Crown K1 amplifier repair

[@brig.4398]

I used to work in a repair shop, you can have a lot of electronics knowledge but learning to take things apart and put them back together is important. Anyway you did an excellent job here, much better than I could do.

[@Specrotors]

Pick up your spirits bro and shake off the depression, you expertise is vital to many on here and you are greatly appreciated...stay cool

[@AnthonyDiSano]

Thanks for the video. Such attention to detail! So rare these days. It's a wonderful feeling after you get everything back together and flip that power switch for the first time and she goes "all green!" .. Good job and keep the videos coming. I really enjoy them.

[@rubber-chicken-productions]

Hey Max, love your videos. Great amps the crown K series, I have 2 K2's used to drive some double 18" 1kw PHL drivers in bridge mode, the back of the enclosure said both drivers when in parallel were 4 ohms. Before i sold the PHL I took the fronts off and had a look at the drivers, it turns out they were 6 ohm drivers so a load of 3 ohms in parallel, meter read 2.5 ohms! These cabs were driven in bridge mode for 5 years night after night just below clip 35hz - 120hz never missed a beat!

[@maynardcat]

Great repair job, this one is for well trained technicians like yourself, requires attention to detail and knowing what you are doing. It's not for the people who like to just tinker with electronics as a hobby. Just think of the money you save doing these repairs, and also the value the items have after you repair them, going from having only a value of junk for parts to having a high value of a first class operating amp professionally refurbished. The amp sounds really good.

[@Maxxarcade]

They have their ups and downs, but most companies do. I went with these because I was able to get a bunch of non-working ones and fix them. If I were buying new, I'd probably use QSC or Lab Gruppen.

[@mxslick50]

"Ups and downs" is putting it mildly. Crown amps are by far the worst I ever had to deal with, and in my 35 years in cinema and live shows, Crown amps failed far too often (frequently taking speakers with them) compared to all other brands combined. They were unreliable, and often downright dangerous. They never lived up to the hype, sounded worse than most others, and cost far too much for what they were. Plus they are a pain to repair. If you are going to use them, put fuses in the speaker lines and NEVER leave them running unattended. QSC on the other hand has been a workhorse with so few failures that out of the 2000+ QSCs I have installed, less than 10 ever failed on me, and NONE have ever taken out speakers in the process. QSC also has excellent support, they once repaired a nine year old USA Series amp for me at no charge and even paid to ship it back to me.

[@Mosfet510]

Wow, broken solder joints on the filter caps!? That poor amp, must have been through hell, probably dropped to do that. Well done, and great video!

[@ericlewis846]

Yea, that there was the problem with this amp I betcha. Oh and the scratchy pots. All pots do that eventually especially given how dirty that thing was.

[@mdzacharias]

Kudos. I work on a lot of consumer receivers and amps but the Crowns, Crest's etc scare the crap out of me. They sure put a lot of circuitry in there for "just" a stereo amp...

[@SDsailor7]

Great video Maxxarcade, very informative. Thank you for posting

[@ThunderRoadDreams]

Hey maxx I had some success standing the amp upright loosening the pot nuts then spraying a lot of switch cleaner down into the pot... seems to have brought the volume pots back to life. Thought I would post you this .... very interesting thread

[@Landotter1]

I disagree with the silk pad comments. As long as there is a clean seperation between a part and the pad, all one has to do is clean the pad and reinstall it. I have NEVER had problems with re-used pads as long as they haven't delaminated. Yeah, Crown makes great stuff! I consider them to be the best. A bit over engineered but built and designed to last through the thick of it. I have a CE1000 and a new class D, whaterver,,, 2500.... I love them both! The old macrotek amps but they are bocoup money, even used and not working. Very complicated circuits that take an indepth understanding to repair. Great vid man. Would like to have seen how you adjusted the "overlap".... Cheers

[@Maxxarcade]

I was told by Crown themselves to not re-use the pads. On some smaller stuff you can get away with it, especially if they were not used at high temperature or mounting tension. They do seem to last longer than traditional silicone paste though. I've seen that stuff turn to powder.

[@Landotter1]

Maxxarcade I have seen the same but the silk pads are fine as long as they are in tact and not flaking apart. Like I said, I have never had trouble with reusing good silk pads. Yours came off clean so I would have reused them and as you stated about metal shavings poking through and shorting.... but that's what they make continuity checkers for! :-D

[@Maxxarcade]

They are similar to class D, but have lower distortion. They are passively cooled via the aluminum case.

[@Maxxarcade]

Ya, the K series can be a pain to keep running sometimes. Crown gets astronomical amounts of money for parts and repair for them too. But nothing can compare when it comes to subwoofer amps.

[@slimjim119]

sweet they have nice clean highs and all around great find

[@Maxxarcade]

Yep, the K2 has a bigger power transformer, dual rectifiers, and another set of output transistors. The boards themselves are the same other than a couple minor component changes.

[@brig.4398]

This reminds me of fixing VCR's, if you put the screws back in the wrong place you could damage the unit. I remember the owner watching me and insisting all screws went back to their right place.

[@rubber-chicken-productions]

My pots needs cleaning (seems to be a common problem) now I know how to get this amp apart and what's involved :-) Thanks.

[@jrcimini]

I read the power transistors are no longer available. Do you know if this is true?

[@Maxxarcade]

Ya, I think the HD stuff comes off a different YT server. I love how the video gets blocked for short clips of music recorded through a camera mic.

[@jonathankeenan80]

What are the most dangerous parts of an amplifier like this. I have a Yamaha cp2000 and I am just curious in case I have to go under the hood.

[@tommyteeth5874]

What an outstanding video! Talk about knowing your stuff. Wow. I am needing to replace a broken black speaker binding post on my K2. I dropped it on my trunk channel. I Wouldn't even know how to open the amp up if it wasn't for your vid! Max- do you repair amps as a business?

[@aaronedberg4643]

Was just gifted two k2, one working, one that won't do anything. Leds will light maybe once five seconds after powering on, not the clip leds, and then nothing. Any thoughts. I know it's old as heck now, but would love to toy with it. I know very little about electronics

[@Maxxarcade]

The original caps weren't necessarily poor quality in these, just worn out. The amps run hot and the caps were only 85 degree rated general purpose type. They were made by Elna.

[@MrMsrsound]

Hi Maxx, got a K1 that won't start up... a both channel situation. So assuming a Main board problem as you suggest. One of the 7 main power supply resistors had leg not even soldered down thru the board so thought that might be it. I hear the relay clicking on but no Green LED power light....so I pulled Capacitors C23 and 24 they read 33uf...when I test a new 100uf cap it reads 100uf...so these are too far out of spec I assume? I pulled a few other of the 100uf caps..they all seem to read around 33uf...whats up with that? Any suggestions?

[@bmjsoundstt6624]

i have a crown xls 5000 amplifier the inrush thermistors blew up they are 32mm i am looking for a replacement online but cant seem to get one and the values i do not have the closest thing i am getting is a 25 amps 2 ohms thermistor will that work?

[@therandomchannel6103]

I have a crown 800w mt amp and ch2 works but the ioc light is starting to dimly glow. any suggestions on what is wrong and what i can do?

[@nightlife1970]

I have a K2 that is getting some noise on the gain controls. I have not torn into one of these yet, as I have never had any trouble with them. Is it necessary to pull the face plate or can i just spray with contact cleaner and be done with it?

[@SDsailor7]

Maxxarcade i posted a question on static electricity and i was wondering what can be causing the problem...when i touch the face of the stereo i can feel the static electricity. The face of the stereo is aluminum. Its a Yamaha cr-820 any help will be appreciated. Thank you

[@Maxxarcade]

Most of my parts come from Mouser Electronics. I have a few other sources depending on what I am working on. I also like to use surplus parts whenever possible.

[@fordbroncodave]

can I use deoxit d100 on potentiometers for volume, squelch, rf gain and mic gain on a cb radio? does it get rid of the scratchy noises? does it lube it to make it feel smoother?

[@myozone]

Yes indeed, I've seen it when someone has disconnected the earth !! (ground) for what even reason - ELCB (Earth leakage circuit breaker ) triping maybe. Still keep safe !

[@SDsailor7]

I am having problems with static electricity on the face of my stereo, could this be a problem with grounding or the lack of it? Can anyone offer any suggestions on how to get rid of the static? Thank you

[@ronnypatterson4011]

I have some Crown Com Tech 210 amps I purchased from Gov Liq. all the amps have a ribbon cable as the input point. I called Crown and they want $96 for each amp pip card to convert the input to a 1/4 inch plug. Is there anyway to do convert the amps inputs.

[@juopotski]

I like your repair videos! More of these, please! :)

[@jesterraj]

hi any idea on a crown 3600vz macrotech......the odep led dim on one ch....any idea whet to check?

[@Maxxarcade]

Odd, on my schematic C2 and C3 are not on that board. Are you referring to the little board that has the power relay on it? According to my diagram, R1 is a 5 ohm PTC thermistor, and C2 and C3 are .0047uf line filter caps. They are probably 250v Y1 type.

