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Courtiestown - Naim Amplifier (Avondale) Upgrade Project

Alan,

What is wrong with using an LCR meter for testing capacitors???

I'll be using the TeddyReg's for the front end supply on the NCC200's.

Regards

Richard
 
Mike,

There is a LM3*7HV which can, at a pinch, go to 60V. I'll be guided by such as Martin on this.

My thinking is that I don't need to push the NCC200 to the limit as I have 10 channels of amplification driving the Isobariks so maybe pull back the rail voltage?

This is the version of Teddy Pardo's FE regulation I plan on using:-

jVTZeke.jpg


Both D1 and ZD1 will be 1N4004's. Now to brush up on rusty Stripboard skills.....

In response to Alan's earlier query, I'll be using the above circuit in the same was as Teddy Pardo did and posted at the time:-

Sig8jfV.png


Courtesy of information supplied by Reg Horne I have this updated version but not yet found it posted:-

e5iV6Zr.png


The former, simpler, version looked like this:-

IVMh4Mb.png


and applied like this:-

mRqxD5t.png


Regards

Richard
 
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GWM said:
Why not just use the hackernap front end reg, proven and used by many on here.
Click to expand...

Wot like these?

fVP0if7.jpg


OK so four of these are populated with larger capacitors than recommended for a front end supply but it is an option.

I have yet to take the lid off my first NAP250 but I know space will be an issue. Yes the Naim PSU capacitors will be coming out but I need to find room for a Cap6, a SSM2, and a Velleman 4700. Going the HackerCap route means I'd have to find room for a suitable transformer in addition to the HackerCap PCB.

Two 'small' bits of Stripboard will take up considerably less space?

I'm open to any and all suggestions.

Regards

Richard
 
The CAP6 is synonymous with the HackerCAP, not the HackerNAP.

The HackerNAP is an amplifier board, somewhat like an NCC200. I've had no experience with them myself, but according to GWM's message, they include some type of input stage supply regulation. The Avondale NCC300 has input stage regulation, but the NCC200 and NCC200/QUDOS modules do not. (That's what the VBE is usually for.)

As for the HackerNAP moniker, I'm assuming the NAP alludes to a Naim amp module NAPA (Naim Audio Power Amplifier), but was shortened to rhyme with the pre-existing HackerCAP.
 
Mike
I think what GWM was meaning is if you had a couple of Hackernap boards you could use them just populating the Reg sections and ground.
You could cut half the board away and just use it as a reg board?
Or populate the whole thing and do away with the NCC200
Or use a couple of VBE boards with the NCC 200

Alan
 
337alant said:
Mike
I think what GWM was meaning is if you had a couple of Hackernap boards you could use them just populating the Reg sections and ground.
You could cut half the board away and just use it as a reg board?
Click to expand...
Yeah, I suspected that was the implication. I was ensuring that Richard realized that a HackerNAP is not a HackerCAP. :)

Given he wants to fit a stereo amp into an Naim NAP250 case, he's limited for space. He can easily fit the SSM on its side, and a CAP6 or HackerCAP can replace the bridge rectifier and big pair of caps. Fitting the Velleman board is going to be tight. I don't think he has much extra space for additional regulation.

Also, the NCC200 needs its input stage voltage as high or higher than the output stage, and regulators have a voltage drop. He definitely doesn't have room to add another power supply for the front end, to get that higher voltage pre-regulation.

Yes, he could switch to HackerNAPs, but he's already got the NCC200 boards, and he seems to want to go that direction.
 
Good Morning All,

Apologies to GWM I misread his post concerning using the HackerNap, you'd think the reference to FE regulation would have been a clue!!!

I have elected to go my current route with the NCC200 because I want the self build involvement. There would be nothing stopping me going further at some point in the future even if that then meant re-casing the amplifiers. I don't think there is much stopping a NCC200v1.5 PCB being 'modified' to perform as a NCC220???

In the meantime I dragged my quite old Dell Inspiron 6400 laptop out last night to use the old copy of LochMaster3.0 to create this:-

gwB0KkM.jpg


This is only the first draft as, depending on space, I might have to lay the LM317T down. The 2k7/ 2W resistor is to provide a constant load to keep the regulator 'triggered' (proposed by Martin Clark), I'll obviously need to see what heat develops in the regulator and resistor.

Regards

Richard
 
Yea I was referring to the built in FET based VBE on the Hackernap designed to feed the front end, the rest of the board is based on the NCC200 using the same parts values but obviously a different board layout.
I have a pair of Hackernaps and compared it directly to a version 4 Voyager I built, the Voyager is better but not by that much, I have NCC220 in the voyager now and that is a good improvement.
 
Good Afternoon All,

I've now taken the lid off my unserviced NAP250 and had a look see. It's one thing seeing it as a picture on a forum but that doesn't tell you everything.

OK so lots of people will know what the inside of a NAP250 looks like:-

0cgY55M.jpg


I can see no reason why all four boards can't be moved approximately 4cm to the left???

Next up is the difference in length between the Cap6 and the HackerCap, this amounts to circa 3cm:-

Qm3ddyg.jpg


Theoretically that creates a potential circa 7cm wide space which could, I say could, potentially accommodate a transformer to power a VBE. Can anybody advise the size of transformer I believe LesW can supply?

The next question would be "Where are you going to put the VBE PCB then?". A fair question but there is, I think, a possible solution. Take a look at this next photo:-

fFtsiS2.jpg


There is a space under the regulator and power amplifier PCB's. The overall height of the NAP250 internal space is circa 61mm. A NCC200 stands at 44mm and the existing space is 19mm high so this could be increased to a maximum of 36mm by using an (aluminium) spacer under the NCC200's. A VBE could fit in this space?

I have to ask a question here about exactly how much power the FE of a pair of NCC200 requires i.e. do you need a 50VA transformer or a VBE with a pair of MJ15003/ 4 output transistors???

It might be easier to fit a pair of SuperTeddyRegulators instead??????

Nearly forgot the one other board - the Velleman 4700. It is a tight squeeze but it does fit along the back panel. There is room to move the regulator and power amplifier's toward the front a few mm to improve things here but, again, this could fit under the power amplifier PCB's if raised?

rwHiVCd.jpg


Regards

Richard
 
I have yet to take the lid off my first NAP250 but I know space will be an issue. Yes the Naim PSU capacitors will be coming out but I need to find room for a Cap6, a SSM2, and a Velleman 4700. Going the HackerCap route means I'd have to find room for a suitable transformer in addition to the HackerCap PCB.
Click to expand...

The NAP250 is a fully regulated amplifier so the obvious choice would be the HCR 200 / NCC200 which LesW designed as a drop in replacement and you already have so it would be a straightforward replacement, you could change the 2 large power supply caps with a cap6 if the case height and space permits ?, you may be able to get the Vellaman in there
IMHO you don't need a SSM the velleman will give you a switch on delay that will overcome the switch on thump.

Alan
 
I'm with Alan on this: use the HCR200 if you want it to be a stereo amp.

As for the VBE, even if you could squeeze it in there (remember it needs a head spreader too). The transformer I got from Les is about 9x8cm. Also you forgot about the rectifier and smoothing caps for the VBE. You really don't have space!

The Velleman is more important than the SSM, but the SSM takes up very little space, so I would include it. Some people feel a slow blow fuse is just as good as an SSM, and they may be right. However, the SSM can also monitor a thermal shutoff switch, which I've started to include in my builds.
 
Good Evening All,

I was hoping to avoid the build it from scratch option........................ but as it has come up let's look at that.

A quick look at a well known internet site shows the average price for selling an olive NAP250 is £1025 out of which you're going to 'lose' some 13.5% in 'fees' so call it £885 per unit.

Assuming I'd want to be fitting:

1. 2 x NCC200v1.5
2. 2 x HCR200
3. 2 x CAP6/ HackerCap
4. 1 x VBE (assuming this would power the FE of 2 x NCC200's???)

