Holton - DIY Kit for Stereo HPA-NXV800L R4 Amplifier

[Full Range]

@ghost4man

 

Re VU meters 

You will need 2 of these 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F281404132418

 

And 1 Of these 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F281782123346

 

[ghost4man]

28 minutes ago, Full Range said:

@ghost4man

 

Re VU meters 

You will need 2 of these 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F281404132418

 

And 1 Of these 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F281782123346

 

I'm getting excited!

Hmmm its lucky the better half doesn't frequent these back alleys

 

[ghost4man]

Little bit of engraving

@Full Range

@Aussieamps

@Upfront

@125dBmonster

What do you think guys.

Ozzie

 

 

[Full Range]

Excellent job 

First class build and sexy engraving ?

 

[Upfront]

Very nicely done mate. Your going to great lengths here! I like it!

[Guest]

On 11/3/2017 at 5:04 AM, ghost4man said:

Little bit of engraving

@Full Range

@Aussieamps

@Upfront

@125dBmonster

What do you think guys.

Ozzie

 

 

Just returned from the big smoke Mate, gee @Aussieamps I like that black anodised face plate

 

Excellent work Ozzie, must be getting close to craning in the transformer 

[ghost4man]

@125dBmonster

 

Coming along buddy.

 

Out of courtesy to Anthony I was thinking about continuing the tradition for names and was going to have

something like: EIGHT-ZERO-ZERO, with HOLTON underneath.

In the end I went for what you see in the photo and I am really really happy with the end result.

 

Transformer to come soon

 

 

[Guest]

On 10/22/2017 at 1:27 AM, ghost4man said:

Okay plenty of photos to add here.

Over the last couple of weeks I made the decision to go for the 3.0KVA transformer.

There is a big difference in size but I can still accommodate putting one in. My main motivation however was guided by the fact

that price wise there is only a 50 Euro difference between the 2.5 and the 3.0KVA. No brainer.

To accommodate the transformers I have had to make some modifications to the chassis.

I had a 4mm plate cut to size to add to the bottom plate. 3mm was simply not enough thickness to allow for a transformer

that will be heading towards 18kg in size by itself!

 

The next thing was incorporating a mounting plate which I had cut to size as well. Toroidy do NOT provide mounting

plates for transformers that big.

So I went to a fabricator which specialises in all things aluminium to do the cutting.

 

The mounting plate measures 250 x 250 x 5mm thick.

 

I added the bottom plate and the riveted this with the existing plate together.

The next thing was drilling. To get the accuracy on terms of alignment, I used masking tape to sit the mounting plate on top of the bottom

plate(s).

 

Then more tapping.

 

Once that was done I applied the primer to the aluminium and then finally the top coats. 

All in all it came out really really well.

You will notice in one of the photos the underside to the chassis to give you an idea of how "busy" it is in terms of screws and the

like.

 

If you have a look you will also notice three coupling spacers that are arranged in a triangular fashion. The reason for this is to

spread the weight of the transformer around on the mounting plate now onto 7 spacers instead of 4 only from the corners.

In the final picture you will notice the circle cutout sitting on the mounting plate. That will give you an indication of the size of 

the transformer compared to everything else in the unit. 

I have spent a lot of hours over the weekend gone really just to beautify an area that wont even be seen.

 

There was a lot of work to do in pulling it down, taking the power controller out, attaching the new bottom plate,

riveting together, making sure the mounting plate and bottom plate were aligned, screwing in the coupling spacers from

underneath, reattach the legs all of which required a whole heap of drilling and tapping yet again.

 

All of this leads to placing the transformer on top of the mounting plate, The underside of the transformer has a 10mm 

thread to it. What I will do is come from underneath the chassis up through the mounting plate where I have drilled a 

similar sized hole and then use a bolt to secure the transformer with. By doing this the transformer will be held and pulled

by that bolt hence the reason for the extra reinforcement all over.

 

The the coupling spaces measure 25mm. The reason for this instead of simply securing to the bottom plate is that I am going

to use this created cavity to run any necessary wires underneath the mounting plate and hopefully remain inconspicuous.

Let me know what you think guys.

Getting there. Now to order the transformer now that this has been prepared.

Really cool love the black

[Upfront]

[mention=149865]125dBmonster[/mention]
 
Coming along buddy.
 
Out of courtesy to Anthony I was thinking about continuing the tradition for names and was going to have
something like: EIGHT-ZERO-ZERO, with HOLTON underneath.

In the end I went for what you see in the photo and I am really really happy with the end result.
 
Transformer to come soon [emoji4]
 
 

Looking forward to seeing this transformer!

[ghost4man]

4 hours ago, 125dBmonster said:

Really cool love the black

@125dBmonster

 

Matt I'm not sure if Anthony does a black chassis?? All of the photos I have seen of the builds he has done have all been the

aluminium silver.

[Upfront]

[mention=149865]125dBmonster[/mention]
 
Matt I'm not sure if Anthony does a black chassis?? All of the photos I have seen of the builds he has done have all been the
aluminium silver.

Don't forget titanium. My personal favorite.

[ghost4man]

@Upfront

 

I agree.

The transformer will be the centre piece to the entire system I feel.

 

It will be 3.0KVA and it will be massive. Ultimately I want this amplifier to smoke a lot of high end gear out there when its done.

 

I think everything that I have done so far is putting the best possible foot forward to achieve this goal.

