Great tip - I was having issues with a dead DSP and read this and went and checked the crystal. Now replaced and she's working again, so thanks for that! 🙂
Hello again from Texas. I just bought a Thump-15A, w/button that has 4 preset EQ, so non DSP model. Plan to use it for a hard hitting Cajon players' monitor, hope it holds up. Sorry to see you now had a Mackie Thump repair. I'm hoping my next MI gear purchase is not one that has ended up on your workbench, 😁. Cheers, e.
Very interesting. I took another approach to the ones I fixed. A ready made 4 pot pre-amp circuit from china and bypassed the entire front end but your idea is probably quicker and cheaper.
@@jaimebonet964 Bought from Ebay for sale as a guitar EQ. Remove sliders and wire up instead to the original control pots (after cutting the pcb tracks)
Hi mate, I just wanted to fill you in with my experience on the TH-15A. The DSP board appeared dead, no clock pulses on any pins. I assumed the worst, but after studying the datasheets for the converter chip and DSP 176 pin QFPN chip, I found that one of the electrolytics was dragging down the RESET line to the DSP and not allowing it to start. It was a 60c part, and now she's good as gold.
wow, nice piece of diagnostic work. This input blew-up somehow when the base chip blew up, not sure how because from memory, I believe the output of the dsp board is ac coupled. Thank you for the tip.
@@JohnB-2021 true they are ac coupled...those coupling caps...{10u/50v} , (main culprit behind such failures) are on the power board , under all that white glue..so can't make out when they are blown....have to remove all that glue but do replace them anyways and with a higher volt. rating..
Hi John, great video I really like how you explained everything as you went along very clearly. On mine the thermal overload is triggered. I've tried to bypass it but I've had no luck, I simply get nothing. So far I've tested the power supply and it's fine, tested the drivers and it's fine, tested the signal is coming in and the dials are operating. I just can't seem to get round the dsp which I think has stopped working although on the scope it seems to be fine. Any suggestions?
Most Mackie 2 way actives are crossed over around ( 1.8-2.5 )kHz.... around 18/24dB/ Oct. L- R xover.. Thump 12/15 , or TH 12/15 /( A )...,SRM 350/450(v1) .. , 450 V2. .. The preamp boards of the Thump can be swapped with TH series boards..both have similar I/p sensitivity.., and o/p gain..flatpin connector btwn. the 2 boards also have same electrical pinouts & match 1-1... Only controls are different..
I've got a th15a and the overload kicks in and the woofer clickd. The tweeter is fine. It's not being overloaded and happens at relatively low volume. I'm guessing it may be the cap leakage on the lf side of the amp?
Unless of course one has the Peavey pro 200 series rack mounted amp with a valve front end amplifier. (For the valve aficionados) A component is now obsolete so renders the whole system useless. Or all of the expensive & powerful Dynacord mixer amplifiers, when they get old they fail so again one doesn’t have the loss of just one speaker, one loses the lot. Horses for courses…
I have a th15 A the +15 volt drops to less than 1volt after signal goes in. If no input card is connected there is a +15.68 and a -14.8 Volt on the Voltage Regulators. When you connect the input card to Conn11 the +15.68 goes to +14.6 volts and the -14.68 stays the same. When you put signal in the +14.6 goes to below 1 volt and the -14.68 stays the same. either the input opAmp (LM1558) U1 that has an internal issue or OpAmp U2 (LM1558) or OpAmp U4 (LM1558). Hopefully is not the CODEC (U3 WM8569 ).
Thanks, actually Mr. John he gave me the trick, i just cut the bridge it was mentioned 110v,, thats it, now it's working,, are you a sound engineer? I have some question if I may ask, I have XLS2000 crown Amp. and I want to install in parallel on 8 outdoor speakers, 8ohms-200watts. the amp can handle 2-4-8-16 ohms and I need to wire it on the left channel only the right channel its already installed for stage.any help will end my confusion, Thanks again.
I used to do some business with a John "B" many years ago. He was an electronics engineer and I used to buy the odd vintage item from him when I was out on a buying run down south. Just wondering???
