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Question on THD Hot plate - Impedence

Posted: Sun Jun 24, 2018 1:54 am
by 11tonylevin
I own a THD Hot Plate, 8 ohms. I am not clear on whether I can use this between a rocker 30 and PPC 212. My understanding from the THD owner's manual is that I can connect the rocker's 8 ohm output to the Hot Plate input and then connect the Hot Plate output to the 16 ohm PPC212 cab
Anyone out there that has used this setup and confirm that it is safe to for the amp?
Thanks
Tony

Re: Question on THD Hot plate - Impedence

Posted: Sun Jun 24, 2018 2:06 am
by bclaire
Hmm... that doesn't sound right to me. I would contact THD about it.

Re: Question on THD Hot plate - Impedence

Posted: Sun Jun 24, 2018 5:45 am
by Ronnie Robinson
The impedence should be the same on the Hotplate as the amp output and the cab/ speaker.... You'll need the 16 oh version.

Re: Question on THD Hot plate - Impedence

Posted: Sun Jun 24, 2018 9:05 am
by Les Paul Lover
Or.... since you need a different hotplate to use with your rocker 30.....

Why not buy a Jet City Jettuanator?
Great attenuator, has 4,8 and 16 ohms taps.

I love mine. I believe you can also use it as load box. It has XLR and DI line out too.

Re: Question on THD Hot plate - Impedence

Posted: Sun Jun 24, 2018 11:52 am
by 11tonylevin
Did try to email THD......no answer. What a badly designed product, making 3 different versions instead of installing a switch. I will look into the Jet City or in meantime use my 8 ohm Blackstar cab with the v30s.
Ironically, on line in the instruction manual, it seems there could be a mismatch as long as the amp and THD unit are matched and the speaker impedance is higher or equal than the THD unit which kind of makes sense since the amp sees the load it has to see. I was hoping someone actually tried that with success.

Re: Question on THD Hot plate - Impedence

Posted: Sun Jun 24, 2018 1:24 pm
by Les Paul Lover
11tonylevin wrote:
Sun Jun 24, 2018 11:52 am
Did try to email THD......no answer. What a badly designed product, making 3 different versions instead of installing a switch. I will look into the Jet City or in meantime use my 8 ohm Blackstar cab with the v30s.
Ironically, on line in the instruction manual, it seems there could be a mismatch as long as the amp and THD unit are matched and the speaker impedance is higher or equal than the THD unit which kind of makes sense since the amp sees the load it has to see. I was hoping someone actually tried that with success.
The THD design is quite old now, and whilst very effective, the Ohms issue has been improved on by other manufacturers like Jet City. Another issue with the hotplate is the attenuation settings, which are fixed. A number of newer attenuator have a simple potentiometer where you can set the attenuation exactly where you want it. It makes fine tuning your overall volume a lot easier.

Re: Question on THD Hot plate - Impedence

Posted: Sun Jun 24, 2018 2:30 pm
by Ronnie Robinson
To my ears the 16 ohm output on orange amps sounds much better than the 8ohm one anyway!

Re: Question on THD Hot plate - Impedence

Posted: Wed Jun 27, 2018 2:11 pm
by a.hun
11tonylevin wrote:
Sun Jun 24, 2018 1:54 am
I own a THD Hot Plate, 8 ohms. I am not clear on whether I can use this between a rocker 30 and PPC 212. My understanding from the THD owner's manual is that I can connect the rocker's 8 ohm output to the Hot Plate input and then connect the Hot Plate output to the 16 ohm PPC212 cab
Anyone out there that has used this setup and confirm that it is safe to for the amp?
Thanks
Tony
I own an 8 ohm Hotplate too. Yes, that is how I'd run it. As soon as you are attenuating by at least 3dB (and the first step on the Hotplate is -4 the attenuator (not the speaker!) is the majority of the load the amp will 'see'.

Disagree on the 'badly designed product' comment. It is very solid engineering with solid thinking behind it on the impedance front. Unlike some of the competition who will try to persuade you that they can safely handle any amp output impedance. :wink: