Many Unrelated Failures - Ashdown ABM-500 Evo III

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Webpage: www.bradsguitargarage.com.au
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Equipment:
Soldering:
Pace MBT station w/SX100 & PS-90 handpieces
Hakko 474 w/815 handpiece
Hakko 936 w/907 handpiece
Hakko FX-888D w/FX-8801 handpiece
Quick 861DW hot air station
BOFA fume extraction unit
Loctite Multicore solder (C511 / 362)
Test Equipment:
Fluke 11, 175, 177 & 179 handheld DMM's
Tektronix 2236 analog oscilloscope
Rigol DS-1054z digital oscilloscope
BK Precision 4017A sweep / function generator
BWD 160a function generator
HP 6236B triple output DC power supply
Kyoritsu 3132A insulation / continuity tester
Video equipment:
Overhead cam: Panasonic HC-V785 w/Audio Technica AT9946CM mic
Handheld cam: Panasonic DC-G85 w/Olympus M.Zuiko Pro 12-40mm f/2.8
On location cam: Panasonic DC-GH5s w/Panasonic-Leica 9mm f/1.7 & 12-60mm f/2.8
Capture card(s): Magewell HDMI USB, ATEN UC3020-AT, ATEN UC3021
Headset Mic: Audio Technica BP892xcW-TH
Lapel Mic: Rode Go
Editing: Adobe Premiere Elements
Hand Tools:
Wiha, Felo, Stanley screwdrivers
CK & Engineer cutters / pliers
RS Pro wire strippers
Sidchrome & Gear Wrench spanners, sockets & shifters
Veritas planes & chisels
Materials / Consumables:
JJ's / TAD electron valves
Elixir / Ernie Ball / D'Addario / Rotosound strings
Electrolube & DeoxIT cleaners, lubricants & chemicals.

[@markspurgin8225]

Oh now I see what you saying about that cap between the heatsinks that is frickin' stupid 🙄

[@PsionicAudio]

REALLY good job on this. Double plus like for the Sly.

[@gregmauser574]

Yeah there’s a few questionable design choices, and that damn unleaded solder is always a PITA, but it looks like a quality build overall. Sure sounds good! Nice playing Brad! 😎

[@johnwilliamson467]

NTC are a must with Toroidal transformers at the crossover point on the ac waveform the turn on looks like a dead short even with those small secondary caps. You may not turn it on at the cross point of the wave but when you do it hit with a very very large current spike. Worth the small cost of the NTC.

[@goodun2974]

I was going to ask if Toroidal transformers were prone to generating a bigger inductive spike at turn on than ordinary transformers, but you've answered it for me. Thanks !

[@RaxFx]

wonder how many Ashdown amps have been bought for the sexy VU meters?

[@BradsGuitarGarage]

I reckon 90% of them, mate!

[@gregmauser574]

Being an old ham operator, I fall prey to that stuff.

[@sgt.grinch3299]

Thanks Brad.

[@victorbeebe8372]

Aloha and Mahalo Brad. Very interesting.

[@joemcgraw5529]

This component isnt cheap to buy and people that pay that kind of money want quality engineering and quality parts ,thanks Brad for giving a heads up for anyone thinking about buying one Like you say instead of complaing to Techs that find issues like these to make it usable again ,they should have alot better quality control before they send it out to the public

[@gmasta06]

Great video! My ABM power section just failed today :( Need your help in California!

[@RobbieF]

Thank you for the video, Brad. I've clicked a like and fed the algorithm :-)

[@bugmuff]

Just wanna say you’re a fricken legend and for all your vids I’m smashing that like button and may or may not watch every second…. But also I’m a nerd and yes your vids are super informative and god dang it if I can’t keep watching 🎉🎉🎉🎉

[@maxvockner]

I looked in my carvin R600 bass head to replace a tube and I didn’t want to mess around in there long before I started tinkering with tube amps. I hope to never be in there again and haven’t been thankfully. Any recs on quality solid state bass gear from a techs perspective.

[@Satchmoeddie]

That is the same amp that made that totally unprovoked electrical attack on Brad, isn't it? I am not keen on using it but Ace Hardware sells a high temp red rubber gasket sheet package, and I will put the thickest sheet of that stuff on those toroidal transformers. It will probably outlast the amp, but the stuff gets kind of hard and crumbly after 5 or so years of high temps. A sheet of Viton rubber costs about $20 but it lasts a lot longer.

[@goodun2974]

To get knobs to fit more tightly to a compressed potentiometer shaft, face the pot upward and put a thin piece of elastic band over the end of the shaft before pressing the knob on; or, put a segment of flat elastic band in the slot of the shaft before pushing the knob on. You could use soft, non-hardenng putty, but that gets messy....

[@BradsGuitarGarage]

I use a little 1/4" wide masking tape folded over the tip of the pot shaft, generally give the tiny amount of packing that's required.

[@goodun2974]

@@BradsGuitarGarage , classic Japanese hifi gear sometimes used extremely thin aluminum foil, apparently factory-original, over the knurling on the potentiometer shafts.

[@IainThacker]

Utterly detetst Ashdown kit - always die inside a bit wher I turn up to a gig and this is the provided backline. On-stage is just mush if you get decent volume (e.g. festival gig), always miss my Barefaced cab and Markbass head. Nice playing at the end!

