NCC200 GB Build thread

[S-Man]

TBH non-powered fault finding is tricky, it's often hard to interpret the readings without removing some transistors. Therefore, you another approach in to lift one end of the feedback cap (so you don't damage it with the excess voltage), the amp will still bias up properly, although it will not amplify any audio. Then you can go back to powered fault finding - especially if you have the safety resistors fitted.

If you want to go this way:
1st check the voltage across the 68uF across TR5 - if it's >6V power down and remove it!!
2nd, write down on a schematic the dc voltage on every node in the amp (all relative to 0V) and post it on here.

Option 3: Remove all the transistors and polarised caps. Measure all the remaining components in situ and then replace all the trs and polarised caps with known good ones.

 

[shoom]

Thanks again Dave and Toni

We almost have a fault finding menu for others to follow should the need arise.

From my hazy memory of reading through the Hackernap build thread one other thing that seemed to take a beating and need replacing quite often was the bias trim pot. if I remember correctly that burning out created some pretty strange measured results.

So that may also need checking just to be sure.

but the advice is really useful so I'll move it to the ref section in post 3 if that's OK with you.

Nearly there Alex just a few more steps

keep us posted Toni

 

[Chops54]

BTW, this thread seems to be a 2 man show now. Where's everyone else???

Unfortunately I have more pressing matters to deal with right now but I'm not far behind you.

 

[Meirkat]

BTW, this thread seems to be a 2 man show now. Where's everyone else???

Were all busy building - I guess!

 

[shoom]

Were all busy building - I guess!

Great

keep us posted on you progress

 

[sonus]

http://imgur.com/a/hK76Q
ncc200 album
happy building

 

[Marra]

Nicely done Sonus.

 

[shoom]

Great build sonus.

Superb fit and finish.

How's it sounding?

 

[alexbaxterca]

Sonus, that looks a sweet build. What is your full set up in your system pic..... I can see the Hicap (I think) but not sure what its hooked up to (or is it a phono stage)?

It looks like you have a very similar case to me. How did you go about machining the rear panel for the plugs? And the front panel for the switch etc?

 

[shoom]

Hi Alex

you have mail.

Ohhhh the joys of metal work

I usually buy in a couple of boxes of sticking plasters before I even start.

I start by applying some low tack masking tape to the surfaces before marking out. Then the first mark out is in pencil which can be rubbed out if needed. when i'm happy with things I re-mark in fine tipped marker pen.

That part I don't mind so much.

But the next bit is usually done with plenty of errrrr well you know the drill.

The 3mm back plate is not so bad. I usually use a pillar drill with the appropriate sized bit for the plugs and sockets that I have. For the mains inlet it’s drill, coping saw and file to fit.

The 10mm front plate is a whole different thing and if that switch is the same as mine it’s an 18mm hole. I’m not so good with metal so I bodged it with a pillar drill/step cutter and then just file to fit.

I’m sure that there must be an easier way.

My fingers won’t take to much more.

Please let me know the secret.

 

[sonus]

Hi all
Switch in question is Shurter MSM 22 LA (22mm latching 250v) and I confess someone else not me did the front panel work.
Standard building into a 2U 300mm deep dissipante Modu case with heat spreaders bolted to sides with 2 M5 stainless screws. As you can see space is tight so I advise to go for 3U cases 400mm deep or slim line 350mm deep to avoid problems.
Shaun is right on the metal work and it's how I did bottom and back panels. The secret is go as slow as you can and take your time thinking twice.
Almost a week from final assembly but few listening hours since so it's time to spin some records. Before someone asks dc offset 23mv right and 17mv left, input caps are Wima mks4 10uf 63v.
Good listening

 

[shoom]

Hi Sonus

''Shurter MSM 22 LA (22mm latching 250v''

haa I have the momentary push version for my relay driven on/off and it is indeed 22mm. I was not so easy to make a hole of that size into 10mm with just DIY tools and my fingers still ache thinking about it.

As you say ''slow and patient usually gets the job done''

It’s a great build into a tight space.

Those are nice DC offset results BTW. Good work.

Did you re-drill the spreader and tap the sink to allow side mounting?

 

[sonus]

Hi Shaun
Yes that's right, drilled the spreaders vertical sides (2x 5mm holes) then tapped the sinks but I should add do exactly the opposite to allow for an easier access to the boards later, unscrewing from the outside of the case.
I'm getting used to the bump absence at present thanks to the Vellemann k4700 and I like the very low noise floor (hiss through speakers) of the ncc200 compared to the napa boards. Now let's see how far it reaches in musical terms.
Regards

 

[shoom]

''Now let's see how far it reaches in musical terms''

keep us posted.

 

[shoom]

Hi Toni

any news?

 

[Spider]

Hi guys
I've received my pack of parts and boards all very well packed (thanks Shaun)
I've been reading this and many other build threads and trying my best to get my head around the whole building my own amplifier thing and I'm coming to the conclusion it is way over my head and there is so much that could go wrong.
In truth I don't know a capicitor from a transistor and any of the other parts needed are a complete foreign language to me.
I've heard some NCC's in my system and loved them that's why I jioned the GB thinking I could make some but I don't think I could.
So here is the thing.
Is there anyone who has enjoyed building theirs who would like to help me by building mine?
I know it's a big ask but you would be helping out a enthusiastic hifi fan who would just love some NCC's in his system.
I've got two nice transformers and the parts Shaun sent me the rest I'm willing to pay for I just don't know where to start.
Anybody willing to help.
I live near chesterfield if anyone in area is willing to help me.

 

[Pete MB&D]

I think Les W has made a few, he is in Chesterfield.

Pete

 

[shoom]

Tim

you have PM


I think Les W has made a few, he is in Chesterfield.


Sounds like moonlighting to me.

 

[LesW]

Hi guys
I've received my pack of parts and boards all very well packed (thanks Shaun)
I've been reading this and many other build threads and trying my best to get my head around the whole building my own amplifier thing and I'm coming to the conclusion it is way over my head and there is so much that could go wrong.
In truth I don't know a capicitor from a transistor and any of the other parts needed are a complete foreign language to me.
I've heard some NCC's in my system and loved them that's why I jioned the GB thinking I could make some but I don't think I could.
So here is the thing.
Is there anyone who has enjoyed building theirs who would like to help me by building mine?
I know it's a big ask but you would be helping out a enthusiastic hifi fan who would just love some NCC's in his system.
I've got two nice transformers and the parts Shaun sent me the rest I'm willing to pay for I just don't know where to start.
Anybody willing to help.
I live near chesterfield if anyone in area is willing to help me.

Hello young man,

Please feel free to drop by for a coffee and a chat should you need some help

I'm on 01246 200096 - 07909 546976

Rgds, Les

 

[molee]

Hello young man,

Please feel free to drop by for a coffee and a chat should you need some help

I'm on 01246 200096 - 07909 546976

Rgds, Les

That is pure class. Anybody else thinking of upping sticks and moving to Chesterfield? I look on these GB threads with a sense of awe, yearning and total bewilderment.