Looking at the modushop pages I'm thinking that the https://modushop.biz/site/index.php?route=product/product&path=210_272&product_id=453 would maybe do the job or do I need to go to a 3U case??

I'd obviously need to look into how much Les want's for a suitable transformer(s).

Then there is the IEC mains socket, XLR input socket and some decent 4mm banana speaker sockets, mains on/ off switch............

Regards

Richard
 
I Have a spare transformer from this group buy, pm me if interested
Amplifier Transformer Group Buy | pink fish media
This was the final option chosen

Continuous power rating: 818VA
Primary: 0-230/240/250v @ 50Hz
Secondary 1: 35-0-35V @ 5A rms - 350VA
Secondary 2: 35-0-35V @ 5A rms- 350VA
Secondary 3: 42-0-42V @ 0.7A rms- 58.8VA
Secondary 4: 42-0-42V @ 0.7A rms - 58.8VA
Secondary 5: 0-12 @ 1Arms 12VA
Plus
Electrostatic screen
GOSS band
Dimensions: approx 175x75mm
Mounting: M8x30mm bush
In a potted centre,
Heavy gauge lead outs 300mm long
Alan
 
If this is a stereo amp, then you need two VBEs, not one. The transformer for it needs to have dual center-taps (one for each channel), two rectifiers, and two sets of smoothing caps.

I hate to bang on a drum here, but even if you can jam all that stuff into a single case (which I don't think you can do), you'll never get it wired up. And you'll be plagued with ground loops that you'll never resolve.

Even a mono Voyager almost fills that size of case. Here's an interior shot of one of mine, and I don't have an HCR200 in there:

https://avzine.com/images/voyager/inside.jpg
inside.jpg
 
Not sure what your trying to achieve here, if you have Les's new regs as well just drop them in with the NCC200, no need for the cap6 job done.The voyager is a different concept are you trying to create a new beast with a regulated front end and a separate regulated outlet stage, that's not necessary as the outlet is best unregulated.
You could use the new reg to just power the front end, probably better than the VBE but regardless of wether you can fit a separate power supply you may have too much voltage from your existing transformer to run straight into the outlet stage.
 
Good Afternoon All,

I have just gotten off the phone from speaking with LesW whom I was speaking to in order to get a 'sense check'.

In the first instance I will convert my existing Naim amplifiers simply by replacing the existing boards with Avondale and replacing the banked capacitors with a CAP6 . I will attempt the Teddy Pardo modification above on the first of these and the rest accordingly.

I will also build a separate amplifier with everything that can be 'thrown at it' as a stand alone project as a comparison to one of the above more simply converted amplifiers to see if the costs are 'justified' in terms of improved performance. As LesW says the laws of diminishing returns.........

I am a little clearer in where I'm heading.

Regards

Richard
 
Good Morning All,

Thought I 'd start off with something simple i.e. the Kelleman 4700 unit. Fairly straight forward, only the one incorrect resistor placement......

cowGuRt.jpg


and for the OCD amongst us I got R11 the 'wrong' way around..........

On the subject of the 47uF tantalum capacitors I have and have been bought by others and installed in their builds I am genuinely intrigued as to what exactly they are.

BQdPmJj.jpg


We bought a job lot as being 'wet' tantalum and quite a few were dumped when we received them as they had 'leaked' in the trays containing them. I know nothing about tantalum capacitor manufacture but the fact they leaked 'confirmed' to me that they were 'wet' insofar as they contained something not dry or solid. They are solid cased at the one end and crimped at the other with a sealant 'plug' at the other.

There are qualified EE's out there on this forum whose opinion is going to be more 'valuable' than mine - so what exactly are these capacitors?

As I continue to work my way through all 765 pages on the D.I.Y forum I was minded to look out for the 'original' recommended C6 a Vishay 68uF/ 25V which is CTS13 series device - none of the major suppliers have any in stock but a well known internet auction site has - https://www.ebay.co.uk/itm/15440435...d=link&campid=5338728743&toolid=20001&mkevt=1

Which only works out at £4.10 an item after import..........

Regards

Richard
 
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