@@JohnB-2021 Hi John, It could well have been an old Vox amp rather than the guitar. I used to cruise the west country looking for vintage gear going back 20+ years. I bought more than one item from him back in those days. An old Watkins copycat also comes to mind..
Wow, so basically, Mackie is just crap! Mine blew out and it wasn't even pushed that loud. Going to the KLA QSC series to see if they suit my applications better.
I've just handed a QSC K12 to an electronics repair shop, I took a look at the design and they are not friendly to work on. Something on the input board is blown and putting out 12 volts on the XLR, never had that with a Mackie. I couldn't be bothered to fix it.
@@JohnB-2021 I'm going to go with Das Audio speakers. No more powered speakers for me. They are unreliable. I actually like QSC. They are clean but when pushed too hard, they sound super distorted. I guess you get what you pay for.
I find your videos very informative. Learned many new tricks and tips. I have a question about Mackie Speakers. Hoping you can explain before I buy the new Mackie Thump 12A Series of speakers. The Mackie in this Video says that power consumption is 350W on the back plate which I think is reasonable because of the 200W LF driver chip and 100W HF Driver that you talked about. My question is, I the new line of Mackie Thump 12A (1300 watts peak and 650 RMS) the speaker power draw is only 75W ??? I know class D amplifier is efficient but is this even possible to produce 650 RMS and only use 75W ? Thanks
Thank you for your comments. Very good question and you're right to question the wattage. Unless Mackie have overcome the laws of physics, one can't have more power coming out of a speaker than going in.
Manufacturers usually state 1/8 power at the input side. This is a rating at which speaker will be operating most of the time between high and very low frequency range of audio signal.
I have two newer 1k Mackie Thumps here. One is a 110v US model and the other a UK 240v model. Both have 150w power consumption rating. The older 350w Thump that I have is rated at 350w consumption @ 240v. Although the newer amps are more efficient, you add up each stage and the best you could hope for would be probably 50% (just a guess as I am no design engineer) so for a 1KW output I would expect to see a 2KW input consumption rating.
Most ratings are BS. I used to repair a certain boutique amp that is not longer sold. They made fab amps. Worked well and sounded great. My problem with them was that the first 200w bass amp combo I repaired was rated as 200W RMS. It had a pair of output chips configured in a bridge mode setup. Well thought out design too. The thing is, when I looked up the spec to order new ones I noticed the maximum rating per chip was 75W RMS. They were actually rated at 60W but could be driven to 75w under the proper circumstances. I am no math genius but can add 75+75 so how on earth could this amp ever be 200W RMS? The retail manager of the UK importer used to drop the amps into me in his way home from work so we would often talk and he asked me what I thought of the new Bass combo. I mentioned my observation to him and he was not impressed. After raising the issue with the suppliers/designers (I am thinking why didn't I just keep my mouth shut at this point). The answer? They fit two extremely efficient Neodyne speakers that are far more efficient than any equivalent speaker in any comparable amp. The result is, that this little amp makes far more volume than any of the 200W RMS amps that it competes with. This was actually true but, it still was not a 200W amp even though it sounded like a 400W amp.
The DSP in question is a SHARC DSP processor, I have some experience programming on this platform, to quickly determine if the processor is working, probe the serial pin (see serial flash memory with the sticker on) this will omit the fact that its working or not. other tips would be to check the processor vcore supply, it needs 1.1V, 1.2V check the regulator.
I have one input board from Mackie in lab currently. The problem is the speaker does not play. I've dig to this DSP processor and it makes 34ohm short of 1.2V rail to GND. Is it damaged as I supposed, or is it normal for this kind of microchips?
@@JohnB-2021 there is signal but it is very small (about 1v p-p at max volume level). In similar speaker the output reaches 5v p-p. Opamps checked, capacitors checked, volume potentiometer also checked, voltages all right, so the only last things left are two ICs, one is this DSP chip, second is another cpu responsible for front-end.