I really believe that Anthony Holton is onto something with this design.

 

As I have said before, find an amp that gives you 800wpc into 4 ohms, ~1200 (if not more) stable into 2 with unconditional stability at the same 

load with stability into 1 ohm, a massive 3KVA transformer, all for well under 3.5k and I would be happy to be steered in that direction.

The only one I can think of is a high caps ME 850.

[ghost4man]

Alright latest stage,

 

I managed to get the power button for the front as per @Full Range 's recommendation.

They are minimalist but I tell you I've seen a lot of high end amps with nothing more special than this.

To put it in will be a chore.

I need to drill a pilot hole. Check, can do

The outside diameter of the thread is 12mm. I have a reduced shank drill bit to do this.

 

Now comes the tricky bit. The front part of the button is 14mm. I need to go in 2mm to create a housing for it to sit on and then go in

with the 12mm to push it through. Either a drill bit or router bit?

 

Now the bolt is 65mm with a 10mm and high tensile. Why use one. Well the shipping weight for the transformer is just shy of 25kg.

 

Yep thats no typo. Its going to be big and very heavy by itself. It comes in from under the bottom plate and will go through the mounting

plate as depicted in the photo.

[Upfront]

Alright latest stage,
 
I managed to get the power button for the front as per [mention=112724]Full Range[/mention] 's recommendation.

They are minimalist but I tell you I've seen a lot of high end amps with nothing more special than this.

To put it in will be a chore.

I need to drill a pilot hole. Check, can do

The outside diameter of the thread is 12mm. I have a reduced shank drill bit to do this.
 
Now comes the tricky bit. The front part of the button is 14mm. I need to go in 2mm to create a housing for it to sit on and then go in
with the 12mm to push it through. Either a drill bit or router bit?
 
Now the bolt is 65mm with a 10mm and high tensile. Why use one. Well the shipping weight for the transformer is just shy of 25kg.
 
Yep thats no typo. Its going to be big and very heavy by itself. It comes in from under the bottom plate and will go through the mounting
plate as depicted in the photo.

Not necessarily for what your doing here but these are handy bloody things....
https://www.bunnings.com.au/p-n-4-25mm-hss-metric-drill-bit-step_p6350059

[Jventer]

1 minute ago, Upfront said:

Not necessarily for what your doing here but these are handy bloody things....
https://www.bunnings.com.au/p-n-4-25mm-hss-metric-drill-bit-step_p6350059

I use one since I saw a guy building a steel deck platform using these things.

[ghost4man]

@Jventer and @Upfront

I'm thinking thats an excellent suggestion.

Will get plenty of use out of that actually. 

 

Thanks guys.

 

The transformer has me a bit worried. I'm hoping what I have prepared thus far will do. At more than 20kg it will be the heaviest individual 

component. Perhaps I need to make the mounting plate 10mm instead of the current 5mm. Hmm not sure. Will wait and see how it feels

when put on.

 

I'm definitely using the split washer underneath the bottom plate to give greater surety in connection.

[Full Range]

I like the switch with indicator light - it’s good to have a visual que if the amp is on from a distance 

 

That drill bit mentioned above is great 

I have used a set for many years @ghost4man

Some care is needed as you push down - to much and you go past the size required 

Have a look at the photo I posted and notice the blue tape on the drill bit 

I use that a guide to slow down and take care at the desired hole size 

 

? Keep up the good work 

 

[ghost4man]

@Full Range

Thanks mate. Plenty to choose from on ebay in the 3 piece sets. 

I think I have had a need for this tool the last 20 years

 

 

[ghost4man]

Okay so today I got a little surprise in the post.

 

Actually it was a big surprise.

 

I am not going to make any comment for now other than to say that words do not do justice.

Edited November 30, 2017 by ghost4man
Add photos

[Upfront]

Okay so today I got a little surprise in the post.
 
Actually it was a big surprise.
 
I am not going to make any comment for now other than to say that words do not do justice.

Yep. That's large!

[joz]

12 hours ago, ghost4man said:

Okay so today I got a little surprise in the post.

 

Actually it was a big surprise.

 

I am not going to make any comment for now other than to say that words do not do justice.

Excellent,Looks great!

Though you'd better hide those wires.

 

[Guest]

Shaping up to be 1 mother of a power amplifier. 

Good work Ozzie

[Full Range]

 

 

13 hours ago, ghost4man said:

I am not going to make any comment for now other than to say that words do not do justice.

 

I will put some words to it 

 

“Ohh My “

 

[Aussieamps]

Looking Good Ozzie!

 

[ghost4man]

13 hours ago, joz said:

Excellent,Looks great!

Though you'd better hide those wires.

 

Hi @joz

 

For clarity there is a reason why the wires are like that.

I have had to do a modification today. Basically the space between the mounting plate and bottom of the chassis

is too narrow. 

I have doubled it from 25mm to 50mm.

The reason for this is evident in the photos. Those wires that come out are thick and extend 35mm from the base of the transformer.

 

I have the toroidy positioned upside down because the 12mm holes I drilled into the mounting plate are still too small to push the wires

through!! Yep that big.

 

Once I get my hands on a step down drill I will have to make the holes bigger.

 

To get some perspective on the size here a Sanders Magtech I believe weighs 25kg in total. That is the weight of the toroidy that you see

in the photo!

At the minute I am estimating that this amplifier will be over 45kg and possibly hitting the 50kg mark. This is a DIY job.