[@baabaabaa-yp2jh]

Must've missed you getting a zap mate!? Hope the blokes from Ashdown catch this clip!!

[@BradsGuitarGarage]

I think they did, and I think they didn't like it. What's fucking new, mate? Can't show the guts with confidence, don't release the amp, I reckon. But there are many examples that have outlived their warranty, so apparently I'm in the wrong.

[@Jim_Cox]

I missed you getting a zap?! I must have been in a work meeting or something. 😁

[@BradsGuitarGarage]

You didn't miss much, mate. Just me getting the shits and swearing a lot.

[@seanweatherford1251]

​@@BradsGuitarGarage You failed to mention the moment of self reflection.

[@BenState]

16V cap on a 15V supply. Nice.

[@Jonathan_Doe_]

Provided the supplies well regulated, that’s the correct voltage rating to use, if you use a way higher voltage rating than the working voltage of the circuit, the cap won’t reform itself properly with each power cycle, so it’ll be more likely to oxidise and fail prematurely. 16V rated caps basically exist for 15V supply rails.

[@BradsGuitarGarage]

@Jonathan_Doe_ Not saying you're right or wrong, but citation needed.

[@BenState]

@@Jonathan_Doe_ Operating temps of an electrolytic capacitor is directly related to it's voltage handling capability. Temperature is by far the most significant factor in degradation of the oxidation layers in electrolytic caps and subsequent failure modes. Source: archive.isis.vanderbilt.edu/sites/default/files/MARCON_2011_Kulkarni_Biswas_Celaya_Goebel.pdf

[@BenState]

@@Jonathan_Doe_ The physics of failure of electrolytic capacitors is well understood and temperature is the most significant factor. Temperature is directly related to it's applied voltage stress and ambient operating environment. This increase in temperature due to voltage stress directly leads to electrolyte evaporation, degradation of the oxide film and loss of capacitance of the anode and cathode foil. The amount of time a capacitor is operated at or over it's design voltage (rated voltage) the quicker it degrades the oxide film due to elevated temperatures leading to increased ESR and lower capacitance. Kulkarni, Chetan & Biswas, Gautam & Celaya, Jose & Goebel, Kai. (2011). Prognostic Techniques for Capacitor Degradation and Health Monitoring.

[@AprioriMarcos]

Brad, I lost the link to your Dry July fundraiser. Any chance you can pin the link on your video description? I know you're not one to shill, but some of us are all about supporting the actual good stuff in life. Temporary-sober cheers!

[@BradsGuitarGarage]

Hello mate! Here's the link: www.dryjuly.com/users/brad-webb-2 No pressure at all to donate, of course. But it doesn't cost anything to give the non-alcoholic beverage review videos a "like" and comment when they come out. I'll do an introduction video before they start.

[@ColeWheeler4Lyfe]

I’ve been wanting their Geezer Butler signature model bass amp. After watching this I think I will pass. 😂

[@BradsGuitarGarage]

I cannot speak for that unit as I've never seen one in the flesh.

[@ColeWheeler4Lyfe]

@@BradsGuitarGarage they are expensive and if the build quality is the same, (it probably is) then I won’t waste my money.

[@markspurgin8225]

Just finished watching Ola 👀 haven't seen you there in a while

[@BradsGuitarGarage]

Too busy, mate!

[@markspurgin8225]

That's a blessing and a curse 🤪

[@markspurgin8225]

Cool 😎

[@PhuketMyMac]

Energized heatsink?! What?!!!!

[@BradsGuitarGarage]

It's pretty common in SMPS modules, and some amplifiers. Not completely unheard of, but just something I'd change if I was them. But I'm not. LOL!

[@Cpt_Adama]

​@@BradsGuitarGarageVery good to know!

[@seanblythe9109]

I must say I have a bass driver pedal that I got partly for the vu meter and because geezer was paid to say it was good.

[@BradsGuitarGarage]

I cannot speak for that unit as I've never seen one in the flesh.

[@goodun2974]

I cant believe they didnt insulate the output devices from the heatsinks; probably got the better part of 100 volts on each of those, relative to ground, and therefore ptobably has about 200 volts across them ( its a plus/minus supply). .😖

[@BradsGuitarGarage]

You just told me you didn't watch the video past 17 minutes. COME ON, MAN! 🤣

[@goodun2974]

@@BradsGuitarGarage , I didn't participate fully in the original livestream (my wife always has other ideas on how I should use my time!), and was half listening to this video as I was cooking dinner, and so if you mentioned the actual B-plus voltages I didn't catch it, but I've seen plenty of high-powered amplifiers with power supplies in the range of +/- 100 V DC, and having large heatsinks carrying voltage is never a good idea ---- one slip of the probes or a screwdriver and "poof", up in flames.

[@markg1051]

@@goodun2974 I nearly made the same comment, bul luckily I saw the whole video plus my wife wasn't nearby at the time.😁

[@jutukka]

A multi-problematic device indeed! P.S. A very good analysis. 👍

[@tedmich]

Great video but be careful critiquing UK firms Brad, they have terrible slander/defamation laws!

[@BradsGuitarGarage]

News flash: I'm in Australia. And it's only slander if I don't have written evidence.

[@mozztronics]

any power supply should have a bleed resistor, a HV supply that doesnt discharge is just dangerous, a few cents of resistor easily fixes this, sloppy engineering imho