Yamaha REV5 and REV7 Repair and Teardown

Repair of the classic Yamaha REV 7 and REV 5 digital reverberator effect processors. Both have common power supply faults that are easy to repair. We also take a look at the differences between the older REV7 and newer, more powerful REV5

[@ErikHawk]

This is great, thanks for doing this. Lots of great details here. Awesome! I love my REV 5.

[@spoonie1972]

Thanks for posting this, just picked up a Rev7 - and the power-board is pooched. Good to know it's a common - and easy - fix!

[@pedrockz]

Awesome video! thanks a lot, I hope you keep making videos like this

[@cymonalex]

Great Video.. Really enjoyed watching

[@roelofpaas334]

And a Very BIG Thanks to you for sharing you're high knowledge and willing to share to the ones(like me) and everybody who's interested!...BIG THANKS!

[@antigen4]

great presentation thanks - nice to see someone doing a teardown who's more than just a hack!

[@frugalaudio]

I actually see a lot of these with one or more LED segments out. LCDs with dead back lights too. Having carried REV-5/REV-7/ and SPX on the road for years, the first thing that always went bad for me was solder joints at the i/o connections. They tended to crack at the board and become intermittent. Usually a quick solder reflow fixed that issue. Glad to see this good overview of the whole unit. I expect to be refurbing a couple of these soon.

You my friend are that rare creature known as an expert! Great video. Rev 5 repair 5:00-14:10 ...killer info.

[@SchematicAttenuator]

Many thanks to you that i could fix the digit display ❤

[@thanksmomstudio]

Amazing video! Please do more

[@kpeterson2909]

thank you very much ,very informative,I think I can replace battery easy enough now, without this I probably wouldn't try, again thank you

[@Flavum]

I have absolutely no idea what you're talking about, but still find your videos fascinating. I own some older Lexicon units and would love to find someone of your calibre to fix them if they ever developed issues.

[@100ThingsIDo]

Another great video :D I so need to pick one of these up, there is nothing like hardware reverb. Interestingly the Rev5 looks so much like the Lexicon 300 under the hood !

[@antigen4]

about twice as much silicon in the 300 i think - at LEAST 50% more

[@antigen4]

if you want to see some groovy 'architecture' - check out the roland R880!!

[@richardsmith4992]

Great video - lots of info on these great units. I have a Rev 5 and Rev 7, and did own a Rev 7 from new back in the 80's. The Rev 7 I currently have has an issue with the analog EQ section - the Lo and MID freq and level pots are fine, but the Hi pots have no effect. Everything else seems to work OK. Could this be an easy fix, pot replacement or similar? I've not got as far as removing the EQ control daughterboard to check the PCB yet... Update - removed the EQ daughterboard, visually seems OK, some of the soldering looks sloppy, but that its also on the LO and MID pots, which do work!? No obvious PCB trace breaks or cap problems, all the wiring and connectors OK. Bit disappointed nothing obvious on the board. Will have to multimeter somewhat and see what i get...

[@nealshaw3802]

Amazing channel! Do you have a full list of capacitors for each unit, or a shopping cart for anyone hoping to do their own repairs?

[@RockmannMusic]

Thank you very much for your well made, explanatory video. Good info. I have REV7 as well that has all noisy/cutting-out potentiometers beyond repair/cleaning [Input-Level, EQ's & Mixing potentimeter]. Would you have a source for replacements or do you know for which size/type I have to look for? It seems they are all small dual Alps pots from a discontinued series: 1x ER103A - 10K Audio, 1x ER103B - 10K Linear, 3x ER104C - 100K Audio [Reversed?], 3x ER203 - 20K {Linear or Audio?]. I'm not sure if the standard small pots available on the market will fit. Many thanks in advance !

[@DjSabzi]

@bradthx your work is amazing and you are brilliant at what you do. I have a Roland VS 2480 that is now giving an error message of "sub system not response" when I turn it on and won't go any further into booting from there. Could I send it to you for repair? Thank you for considering. 🙂

[@Viriditas]

I also didn't know the display was backlit! I'll have to replace mine now. Thanks for the vid, it's probably the most helpful rev5/rev7 vid out there! Really insightful thanks for sharing the knowledge. I don't want to be that guy asking all the teck questions, but going by your video I think I cen guess the answer to my question, my unit (rev 7) only works in Mono, the stereo (Right) signal is really quiet (setting to mono both output channels work, in mono obviously), I'm thinking this is a power issue going on the assumption that each channel has a seperate power line, so I'm going to replace the caps like you did. Mine also has a weird thing where if you turn down the mix it jitters in and out onto 100% mix and like the bottom 20% of the mix level is stuck on 100% mix, pressing (even just touching) the EQ on/off button sometimes causes the signal to go completely dry. I'm guessing this is from a short circuit somewhere, so I'm going to have a close look to see if there's any obvious signs of that. Anyway, thanks for the vid, any insight into my problem would be GREATLY appreciated, but your video really helped me out so thanks!

