Electronic Repair Time! ASHLY 3102 Stereo Equalizer

[@MrCarlsonsLab]

To learn more about electronics in a very different and effective way, check out my Patreon page. Also, you gain access to my personal test equipment plans and inventions. Click here: www.patreon.com/MrCarlsonsLab

[@SpeakerFreak95]

Mr Carlson's Lab what’s your audio processing on the video intros with that gorgeous mic?

[@unenslaver1333]

Mr Carlson's Lab Would you be interested in a Crown D-150? I'll give it to you if you pay shipping from Wa. Was a great sounding/reliable amp until a rogue signal toasted one side. (and the driver) Can't find original components. Might need masterful re-engineering. Kind of a collector item.

[@unenslaver1333]

I'm only 3 minutes in but I recently repaired that exact EQ for my best friend. Can't wait to see if it's the exact same failure.

[@unenslaver1333]

Didn't see you go over the more stressed solder joints under magnification. The most common failure that I see with audio gear that's been "roaded". This was the problem that I discovered on the bottom board that caused the elusive intermittent signal loss.

[@gatekeeper65]

@@unenslaver1333 I just serviced a Crown D-150 a short while ago for a customer, and it sounded quite nice. It definitely needed a good going over and freshening up, but once that was done, the owner was very happy to put it back into service in his studio. Have a great day.

[@walt3223]

This video has the best audio that I've heard from any KZbin program.

[@tinkerer67]

But, from an audio engineers point of view, it has some issues that can be fixed easily. Lots of mouth clicks. However, it's very crispy and clear.

[@Pauly421]

I presume that comes from understanding audio on a deep level, and also using a nice condenser mic doesn't hurt.

[@Tokaisho1]

Tinkerer How would you fix mouth clicks?

[@brendakoldyk1647]

@@Tokaisho1 Turn down the gain.

[@MaxUgly]

@@Tokaisho1 multiband compressor or dynamic EQ.

[@michalrzmichalrz6656]

Hands down the essence of what an absolutely ideal educational channel would be. I had no idea all those retro-looking devices can be restored and calibrated to be as good or better as more modern devices. Also, we have a saying - 'tell a shoemaker by a toe sticking out his boot' - definitely not the case on Mr. Carlson's -I love his warm, pleasant tone and cadence. Thank you Mr Carlson and thanks to all you good people in the comments for being good sports on every posted video.

[@Major00Tom]

A technician that keeps the settings of analog audio gear? Sir, you are the most considerate nerd on earth.

[@АлексейБелов-ы9р]

.. Самый древний, хочешь сказать..?..)))

[@scose]

Impressed with how many "teaching moments" you found in this simple repair.

[@Loathello]

One of the most valuable and interesting channels I've found on KZbin. I bought several electronics books and one of those "101 electronic projects" kits years ago. They've been gathering dust on my shelves ever since. I've finally started using them, actually learning and doing. Thanks, Mr. Carlson!

[@Kamel419]

I just want to take a moment to thank you for doing a video about audio equipment and not having horrible audio on the video. I can't understand why so many people do that.

[@Thujaplicata1]

This is absolutely amazing. I wanted to be an electronics tech since I before I left my crib as a very small child. I got my wish to work in a tv repair shop when I was 18, in 2001. Your method of explaining things is so simple to understand and follow, I can't say that enough. Even a video that might on the surface seem basic and possibly not interesting, always leads me down an amazing path of learning more than I ever thought. I'm constantly trying to learn more!

[@tamle2667]

Unbelievable ... You are very good and your speech is so clear and makes the listener so understanding

[@Moraren]

That scope is just the cutest little thing!

[@jlucasound]

I was thinking the exact same thing!! :-)

[@InXLsisDeo]

There is a video where he refurbishes it.

[@RyanSandorRichards]

Haha, I said the exact same thing out loud when it showed up on the screen.

[@ForViewingOnly]

I imagine that having an old stereo device to fix, where one channel is working and the other isn’t, is an absolute joy! That was the case with my old stereo valve amp, where I was able to quickly compare measurements and signals between the working channel and the broken channel. Having said that I haven’t finished watching the video yet, so this might not be the case on this repair. Anyway, keep up the great work Mr. Carlson, these videos are excellent.

