Dx Blame MKIII-Hx - Builder's thread

[a.wayne]

Originally Posted by Woody1911a1

i'd be interested to hear what everyone is using for transformers . especially those in the usa .

i usually buy mine from antek .

cheers Woody

I was going to give antek a try also, was not able to find any bad on them ...

[gychang]

Originally Posted by Woody1911a1

i'd be interested to hear what everyone is using for transformers . especially those in the usa .

i usually buy mine from antek .

cheers Woody

glad someone is asking this question, also heat sink in USA.

[destroyer X]

Full power connected to a speaker may blow it...so..use dummy load..video explains how to make it using cheap multimeter, a couple of resistors, a signal generator or a low voltage AC transformer as audio generator.

Dx amp. dummy load to measure power, medir potencia com carga - YouTube

regards,

Carlos

[a.wayne]

Anyone up and running yet , any word on the antek trannies?

[ByronInLawrence]

Up and running? Do you mean finished? Or do you mean started building? Even though I had most of my parts before the boards arrived, I haven't even started. I have a deadline on a pair of speakers.

[Francois G]

The output inductor is shown on the schematic as 2.2 uH and on the PCB it looks like 2.2mH. I assume 2.2 uH is correct.

Is there some guidance on how to wind the inductor - wire gauge, coil diameter and number of windings? I assume for this huge output some large gauge magnet wire is needed.

Thanks,
Francois

[AndrewT]

Use enameled copper wire.
Choose between 1.0mm diam and 1.6mm diam.
Find a former of between 10mm and 20mm diameter.
Wind on between 8turns and 20turns for less to more inductance.

The smaller diameter formers will need more turns to achieve similar inductance.

A single layer winding is OK.

[destroyer X]

you can use a software i can send you...it is ony 1M size.

There are several coil calculator software around.... if you want this one them write to uncle charlie:

nanabrother@hotmail.com
carlos.eugenio1951@yahoo.com

Them i will send you the software.... there are some sentences you must translate to your language....but only a few sentences...see the image.

You can have any inductance value with any wire thickness...we use 1 to 3 milimeters thickness because they are easy to find, easy to make coils or (thick ones) they are mechanically resistant to continue having its shape even if you hit them with your arm, finger or any tool...you can make 2.2uh with any wire thickness, it is up to you to make it large or not large.... software offer mathematics calculation considering wire thickness, coil diameter, coil length and number of turns.

Image shows a picture with a small coil (more turns, small diameter) and other image shows a big coil, the one has less turns, thicker wire and large diameter.

regards,

Carlos

[sandbasser]

From the printing on the Byron board it looks like a resistor goes through the middle of the choke, is that correct; and what value is it???

Thanks,

[AndrewT]

If the resistor has any magnetic material in it's construction (eg. Fe iron and others) then do not run it inside the coil (inductor).
Pass the resistance/s outside the coil to avoid (or at least minimise) any magnetic effect.

Since the resistor passes the HF, it should have the shortest route through the Network from amplifier to speaker. The inductor passes LF & MF and so can be offset from the shortest most straight route. If one is PCB mounting this part of the Thiele Network, then locating the resistor under the PCB in line with the traces would achieve the HF performance. Locate the inductor on standoffs (extended legs of the wire) on the topside of the PCB.