Cabling an attenuator?

the_jaffa

I've got a Jet City Jettenuator due to arrive tomorrow to use with my 68 Custom Vibrolux but I'm not 100% sure on what cable to use with it. I know I can't use and instrument cable due to the loading but would normal hi-fi speaker cable (good stuff, not bellwire) with Hicon pancake jacks be ok? The attenuator will only really be for home use so shouldn't lead too stressful a life.

I've got a fair few pancake jacks and various different bits of hifi cable (Linn K20 and some QED stuff) floating about spare. Will these work well enough?

Cheers

ICBM

You *must* use a good quality speaker cable from the amp to the attenuator - that connection is under a far bit of current demand when the amp is cranked up - which is presumably most of the point of using an attenuator…

Personally I would not use pancake jacks, they have a poor construction and can occasionally fail at either the centre rivet or the joint between the 'pancake' and the plug sleeve, either of which will leave the amp with no load. I would always use Neutrik NP2s (C or X, or RX if you need right-angle to save space) or at a push Switchcraft. Hi-fi speaker cable is OK, but won't be held properly by the cable grips - although not really a problem at home.

Is the combo speaker cable long enough to reach the attenuator output? If not, you'll need an extension cable, and again I would only use a Neutrik locking cable socket for that, the cheap female-to-female plug adaptors you can get are also risky.

If it's with a separate cab, actually the second cable from the attenuator to the cab is much less important, and as long as the final level is not high it's fine to use an instrument cable for that, since it will only be carrying a fraction of the current.

shaunm

Great question, I was wondering the same myself. 

@ICBM  do you have a link to any cables you'd suggest, especially the speaker to attenuator extension 

Oh and side question, the Jettenuator would it be ok with a 50 watt jcm 800?

ICBM

shaunm said:

@ICBM  do you have a link to any cables you'd suggest, especially the speaker to attenuator extension

This is one, there are probably others…

http://professionalaudiocables.co.uk/FTRS-SP15-TS

shaunm said:

Oh and side question, the Jettenuator would it be ok with a 50 watt jcm 800?

It should be - just! It's rated for 80W, which is about the full distorted output of a 2204.

shaunm

As always @ICBM thank you for sharing your knowledge 

the_jaffa

Excellent info, cheers ICBM. I'll get hold of a couple of the Neutrik jacks and use my thicker Linn speaker cable.

ecc83

On the subject of gripping cables and strain relief, often the downfall of "non Nuke" plugs, the intelligent use of heatshrink sleeves can "lock" the cable in and provide relief.

Dave.

Marktigere1

I made mine using mains flex.

Have used with the Jettenuator and JCA22H for 2 years no problem.

Think the cable came from an iron if memory serves me best.

Gassage

@ICBM speaks the truth.

If you're in any doubt, I tried a Dr Z AirBrake into my Hiwatt a few weeks ago- it almost incinerated in 3 mins so don't underestimate how much power going into those things.

IvisonGuitars

Gassage said:

@ICBM speaks the truth.

If you're in any doubt, I tried a Dr Z AirBrake into my Hiwatt a few weeks ago- it almost incinerated in 3 mins so don't underestimate how much power going into those things.

But......

That was an attenuator rated for a maximum of 40w and your head was 100w to start with.....!

the_jaffa

Would I be better using mains flex than the hifi speaker cable?

I'm going to get some Neutrik connectors and will do the locking female jack socket as having got the thing home I can't just use the combo's cable; it's not long enough.

ICBM

the_jaffa said:

Would I be better using mains flex than the hifi speaker cable?

Yes, if you use the round-section stuff (ie vacuum cleaner flex ) rather than the flat-section two-core - the cable grip won't work properly on flat-section.

the_jaffa

Ok cool, I'll get me a bit of decent round stuff.

Cheers (yet) again

the_jaffa

Just been making up the cables for this and they've gone well but I've discovered that the existing cable from the amp to the speaker is really thin wire and also just attached to the speaker terminal with crimped on spade connectors.

Is that normal (clearly it has been working fine) and should I do the same? I was expecting them to soldered connections.