[@DJPhantomRage]

Thanks for the info on this. I have a rev 7 and the display is starting to fad. It's the light blue backlit one.

[@richardsmith4992]

Can't remember if the Rev 7 LCD was originally blue or yellow...think it was yellow - yours might have been replaced with a later backlight in blue? My backlight was also not working so just replaced it with a new backlight (1 x 18mm x 74mm ) in blue, looks very nice now. If it's actually the display contrast that's fading you'll have to dig a bit deeper in the unit for voltage outputs etc to that display part - it may just be starting to go bad, but is quite easily replaced with an eBay part - other Bradthx videos have details.

[@Mixarteaudio]

Hi Bradthx Excellent work Congrats I have a REV 7 that the right output stopped working. You have any idea what could be happening or where I could start checking, I have changed some electrolytes from the sources which were devalued but it still does not emit the right output. From already thank you very much

[@lukaslukas6603]

Excellent video. You refer to differences in the power supplies for Japan, UK and US/Canada. Are they similar enough to be interchangeable with a little modification? I’m hoping to convert the US model to UK voltage.

[@ferraridinoman]

Lets be honest the SPX 90 II was (AND IS) The business!! (Love 'em !)

[@davidb258]

Omg! Thank you so much for this!! How do I get in touch with you about doing a repair in my Rev 7 and Lex LXP 15??

[@ScottFrankfurtStudio]

Great Video. Just curious if you have ever encountered issue with wet/dry knob. I'm considering a REV7 that seems to be scratchy and "stuck" at about 70% wet and can not go full wet or full dry. Issue with the pot? Is it fixable? Any suggestions?

[@AndersEngerJensen]

Very informative video! Got a sub! But I have two REV7s with some issues. They power on and work, but one has a lower level on the right input (or the left is too hot) and the other has a substantial loud noise floor. Would you be able to help me pin point what and where tackle these issues?

[@louisjohn4879]

Hi Brad, Hope you see this. Love your videos. I Recapped an SPX, and two Rev7's following your steps!! 1st recaps ever! Had problem on last rev7. When I finished recap, voltage on the +5 side and -18 side checked out fine but when I touched the MM prong to +18 side I touched the wrong, adjacent terminal and it made a tiny spark. When I placed the MM on correct terminals I couldn't get a reading on the MM. looked around board but didn't see anything obviously bad. Even so, after leaving the Rev on an hour it worked fine. turned it on following day and it continued to work well. Should i be concerned? did I damage something that will pop up in the future? thanks for the help.

[@joeljaemaa9586]

Great video! I have a Yamaha Pro R3. Where does it sit in the lineup?

[@jacknewton3150]

Hi and thanks for posting a great video very helpful I plan on doing a re-cap on the power supply board for my rev7 and replace the same caps that you replaced in this video on your rev5 and rev7. I can see the issue you talking about in the video of Yamaha using Epoxy on there capacitors and regulators and I'm going to remove that as well. Something I need help with is the back light for the LCD display this is common problem for the units so to start with I used my MM to check for voltage and I'm only getting 1.5 volts DC and I think it should be 5.0 volts can you confirm this? and where does the power for this LCD come from. the 5.0 volts that's providing power for everything else or does this back light have its own power from some other point in the power supply? I bought a back light off of Ebay it came from Croatia, Republic so without removing the old backlight I took the one I bought and touched the 2 legs to were the old one is soldered but I could never get it to work after contacting the guy He said it works using an Inverter and needs between 90-150 volts AC @ 400 hz so I'm thinking this guy sold me the wrong one. so do you know the operating voltage of this back light and is there a place in America were I can buy one thanks

[@cowboyscanskate4113]

Awesome video. I have a rev7 its passing audio fine. Both LCD panels are not turning on. The pins all look fine on the multi connectors. Any idea what the problem could be? Thank you

[@VA3JPX]

Thanks for the video. I have a REV7, the only problem is the backlight. Do you know where I can buy a quick plug and replace display? I've found one on Ebay and its over $100 canadian. I know I can get the display units and solder the connections myself, but I don't have a stead hand and would rather buy one that is plug and play. Any ideas? Thanks

[@joefocarile9440]

Thany you for the video. Do you know the factory reset proceedure for the Rev 5 and Rev 7? Your help would be greatly appreciated! Joe

[@davemaverick8438]

hey thanks for the video, recently bought rev7 but cant find any technician near to fix dead opamp in right input and erratic behavior of those eq rotary knobs, are they easy to replace or fix?

