Beginners Guide: DIY Hifi Amplifier Upgrade, Power Supply
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- เผยแพร่เมื่อ 4 ธ.ค. 2024
- Following on from our speaker crossover upgrade video, Elliot decided to buy a Cambridge Audio amplifier from eBay to see what DIY upgrades (Nick) we could do.
What this amp provides at the secondhand price point of £40-70 is plenty sufficient: four line inputs, treble and bass controls, tape monitor, space for an optional magnetic phono preamp and a sound when combined with the newly upgraded speakers that was, to some surprise, pretty good. Not lacking in definition, already this little setup started showing promising signs. In this video Nick takes us through opening an amp for the first time and upgrading the capacitors in the power supply.
Check out some of our other tutorials on the HiFi Collective site at www.hificollec...
To see the capacitors use in this video please head to www.hificollec...
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This video is educational gold. I am going to repay Nick by purchasing a good bit of kit from them!
It'd be nice to have a before and after comparison on this sort of video. Did it improve the sound or not?
This was my first question at the beginning at this video too.
Hi There,
I am inspired open up my 30 YEAR OLD NAD intergrated amp. Great video
You really didn't discharge anything when you tapped the PCB like that, the green color comes from the solder mask, and it doesn't conduct electricity so you basically just tapped the circuit board with a grounded wire. Which did absolutely nothing. You should use a 5W resistor and place it across the pins of the capacitors, or worst case (100x better than what he did) just short circuit the capacitors. This is deadly if it's not done correctly. The filter capacitors can hold a tremendous amount of charge and depending on the voltage rating, a voltage of for example +80VDC, which is definitely enough to send you down the grave. Please, please don't do it as he did in this video, what he did, didn't do anything to actually discharge the caps. If it's not clear what I meant with using a resistor, just do a quick google search for how to safely discharge capacitors and you will find hundreds of examples and videos, without a doubt.
I know, I'm thinking what the hell? Doing that to his front door would do the same thing.
Brilliant video, got an old amp that I would love to give this a go on :)
You look like your scared to death handling it and when you "discharged"the caps you touched the clips to where there is no conductive metal. You touched the green insulated part you need to touch the alligator clips to the solder joints of the capacitors. Take your multi meter and continuity tester and there will be no beep if you touch the same spots.
I'm amazed how empty it is inside.
Nice video! Good caps certainly make a difference. Wouldn't the solder mask insulate the caps from being discharged like that?
Thanks! Dont have to worry to much about discharging the board but Nicks been doing this for a long time and some habits die hard!
@@hificollective I'll be upgrading my caps too and this is my biggest conernern. I'm an amateur. I did a crossover upgrade with parts from hificollective. It went well and i'm amazed buy the results. I want to tacle the amp (Atoll In30) too so i'm looking everywhere information.
I'm not afraid to dismantle things but i know there is danger in amps. Specially those power caps. Any advise, or video link would be much appreciated.
Thanks for all your content !
I think it is necessary to put 4 caps for the low impedance not two and a fast recovery diode. A low esr capacitor is enough.
There's only an 'incredible improvement' changing the caps when the existing ones are worn out or seriously uncervalue. A long time ago it worked but now manufacturers are more savvy.
This seems to be common on TH-cam, I would prefer to see someone upgrade the preamp section, I can't find videos on this anywhere.
brilliant vid...i have a 35 yr old Technics Amp....I would love to upgrade. but i'm a complete novice...what would happen if replaced all 4 caps with bigger caps ?
You need to stick to the same capacitance as the original although for the larger reservoir power supply capacitors you can go up slightly in value. This will improve the smoothing.
Wats the big block power supply made from? The square shaped ones ? I'm after its weight to apply to something else !. Thanks if you reply:):)
did you use the mundorf solder for the caps? thank for the video
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Strange method, usually it's preferable to have 4 caps rather than 2 even if the total capacitance is the same. This feels like trying to make the wrong caps fit.
Well yeah theoretically having parallelled caps reduces the impedence, but I've never heard a difference changing things in this area.
@@bobshifimods7302 bit of a slow reply, maybe its the impedance.
Great stuff. What’s your thoughts on bypassing them with small value polypropylene caps?
Fairly common practice these days, can tighten up the low end and people usually use caps with 1/100th of the value being bypassed!
SO. COULD YOU TELL US WHAT HIGH QUALITY CAPACITORS SHOULD WE USE IN THE POWER SUPPLY?
We nearly went for Audio Note Kaiseis on this build, but which caps to use depends on personal taste, budget and the rest of the amp. If you'd like more detailed assistance please contact Nick at info@hificollective.co.uk
The Mundorf AGs used here are superb. Much lower impedance than most equivalent caps.
@@Sparta155 We're inclined to agree as they've burnt in lovely with this amp, thanks for the feedback!
Won't it be easier to drill with a Dremel at low speed?
Sorry about being late to the comments, but aren't you making the project just a bit more complicated than it should be? I mean, the 1st hole can be the factory drilled, your new hole could be anywhere on the +/- side so long as you remove the green layer. I use fiberglass pencil to do this (I'm not sure what you folks would call it).
He could just solder it to the green insulator where he discharged the caps, haha
you kind of seem like you don't know a whole lot - have you ever designed and built an amp from scratch. Once you do that you insta-know what most bits are if its a standard design. I'd just use bog standard filter caps like Elna ... cheap, good ... its just charge. Pairs of smaller cheaper ones have benefits too ... multi-stage filtering. Its not like the pre-amp input cap. Still, kudos for going at it.
What a bizarre way of soldering? I was time served in electronics and have never seen people wrap solder around the component leg like you showed. 1) Mechanical joint. 2) Heat joint 3) add solder to the joint - not the iron.
I believe its because the new caps needed mod to board and tied the old holes pad to the new for conductivity.
Sorry to criticise. I did have respect for HIFI Collective, but after watching this, you've gone down in my estimation. Why did you try to discharge through the solder resist? and you should never discharge by shorting them. always use a resistor. Why not use 1 x 10000uf per rail and may be also change the bridge diodes for fast recovery type. Also, Cambridge audio put 4 caps in parallel to keep the impedance lower. I would also have cleaned inside it first.
I don't know, may be I'm out of touch with everything. It has been a long time since I've done any DIY. I'm sure people have benefitted from your video though.
Nonsense! I would use higher capacity less expensive epcos or panasonic caps, the same diameter (18mm) and raster (no drilling required), but slighly taller (it would fit perfecly). It would be 4x 3300uF 35V per (+) and 4x 3300uF 35V per (-). Much lower ESR. The amp would sound noticably better than original.
Those tone controls and balance control are disasterous for the sound quality,
Oh jesus , discharging caps by hitting clips off solder mask....wow.
У него даже нет шуруповерта! Жесть.
what they said ......AND you talk funny
How can you how can you do an audio video and have terrible audio for your own
Oh no, this is all kinds of wrong. He didn't even take a razor and lightly scrape the old cap leakage off of the PCB. In time that can eat through the board. You can also use Goo Gone and a light abrasive. In any case, this guy is seriously testing my OCD.
Dont do what this guy says he has no idea.