[StevieDvd]

I've knocked up a new amp based on the gmoy I bought from Pinkfloyd and just needed to add the in/out connections and power/led etc and of course case it.

I'm using rca connectors in and a 1/4" jack and wondered whether I need to add a dummy load on the jack. I've not seen anyone adding these to basic cmoys in the past but then they are usually 1/8" jacks.

So is it necessary to put dummy load resistors on (and what value should I use)?

As soon as I've tidied it up a bit I'll post a few piccies just so my diy makes everyone else's look that much better

Thanks

Steve

 

[BrokenEnglish]

not necessary, steviedvd. in fact the wna is the only amp i'm aware of, that literally needs that feature.

 

[StevieDvd]

Danke,

Sorry missed your reply otherwise I would have thanked you earlier. Yes it's the resistors I've seen in the WNA - I suppose I could have opened the WNA but not sure I would have got the correct resistors even then.

Just have to find an led holder and a grub screw for the Maplins knob and it's done.

Oddly enough the gmoy is in the original WNA case so thr Pinkfloyd connection continues.

Steve

 

[DaKi][er]

Quote:

Originally Posted by BrokenEnglish not necessary, steviedvd. in fact the wna is the only amp i'm aware of, that literally needs that feature.

The tpa6120 headphone chip (one I used in one of my amps) from Ti highly recommends a resistor right on the output pin of it of 10ohms as it doesn’t like driving capacitive loads at all and any stray capacitance will cause problems

But you won’t have the problems with a cmoy

 

[nikongod]

i put dummy load resistors on my tube amp. it has output transformers that apparently like to "see" an 8-ohm load.

very fiew solid state amps need them.

something of an advantage for the ss crowd is that they do "stabalise" the imdeance of the load as seen by the amp circuitry.

 

[PinkFloyd]

Hi Steve,

A dummy load is not necessary in this application but in the WNA a dummy load is required to prevent the LM6171 from oscillating.. you won't do any harm fitting a dummy load to the head-socket and if you want to fit dummy load It's as follows:

 

[StevieDvd]

Groovy Baby,

I'll put some on just for practise as m soldering on Sunday was atrocious

Ta,

Steve