[@curtisfoster9802]

hello.would love to ask a stupid question.i own a crown microtech 2400 which I thought was one of the best amps ever built!But I recently got a crown xxti 2000 wow what a difference the xtis kicks the crap out of the microtech!Is this normal?,Any input would be appreciated. Thank you curt

[@anon7039]

I just received a k1 with dead channel yesterday as throwaway inventory from a pro audio shop that went out of business. Nothing looks or smells burnt so im thinking it may be resistors or caps. Do you have a component parts list u can share?

[@FamousByFamily]

cheers up man. when was the last time you went on a holiday? you sound like you work hard all the time. take a week off n treat yourself to something nice.

[@TechMaxWare]

Wondering if anyone could help me with my Pioneer sx-2300. Not sure if this is a bad filter cap or something but my B speaker terminals dont work at all on it. Ive tried multiple inputs on it and hight volume doesn't fix it either lol.

[@douro20]

I think balanced-current class-D amplifiers are a bit of a compromise between a class-A and a regular Class-D amplifier; they're more transparent than regular Class-D amplifiers but still not as much so as class-A or class-AB.

[@Maxxarcade]

The desoldering gun pulls all the solder out. You can see it in use in my Yamaha RX-300U video.

[@basslover201]

seriously how did u determine that the caps were bad did u meter them and they were off or just took a guess

[@CARMINATISOUND]

Hi there. Have you worked on one of those XTi amps that turn off during start up or a few seconds after being turned on?

[@curtisfoster9802]

Hey Max are they any way to get more power out of a qsc gx5 pro amp I wanted to know,i bought one of the amps and it doesn't have enough power for my pa speakers I needed the gx7 instead of the 5.

[@curtisfoster9802]

Arlen Moulton2 thank you

[@maulong6890]

Công suất am rơn nay sử dựng bao nhiu sò công suất bạn oi

[@Maxxarcade]

Yep, 8" Eminence woofers with Philips dome tweeters. No EQ in this vid. The funny thing is, these are supposed to be midrange speakers for PA use. They are similar to the Eminence Beta 8A I think.

[@Maxxarcade]

The manual only lists it as 5 ohm PTC. Maybe I can put one of mine on the bench this weekend and get the part number off it.

[@Maxxarcade]

You could replace the worst ones, but you would just end up needing to replace the rest later anyhow. You would also need an expensive ESR meter to find out which ones are bad.

[@ajxerri1]

What does a repair like this cost I have a k1 it's working fine .can I send it to you if I have problems thanks

[@AaronBilger]

Is there anyway I would be able to tell how long my Crown XLi 800 will last I have had this for 2 weeks now but I use it on my home computer for my speakers I don't play music or videos not that loud but everything is at a 4 ohm load.

[@madtater5948]

Do you know how to repair the crown xti 4000 amps I have 2 would you be interesting repairing them for me u repair them both send me one back and you can keep the other one for payment

[@jbyrum1965]

Thanks for the vid! Do you have any experience with the Crown XLS 402? I have one that's going into fault and was wondering what I might be getting into before I tear into it. I suspect there are some faulty output xisters and probably some bad caps as well.

[@thebestofall007]

you would think that with all of the bad caps due to the capacitor plague manufacturers would come out with solid state caps more often than they do, like they do in some pc motherbaords.

[@Maxxarcade]

Ya, they are pretty complicated when compared to a traditional analog amp. In fact I've got another one that has me baffled with it's odd main board problem. Not even Crown themselves could figure it out over the phone LOL.

[@Maxxarcade]

Always make sure the ground connection is intact.

[@Maxxarcade]

They are very similar. Though I think these are a bit more heavy duty.

[@rthyrsthdrfhfrdh]

Great video!. Thanks.

[@robot797]

nice amp you have there but i still like clase A tube amps more

[@walkingfreak]

I had to subscribe these videos are insanely awesome!!!

[@MrDarth64]

@Maxxarcade Where do you get all of these crown amps from?

[@DavidSmith-dm8ew]

Hi, have you ever worked on a pyle pta1400 or know if they are worth buying?

[@soundblastmm]

I am very curious, what are your test speakers? They have always sounded (and looked) very nice. I need a set of test speakers for my bench as well. Apologies if you have already answered this question, I have not seen an answer.

[@Maxxarcade]

Yep, but Faderlube is better if you can get it.

[@Despero96]

"This Video is not available in your Country (Germany)" I love ProxyTube! :D

[@haz939]

Wow its quite surprising how clean that amplifier was inside, with the outsize being in such a bad shape. Is the crown K1 a class D amplifier? The huge choke coils on the output modules are a give away. I found it quite funny how the main board had what looked like a 24 pin ATX connector found in computers.

[@drabara]

Thats a video i like! More of these !!

[@evanjohnmo]

This video is awesome. I bought a pallet of 6 srm450 monitors. Three of the amps are working great, but three blow the circuit board fuse 6.3 250 once they are switched on. I'm gonna replace all resistors and caps, but there are two rows of transistors that are not reading properly especially in comparison to the working amps. Did you replace any transistors on this rebuild?

