THD Hotplate

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Reg18
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THD Hotplate

Post by Reg18 »

Need some advise on ohm matching.
I picked this up yesterday as an impulse buy because it was a reasonable price but it may not be suitable for me.
Its 8ohm and my cab is 16ohm.
I can still use it as a load box with my head at 8ohms but if it’s unsafe to use with my cab it might not worth keeping as just a load box.

How unsafe would it be to use it with my 16ohm cab?

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Re: THD Hotplate

Post by Molly »

I'm sure that's fine. 8 goes into 16 so it's a safe mismatch. Hang-fire until someone who knows their shit chimes-in. :-)

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Re: THD Hotplate

Post by sizzlingbadger »

Set the amp to 8ohms and it will be fine.
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Re: THD Hotplate

Post by Reg18 »

sizzlingbadger wrote:
Sun Sep 13, 2020 3:10 pm
Set the amp to 8ohms and it will be fine.
So will it hurt the amp setting it to 16ohms to match the cab?
Or is it a case of slightly less stress on the amp setting it to 8ohms?

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Re: THD Hotplate

Post by jeremyb »

The obvious answer is you need another 16ohm cab to run in parallel, full stack here we come baby!!!

You won't hurt your amp running it at 8 ohms into a 16 ohm cabinet, but you will potentially have issues with running it at 16 ohm into an 8 ohm load if you have the volume up, best to play it safe I reckon! You'll get a few extra dbs of attenuation by running an 8 ohm amp into a 16 ohm cab :)

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Re: THD Hotplate

Post by sizzlingbadger »

Reg18 wrote:
Sun Sep 13, 2020 3:48 pm
sizzlingbadger wrote:
Sun Sep 13, 2020 3:10 pm
Set the amp to 8ohms and it will be fine.
So will it hurt the amp setting it to 16ohms to match the cab?
Or is it a case of slightly less stress on the amp setting it to 8ohms?
probably not, but setting the amp to 8ohms will be a closer match.
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Re: THD Hotplate

Post by Reg18 »

In light of the fact this should work fine for me, anyone want a reactive load box?
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Re: THD Hotplate

Post by chur »

Reg18 wrote:
Sun Sep 13, 2020 3:48 pm
sizzlingbadger wrote:
Sun Sep 13, 2020 3:10 pm
Set the amp to 8ohms and it will be fine.
So will it hurt the amp setting it to 16ohms to match the cab?
Or is it a case of slightly less stress on the amp setting it to 8ohms?
I remembered this was in the manual for my old hotplate -

Q. Can I still use the Hot Plate if it has a different impedance than my amp?
A. ONLY if the impedance of the Hot Plate is EQUAL TO OR GREATER THAN that of the
amp. However, this will lessen the effectiveness of the Hot Plate’s tone controls.

As everyone else said, put your amp onto 8 and you should be golden.

How do you find that -16 setting I see it on?
No one ever died of hard work.. but why take the risk..

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Re: THD Hotplate

Post by Reg18 »

chur wrote:
Sun Sep 13, 2020 5:31 pm
Reg18 wrote:
Sun Sep 13, 2020 3:48 pm
sizzlingbadger wrote:
Sun Sep 13, 2020 3:10 pm
Set the amp to 8ohms and it will be fine.
So will it hurt the amp setting it to 16ohms to match the cab?
Or is it a case of slightly less stress on the amp setting it to 8ohms?
I remembered this was in the manual for my old hotplate -

Q. Can I still use the Hot Plate if it has a different impedance than my amp?
A. ONLY if the impedance of the Hot Plate is EQUAL TO OR GREATER THAN that of the
amp. However, this will lessen the effectiveness of the Hot Plate’s tone controls.

As everyone else said, put your amp onto 8 and you should be golden.

How do you find that -16 setting I see it on?
I just tried it and it sounds great! It does change the sound at that bedroom level though, turned the amp
Gain up full and set to -16 gives a very saturated brown sound. Started playing Van Halen riffs as it sounded spot on!

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Re: THD Hotplate

Post by Dharmajester »

Reg18 wrote:
Sun Sep 13, 2020 5:42 pm

I just tried it and it sounds great! It does change the sound at that bedroom level though, turned the amp
Gain up full and set to -16 gives a very saturated brown sound. Started playing Van Halen riffs as it sounded spot on!
Yeah. Amp and hotplate at 8 ohms into 16 ohm cab will give you a nice early breakup and a decent volume reduction too :thumbup:

The mismatch issue is not a problem for the speakers in the chain but the amp's transformer which can with a mismatch get a voltage fed back to it and consequently fried. You should be safe with your setup though.

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Re: THD Hotplate

Post by jeremyb »

Have you bought another 4x12 yet Reg? :mrgreen:

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Re: THD Hotplate

Post by Reg18 »

jeremyb wrote:
Mon Sep 14, 2020 7:54 am
Have you bought another 4x12 yet Reg? :mrgreen:
Maybe I should build a dummy 4x12 bottom
Cab, if I plug into that it should be ok at 8ohms aye?

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Re: THD Hotplate

Post by chur »

Reg18 wrote:
Mon Sep 14, 2020 9:05 am
jeremyb wrote:
Mon Sep 14, 2020 7:54 am
Have you bought another 4x12 yet Reg? :mrgreen:
Maybe I should build a dummy 4x12 bottom
Cab, if I plug into that it should be ok at 8ohms aye?
I had a full stack for a bit, as much as it looked cool, the worry of another earthquake killed that buzz. My JCM took a nose dive from a single quad last time, and I got away with it, don't want to push it from the top of two cabs :wink:
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Re: THD Hotplate

Post by Kris »

I live in a house full of jenga peavey bins. I've been waiting for ages for them to fall over (on me hopefully) but not such luck. Probably fall all the way thru the earth and out the other side.
I'll probably use a tie down to stop them vibrating apart when I do crank the idiot stack up tho. Every one needs a wall of amps at some point in their life

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