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Posted
  On 29/01/2016 at 7:44 AM, Ozcall said:

Just finished re-purposing my Lampizator Amber board for use as a line stage:

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i bought the Amber board when it was on sale for 125 euro and added Deuland cast output caps and a Full music 274b mesh plate rectifier.

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I am using my DIYHIFISUPPLY electronic volume control in passive shunt mode to drive the Amber gain stage.

Sound quality : Well it has only been playing for a couple of cd's but it sounds better to my ears using the volume control in J-FET  buffered mode.

Case is temporary until I can afford a new one that will house both the Electronic VC and the Amber board.

Explanatory schematic?

 

Cheers, Owen

Dark Lantern blog - http://darklanternforowen.wordpress.com/

Posted (edited)

The Holton project is ready to power up. :) Should be Ok. Twin supply dual mono, with on switch and 12v trigger on.

 

2 holes to drill for protection operate and on LED's in the front panel (orange and green), glue them, wire and bolt final check

2 holes to plug in the back and bolt the lid on.

 

Use a globe in series on first start. 

The Amp will then meet it's maker, Anthony in Launseston, so as the final Amp bias is set properly.

 

Edit, note, for interest this one has been wired in solid core copper from the IEC to the speaker terminals, stranded 2.5mm for earth, hi temp insulation on 99% of them including teflon 75ohm silver mil spec coax

A few other features, current limit start, timed on and a dc detector on the speaker +

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Edited by Guest
Posted (edited)
  On 04/02/2016 at 12:06 AM, PonyTail said:

@@125dBmonster Take a close look at your power on relays.... as I have seen many times before they are rated for 120VAC NOT 240VAC !!!!!!!!!!!

 

Jusy sayin...

Hi, yea, no worries, Ill check that with Anthony Holton on that one, well spotted.

I would assume them to be correct, but assumption is the mother of all mistakes in Electronics.

 

Sadly I have no schematic diagram.

 

 

PS AND EDIT, Have made inquiry to Holton Precision Audio for clarification, the thing owes me well over 2 grand so, going to wait, before the smoke genie comes out.

This is my first amp build other than some easy stuff for work and basic little projects, I solder Ok though and have enjoyed this project very much.

And, yes the relay had been touched with the iron tip, bugger, it's only the corner and the size of a pin head the mark. Didn't notice it until I took a picture.

 

Part of an Email, Anthony is a great guy to deal with.

Hi Matt

 

I get asked this question every now and again.

Despite the printing on the relay's they are actually rated at 380VAC.

Here are the specs

Max voltage:380V AC, 75V DC

Max current:30A

Max VA (Watts):2400VA (360W)

Contact material:Silver Nickel

Coil resistance (24V):360 Ohm

Max coil power:1.6W

Insulation resistance:>100M Ohm @ 500V DC

Dielectric strength (for 1 min):

1000V AC between open contacts

5000V AC between coil & contact

Electrical life:100,000 operations

Mechanical life:10 million operations

Dimensions:˜25W x 20L x 20H mm

Fully sealed construction (immersion cleanable).

*Specifications are subject to change without notice.

Your amp looks good BTW, good job on the build!

Look forward to catching up with you.

Edited by Guest
Posted
  On 04/02/2016 at 12:06 AM, PonyTail said:

@@125dBmonster Take a close look at your power on relays.... as I have seen many times before they are rated for 120VAC NOT 240VAC !!!!!!!!!!!

 

Jusy sayin...

120V @ 1A or 240V @ 0.5A

Posted

120V @ 1A or 240V @ 0.5A Where did that come from? in any case it is too low a rating for this amplifier.

 

The relays used are readily available in 120VAC but can be a little harder to find in 240VAC/277V. 

Posted
  On 04/02/2016 at 3:42 AM, PonyTail said:

120V @ 1A or 240V @ 0.5A Where did that come from? in any case it is too low a rating for this amplifier.

 

The relays used are readily available in 120VAC but can be a little harder to find in 240VAC/277V. 

Please read edited post above, the relay "actual specifications" are there in detail. Have no reason to doubt otherwise now.

Thanks for pointing out the possible issue, appreciated, thanks Man.

Posted (edited)

It is a little evil but that Holton's burn in will be driving a pair of Maelstrom X 18" subs in a 400 liter sealed enclosure.  :D 4 ohms per channel.

Edited by Guest
Posted (edited)
  On 04/02/2016 at 1:15 AM, 125dBmonster said:

 

Despite the printing on the relay's they are actually rated at 380VAC.

Here are the specs

Max voltage:380V AC, 75V DC

Max current:30A

 

Those are 460W devices and, if those are 500W transformers, they are right on their maximum rating of 1.9A at 240VAC. Top right curve below.

 

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However, for a home audio device, not worried. They would fail in service on a hard-working pro amp, though.

