Dr Z MAZ 18 With Reverb | Part 3 : Mil Spec Wiring, Reverb Tank Hum, & Good Progress
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- เผยแพร่เมื่อ 10 ก.ย. 2024
- Why mil spec wiring is crucial, but it isn't what most people think.
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• Dr Z MAZ 18 With Rever...
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From an old die-hard Marshall guy, that amp does have a very nice tight tone.
I did quite a bit of 'mil-spec' soldering while doing contractor work for the Dept of Navy. To really get qualified, they would send us to a school in China Lake CA to get certified....tough going ! ! !
Did you do their SMD soldering qualification or not? That one was a real bear, back in the day. Ground planes and heat sinks onto dead trace plate, and it all had to be 100% perfect. I should still have my China Lake SMD board somewhere.
@@Satchmoeddie SMD was not around back then when I was doing all the MIL-spec soldering...I learned that on my own. I have equipment here now to do any type of small SMD stuff except for the large IC's. I did quite a bit of MIL spec fiber optic work.
Excellent! I had a reverb noise problem with my Deluxe Reverb that I finally fixed (after 4 years). It was the ground point on the reverb return jack. I ended up soldering it almost exactly like you show here. Your video is a must for those wanting to know how to solder the right way. Don’t let the noise about your camera bother you. It’s the only information that’s important. Thank you!
I thought it would be good to mention that a fair few years ago now Dr, Z Amps became ETL certified, the amps were always built pretty good but after the ELT certification they started using NASA grade soldering techniques among many other things. Basically there was a step up in design and quality compared to say the old MAZ MK I which had it'd issues. ELT certifications are very extensive testing on product to meet the standards.
Ideally, since components are more likely to need be removed during servicing than the wires are, I'd prefer to see the wires soldered at the bottom of the turret, close to the board, with the component leads attached higher up. Unfortunately, this is more difficult to do when the boards are pre-stuffed with components *before* being wired up inside the chassis, as is typical. Also, the turrets for that resistor we watched you change are simply too damn close together! Its a lot easier to unsolder and remove a component if the leads have some length and flexability to them. Turret posts with center holes in the top are nice to work with; turrets with a slot in the top are even better.
From Leo: Good call on the reverb tank orientation. Workmanship is pretty much gone in the repair business. I find lots of sloppy work where the solder is used like a glue gun. I appreciate your workmanship. Remember wire wrap breadboarding? What a mess that turned into, luckily we did not see that in Amplifiers. The digital guys thought it was great until they had hundreds of intermittent connections a few years down the road. Thanks for your work.
I've worked on many hundreds of vintage analog Japanese hifi receivers, Pioneer, Kenwood, Sansui, Onkyo and the like; only twice did I encounter an intermittent wire-wrap connection. I don't know what method and tools/equipment they used in the 60's and 70's to do the wire-wraps ---- by hand, or by machine? --- but done right, wire wraps are, or can be, extremely reliable. As a tech myself, wire wraps do have a service-related disadvantage: unwind one off of the post and the wire invariably breaks before you get it halfway unwound, and there's typically no excess wire there to play with, which means you couldn't wire-wrap it back on even if you wanted to (or are experienced at it and have the right tools, which I'm not and do not).
From Leo: @@goodun2974 My experience were on CNC machine tools. Heat, humidity and vibration were a big factor. I can see where wire wrap could be viable on home audio, they were terrible on plant floor equipment. I have no idea if they were a trigger gun, electric gun or twiddle stick constructed.
When I saw mil spec in your title, I was worried you were going to diatribe on the veiwer who was throwing his two cents in on the build quality. I'm a student of amp building and am no expert but I love the old amps. Love your channel! Uncle doug too!
I guess you don't watch the video 😆
@@auntjenifer7774 no that was related to a return moment that I made the vid before!
Really appreciate this solder/de-soldering demo... 😵💫
Be like an old Valco assembler, wrap it around once or twice and then tie a granny knot in it too! Those little solder pick n prod tools with the split end shanks and straight picks combined together are really good for untying knots around pin terminals and knots through flag tag terminals. My mother used to work on electronics assembly for Denver Burglar Alarm many years ago, so the hooks lops and knots kind of make sense in a way. One person would prefab a board, another prefabs the control panel, etc. Final steps are other assembly line workers solder stuff in. BEAN COUNTER'S SYNDROME!
Great video again. For all you need to know about soldering this is it. NASA-STD-8739.3. pdf
LOL "Going Back in!"
Early into the video you make mention of the "Military Spec" concerning the build practices/specification.
