After blowing up another thread about low power tube amps, I am seriously considering a hot plate/attenuator for my DT-25. There are a number of different ones out there at various price ranges. I kind of like the Jet City Jettenuator, variable attenuation, adjustable line level out, XLR out with mic sim for FOH, and good for 100W amp., for about $240.
Now I want to hear your experiences using one, good and bad, what brands you like and prices, values. Should I anticipate any downside for my amp by using one? Tube or transformer wear and tear?
Other than putting an equalizer in the DT's FX loop for global EQ I think this might be the last piece of the proverbial puzzle...
I've got a THD Hotplate (8ohm version) that I've used with my DT25 quite extensively and over the past week with my new Or15H...
Its a great piece of kit with some limitations. The downside of the THD in particular is that it's not switchable bewteen 8 and 16ohm impedance. If your only using it with the DT25 then you'd only need 8ohms anyway, plus you could technically still send it to a 16ohm cab as well (as the impedance rating is higher) but that may slightly reduce cabinet output. Because each model is only 1 impedance it's also cheaper, particularly if you buy on ebay. I got a 2nd hand model in good condition on ebay for about £150 (new Rivera Rockcrusher £399!).
I researched it all quite extensively prior to buying and the consensus from amp experts and designers is that attenuators are safe when used properly. The amp head doesnt know what its attached to directly as long as impedances are matched...8ohm output on DT25 to 8ohm rated THD Hotplate. "Wear" on the tubes and transformer is as high as it would be without an attenuator and the gain and volume knobs all set the same.
However.....I think the use that you're putting it to determines if its a worthwhile purchase or not. If you're using it only for "bedroom" volumes i.e. TV level volume then you'd generally need to set the hotplate at -16db attenuation or beyond in 25watt full power mode. In my experience the hotplate maintains great tone up to around -12db attenuation, ideally -4-8db for "perfect" tone reproduction. In my experience with both the DT25 and OR15H using the hotplate for >12db attenuation (i.e. -16db mode) is NOT WORTH IT. At that setting tone quality deteriorates considerably to the point where tone on both amps is actually better in full power mode with the volume (master volume in DT's case) down low to reduce volume.
So what I'd suggest is that the Hotplate is excellent for home use if you can manage slightly louder volume levels at home (-12db to -4db attenuation). It's perfect for stage use where you wouldn't be attenuating beyond 12db anyway, i.e. turning the volume up slightly between the start and the end of the night.
If it's only for home use at very quiet levels (-16db and beyond), in my experience and after much trialling, I'd stick with the amp alone and use the DT's master volume.