[@huemungus69]

Mr Carlson, not only do I appreciate your thoroughness in repairing electronics, but your attention to detail and tips to other repair persons is very refreshing! Thank you for all you do, keep up the amazing work!

[@MrCarlsonsLab]

You're very welcome Garrett!

[@DJRobbie54]

Mr. Carlson, you are the best teacher I have ever seen in my life, I wish one day I can meet with you, I'm 65 years old. I left that profession to become a sound engineer and a TV engineer but watching your videos is a joy, thank you so much, Your are teaching method, is extraordinary Thank You. You Are The Best.

[@kusgilb]

I've been a hardware engineer (digital realm) for more than 30 years and greatly admire your knowledge and approach to debugging problems. I would have been thrilled to have had access to a resource like KZbin and your channel as a young man when I was teaching myself electronics.

[@TempoDrift1480]

Very cool! Ive been a commercial electrician for many years but these big guys on KZbin are teaching me shit I only dreamed about.

[@panthony1525]

Can't fault this channel, never understand the thumbs down. Good job as always.

[@hannescamitz8575]

Thumbs down, comes from the ones who sell new stuff that's not meant to be repaired. 😉

[@DataWaveTaGo]

Thumbs down are from dyslexic people who slip up when selecting the "thumb". ;)

[@TempoDrift1480]

Well sometimes it can get a little droaning when he describes the most simple things like how he's going to take out screws or turn the unit around. I think if he left out such simple things, more people would watch. That is my opinion anyway. Generally when I see someone working on something and the next frame it's disassembled it is usually common sense to determine that he removed a screw and in doing so, turned the unit around. I think people dislike things like that.

[@SpeakerFreak95]

This is my GO TO EQ for live sound. Always. Glad to see someone repairing them. They’re incredibly clean and durable. They weren’t too cheap in their day either.

[@jaymz168]

Yeah these and the old Klark Tekniks were the best analog GEQs out there.

[@jlucasound]

Good stuff. Glad it was an easy fix. The owner will be delighted.

[@KozmykJ]

I have a similar looking unit by BSS. Perhaps a little older than 1995. My main FOH Graphic. Never had call to get the back off so I don't know how different it is inside.

[@riccardoz2953]

@@KozmykJ time to verify and change capacitor. they're more than 20 years old. before they leak service it. it will deserve :)

[@KozmykJ]

@@riccardoz2953 Oh don't !! I have racks and racks of stuff that are over 20 years old ... 🤯

[@kikinnit]

I don’t know why, but I actually understood your repair of this EQ - you made it so simple

[@smstiao-tecnologia]

Dear Mr.Carlson's, much explanation and repair development, very grateful for your classes!

[@donalddurga9742]

You are an awesome Instructor and Teacher, I have some knowledge of repairs, dont have your tools, but watching you I can confidently make that repair, I subscribe and would continue to watch your well informed repair procedures, nothing was left out or to chance, you absolutely nailed every sector of this repair, many Thanks, Surface Noise NY

[@Toobula]

I didn't pull too many chips out of sockets, even little 8-pin guys like those, before I went and got a chip puller tool. Gotta do it. Very good channel. You're a good teacher.

[@tjtreinen7381]

I know very little about electronics, except what parts are. This is the third video I've watched and you make it very easy to follow.. Great videos!!

[@HJCF0520]

Amazing video! I have massive respect for you for the beginning comment on documenting the EQ settings. Hats off to you!

[@coldfinger459sub0]

I’m almost good enough to feel confident to build all your modified test equipment I’m getting there soon. I’ve learned more watching these videos of hands on how to repair than three semesters of college level Electronics class.

[@MacNifty]

You got that right. School always has dumb projects and the monotone teaching is hard to soak in.

[@EPiCxPS3]

Very much agreed, I've completed two years as an electronics technologist and their teaching methods are nothing compared to Carlson's.

[@MacNifty]

@Etienne Everyone I knew that took elecktronicks in the military when they got out they couldn't apply it. That or they just really didn't learn anything. Not talking about you but just how about people I know personally I went to school with in high school and they went in the military and came out and ended up being ironworkers and window glazer's.

[@InXLsisDeo]

To be fair, Paul Carlson drops practical knowledge in his videos that you'll never learn in any class. However classroom teaches you the theory which is important too, so they are complementary.