[@rg2027x]

Do you know what the deal is when one side is louder than the other in stereo on a REV 7 ? it's not the mixer, cables or anything else, but something internal to the 7 itself. Any help appreciated!

[@nicom7808]

Great video! Very informative! I have a Rev 5 that's giving me some trouble and I was hoping you can shed some light on my situation. I recapped my power supply and took the glue goo off, replaced the battery, and replaced a few caps in the a/d section, but my unit still isn't working. The screen lights up, but the top row of the lcd screen is all black squares, and the bottom is blank. I get an 8 on the led display, and nothing that I do changes the displays, or makes relays click. One relay does click a few seconds after I turn it on, but that's it. Does my rambling make any sense? I would appreciate any help you would be able to give me. Thank you

[@IrZombieGenocider]

Mine has the exact same problem! I metered a bunch of components and haven't found an issue yet that would explain this...but my LED display inexplicably changed from an 8 to a 10! GOTTA figure out what the issue is!!

[@cliftonwright7081]

Anybody know how much 18v amperage the analog section requires to function? Been replacing power supplies on a bunch of units since moving to Europe

[@kuboboksansky6981]

Thanks for the video. It sounds like the Japanese version of the PSU can also handle 240V input, right? I have a JP version of Rev5 here which I'd like to rebuild to EU spec, but I wonder if it is simply a matter of swapping the power cord?

[@jesseanderson3835]

Hi there, recently swapped a Rev 7 screen thanks to one of your videos. Any chance you know which screen is in the Rev500 unit? I'm having a hard time finding any info.

[@espacoipiranga]

i have two with fried transformers, the TMA007. legs 3 and 4 have no inductance and 0.5 ohms resistance. Do you know what would be a good replacement?

[@lukaslukas6603]

I have exactly the same segment out

[@pedrockz]

I have 2 rev5s here. None of them were powering up, so I did the PSU recap. I double checked If all the caps are correct and on the right polarities OK Also there are no solder bridges OK Now one unity reads +/-33v and the 5v reads 6v the other reads very low voltages, 3v on the 5v volt rail and about 8v on the +/-18v can you guess what parts can be damaged?

[@ThresholdZhor]

Hi Brad, I am working on a REV5 there is no relay click when EQ is engage is that the normal operation or Eq on must make a click? also there is no sound in the mixing Pot in Rev

[@ThresholdZhor]

Uff I've just found 4 memory's MB81464 overheating they are bad, this DSP board use 18 of them with 3 YM3804 in this case 2 overheating in one YM3804 and the other 2 in another YM3804, if those are bad it seems it will kill all the effects what do you think?

[@user-jg4xd5pq6x]

Thank you sir :)

[@paulfergonise8008]

Hi can you plz include links to parts used?

[@ASH-ou4cg]

Ugh, of course! I learned something today from your video and a little too late! I was 'that guy' that used paper towel just earlier this week to try and clean the plastic cover for a screen of another synth and sure enough, I have scuffs and scratches now. :(. Is there any way to remove those, or at least minimize them? I would really appreciate any pointers or advice, as seeing them is really bugging my OCD. :`(

[@thibautkingofwar]

Hey ! Thanks for your work. I've picked up an old REV7 which works perferctly except one big problem... When I turn the knob MIXINg to add the effect, there is a big noise in background. The effect works but with the awful white noise. Is it the battery for you ? I'm totally lost

Bradthx, I bought one (Rev 5), replaced all the caps in the power section, turned it on and it blew the YM 3608 chip (literally up in smoke/cracked in half). Any idea what could have caused this? Appreciate any help you could provide.

[@andyanderson398]

Do you still repair them? I have one REV7 , I'm located in orlando Fl.

[@MSM5500]

Hi there, I acquired REV5 US version some time ago. Originally the unit was claimed as recapped but it arrived being faulty. The date of recapping is written on the inner side of the unit top cover. It looked like they really did something there as all the factory compound was removed already from the SMPS PCB. When the unit was powered ON the lcd came up with a firmware version only and it was constantly blinking as the unit performed a continuous reset cycle and it was never able to get through boot up procedure completely. Whenever I disconnected the DSP board the boot up cycle finished successfully. So then I checked the power rails and found out that 5V actually had 4.2V instead so it made reset circuit (IC142, PST518, 4.4V detecting threshold) being continuously triggering LOW RST signal for the entire digital circuitry. After changing C23 in the PSU it started giving 5V as it should and the fault is gone. However my REV5 still have another issue. The thing is after keeping the unit on for let's say 5 or 10 minutes the left channel gets very noisy. The noise nature looks rather digital than analog. Sometimes the sound is so like if something gets self excited there. If I touch LFP102 filter ass'y the noise completely disappears for a while then gets back again. I replaced all the electrolytic caps around the LFP109 but it didn't do much. Sometimes the noise may stop coming with no reason. So has anybody come across such an issue ever? If so what would be the place of the circuit to have a look at? Thanks, Ross.