I would be happy to find a MIL Spec Solder Sucker that lasts for more than 6 months!
Get yourself a Soldapult. I have had one for over ten years and it works great. All you ever have to replace are the tips.
I've had a blue Soldapullt and a SIlverStat static-free Soldapullt for nearly 35 years with no problems, although it's getting harder to find the carbon impregnated tips for the SilverStat these days...You just have to learn how to maintain them properly...
The old light blue "Soldapullit" solder suckers ---mine is 40 years old and still works, and I went thru a phase long ago where I was desoldering zillions of parts from boards. For tube stuff they are unbeatable unless you have a real vacuum pump deal. Buy an extra tip if you do lots of work.
@@roberthurless4615 Much Thanks Sir, I just ordered myself one as well as a maintenance kit!
These are the exact same units we had when I worked at the Aircraft Instrument Shop.
@@pneumatic00 Thank You, so amazing to have so many reach out so quickly to provide guidance and assistance.
+1 to this group here.
Now this is how great amps are made... point to point with turrets and loads of craftsmanship. Dr. Z amps are second to none.
Not to sound like a jerk, but the point of this video was that Dr Z does not exemplify craftsmanship. I'm painstaking correcting their errors.
The amp isn't point to point either, but most players misuse that term. I'll be doing a video in the future on what that actually means (and why it is really a bad thing most of the time). Note that I mean actual point to point, not what you find in old Fenders.
@@PsionicAudio When you say point to point, you mean no board, right? AKA "rat's nest"?
Right, or components from tube pins to terminal strips.
@@PsionicAudio EXACTLY
So without trying to sound like a jerk and with you not being real high on the build quality of Dr. Z amps from your response to my earlier question about Dr Z amps. Did the version of the Maz 18 in the MKII make any improvements of the original Maz 18? If I remember you could send your Maz MK1 into Dr.Z and have a mod done to bring it into the MKII level to correct issues with the original model MK 1? Just trying to learn before buying an amp. I looked at Parr, Top Hat and Suhr amps based on your recommendations but finding places to buy them from where very limited. Maybe your amp will be available one of these days?
The old light blue "Soldapullit" solder suckers work about 50 times better than those little anodized ones. They are big, a bit klutzy for PC board use, but for tube work, they devastate those little s**ts.
Yup. I'm waiting for the new big blue to arrive.
Those turrets look like a pest..! Nice work and info..Ed..uk..😀
That warping back panel dress label is making me crazy…..please get it out of there and replace it before I have a nervous breakdown. Otherwise excellent work and troubleshooting. I took the reverb tank out of my dsl50…just because of the vibrations driving to all the gigs. Could not stand it
I thought the reverb pan bag had some type of shielding or damping so that the reverb pan input doesn't interfere with the amplifier output transformer, it's creating some type of magnetic feedback loop?
Usually nice to see the resistors all oriented the same way
I strongly suspect the shielding and grounding of the cables to the reverb tank, also why would the output transformer induce hum? If the output tubes are well balanced, there should be little residual magnetic flux around it. Earth loop? I await the conclusion. Cheers, Steve.
Time for class!
Dude, you are a braid waster! ; ) Excellent video made me a subscriber.
Could that resistor have failed because it got too hot during its initial soldering installment?
Or because the humidity was X or because the day ended in a Y.
Old CCs fail. But yeah, heat is not their friend.
@@PsionicAudio , a tech in Australia (Brad's Guitar Garage channel, IIRC, something like that), uses loop-forming pliers to put a smooth half-circle kink in resistor leads, not only to lift them up off of a PC board for heat dissipation, but also to allow for straight-line expansion and contraction if the resistor is soldered onto turret posts or into eyelets. This strikes me as a sensible idea.
Brad's a mate of mine, and I just sent an Aussie with an AC30 to him.
That's a technique for PCBs, not needed for turrets.
@@PsionicAudio ,he uses the loop-forming pliers for turret-mounted components too, to form an expansion joint of sorts. I've formed many such resistor-lead loops by hand over the years, to lift the parts off the board, and those special pliers would be handy, but they're expensive.
Not needed on turrets. Good on horizontal components on eyelets.
What temp are you running on your solder gun in the beginning?
That was 10 months ago. But usually 750 for turrets.
how can someone get ahold of you for work to be done? tried emailing with no success
Sorry, I'm a terrible secretary. Let me check the Spam folder - sometimes it grabs legit emails and hides them from me.
no problem! I am just really hoping to have you do some work if possible
my email is my youtube name@gmail.com
You would think DR. Z could of done a bit better with the turret card layout. Working in the shade is fine for cars...amps, not so much.