I just bought 2 Brand New Mackie Thump 15A 1300 powered speakers. one of them didn't work out of the box it has low volume and turn it up it distorts really bad the other one I was using it playing an electric acoustic through the mixer low volume. Took a break turned it on the same thing happened with the other speaker. low volume and distorted no power pushing. unbelievable Both speakers not working.
you could, but that would add latency. best bet would probably be to add your own passive RC filters, as shown in this video, or even a purpuse built signal processor. it's not worth it passing the signal to a raspberry running linux and then outputting it with its sound card. That's what I'm going through at the moment, since one of my DSPs failed again and I can't stand them anymore. A well-built passive network will perform great, you loose to contour eq, but I never really used that, as any serious setup will incorporate a mixer.
Johne B Thank you sir for this awesome video! Do you have any information on which chips drive the new mackie thumps? I own 2 of these and I always wanted to find out the real rms power, because mackie only gives you peak power numbers. Can you please tell me which amp chips are built into the mackie thumps? Thanks a lot!
I have a Mackie thump 15 that has a bad hum sound and makes a nasty noise if I turn volume up or down, I can still hear music if anything is playing. What do I need to replace?
Hi, I think it is possible, the SRM450 v2 just had one link to remove so I imagine the Thumps might be the same. You need to check the schematic and your board
@@JohnB-2021 Thanks John. I ll check the board . What I saw from the board small tiny jumper and it written 110v. I m not sure if I cut it or not. And all capacitors are mentioned 200v . I think Im going to replace them 450v. (:/
Hi, thanks for your comment. What is the BF-531? Edit, Just found the 531 processor. I figured, if (a big if) I was able to replace that processor, it would be a waste of time if the programmed chip was blown up. I searched for the boards, they are no longer available. I changed the amplifier and still no sound, no signal out of codec chip. Changed the 24 codec chip, still no sound, no sound to bass and treble.
Hello John, I have a th15a that intermittently starts to make some noise and crackle, and when that happens it does not play any audio. As if there was bad cable contact. Could give me any hints of what might be happening.
Hi John, i have a Thump 12 1000w and the reset red light is on. i understand that it is blown but is it possible to repair ?if so do you know how ? cheers! Joe
Hi John, you ever work on a mackie dlm12? A customer brought me 1, told me there was no power, i plugged it in, it had power but no sound. Just thought i'd ask you first before i dive into this.
@@JohnB-2021 I measure about 4,5 ohm on the woofer and 5,7 ohm on the tweeter so that seams normal to me, really can't seam to find anything else wrong with it, and a replacement amp is arround 200 dollars, it makes more sense just to replace the lot because a new one is arround 300 dollars here
@@JohnB-2021 I Don't know how that happened, I've looked further into the cause of the OL led that was on, and it's because of a fault in the power supply board
I have a pair of these and on one unit when i press in the eq button on the back it starts to like hiss really bad and the audio is amplified changing the dials on the eq doesnt change this. if i turn the eq button back off the music coming through is perfect. any ideas what this could be? thank you
Shorting driver. if either the woofer or tweeter has some sort of short in it it may still play but due to the short it may cause the amplifier's protection circuitry to engage when turned up. Check your drivers with a multimeter for DC resistance!
I collected the same mackie from a client.. Checked all voltages and found the same fault... The client who owns a large pub near by is moaning about the fee of 35 qid inspection to remove the board and spend time checking it... She will charge the earth for meals and bands to use her place. Us techs are not doing this for fun or free..
@@JohnB-2021, yes the old gray v1 unit.. A good 12 old years back I worked on them with many different faults from blow top driver to amplifier and preamp supply faults.. The v2 units have a 18v zener round the psu part that's fed via a drop down resistor.. When there working right they sound good.
I have a TH15A which powers on okay, but has virtually no output,however at maximum volume, you can hear a very low volume output which is distorted. I cracked it open and there was some galvanic corrosion inside the EQ circuit EMF shield which looks like it had showered the PCB in oxide dust. I cleaned it off and tested it. Still the same. Any ideas?
Don't know if these products are " also " manufactured / assembled in Mexico or elsewhere ..other than China.. but those mfgd. in China are real poor quality ..even a brand new one.. so bad even scrapping them screws up te environment...not fit for parts cannibalization either..
