Nikko Alpha II repair
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- Опубликовано: 23 сен 2024
- Stupid 220V gear. This always happens.
The Nikko Alpha II is a very impressively performing amplifier, with the lowest noise floor of any amplifier I've ever measured, even exceeding the Yamaha AX-590, which has been my benchmark for low-noise amps for a long time.
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I love it every time my phone tells me you've uploaded a new video mate
Watching this video again July 14 2019. I have matched pair of Nikko Alpha ll Amp, Beta ll preamp I bought them back in 1979/1980. Great reference video thanks a bunch!!
Excellent repair and explanation - you're a true technician!
+mjqctg Thank you, I'm glad you enjoyed the video.
You are welcome - having some background in electronics I can appreciate your knowledge and experience!
I have an opportunity to pick one of these up along with the Beta 20 pre amp. Both are restored and re capped. These type of units are timeless designed to do one thing well vs multi purpose AVR's with DACS. These all have their places but I'm drawn to these pure audio units. Thanks for showing us the restoration as well as giving your impressions of the results. All the technicalities are well over my head but I've watched it several times!
I'm sure no one will read this but,.... I bought this amp and an Alpha Beta 20. Both totally restored by a shop that exclusively works on vintage audio. It's in the mail. This will be very interesting.
@@WalterDavidRiffmon i read this ... and how do you like it ? with which speakers are you using it ? i have one but faulty now
I wonder if to service it or not It will be expensive i guess Regards, gino
@@gino3286 I don't regret the purchase that's for sure. I paid a lot but that's due in large part to taxes and shipping costs which added considerably to the sale price. I have Ascend Acoustics Sierra 2 EX speakers. * ohm speakers but not the most in room sensitivity. I think approx 87 dB in-room. But the amp pre amp combo in fully restored condition power them fine.... no lack of dynamics and power. Worth restoring considering what a dual mono transformer amp with separate pre wold cost you new.
meant 8 ohm
@@WalterDavidRiffmon thanks a lot again i read something a nikko brand on audiokarma site and it was interesting Great brand indeed Kind regards gino
Can't wait to watch this after the kid's go to bed! My Alpha II has a channel losing power and getting static-y so I think I need to address some problems, but have no idea where to even start. And after that, maybe have a look at my Alpha 600. Cheers mate!
I am currently doing a total re-cap of one of these amps that I had put away for 5 plus years. It seemed to work ok when I stored it away. Since I have all the boards removed, was wondering if there are any other specific components you would recommend that I replace while it is easy to get at them. I do not have anything more than a multi-meter to test. I do have all the prints and service manual. I will be using this amp with Klipschorns, so any noise at all will be heard. Thanks!!! Great Viideo!!
Not really, these are pretty fine as they are.
how much I wanted one of those when I was young, I knew the brochure & specs by heart
only had enough money for a 26 watts/channel Akai am-uo2 (I was 12 when I bought it) a far cry from this Nikko
great video
+PTTM2006 Your younger self had most excellent taste.
+FFcossag and my actual self wish you didn't live so far because I'm looking for a good tech to fix my sugden A28 II ha ha.
But I think I found one, miss my class a
Wow.. Now I want one ! Nice job
The volume control potentiometre was made by Noble and has very precise plastic film steps. It is now valued at $200
Great video. I am envious of your ability to clean the capacitor residue off the boards. How do you suggest removing that gunk? I've limited myself to denatured alcohol with a soft brush in the past but don't seem to have been as successful as you. Also, do you make any effort to clean the residue before attempting to pull the old caps?
That yellowish gunk you often find is glue, and it usually comes off with violence.
Very nice Nikko repair; manufacture is well known for applying adhesive to components that become conductive over a period of years. I can't tell how many repairs that I have done because of these problems, my guess they want you buy new when the glue's chemical reaction changes from none to conductive after five years or so.
+John Cunningham In all honesty, I don't think there's any malice in their use of adhesive like that, at least not in high-end products, but rather ignorance.
How can I change the lights to a led?
Ive got an alpha 130, and it sounds fantastic. However I don’t know the difference between that and this.
That diode on the driver board, it has an odd symbol? is it some sort of "dual" diode ? I thought you called it a VDS1212, is that correct? I have this amp, bought new along with the preamp, must have been 1980/81?. I stopped using this when I discovered the main caps were leaking, that was in the early 90's. After seeing your repairs I'd like to get mine up to speed, Thanks for the video
It's been a while since I filmed this, so mind any errors, but if it's one of those diodes that mount to the heat sink (for bias compensation), then it's basically 3 1N4148s in series.
Love these repair vids. Kinda interested what power supply you're using? Kinda rare to see a bench PS go above 30VDC.