[@LaLaLand.Germany]

Thank You Mr. Carlson for this delightful contribution. This was a quite quick fix- when I look towards the Vedolizer where You took perfection to the next level, in my humble opinion. If You weren't overseas I would have asked to visit You years ago with my jaw dropped to the floor over Your place. In Germany we call someone like You "Pfundskerl". Hard to translate but means like five star best buddy. I learned so much about the things I like from You that I hope the world won't go south while we're still alive so I always could reach out to You just to say what I think what great guy You are.

[@dave6501]

thank-you Mr. Carlson. I am encouraged to use my skill more often. the mind is a terrible thing to waist I'm grateful for your videos.

[@John-we7jx]

Your commentary is very rich with so many little tips as well as the big picture of repair - excellent 👍

[@shermanikk]

I love seeing that adorable little Tek 224 scope back and being used like it was always meant to be! That tiny little CRT is just so dang cute! Love your videos, keep up the great work. Hope to see that itty-bitty scope again in the future :3

[@mik310s]

Man what a useful tool, I just spent 5 hours trying to diagnose a fault with an oscilloscope, turned out to be a op-amp, this would have made my job so much easier

[@markphilpot4981]

Mr Paul, your videos are always good, your troubleshooting is concise and your conclusions correct! Never any doubt and no fumbling! Good job and keep it up!👍🏻😊

[@americanmultigenic]

I really love the troubleshooting. My line is computer software, and circuit troubleshooting and code debugging are essentially "twins, separated-at-birth." Very enjoyable!!

[@ronniepirtlejr2606]

That has to be one of the coolest little Scopes I've ever seen!

[@RussMcClay]

Mind. Blown. And enlightened. Thank you, Mr Carlson.

[@MrCarlsonsLab]

You're welcome Russ!

[@I_wish_I_knew_something]

One of my favorite EQ’s in the analog Audio days of the late 90’s-mid 2000’s.

[@Gizmologist1]

One of the first things I did when we bought these units was to change out the XLRs for brand new gold plated jacks as we kept them functional for any type of use in the field in our portable rental inventory and even for rack mounting. The most common issue with these units is a very simple fix. The PC trace lands surrounding the screw terminals very frequently fractures and simply reheating the terminal block contact and the PC trace land will solve the issue. This is why the repair guys in our industry HATE direct contact to the PCB from all outside world connections. We will frequently cut the terminal block contacts and insert a short piece of insulated wire from the PCB to the terminal block to act as a shock absorber.

[@phillipbartlett1819]

Back in the 90's I used to convert these to 12v for car audio. I also made Ballance line drivers to get clean signals to them. Lots of fun and experimenting in those days. Thanks for the memories

[@jlucasound]

That's Awesome!!

[@Will-fn7bz]

I'd love to see how you found room for this in the dash. It's like 25 feet wide.

[@phillipbartlett1819]

@@Will-fn7bz it was in the trunk. I made a Ballance line drivers for the pioneer head unit to send the signal to the back via twisted pair. It worked pretty good and a few of my builds won their classes in the mid ninety. It's was all about experimenting and having fun. I used a old color tv delay line on my tweeters to better match the mids and base. Poor man's time alignment lol.

[@kingsqueak2221]

Love your channel, mostly for radio/RF stuff but as a former front of house sound engineer I worked with probably a hundred of these EQs so this caught my eye. I liked these EQs quite a lot back in the day.

[@JR-W6JBR]

Thank you for yet another fantastic video. Your troubleshooting work and explanations are most excellent. One thing that I might recommend in regard to final checkout of this 1/3 octave stereo graphic equalizer: These units are normally used in conjunction with a broad band pink noise signal source, so driving it with pink noise and checking each slider sequentially while monitoring the output on a 1/3 octave spectrum analyzer would quickly verify it’s proper operation in each filter band. Alternately, you can use single frequency tones matching each filter band, as you did with 1KHz, and cycle through each slider while monitoring on the output LEDs, or on an oscilloscope or voltmeter/VU meter, to verify that each band is functioning correctly. TNX & 73. JR

[@VintageGearMan]

I just bought a Ashly 3102 and it is a smoking great EQ.

