Mark IIIs, IVs and power attenuators

[doonyakka]

I'm a long-time happy owner of Mark III and Mark IV combos, and I'm looking into buying a THD Hot Plate power attenuator. These come in various impedances, including 2, 4, 8, and 16 ohms. I know that mixing up amp/speaker impedances can have nice results (sonically, although with some accelerated tube degradation), but I wanted to see if anyone here had had any experience with this kind of thing.

The standard ('correct') choice for these amps is probably the 8 ohm version for mono. Are there any reasons why I should or shouldn't consider any of the other models?

Cheers,
doonyakka

 

[tony777]

The standard ('correct') choice for these amps is probably the 8 ohm version for mono. Are there any reasons why I should or shouldn't consider any of the other models?

As long as you use the 8 ohm speakers, the 8 ohm power attenuator is your choice.

 

[srommes]

You could also get a 4 ohm THD and run out of the 4 ohm out on your Mark into either an 8 or 4 ohm speaker load. I did that for a long time and it sounded excellent.

 

[kmanick]

I use a hotplate with my Mark III with great results.
I have the 8ohm hotplate. I have 2 8 ohm cabs and one of the nice things about the Hotplate is that I can run both cabs thru the plate (plug into the 4 ohm jack on the back of the head, per the guys as THD).
One cab with V30's and on cab with C90's so I get a nice mix of tone.

 

[boola]

I would strongly recomend against a hotplate with the mark iv. It really sucks the tone from the amp even on -4db and more than that it isn't even necessary, you get a better tone from the amp with the volume turned down. I can play no trouble at all at bedroom level on tweed/simul/pentode.

 

[doonyakka]

Thanks for everyone's opinions and tips. Interesting point about the Mark IV (boola), but I think I'll still get the 8 ohm model for use with my Mark III, which is definitely lacking at low gain, especially on simul.

 

[tony777]

Mark III, which is definitely lacking at low gain, especially on simul.

Are you sure your preamp tubes are good enough? my MkIII has gain enough to the moon and back even on low volume, equipped with five mesa 12ax7 (russian2) tubes.
I have a THD hotplate as well, but never really see the need for it with my mark amps. If you have a recto for instance I would support it.

 

[gonzo]

BEEN using a Weber Mass Lite attenuator with my Mark2B for 1.5 years now, very happy with it so far.

100 watt attenuator, on a 60 watt load.....

 

[lesterpaul]

I would strongly recomend against a hotplate with the mark iv. It really sucks the tone from the amp even on -4db and more than that it isn't even necessary, you get a better tone from the amp with the volume turned down. I can play no trouble at all at bedroom level on tweed/simul/pentode.

+1 -I quickly sold mine (I had used with my old Marshall 74 head NON master...it was a must)...at bedroom levels, it just got in the way-I sold and used the $$ to fund other goodies!!