Dummy load box

[rhdwave]

Yes, i was considering either the Behringer Ultra-G di or the Palmer i think it's the PDI-09.  The Behringer is quite a bit less expensive, and i've heard very good things about it.  I've heard excellent reviews on the Palmer as well.  So, that part of the equation i was definately going to purchase.  But as you said, i will still need a dummy load to use it without outputting volume in the apartment.  So, i was either going to build a simple one and see how it turned out or get a weber mass-lite which is not cheap (like $160 or so), but is supposed to be an wonderful unit.  It apparently does not use a pure resistance load, but has some kind of a motor which is designed to emulate the moving parts in a speaker (as you were talking about Pete).  So, i may try to build this:   http://www.aikenamps.com/DummyLoad.pdf

Lastly, i do have a line out jack on my amp, but i didn't want to use it as it comes after the preamp stage and before the power amp.  i've heard that this really changes the tone and you lose a lot of the juice and crunch that may be associated with a tube amp if you go this route.

It's definately been learning experience just trying to figure out what direction to take here.  I really appreciate all the responses!

[runmikeyrun]

here's what i did:  a little involved but worked quite well.  I took an old speaker with a rating i knew exceeded the output of my amp (which was only 15 watts) and cannibalized it into a dummy load like so:

Cut surround all the way around. 

Carefully using a hacksaw or tin snips, cut the frame of the speaker down to the magnet assembly.  Save the speaker terminal mounting board or tabs.

Cut away the cone down to where the wires from the terminals enter the cone. 

Cut around the whole circumference of the spider and pull out the voice coil. 

Remove all of the spider and epoxy the voice coil and remnants of the cone into place.  Epoxy the speaker terminal(s) to the base of the speaker. 

Hook up your amp's output to the speaker terminals.  Check in the first minute of use to make sure it's not overheating.  This is why i recommend you use a speaker rated higher than the amp.  I suggest a 12" or larger with a 3 or 4" voice coil.  You also have to be careful that you don't blow it, remember it's not going to make any sound if it blows so you have to keep an eye on it.  This is supposed to be closer to a reactive load than a standard resistor and helps the amp to act like there is an actual speaker on the output because the current is flowing through the voice coil, which has the right impedance, and because that coil is inside the magnet assembly. 

Good luck!

[d95err]

Get the Behringer Ultra-G DI Box.  I use one with my rig.  Speaker out to the box, balanced out to the console, with 4x12 speaker sim on.  Also enable the ground lift when using the speaker out of your amp.  Yes, it will handle it.  My amp doesn't need a load on it this way but I'm going to anyway so I have a monitor near me.  My amp is a Vox AD50VT by the way.  For use with your amp, you will still need the dummy load though. 

Just out of curiosity, why not just use the headphone/line out on the AD50VT? Do you get ground loops with it?

[tazwolf]

runmikeyrun: Thats a great idea! I've got an Orange Tiny terror amplifier head on order and was wondering how I could go about recording
it at home (very small apartment and very thin walls) I'm going to try your idea.

I wonder if using some kind of thick gel or high temp silicone would be better than using epoxy as it would still allow the voicecoil to move.

/Taz

[tazwolf]

d95err:
The headphone out on the vox ad series is before the valve and the valve reactor circuitry which is what gives them
amps their valve charcteristics.
Sounds very cold harsh and 'orrible. The VTX series has line out/headphone after the valve reactor circuitry and sound a lot better.

/TAzwolf

[vanhansen]

d95err:
The headphone out on the vox ad series is before the valve and the valve reactor circuitry which is what gives them
amps their valve charcteristics.
Sounds very cold harsh and 'orrible. The VTX series has line out/headphone after the valve reactor circuitry and sound a lot better.

/TAzwolf

Taz hit it right on the head.  With the 4x12 cab sim on the Ultra-G engaged, the Line Out sounds pretty good, really good actually.  But, going speaker out sounds way better, for reasons stated above.  You have to have the 4x12 cab sim engaged though or it doesn't sound so good but with it engaged, excellent.  The ground lift also needs to be engaged (pushed-in) when using the speaker out.  If figured, if the Ultra-G can handle that load, then why not use it.  The AD50 doesn't require a load on it like a tube amp so it's OK to not hook up a cab to the direct link jack on the Utlra-G, but I'm going to anyway for my own monitor.  Just rigged up a jack on the other lugs on the speaker.

[rhdwave]

So, the Ultra-G is a good choice i gather? I see a couple of very positive comments and the price is definately right.  Has anyone tried the Palmer PDI-09 or any other DI boxes that can handle the output of a direct amp connection? Wondering if there are any boxes that can also simulate other cab and speaker combinations like 2x12 or 1x12?

[vanhansen]

For the price, the Ultra-G is a steal.  I've yet to see a negative comment about it.  Another cool thing, if your board supplies phantom power, it will run on that instead of a battery.  I haven't tried any of the others.  I'm usually not too hip on a lot of the Behringer stuff but this thing is great.  You may never mic an amp again.

[rhdwave]

I think i will be ordering one today, thanks for the feedback!

[Gilles C]

I agree for the Ultra-G. One of the good buys.

But I can't use it without a dummy load with my tube amp. That's the only thing I wish I had I think, a cheap dummy load for my HRD.

Gilles

[rhdwave]

Hey Gilles, that's why i was asking all these questions, i'm in the same boat as you. ...
I think this might work well:

  http://www.aikenamps.com/DummyLoad.pdf
Either that or the weber mass lite is like $160 for 100 watts.  It's also got a motor which is supposed to mimic the action of a real speaker and as Pete said the movement.  However, i was thinking that if you're using the Behringer which already has a speaker emulator than i'm not sure you need that...just the dummy load part.  I was thinking of building this and then mounting a fan inside with vents on the box to keep it cooled.