Some Updates and Carver M-400 Part 1

[@1959Berre]

Recently, Paul Carlson has designed and built a peculiar cap test device. It detects leakage, obviously; but unlike other test devices, it also tests if the cap is on its way to failure before it actually goes bad.

[@HammyTechnoid]

I have an M400t.. and it works great. Love Carver/ Phase Linear....

[@mohinderkaur6671]

Dimmer Triac based amplifier. Nice work designing it.

[@acefeeley5884]

I had an M400 for years, along with the sonic holography unit. It was the best amp I ever owned (was destroyed in a flood, alas), and the holography unit was pretty damned trippy.

[@charlescartwright6367]

Just a comment, valid or not, back in the early 50's & 60's we fudged on the basis of working voltage etc. because we believed to get passed the component had to achieve a +50% test. so we felt it was ok to fudge a bit. I not saying this was good practice, but we did it sometimes. Could this be the mindset of the design engineer???? Keep up the good work it helps us old farts who can't see the small parts, I was taught in school that a 1F cap was a physical impossibility, somebody lied to me!!!!! Aloha

[@randomrepair1680]

Have fun with the cube. Compact in there. Good little amp

[@AxelWerner]

I disected an European proved computer smps that also had two paralleled full bridge rectifiers in it, screwed together for temperature coupling . Never seen something like that before.

[@mdzacharias]

I know what you're saying about transistor substitution; but I've been a very active audio technician going on 40 years - had very good luck substituting. Mostly just match things like Vcbo, collector current, power dissipation, etc. Rarely a problem.

[@peterzeboroff7448]

Almost every modern computer power supply has 2 full bridge rectifiers in parallel

[@BobPegram]

Basket case is right! At least you're now familiar with the architecture. The exterior notes mentioned blown transistors. Just looking at your video, I don't see obviously blown transistors. I know you'll test them all somehow. I don't think that one little burnt resistor could make all the stink you reported. Good hunting!

This Carver Cube should be called the Carver Kludge, after seeing it disassembled a good option would be to re-assemble it on a new chassis that will make it serviceable. But that wouldn't be any fun.

[@poormanselectronicsbench2021]

I did not see, and you did not mention or show, that, the top and sides of the mounting plate for the TO-3 transistors should be SLATHERED with heat sink compound from the factory to transfer as much heat as possible to the rest of the cover for better cooling ( I've taken 2 - 400's apart, both had it). If you didn't have that compound, someone else had been in it, cleaned it and neglected to replace it before reassembly.

[@dhpbear2]

41:20 - Maybe the penciled-in '+' and '-' signs were wrong?

[@BobPegram]

Looks like you might add a bit of punch to the base, when you enlarge the big caps, in voltage and I hope, in capacitance.

[@TrainMasterMan]

Those two 80V caps are marked 80 WVDC or 80 Working volts DC, meaning they are fine to use, and even exceed (a little) 80V.... The safety margin is built in- those may actually be 100V caps~

[@peterzeboroff7448]

Hi,you asked about power supplies using 2 bridge rectifier in parallel and most computer power supplies have 2 rectifier in parallel.

[@dhpbear2]

47:44 - Why not just split off each bridge's output to its own filter circuit, creating two sets of +/-25V outputs? Use one for each channel. Now, THAT would be innovative!

[@jonka1]

@32:50 Is rewinding the transformer not an option? I have rewound many in my time and it's more a state of mind than an impossible mountain to climb.

[@apollorobb]

Now days we sacrifice component tolerance for size. everything is smaller and materials thinner this is why capacitors dont have the tolerance they once did.

[@jlsagely6892]

Smiling at all these comments. Internet engineers....Get this amplifier back to proper working order, and you’ll be amazed.

[@danielgendron6344]

Mr Tony, I've been watching few of your épisodes and I have to admit that you aroused my interest in electronic. One thing always surrely puzzeled me, where do you get all the service manuals and schematics needed?

[@ImTheDudeMan471]

Mine says, Carver M 400 "t" ?

[@JVerschueren]

Oh, noes... not another amplifier from this unhinged 'genius' (i.e. yet another specific, obsolete component characteristics dependant circuit). :D

[@Joetechlincolns]

Try smelling an automotive coil-on-plug after the driver transistor shorts out and smokes the coil. What a smell. Lol

[@trickyrat483]

Salesman NEVER have any idea of how the products they are selling work! :)

[@JVerschueren]

I'd have to disagree, certainly as far as technology salesmen go. I've met a lot of really impressive people over the years. As an engineer, it's also very easy to spot those who rely on pure salesmanship.

[@harbselectronicslab3551]

Another Battery charger....I have yet to see a Carver that has any redeeming features inside......very poor design, running way to close to the limits, so from a Tech or Engineering point of view a total fail in my books.....good luck with that !!....... I do like your video's though ;)

[@adrongarretson6195]

Well my name is Chuck and I was wondering if it all possible for you to maybe I can hire you to work on my Icom to 11 and you can make a video out of that just let me know how when and where we can talk about doing this if you want I can give you my number we can talk on the phone it's a business transaction I really want to get this radio fixed I'm sick of it being a shelf Queen please get back to me

[@tomdewey9907]

What a total bodge mess construction quality. Lead pitches on the caps aren't even close to matching the holes in the boards. Nice design work there Bob Carver.