[@glenwhatley4125]

Replacing the op amp is obviously the quickest way to determine if it's bad particularly if it's socketed. Otherwise, the next best indicator since we know all of these audio amp op amps are in closed loop arrangement is to look for any difference in the DC value of the two inputs (which there of course should be no difference) as well as those inputs having the same dc value as the output. We find most op amps fail with the dc voltages off from what we expect to be 'normal' for a closed loop set up. Great videos. Thinking very strongly about joining your site on Patreon. I've been repairing quite a few 1940's radios and even at 67 I'm learning great tips i never knew. Thanx!

[@SuperBigdaddybass]

Ahh Mr Carlson! I used to own one of these and an Ashly ftx-2001 series 3 - nicest sounding solid state amp I've heard to this day! Love Ashly gear!

[@monroefive-o40]

Brian Proulx Yes. I think for the money you can’t find a better sounding EQ. I’ve got six of them in my rack. Three per side. Never had an issue with any of them and I’ve been using them sense 1998. I’m still one of a few in front of house that has refused to go all digital so far in my area. I’m holding onto analog kicking and screaming.

[@alcampbell]

I have a Sony stereo EQ I bought back in 1979. It was part of a big system I bought. This video prompts me to open that sucker and clean it and fire it up.

[@jeepaddict4life]

Very interesting repair! Ironically, I drove by the Ashly factory just a few hours ago!

[@adamkane3736]

These Ashly EQ's are top notch and well respected pieced of gear in the pro audio industry. Pretty rare to see a piece of Ashly equipment not working. Can't remember the last time I pulled one of their pieces of gear out of a rack because of it not working.

[@oneofbillions691]

That is one sweet looking and functioning piece of gear. As always Mr. Carlson, you've brought this audiophile's day a bit more enjoyment. I build graphic workstation computers as an avocation so I work with modular components basically pasting them together, not so much the skill and knowledge you possess, but I always learn something from your videos. I've said it before in the most complimentary of terms: you sir are truly "King of the Nerds". :-)

[@VeraTR909]

I really appreciate your attention to the proper order of troubleshooting, I used to repair/setup guitars in a shop with a similar approach and I think this way of thinking is applicable to many types of mechanical troubleshooting.

[@MacNifty]

It is the principle of trouble shooting itself. The same goes with programmable logic controller and software.

[@MacNifty]

It's like when I apply for a machine repair position and if they machine I've never seen in my life and I apply for the job in the ask me why am I here for the interview? And it's very simple I tell them when you understand the principles of all 5 energies and sources that power machines and work machines how machines function it's like nuts screws and bolts they haven't changed forever. The same goes with machines hydraulics have been around forever, pneumatics have been around forever, As well as electrical circuits that control a machine to do what it's supposed to do. If you can repair a CNC you can repair a stamping press if you can repair those 2 you can repair a robot if you can repair the robot you can reperi computer everything is with basic principles. The only thing you need to ask the employer the manager the worker or customer if you don't know that machine I simply ask what was it supposed to do what did it not do when did it stop at during what part of the sequence and the rest is history.

[@smjones4238]

Great video, again, of course! Brought back memories. Someone brought in a 16 band mono board to the shop I was in (1973) and said they had been trying to get it fixed for several months but no one would open it up. I can't even remember the brand, just had two fried transistors in the first stage, familiar? All of the shops that the customer had taken the unit to were tv repair shops in the other small towns in the area, rural South Dakota. I had just gotten out of the USAF and knew what the unit was made for and from experience, was not afraid of at least opening the box to take a look... We got a solid new return customer after he and I repaired it 'together'. Boss was impressed, he wouldn't open it either, gave me the choice though! Michael in Colorado.

[@jlucasound]

Thank You, Mr. Carlson. You have provided us with a BOATLOAD of understandable troubleshooting information. I am now beginning to understand. I have to get past the animosity of components. An Op amp is an Op amp. I think once I get familiar with the (common) components (IC's), the view will become clearer. You are definitely helping to clear the "fog". I love 555's. ;-)

[@dave1812]

I wish i had you as a teacher, back when i was an apprentice. Your Videos are really awesome and informative!

[@davidbeard6851]

Thanks Paul. This was a great info-packed video from someone who knows the subject inside out. I am learning so much so fast watching your videos - and I thought I was up to speed - nope, not yet! That will change for the better as I take in more of your expertise. Very impressed with the build quality and spacious logical layout of that equaliser - makes troubleshooting a breeze, much easier than struggling with SMD’s and failing eyesight. Looking forward to your next masterclass.