 

[P.S. the curve shows why they are marked as 120 VAC: that is their safe max current (5A) rating, and above 120V they are de-rated for current.]

Edited by Newman
  • Like 1

Posted
  On 04/02/2016 at 4:26 AM, 125dBmonster said:

It is a little evil evil but that Holton's burn in will be driving a pair of Maelstrom X 18" subs in a 400 liter sealed enclosure.  :D 4 ohms per channel.

 

LOL, exactly the sort of stress test those little $2 relays aren't built for. :) 

Posted (edited)
  On 04/02/2016 at 4:31 AM, Newman said:

Those are 460W devices and, if those are 500W transformers, they are right on their maximum rating of 1.9A at 240VAC. Top right curve below.

 

 

Even if they are large transformers .... that graph is of the switching current so unless you're trying to turn the amp on/off exactly under full load transient then things should be quite a bit below that rating. That's all about being able to extinguish the arc when making or breaking contact.

 

They would however need a soft start or the transformer inrush current would become an issue.

Edited by hochopeper
  • Like 1

Posted (edited)
  On 04/02/2016 at 6:13 AM, mwhouston said:

I feel these are right for this amp. We are no sure exactly how and where they are being used.

Yes we do. You can see the output of the board runs to the transformer. The only device likely to be switching that line is the relay, that part of the circuit is not exactly hard to puzzle out! The relays are in series with the active conductor between the IEC socket and the transformer.

 

I believe the most recent version of that design has a current limiter circuit to address transformer inrush - http://holtonprecisionaudio.com/collections/ac-mains-controllers/products/hpa-power-one-mains-controller-r3-0-with-high-powered-ac-mains-limiter

 

Can see thermisters in the photo of the unit. 

 

Just depends what version @@125dBmonster has. I have one of the earlier versions but I use it with SMPS and 2 x 50VA transformers so no inrush issues.

Edited by hochopeper
Posted (edited)

Notice the iron core chokes on the Tannoy top of the range speakers - Kingdom Royals - are the same as Jaycar sell and I have used, 9mh

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Edited by mwhouston
  • Like 1
Posted
  On 04/02/2016 at 4:31 AM, Newman said:

Those are 460W devices and, if those are 500W transformers, they are right on their maximum rating of 1.9A at 240VAC. Top right curve below.

 

attachicon.gif4120Contact rating.JPG

 

However, for a home audio device, not worried. They would fail in service on a hard-working pro amp, though.

 

[P.S. the curve shows why they are marked as 120 VAC: that is their safe max current (5A) rating, and above 120V they are de-rated for current.]

 The Harbuch transformers are 625va and I believe you are right about the ratings although I believe this is a "trusted" power controller. This Amp probably won't see a pro gig  :) Just a really nice little 200w high current A/B mofset Holton, power for most medium sized floor standers. If it is as nice as the 6 channel Holton I have I'll be really happy, was built to be a small sub amp.

Posted (edited)

First proper electronics build doesn't go without finding a mistake and fixing it before start up, in this case transformer secondary connections :wacko:   :unsure:, lucky

 

. Power up didn't go well traced to a faulty extension lead socket I had it plugged into, scratching head for while :confused:  amp did all sorts of weird things, didn't panic  :(   So over to the old Clipsal double pole power outlet (trusty never fails).

 

Power on, green LED on controller, Push button, green and Blue LED up for 3 seconds and relay operation, all green LED's on amp modules, blue LED off. Did a few volts checks were Ok 68vdc + and - on the amps. Behave you Amp. Switch off Ok, wait for LED's on Amps top go off, 4 minutes, green LED on control module still up. Another start up same again noted dim green LED on front panel works, I also know the orange protection LED Works as well as I saw it up when I had problems.  LID ON  :party

Tomorrow, it plays music into some Compression Drivers for test then on to bigger things.

:rolleyes:  :cool:

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Edited by Guest

Posted (edited)

Just read in Stereohpile you can purchase a US$12,000 Nordost phono cable to run from you TT to preamp. I wonder if they come in a variety of colours. Should the wife be wondering what to buy you for a birthday or Xmas gift, suggest this "must have" cable.

Edited by mwhouston
Posted
  On 04/02/2016 at 10:33 PM, mwhouston said:

Just read in Stereohpile you can purchase a US$12,000 Nordost phono cable to run from you TT to preamp. I wonder if they come in a variety of colours. Should the wife be wondering what to buy you for a birthday or Xmas gift, suggest this "must have" cable.

Like a Ferrari, comes in any color you want, red.  ;)

Posted

If anyone is interested I have dropped the price of the new DIY 180W Tripath T4 amp from $750 to $700 + postage. The amp went up for sale on the site a few weeks back. The FS post is still up.

Posted

@@awty New Holton Amp is tested and 100% completed, sounds lovely so far.

:)

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