[cafe zeenuts]

Hi Guys

I like to build a 100ohm impedance adapter for my balanced Grado HF2 to use in my LD MK6 tube amp. Can someone help me out? How do I wire the resistor in this setup?

What is a good resistor and for doing this job? And what value resistor should I buy? 1/2W or 1Watt???

Cheers

 

[Punnisher]

1/4 watt will work just fine. Though I don't know of any boutique brands to go with.

 

[cafe zeenuts]

OK thanks, what about wiring the resistor??? I assume i need 4 resistors right? one for each pin and wire? So is it simple as just solder the the resistor between the connector pin and the wire??

 

[Steve Eddy]

Are you going to be doing this within the headphone amp or a separate adapter like I built for iPodPJ?

And yes, in order to maintain balance, you'll need four resistors. If you want the total impedance to be 100 ohms, then each resistor will need to be 50 ohms.

k

 

[cafe zeenuts]

Hi

Yeah separate adapter, so i take it i need 4 x 50ohm and solder them in between connector pin and the wire, correct?

What if i use 4 x 100ohm resistors, what is the total impedance?

Thanks again.

 

[Steve Eddy]

Quote:

Originally Posted by cafe zeenuts /img/forum/go_quote.gif Yeah separate adapter, so i take it i need 4 x 50ohm and solder them in between connector pin and the wire, correct?

Yes. Just wire the resistors between each corresponding pin number (i.e. pin 2 to pin 2, pin 3 to pin 3, etc.).

Quote:

What if i use 4 x 100ohm resistors, what is the total impedance?

That'd be 200 ohms per channel. Don't think I'd recommend going that high. I'd keep it at 100 ohms or less.

You might want to think about cobbling something together that would let you easily swap out different value resistors so you can dial in the impedance that works best for you, and then build the actual adapter.

Quote:

Thanks again.

You're welcome.

k

 

[cafe zeenuts]

Cool...

 

[ting.mike]

what about 100 resistor x2 only in the signal wires? would that work as well?

 

[Steve Eddy]

Quote:

Originally Posted by ting.mike /img/forum/go_quote.gif what about 100 resistor x2 only in the signal wires? would that work as well?

It would "work" in that it would give you your 100 ohm output impedance. But if you're doing that with a balanced amp, it would unbalance the output by 100 ohms.

k

 

[ting.mike]

ah, right... this is for a balanced amp. hence the XLR connector. right. thanks!