[@stevew4910]

I would reflow the solder joints (leaded solder, not Pb-free) around any component that causes crackling (or otherwise changes the sound) when moved. The LP filters are quite tall, and if they were knocked, might have invisibly cracked the joints beneath. The boards are very good quality - proper plated through-holes - and seem to hold up well to resoldering.

[@MSM5500]

@@stevew4910 hi there, I lean towards thinking that the problem comes from the LPF module itself as I came across some chat in Dutch where one bloke describes exactly the same behavior of the LPF in his REV5 : www.synthforum.nl/threads/70365/. I used Google translator to read that. It's very likely that the fault is caused by intermittent contact within LPF ass'y. But prior to start pulling one apart I'd like to get backed up with having some spare parts first if not successful. So I purchased Yamaha DEQ5 digital parametric EQ from Japan for $20 to source the LPF from but the bad part of the story is that Japan almost has entirely shut down outbound mailing services due to corona. So the item got stuck there with only chance to be delivered with DHL for $250(!) which makes the entire transaction pointless. That's where the case is up to so far.

[@armenioramos4428]

Hi there, just got a rev 7, it works great, but found a little issue, when I switch off the eq button, the effect stops too, the signal passes out but totally dry, like if the unit was bypassed, but the bypassed led is off!!!! If I turn on the eq button, 100% ok!!👍🏽 Any guess, did you ever encountered a similar problem?? Thanks, keep up the good work!!!!🙏🏽🙏🏽

[@armenioramos4428]

Not a big issue, since the idea is to use the eq, so the button will always be ON, but I’m curious, am i missing something??? Maybe it’s a configuration issue!!!! :)

[@stevew4910]

Is the pre-effect EQ analogue? I recently refurbished a Yamaha ProR3 which - AFAIK - followed the REV series, and has semi-parametric pre-effect EQ in the same place on the front panel. Expecting to find an EQ circuit I was surprised to find that the six EQ pots are all 10k lin on a common 5V rail, with their (single) wipers connected to 6 inputs of an ADC (IC24, ADC0809CCN) digital outputs of which feed into the CPU (IC25). This is a second ADC, dedicated to the front panel EQ controls. Audio A-D conversion is handled by an AK5390. That is, the EQ on ProR3 is implemented by the DSP. I've never used/seen any of the REVs, but I'm really pleased with the R3. Nice DACs too (PCM63, albeit not the 'K' grade)... Thanks for sharing your knowledge and expertise (and love the dentist's tools and 'GOOD CAPS box ;) ).

[@bradthx]

Hey Steve, the EQ is indeed analog. It is based on JRC NJM4558 op-amps, one for each band and is fully defeatable. Interesting regarding the EQ on the R3. By that time it was probably cheaper to just handle the EQ in DSP. Thanks for watching!

[@stevew4910]

@@bradthx Thanks to this vid I've been keeping an eye out for a Rev5, and have just finished refurbishing a very beaten up (but cheap) one: full re-cap, battery change, chassis straigthening, deoxit - the works. Sounds good, too - very eighties ;)! One gotcha: the silkscreened orientation markings for the two decoupling caps around IC148 are incorrect. They're under the little mezzanine board in the analogue section - C263 and C262 (+/- 15V rails, respectively) - and should be replaced with negative/striped sides toward the back of the unit, opposite to that shown on the PCB. Hope this helps someone avoid a couple of small bangs :) There's no PCB revision number, maybe later/other ones exist with this fixed - if in doubt measure... Keep the vids coming, they're excellent!

[@Shawneverette]

Thank you sooooo very much. I have one that will not power on. Can you please tell me the values of the caps. Thanks so much.

[@paulfergonise8008]

Shawn Rogers I believe he mentions it around 11:00

[@Shawneverette]

@@paulfergonise8008 Ok I'll check thanks

[@Shawneverette]

@@paulfergonise8008 No he mentions the type but not the value of each cap he is replacing.

[@ryanbates362]

@@Shawneverette Check the schematic/service manual, it will generally list all the caps and their values.

[@Shawneverette]

@@ryanbates362 Thanks but I do not have it and have been unable to find it. I called Yamaha and they did not have it. If you have it would appreciate if you could send it to me. Thanks.

[@danostlund3032]

Great video! Anyone that’s got the schematics pages that’s missing in the online service manual. Page 40-41

[@buildstoys]

.

[@milanrecordingstudios9042]

We would love to have a clean good working Rev5. If you know where we could find one please let us know by the following link. www.milanrecordingstudios.com