[@reallyniceaudio]

The ending to this video is amazing. From 29min you get to see forensic level repair diagnosis. Great stuff!!

[@johnnytoobad7785]

This episode is *GREAT* for me since I own an Ashley 15-band EQ !!

[@khronscave]

There's no "e" in there ;)

[@Warren1814]

I get amazed every time i watch his videos... I would love to start doing what he does.. Excellent work Mr Carlson!!! 😃👍👌

[@ciprianwinerElectronicManiac]

Wow, that screen saving mode on that RCA oscilloscope (curve tracer) just killed me. I absolutely love it. Keep up the good work. Cheers :)

[@johncunningham5435]

Very enervative approach to repairing this very nice ASHLY 3102 STEREO Equalizer; "excellent presentation".

[@ezion]

Your videos are concise and entertaining. I just signed up for Patron and will become a donating member soon. Thank you!

[@MrCarlsonsLab]

You're very welcome!

[@finnschu]

I dont know, but what ever you throw to this guy he know exactly how it work and with a cotton stick he can tell if it's recently been used. I also notice when he open a device and it has been serviced before, Mr "Sherlock" Carlson can after a few minute tell the service history and what went wrong...I dont know much about electronic but his videos and his voice are just hypnotic and it often end up with hour learning about radio tubes and capacitors I actually have no prerequisite to understand.

[@jussikuusela7345]

Some years ago I had to repair a Soundcraft mixer console... taking photos was important to have all of the knobs back in their right places too, just as well as a couple similar wire looms. The console had to be entirely torn down to access the faulty parts. I installed an upgraded power supply at the same time, but the original problem was DC on all outputs. It had 3 busted op amps, all of them SMD. I was in a bit of hurry and only managed to acquire through-the-hole models of the part, and one of them was a FET version. I also got sockets for them so later repair would be easier if ever needed. I put the BJT versions into the recording/monitor outputs and the FET one into the headphone output. I took pieces of old IDE ribbon cable that I could solder onto sockets and onto the SMD pads, made it as short as possible to still be manageable. Luckily there was just enough space between the slide potentiometers and the top cover. Everything worked right off, although the owner, a half deaf guy, was first concerned that one part being different would affect the sound. Had to explain to him that it is exactly why I put it in the headphone output. Later on the console has changed owners at least twice and nobody has had any complaints that I know of. One of my more successful repairs. 😁

[@djvartan]

You have the best videos for these kind of repairs. I WISH YOU WOULD DO MORE MODERN STUFF LIKE THIS!

[@mike94560]

Hey cool! I just did a dbx 2231 very similar to this unit. It got damaged in shipping. I had to use a hammer to fix the front panel. Not an electronics repair tool I use very often. I really had to pound the heck out of it. Looks good and works great now.

[@garyeggleton1142]

Ashly is a company just up the road from me in Webster NY......very good equipment, and I use one of their power amps

[@bskarpa]

I sure love how informative your videos are! I love anything electronics

[@Will-fn7bz]

My 2000 Camaro won't start. I bet it's the op amp. Gonna go check right now. Thanks, Mr. Carlson!

[@robinsonsoto8471]

Nice Job!!!!!!!!!!! You are a very experienced Engineer.

[@ElectronicsComputers]

I wish I had a TEACHER like YOU! The university was useless compare to your content.

[@electronic7979]

Very good 👍

[@deadfreightwest5956]

Another tip re: sockets and thin nuts: Some sockets (and nut drivers and box wrenches) have excessive chamfers - so much so that the contact on the thin nuts used on connectors is tenuous at best. Sand, grind or file the end of the socket or nut driver (or side of the box wrench) to minimize the chamfer to protect the nut. You only need a trivial chamfer, really, as it is only an aid to orienting the socket or wrench to the nut. The other benefit on wrenches is that thinner ones get into cramped spaces more easily. Granted, this may remove chrome plating, but you can replace that by electroplating.