It's a TTI EX752M. A fantastic tool for amplifier testing.
FFcossag Thanks, spec looks good indeed!
if only i had a tech like you in our area, i have a Nikko Alphpa II im using as a studio reference amp i would like to have re-furbished
hi can you help with the replacement part number for the transistors alpha450 transistors 2sa1095a 2sc2565a d882p
I build i quad channel power amplifier that run on 240V on 220-230 V transformators toroid type in 2015 and use 63 V caps with no problem.Old caps was rated ac V.Today are rated after how much dc V they are rated for.Had some integrated nikko amp.s and a Nikko alpha mosfet power amplifier back early 80,s..62V on 63V dc rated caps are a bit high mine run,s at +49 Volt-0-negative 49Volt have 60 000 uf pr channel circuit is a no negative feedback local or global type.Have build some sets of 2 channel before.They are designed by LC Audio model The End xp millenium.i use 2 the 4 channels to drive 2 tweeters direct and 2 mids direct with drivers sensitivity at 96DB and is the most quiet amp i have tried.some mid end and high end a could hear the hizz from my listening position with this i can hear the AMT type tweeters faint hizz with my ear close to the tweeter i a active setup.I use Ground sound 4 way or stereo 2 way dsp crossover modules times 2. both crossovers are set in mono mode 4 way and used in a dual mono 3 way setup for better channel separation.They are also very quiet.power amp is 4 times 95 watt.No self oscillation problem at all.The first versions of The End early 90,s had problems if not build right with that the 1 version that vere real good had 4 stages (The End MK3,1) and the last versions had 5 stages(The End XP millenium) very linear and clean.You can look for LC audio The end XP millenium build description on google.Bruel Kjær well known messuring company used The end XP mill for some time i read i a hi fi magasin.They aso came out with class a version called Zapsolute no negative feedback.They dont change tone when volum goes up like those with local or global feeback.would rate the sound quality at high end no doubt.
great video! where did you get all the parts from--caps and heat sensors in particular ? thanks
I think I ordered everything from Mouser.
the heat sensors as well? thanks much
I meant temp sensors
If I replaced them. I don't remember everything I do to an amp, this video was shot in 2015.
Hi ! thanks a lot for the very interesting video. Did you manage to restore the amp ? how does it sound ? do you think it still represents a good value amp for today standards or it is obsolete ? i would like to search for one and any your opinion would be very precious to me. I Always look for a clean sound and good 3D soundstage. (Sorry for the poor english)
It's very good by modern standards, audio amps don't really go out of date.
Hi ! this is what i wanted to hear. Thanks a lot, gino
gotta love it. priceless education.
hi, need to install/replace the 4 10000 uf 63v caps - - I cannot read the poor schematic I can find on the net. Do you have a photo or a simple color coded wire diagram for these 4 caps ? The caps are missing so I have nothing to go by.
THANK YOU - - YOUR VIDEO WAS AWSEOME AND VERY HELPFUL!
I usually grab schematics off of hifiengine. It shouldn't be too hard to figure out though - just measure which wires go to case ground and which go to the rectifier.
@@FFcossag Hello, I want to change the caps in my NIkko Alpha, one channel isnt working anymore. Did I understand you correct that you advice 80V for the big caps instead of de original 63V for big 4 10000uf caps? because of 230V?
Very nice video.
Hello Audio Junkabus, how did you solve this. I have the same problem. I don't know where te wires need to for the 4 big caps. I hope you can help me.
FF i have a question ? can you help me how i can fix the bulbs/lamps of the Nikko Alpha II, are any fuses ? i see no fuses
Are you sure the bulbs aren't just burned out?
Hi, i located the fuses i had to get of the backplate stupid me :) all the fuses are okay, i don't have a loop but i see 1 bulb is not good can this have a reaction on all the bulbs ? or are all broken ? tanx that u responsed so fast
you know the voltage of the bulbs ? and how to replace and buy then in Holland EU
It can. You'll have to find yourself a schematic and figure it out.
i have the schema but i ám not a technician so i will bring it over to my friend and pay him something, the sound with my nikko alpha and beta 400 is superb but with the Alpha 2 much better tanx for replying me :) greets from Holland
I really love watching
That is a thing worth loving.
How many watts per chanel
I don't recall, Google is your friend.
Are you a regular user of freenode (IRC)?
+emolatur No, I'm not, I'm more of a Rizon kind of guy.
I see. You just look a lot like one of our more intelligent regulars, and are working on his genre of equipment (analog audio) as well, so I was curious. :)
Sure wish i had a clue what you were talking about lol.. im screwed im afraid