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Destroyer x Amplifier DX HDII version.

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Excelent work Nordic .... much more than i always hope....you are great

Despite all that can be good for you health..... menthal health in special, as we feel good cooperating with folks.... love is always the answer... so easy... so easy to feel good when we do things for others, without any bigger interest than to see people happy and smiling.... this is an enormous payment, despite people do not realise that.

I really think, dear Nordic, next group buy.... a second package that will happens when those folks construct, publish their findings, reviews, comparisons, personal evaluations, pictures and all stuff.... if no bad surprises appear.... for sure a second package will happens and should give you a small return.

The price is very small.... i really think, to the second package you should include some small and discrete profit, kindly inserted into the cost price....not fair to bother your lovely wife working this way... without no return... at least some small profit that would produce some flowers to her would be great.

Give flowers to her dear Nordic....but be carefull.... all flowers i have offered, or sent to my wives resulted in one more son...ahahahahaha.

Flowers are great... you should think about my suggestion.

I wish i could give you a Hug dear Nordic.... you deserve a nice and warm hug.

You made very well.... job very well made... i think you are able to manage boards to many group buys, to many projects...you are going to details, those supply voltage terminals.... those small details are lovely...everyone loves those things...this is excelent.

I must say what is going on inside my heart.... i also cannot wait to receive the boards you are sending me... thank you very much..... this Christmas i will have a nice gift from you.

Please, post pictures during your construction.... they are good to see....let me enjoy together you.

regards,

Carlos
 
Hi Nordic,

The DX HRII PCBs have arrived in Australia !!! in perfect condition.

You must own shares in plastic bags and sticky tape companies. It took me half an hour to cut through the packaging. 😀

I really appreciate your efforts, many, many thanks.

BTW: Karma is the best reward.

regards
 
Thanks for the update Greg, Yeah , I don't feel like haveing the customs fools mess with stuff and drop components. Your package was a test mail and went off about a week before the next parcels, so everyone else, please don't get excited yet... yours should take at least a week longer.

I just completed assembly and installattion of my new boards, it is playing now and I'm speechless.

Bob, you can order here securely ... https://www.dxamp.com/catalog/
 
Hi Nordic,
From DX's original thread:

I think those ISC transistors do sound better than the Toshiba ones.... lucky find.

I was about to buy Toshiba's power transistors from Ampslab.com ...where did you find those ISC again, please?

IMHO, a power transistor and a small capacitor bag offer would be welcome :angel:
Yeah, I feel lazy approaching the end of the year 😀

Cheers,
M

PS: about the profit "controversy", don't feel guilty, as it is perfectly ethic to earn a reasonable income for a work well done...and I'd prefer anytime to send money to a good man (and good friend) instead to a large multinational company 😉

PS2: Karma (Sanskrit: kárma, kárman- "act, action, performance")
 
I got them localy from one of my suppliers... If you can get real toshiba's go for them, I still suspect mine not to be authentic...

Main reason is we don't know how durable the ISC transistors are in the long run... I will see if they can last a month or so, once our summer heat sets in.... If today's measurements are reasonable, then I expect heatsink temperatures around 50C once we hit those 40C+ days....
 
Wow Sheldon, I needed a bit of a pickup, not been my day these last two days.... mom was diagnosed with cancer again and I made a little booboo which is going to set me back $300 etc... **** normally happens in 3s, so I am keeping a low profile now 😛

Please use the 18R resistor and a parallel inductor if you are not 100% sure your speakers are very easy loads... and test with a cheap speaker first... now that you guys are starting to get your stuff I will have to squeeze in a few minutes to update the construction details on the site...

DJ my bra, hit the e-mail button under my name, I will let you have boards at a bit cheaper than the website as we avoid creditcard transaction charges etc... I estimate about R150 includeing overnight shipping for a set... although I am still 4 sets behind in shipping... so it will ship overnight, but not neccesarily be ready in one day... I picked up extra parts yesterday... so if you are interested in the kits just drop me a note as well.

Each set requires two quad sets of matched input transistors so that is 8 transistors to be finely matched, then there is matching

Then transistors that are not in pairs like in the VAS need to be matched so that the two channels are matched etc... it is ALOT of work... and at the current priceing a basement bargain... not to mention the matching of resistors etc... it could only be done to the quality levels of my cheap meters, but it is still done and still takes the same amount of time...

If you ordered transistor kits, you will noticed that they are grouped in 2s 1 pair is for left other for right...
 
Re: BIG power trannies on eBay for your HRII

Francois G said:
If you are in the US and need a power transformer for your Dx HRII (and maybe HRIII) take a look at the item below on eBay.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=290184977330&ssPageName=STRK:MEWN:IT&ih=019


Toroid International model TI-043222C Power Transformer (1KVA)
2 outputs of 29.6-0-29.6VAC each from 100/120/240 VAC in.

No connection except that I plan to use it in a souped up HRII

Best regards,
Francois

I wonder how suitable these are with given that they are meant for 50hz operation....
 
Good question

Thanks for pointing out the potential problem. Buyers beware!

That said, I'm not concerned. It's specified as 1KVA transformer, so it should be able to provide, even at lower efficiency, the needed 500 watt or so. Additionally,

My understanding is that a transformer with a core designed for 50 Hz will work well at 60 Hz (have higher inductance?). The other way around is where one should should be concerned (a 60 Hz transformer may not work according to specs if used at 50 Hz).

I'm not an EE so others please comment.

Regards,
Francois
 
Remember to tweak the rail regulators zener diodes when using higher voltage than the

normal 35 to 37 volts suggested.

The rail regulators produces a losses that goes from 2.5 to 5 volts DC to each rail, so, the zener are there to produce the needed reference voltage.

Using higher rail voltages (no problem) you will have the need to increase the zener or, at least, to introduce Led in series to provide increasings of reference voltage.

The use of lower voltages than the suggested will turn the rail regulator unefective... they will need tweaking to loose 2.5 to 5 volts, each rail, refered your selected supply voltage.

The amplifier will work from 15 volts (stable) to 42 volts without any modification.... bigger than 42 volts will need some small tweaks, for instance, the 12V zener diode feeding resistance.

If you decide to big voltages, remember that you will need more output power pairs too.

Also, you can remove the rail transistors and install resistances from colector to emitter, calculated to produce the needed loose of voltage to separate the input from the output... the thread has details about that some pages ago....not only about supply voltage increasings, but also, even older post, about how to calculate the rail regulators, how they work, how to tweak them.

Also the current consumption, refered to the first stages was informed, and with this one and ohms law calculation you can substitute the whole thing by simple resistances.... you may need to do that till you find the needed zeners for your new supply voltage.

I hope you will appreciate the sonics...please, do not forget to publish pictures and your evaluations into the main thread related those amplifiers.

Be very carefull with supply polarity.... a lot of good folks already inverted those wires... i did that, in my whole life, more than 200 times!

If you have doubts and need some information, i am gladly receiving mails into:

panzertoo@yahoo.com

regards,

Carlos

.........................................................................................................


Congratulations Nordic

You have mailed many boards and some of them already arrived.

I am sorry by your mum.... mine gone 15 years ago.... she lived with cancer into the blood for 14 years long..... well.... you can be with her..... i cannot.

I am very sorry..... last month was you cat.... you also had heath problems... this explains you have disappeared from our forum.

I have been missing you dear nephew.

Picture is my mum, a couple of year before i born..she would have 82 years old today if the cancer had not removed her from our world.

regards,

Carlos
 

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