nad 3020e

Status
Not open for further replies.
hello every body wonder if you can help i have been in to hifi now for about 30 years and fell in to the trap of selling my decent hifi gear for a home cinema system and these amps are just no good for serious stereo so i bought a nad 3020 off ebay and wanted to know which parts to upgrade i have cleaned all pots and switches and allso fitted a screaned mains cable any more info woud be great CHEERS STEVE
 
What are you trying to change?

I have no direct knowledge of the NAD3020 (other than having to listened to a friend's one 25 years ago). So the following is a general tip, not specific to the NAD.

Rather than try to change the sound of an amp this age and type, I would concentrate on ensuring it's going to be reliable. In particular you don't want it to fail and kill your speakers (unless you want to buy new speakers, that is).

Large electrolytic capacitors have limited lifetime. If the power supply caps fail, you will get an extremely loud 100Hz noise through your speakers which is not good for them.

You might want to look at replacing the power supply caps. I'd suggest to keep the same value (microfarads) but go for the same, or higher working-voltage. This is in the interest of reliability and lifetime. I have used Panasonic caps in a recent repair and they seem OK. Should cost a few quid for this (less than £10 all in).

If your location is Sheffield, you could try Maplin for these parts, or else (the more professional-oriented) Farnell, who are in Leeds.

Also take a look at Mark Hennesy's amp refurb advice here. While it's specifically about Musical Fidelity amps, the "maintenance" section is of general use: http://www.mhennessy1.f9.co.uk/mf_a1/technical.htm#later
 
hi thanks for reply problem i am having is balance seems off it is more to right i have cleaned all switches and pots even swopt speaker leads round but still same i think your right though about some of the components being doughf i am not very up electronics but i can use a soldering iron if i know what parts and part numbers to get thanks
 
Have you tried swapping the actual speakers around, just to check it isn't your speakers?

Does the NAD have a balance control?

Does the imbalance happen on all inputs?

Without test equipment (as a minimum you'll need an oscilloscope), plus some electronics knowledge and faultfinding skills, you are unlikely to be able to fix a problem like that if there is a fault inside the amp. Just replacing things at random, you could easily spend £20-£30 on components and be no further forward.

Maybe you know someone nearby with the skills and could buy them some beers to fix it?

You may be better off buying another amp off ebay of similar age and quality and hoping it works better - e.g. Rotel, Creek, Cyrus etc. depending on your preference.
 
hi no i havent tried swoping speakers over i will try it but i think its the amp because since cleaning tone controls and switches it as caused the problem but it could allso be a component problem as when i switch the amp on it takes about 10 seconds for sound to come through but if i change any of the caps or power transisters do i do streight swaps or higher rated ones thank for help i will try it
 
hi, i would not change any of the transistors over if theres nothing wrong with them, which there dosent seem to be.

i'm wondering if your balance problem could be you not cleaning the balance pot properly? get some switch cleaner from maplin, spray it in the pot, then work it full round and back for around 1 min.

as for other mods i normally work on the original 3020's but do have the service manual for this so i will look ad see what can be done.


chris
 
hi thanks for help i did clean the balance pot by spraying cleaner in the pots and then just working them back and forth i did try swoping phono leads round on cd player which seemed to help but it just sounded confused and grainy it is doing my head in before it had real sharp centre image now vocals are about 10 inches from right speaker
 
it is simply a FACT !!!!!

THAT ALL SMALL ELCTROLYTICS IN SUCH AN ONLD AMP ARE GONE !!!!!

also excuse me but all your comments about psu caps are worthless since if these caps are drifted or lost even a big ammount of capacitance this will have of course effect in the performance but this will be only noticebale at some ammount of volume ....

on the other hand a broken electroyltic in the signal/feedback/preamp section could just as well be responsible for a total stop of the amplifier ....

you may wana take a look at this
http://www.diyaudio.com/forums/showthread.php?s=&threadid=136261&highlight=
 
i wouldn't say its a fact that all the caps are gone, yes with this particular amp some might have, but all? i wouldnt have thought so.

however, because of you lack of equipment, yes i would recommend replacing all the capactiors in this amp, it shouldnt cost that much and is good for practicing soldering in my opinion, but saying that the have all gone?

also its worth noting that changing the signal caps to better quality ones will change the sound of the amp considerably, to a point that you may not like it (that is if you liked the sound in the first place).

thanks
 
redish ....

the approach is very simple .....

lets suppose that one cap 100mfd/25volt is leacky or gone .....

can you define what caused this ???? NO!!!!!
is there other caps alike the above in the amp ???? YES!!!!
can you have expectancy of these caps ???? NO !!!!

replacing all of the will probably cost something like 5-10 usd at the very maximum and atleast you are going to be sure .....or provide another 30 years of very happy operation to your amp ....


the particular cap might work today but tomorow ???? after one month ???? after one year ????


as about sound quality there might be a tiny lilte improvment there since now days caps are smaller ,have better esr , and also given the replacement oportunity higher quality, voltage ,temeprature , or capacitance could be easily installed without any size problems so finally there is going to be except a repair but also some upgrade there ...

its all in the above link .... take a look
 
on the other hand

if you get 3% better sound form psu caps
another 3 % from replacing or upgrade all small electros,then another 3% from changing ceramics with styroflex or other
another 3% by replacing vas miller cap with something smaller and styroflex
another 2% by adding decoupling and bypass where needed
play a bit with zobel and wiring
ground and signal rooting, match and common heatsink ltp stage

you are looking at changes that will change distotrion and performance figures dramaticly up to 20% totally .....

hell this worth trying !!!!!
ofcourse this will require expirience , instruments and time .... but its very possible !!!! cost may be 20 usd and a lot of time ....

this what we do in my company ( among others ) and we have grate fun with it

( just last night finished a 28 years old marantz that performed a perfect square wave for the astronomical frequency of 30 khz !!!!! preamp included !!!!)
 
hi cant thank you all enoughf the amp does sound a bit blured from the one i had about 7 years ago i was going to get some of the caps replaced as i have heard that they do go down and the amp is old but unsure wether to just swop the caps or change values of them aswell i have read that its best to change the main supply caps originaly thay are 4 2200uf and change to 2 6800uf does this make sence as i said i can use a soldering iron and know what different components are but i dont understand the values
 
i there are indeed 4x2200uf caps (please check as i know nad changed these in the 3020i) then rs components have some 3300uf 35v panasonic fc's perfect for power supplys and will fit in the original place no problem.

at the same time try replacing the signal caps, maybe with blackgate n type from hifi collective, you might think these are a little pricey but they are the best you can buy.


thanks
 
Status
Not open for further replies.