[@Maxxarcade]

Can you send me a PM with the details of what's wrong with them?

[@djrockwell5722]

Do you sell any of the amps you repair?

[@DJDickieH]

Great video.

[@douro20]

Do you service a lot of these amps?

[@Microwave414]

Sounds like it's pretty flat, if there is any coloration I wanna say it's comming from the speakers, so basically it sounds like my current fisher amp but with 250 more watts, nice.

[@GUILLERMORODRIGUEZ-ts4vn]

HI Just wondering how did u know exactly which filter to change??? very good video thanks

[@jbyrum1965]

This one is fairly old, not certain how old exactly. Yeah, pain to get apart with the cables soldered in!

[@Maxxarcade]

I've never worked on one, but I know they are budget amps. Kind of in between home and pro grade.

[@ThunderRoadDreams]

Hi max thanks again for this video , one of my trusty K2's have gone down first problem in 13 years of weekly use , I have no lights at all , I have followed the service guide discharging the caps then unplugging each output board but nothing will make it power. .0.7 of a volt on pins 3 and 12 of U7 and the soft start resistor R1 is continuously on getting hot , no relays click either , I'm thinking it could be bridge rectifier any ideas ? I've fixed A/B power techs before but this is a different beast :-) always look forward to new max arcade videos !

[@Radxr33]

Would you do a update for the work shop tour?

[@Maxxarcade]

LOL, I'm working on an XLS402D right now that's driving me nuts. I found that channel 1 has an oscillation that's causing the output stage to conduct and trigger the overload circuit. How old is yours? I'm wondering if you might have a similar problem. I'm disappointed with how cheaply constructed the XLS series are compared to "real" Crown amps. The circuit boards and copper traces are flimsy, and everything is wired together with soldered in ribbon cables. Send me a PM if you like.

[@MostafaGoher]

a job well done

[@Maxxarcade]

These are not class D, but a similar variation. The distortion is very low.

[@ElectoneGuy]

That microphone on your video camera is incredible. What kind of camera is it?

[@TheWorstCSGOPlayer]

Some of those power connectors looked like ATX power connectors.

[@planchernewfinish]

I have one k1 and k2, love the sound, i had installed a conmector to plug What ever ac cable i wanted. Would you call this a class ab ? Thx !

[@Maxxarcade]

It's more like a class D amp. They were ahead of their time and sound really good for their age. I'm still using several of them in my home theater. Great sound, tons of power and no fan noise. But when they break, they can be a pain to fix. Crown stopped carrying parts for them a while back.

[@alexverias7104]

its a class D amp isnt i repaired some amp that looks like a maybe 1kw bridge mode and 2x500w stereo

[@aarongunter5582]

Were did this guy go to 😢

[@RediffusionMusic]

Yeah, my school had two K2's and only one is still running without a repair, installed 2004.

[@Maxxarcade]

With this video?

[@H3adcrash]

Are these class D amps? Looks like very little cooling otherwise.. :)

[@weasel2htm]

WOW, were those your bench speakers playing, those sound REALLY nice! Good job on the repair.

[@djkaboombx1]

Where is your service location?

[@Maxxarcade]

Ya, and also The Rock and Napoleon Dynamite.

[@fredyearian4968]

That contact cleaner is not good for pots. Either use Faderlube or CRC226 which is available at HD in the electrical dept. Contact cleaners remove the lube on the control resistive element.

[@Maxxarcade]

I've never worked on an XTi. Most of the stuff I work on is old and discontinued.

[@soundfreak8892]

yea the k2 rocked to bad they dont make it anymore :(

[@DavidSmith-dm8ew]

specs say that watts into 8 ohms is 350 and 700 into 4 ohms. For $140 for a pro amp I'm not sure If I should get one...you get what you pay for

[@Tron1731]

i have found these amps fail for no reason so i stick with peavey or qsc but only from the early 1990s because the thin style amps dont have a large enough cooling and the outputs get to hot and die

[@perezthompson3819]

OK QUESTION.. i have a qcs 2450 ap onE OF THE CHANNELL'S ARE Blown AND the other onE PLAY'S But if you carry it pass half it clips out i onLY RUN 2 nON power yourkvilles on IT LEASE RESPONd to me

[@alexverias7104]

see that you replace all caps have you use an EsR meter just to see how many are still good

[@jefames9989]

I have a Crown K2 in need of repair, would You be interested in the work?

[@jefames9989]

I would love to work on it Myself but it’s way out My league.

[@quesocat42069]

you and me both man.

[@douro20]

The caps on the output modules are German made.