[@goodun2974]

Dead Freight West, I have a set of deep sockets that I have modified with "stops" epoxied in place a little less than a quarter inch from the front of the socket. The socket will hold the nut in place and prevent it from angling or sliding deeper towards the rear of the socket. Handy for reinstalling nuts without having to start them on the potentiometer shaft by hand (nor having to start the nut with needlenose pliers if the control is recessed through a tunnel are hole in the face plate of the device). Just glue a same size nut into the socket with JB weld and then drill out the center of the nut somewhat with a Unibit after the epoxy has completely cured; the larger hole in the backstop might be necessary if the nut has to thread into an extra long shaft.

[@inkpapers-1]

This was enjoyable. I've owned an Ashly mixer, and I have noticed some niche experts selling custom modifications of them, upgrading the op-amps to Burr-Browns, etc. They would have quite a time with this EQ!!! .. I think it's more reasonable with a mixer, taking it from a TV studio standard quality to a more high end musical quality device. I'd quite like to see a video like that from you, upgrading a piece of musical gear like that!

[@46bovine]

I always learn something when I watch your videos. Keep up the good work.

[@BirVoltElektronika]

Thanks, Paul. I enjoy your videos and projects both on KZbin and Patreon.

[@Sloxx701]

Great stuff Paul. I always appreciate the great content from you, I learn more every day. Also your Patreon page is really taking off, awesome!

[@BradBo1140]

Fine thread and course thread... that’s awesome stuff. Thanks!

[@flemmingchristiansen2462]

I have worked with equalizers like this -please do remember to take those pictures, it is a real treasure. It do take hours on hours to setup 31 trac per channel. You will reach a point where your ears and brain goes tires and you can't hear a 6 dB difference in one trac. I once made a 6 channel setup. It took the better part of a week to do. Imagine my frustration when i had to do it all over again six month later, just because someone had some fun.

[@MacNifty]

That is where the studio owner whoever owns that equipment as made a flaw and in that make marks on the face plate. Whether it is a paint marker is simply a little piece of Masking tape. Or the owner themself took a picture before they submitted the equipment. A common sense thing to do but not everybody has common sense.

[@MacNifty]

That's just like as well when you are producing music give you ears a break. Come back later and you will realize what you couldn't hear before as your brain and ears tire.

[@evilwarcow]

As someone who has suffered the cut off from when ITT Tech was given the cease and desist order which forced them to close their doors and had not graduated because of it. I thank you very much for being around. Perhaps you are a good helping hand to possibly help me complete my training.

[@inductorbackemf7204]

Thanks as always Paul! Alex.

[@griftereck]

always enjoy Mr Carlsons videos

[@StasiSLG]

Hello mr. Carlson. Glad to see another video from you. :} Respect :)

[@KowboyUSA]

Now *that's* an equalizer!

[@antraciet]

Kowboy USA it is ! People don't use equilizers anymore in their audio, don't know why.

[@ctyragdoll]

​@@antraciet Most just use the equalizers in the DAW these days, or channel strips.

[@thomasandrews9355]

Hello from Rochester, NY where this beauty was made!

[@Siri_Sathdamma_Sewhela]

Nicely explained with very clear guidelines (repairing procedures )👍🏻😉 Very good 😍😍🙏🙏👍🏻👍🏻 Great video Mr.Carlson🙏🙏👍🏻

[@WallStreet749]

I love watching you .. I get so much peace from watching your videos.

[@brianangel8201]

Nice video on trouble shooting , love the cute little o scope.

[@RitchieCaron]

I've used these EQ's a lot doing live sound. Used to be the go to EQ before digital took over.

[@januszkozub5974]

Fantastic, educational, hope you can continue long, long time ahead. Thank you for your efforts. JK.

[@SauvikRoy]

Very modular and simple design. Great work as always!

[@mwiz100]

I thought I knew about a lot of screw head types but I just learned about the JIS Phillips. Also explains why some "No. 2" screwdrivers I have don't have the same shape. Holly wow. I shall be going thru them all tomorrow...

[@MrCrabbing]

Brilliant brilliant thanks very much, was the thing protecting the tester called a choke I used to have a Peco scope and that had a similar thing to protect it when you were testing engine ignition systems

[@simonbeasley989]

Looks a much neater design than the ADC!

[@cedarstuff]

Nice pick-me-up for a pretty bad friday. Thanks!

