ohms bridge mono... and drive a sub out of it... and usually they can't support it so the fuse will blow...
Hi!.. I like all your videos, what I don't understand is why would this be thrown in a landfill? Couldn't it be recycled in some way?.. it all seems such a waste, besides, in a landfill, in 200 years time, this would still be there...
That type of thing is very common in countries like US, UK, Japan, etc... People would rather buy something new than fixing old stuff. Stuff like that here in SA would almost never happen. If it did, rest assured someone else was already there waiting for it to happen lol
I think the guy said it was going to someone who recycles. These scrappers separate the different metals for recycling.
@@JohnAudioTech That means it would be treated as junk either way. You recycle something when there's no use for it in the current state. That would be a lot more sad (it also happens a lot here)
@@JohnAudioTech A scrapper would pretty much only be interested in the aluminum face plate. Although scrap steel is over $200 a ton. But a ton of aluminum is $900. So better money. And if they're real scumbags, and what scrapper isn't, then they can get the copper. I don't know what burnt copper is going for today. Probably over $1 a pound. Bright bare copper is $3.70 a pound. That's like gold!
Hi. I have the same amplifier I would like to fix for my own. Can you read the value of R1 on the PSU management (small pcb close to the fan). This is connected to the triac that manage the main transformer. On the schematics, this is supposed to be a 18R but the one I removed seems to be different. thanks.
quick question....um i have a Carver mxr 150 i turn it on with no load and volume down...i get heat off the top current shunt resistors..smoked one halfway but shut it off in a hurry.....dried out caps ???????????? i love that thing and i wanna save er
Probably shorted parts, like a transistor or heavy bias currents from faulty parts. No way to be specific not having the unit in front of me on the bench.
Good amps
The thing with these amp is they worth a bit of they work. If it doesn't it's probably not economic worth repairing.
Hi there, sure you are too busy to notice this request let alone respond to it, however thought id try my luck. Do you by any chance have any info advice or reference to a amplifier design that does not use a transformer for the input supply? Do realize the safety aspect, however curious to see a really hardcore design that will rectify & stabilize the direct mains input and use that as the supply. In SA that means dealing with a whopping 300 odd volt dc as they supply, but imagine this would be a hefty design to power VERY VERY large cabinates no?
Yes it is very unsafe and the rail voltages high. With class D amplifiers and switchmode supplies, modern pro sound amplifiers are lightweight, more efficient (less heat) and can produce high power in a slim package.
Is it safe to use heating coils as a dummy load? Asking because I currently don't have any high power resistors but I do have a couple of heating coils from a hair dryer and a few fans laying around but I am afraid that heating coil could have some inductance or something that could harm the amp.
Should I make a "load box" out of these heaters or should I wait until I get some high power resistors.
That should be okay. If the amp is powerful enough to make the coils glow, the resistance will have gone up about 10% with nichrome wire. Inductance would be small. Much less than a speaker voice coil.
@@JohnAudioTech OK, thanks
Would you be interested in selling this amplifier I would be willing to do pay pal if you are interested.👍👌✌️🎶🇺🇸
1800 wats
You need to test at its normal operating power ...
Sure - something like that - see if you can drive 2 ohm - that would be why people would take on tour.
Lol, that front panel was in Iraq?
Another "Magnetic Field" (over engineered) piece of amp, by Carver... UA-camr xraytonyb has restored a couple of those. Not my kind of amp.
I Know Where A Whole Stack Of These Are. Check With Your Local Schools Board Office Or A Janitor. They Are Happy To Help. 😉
Sell it to me, tell me how much it is worth, pack it for me and send it to Colombia, I pay the shipping
One of the worst amplifiers ever made.
I hate carver amps everything he made was very unreliable
@@mikepawntee2425 well bob carver is a weirdo if you ever met him
@@mikepawntee2425 u must hate yourself get a life
@@mikepawntee2425 get a life buddy it’s you tube
I had a caver TFM-25 amp & CT-17 preamp. Both worked great for twenty years. Then the preamp went south. Still have them , will check EBay to see if any interest.
I’ve got two them that still work after owning them since the early 90’s, sorry but that’s what I call a reliable amp.