Hi lyle, is soldering from the top hole of turret pin instead of wrapping around still acceptable?
Not to NASA, but yes down here on Earth. If a part is heavy, have it up against the board and maybe wrapped, but most components are fine through the top of a turret.
Note that Dr Z's turrets don't have center holes. So everything is wrapped here.
When I design pedal PCBs, even as someone that is more artist than engineer, I design things imagining someone like you going through them in the future, I believe they're really well laid out for easy service, I don't know why these companies that are way bigger than me making pedals on my kitchen table don't think about this stuff. They don't think that someone might need to desolder and change out these parts in the future or something? Why wrap the leads so much?
Its because they dont care...simple as that. Not impressed with Dr Z quality control
“Mil-spec amps”...
So THAT’S why everyone joins the military! If I’d only known...
Isn't j-hooking mil-spec? I seem to recall it is. If so, why does it get such a bad rap?
Depends on how the other end of the lead you're j-hooking to is connected. Wrap around a turret? Ok. Eyelet? Not necessarily - depends on if there is mechanical support beneath the eyelet. PCB? Never, as you don't know what's happening with the reheated solder joint beneath the board.
If I was a road tech who had to change a cap 30 minutes before show time, then j-hooking would get the job done quickly.
Here on my bench I take the time to do things right.
I would say that 99% of those that claim mil-spec wiring are not even close to true mil-spec. Mill-spec also has an allowance for heating and shrinking of the wire leads. There are about 20 different ways to bend the leads prior to their connection to the turret or eyelet. These different methods range from one rigid end to both ends having some sort of bend to allow for movement when the part heats up. This is on top of the orientation of the part ( so as to see the nomenclature or value ) and the way it physically connects to the turret. And that's not all, there are also different ways to elevate the part on the turrets. The two tiers of the turret are there for more than just looks or connecting two wires. Not even Matchless amps were technically Mill-Spec wiring. Extremely clean work, but as executed, not Mill-Spec.
@psionicaudio
Man the camera is ball breaker...
Better off just buy the MAZ 18 MKii which has ALL the issues addressed and with some cool new upgrades. There more going on in the new version that most people think.
Wait. Are you suggesting that if you own a Mark I you should just lose all the money you already have in it because of the documented design flaws, then reward the culprit by buying a new amp from them where they finally listened to it before selling it?
The Mark I should never have hit the market and they should offer free factory upgrades to the Mark Ii circuit. As they don't, I fixed it for the owner.
So did they address these issues with the MKII? Again not trying to be a jerk but just asking. I know you could send the MK1 in to have these upgrades done but if I remember there was a charge for that? But to me if their where design flaws it should have been done for free but then again. How many amp manufacturers offer free upgrades and repairs on their poor designs and poor workmanship ex: Fender reissues needing 200-350 worth of work or upgrades after 2 years like you mentioned in your amps under 1000 video. Again not trying to be a jerk or disrespectful to you sir. These are just honest questions and observations based on your videos and statements you have made. It is not me trying to argue or challenge you or show any disrespect at all. I am a player not a skilled repair tech like you are. That’s why I like and subscribe to your channel. Thank you, Stevec
@@stevejones7231 it's a bit more complex than that. The mk ii has many different component changes as well as the PPMV, foot switch, NOS 6B14N tubes and reverb Reverb circuitry upgrades etc etc.. Also it has a warmer bolder sound with all the el84 nasty-ness we all love about the mk i. IF you can afford it go with the new one, you won't regret it or get your old one refurbished.
Thanks Aussie. I am looking at a Tone King as well but don’t know how well it is built Vs the Z amp and I was going to buy a Boss Katana MKII Artist but when that thing develops a problem down the road it’s a 600 dollar throw away amp and I want something that sounds great and will have some value when I age out. I can alway buy a pedal board to get the sounds and more of the Boss. I’m not a great player with neuropathy in my hands now but still enjoy bending a few strings and banging out some chords with a blues or rock track. I have a few player friends who like the sound of the Dr. z amps and was surprised to see Lyle doesn’t like their build quality. I don’t mean that to disrespect him because he is obviously very good at what he does and I enjoy watching his videos for hours when I have time at almost 69 years of age and wish I had his skill sets. I love fixing and restoring anything broken to give it new life especially older things that where made so much better back in the day. I wished I knew more about the Tone King Imperial 20 watt amp but I am still trying to find information on how and where they are built? They are not cheap and the Imperial is right at the same price of the Dr Z Maz II with reverb. Thanks again for the Input and keeping it positive and helpful. Cheers