[@vedodesantis4414]

Mr.Carlson I'm assuming your a engineer,I'm a technician your the best I admirer you, your the best, vedo

[@johnholemanjr3738]

This many equalizer controls can really help any reverb to create any room sound, from Jay Leno's garage to the various grand cathedrals, and all the studios in between. I know. I used to be an acoustic engineer in Florida.

[@pierrejobin3373]

So far your the best

[@robertturner4913]

Seriously, you can see electrons can't you? These are the best videos that I've found on the 'tube... Thanks For Making Them.

[@ianmontgomery7534]

I wish people would stop calling them Phillips. There are three types of cross recess that I come across. Type 1 which is what is commonly called Phillips, Type 1A which is commonly called Pozi-driv . As stated you need to have the correct type of screwdriver and also the correct size. Nicely configured unit. I too love the socketed Op-amps. Sensible move to replace the electros.

[@hansroemerszoonvanderbrikk7626]

Nice job! Since this is audio equipement I'd put the same Motorola opamp on the working channel as well. I know it could be unnecessary but when you deal with complex waves (real audio waves) it could put a different distortion in the whole chain so that the JRC driven channel will behave slightly different from the Motorola driven channel.

[@ryangeddes7277]

Oh my god that tiny baby oscilloscope, I want one

[@craigmunday3707]

Master at his craft

[@jaymz168]

I actually have a pair of these, they were one of the best graphics back in the day. They don't get used much these days since this is all included inside every digital console on the market now. Also if the customer can't re-tune the room after the bands are returned to zero then they're not much of a sound engineer. They should try going on tour and tuning a different room every night!

[@isettech]

These are nice to work on. Most everything is with plugs and sockets for easy access. Unfortunately sometimes in rough handling, something comes loose. If you work on mixing boards, some manufactures have the drawings in the manual which show the faceplate without any knobs or slider positions. This can be used to note all the starting knob and switch positions to return with the unit to the customer. A nice touch is to provide a second blank copy so the customer can make his own notes for a venue. There are more than 2 types of "Philips" screwdrivers. Philips is actually one of them. The other is not Philips. It is a JIS or Japanese Industrial Screwdriver. The differences are the Philips is designed to limit torque by Cam forces lifting the driver from the slot. This bit will not insert all the way into a straight side slot of a JIS screw, which is designed to not cam out of the slot. The American version of the JIS is the PosiDrive used for drywall screws and other applications requiring high drive force. The other common "Philips type is the cross point screwdriver which is based off the JIS screwdriver for small precision screws such as the screws in a laptop. Those are also NOT Philips screws. See your tool supplier for all versions of cross pointed screw drivers to have the correct tool for the job. To add to the mix is a hybrid flat and JIS screwdriver simply called a Terminal screwdriver for electricians. Commonly used for breakers, relays, and other electrical power applications. If you see a screw with the slot looking like a hybrid of a flat blade mixes with a Philips, you are looking at a terminal screw. They come in two sizes.

[@goodun2974]

Isetech, those "terminal" screws seen in electrical busses and such work rather poorly as a Philip's screw and seem to be designed to work *best* with a square-drive, Canadian-designed Robertson screwdriver. I quite like Robertson screws! . They're often used for fastening deck planks.

[@isettech]

@@goodun2974 True where the terminal also accepts a square drive, it is known as a The Phillips/square screw drive, also known as the Quadrex, Pozisquare screw drive, is a combination of the Phillips and Robertson screw drives. Not all terminal screws will accept the Robertson square drives. I didn't list the Robertson screw with the Philips type screws.

[@andywason3414]

I really enjoy your videos, having served an apprenticeship in electronics in the 70's and worked on military, industrial, and musical equipment (including tube amps) through the years. I'm still learning lots of new tips and tricks that I didn't know. I was a little dissatisfied with this video though, as it all seemed to be so 'storybook'. Yes, op amps do fail, but you didn't check the power supply to the op amp first, nor did you check the signal path to the main eq boards before removing the i/o board. Often re-seating ribbon cables and socketed op amps may solve the problem. Also, rather than conveniently having a spare op amp, or waiting for one to be delivered, one would typically remove one of the other socketed op amps and try that to make sure that solved the problem. Also, usually pins 4 and 8 are the power supply pins, you could have warned us about not shorting pin 7 to 8 while testing, which is easily done. Minor criticisms, but over all, very well produced video, with patient, clear explanation of what you were doing.