THD Hotplate Purple (8-ohm)

[Crunchyriff]

As promised, I am writing regarding my initial thoughts from the 1st gig I used this at (last night).

I recently acquired the Hotplate used, from a fellow LesPaulForum member. It's virtually new in appearance, and I'm using it on my '83 Marshall JCM800 2204 that I use for strictly crunch rhythm work.

The guitars used last night were my historic '58 LesPaul for the majority of the night, with my '80 Howard Roberts used on about 4 songs.

The logistics/layout of the particular club's stage dictated that, for optimum uncluttered area, I set my amps just offstage of the 6" high stage riser, to my right. Ths stage riser is in a corner or the room so the band is presented with a diagonal view of the room & audience facing you, if you will. That being said, I did not get to actually directly hear my amps; and, because of some shoddy rigging of the house PA, we had NO MONITORS for roughly 1/2 to 2/3's of the night (Yeeeaahhh.....) That's the last time we gig anywhere without our own PA on standby in case of matters like this, (and I should have known better, in spite of being promised no PA hassles) but I digress...

Considering that our drummer uses all V-Drum Pro gear, we are NOT forced to crank up the amps just to 'keep up' with him. So, the use of a Hotplate seems even more of a necessity than luxury, to further tame the knob-sensitive, touchy nature of my Marshall's volume pots, and get every drop of great tone at a decent level.

It does work. As other Hotplate users have said, the extreme -16 and -12 db settings have the most blatant effect on your tone. I set mine at -8db, and set my JCM's master to about 9 o' clock. (6550's have heapum big wampum) to strike a balance for the stage volume I needed.
I did engage the 'bright' switch, ( as I set my treble and presence settings rather low); but I left the 'deep' switch off.

Like I said, I didn't directly hear much of my entire rig that night due to my amps' being about 6' to the right and behind of me; but the cat who does the booking for this club, also a musician himself, was blown away.

In his words (edited for pertinence): "....I could hear everything crystal clear, the drums were smooth, and right on, every instrument was in its place; I could hear every change of your amps & rig presets & settings on your guitar clearly, and the interplay between you and your other guitarist/keyboardist did not clash; and the guitars were nice and warm, with absolutley NO MUD; and your solos were spot-on and right where they should be in the mix. Quite frankly, I'm stunned. In the three years I've been booking bands for this club, no live band has EVER sounded this good in this room, not even close..."

Ahem.. (PRAISE GOD!!) :shock: :mrgreen:

anyway, you get the picture, I think. Next gig things will be much diffferent, and I'll be able to hear my amps more directly and better assess the Hotplate, but I think I have a keeper.

[Crunchyriff]

AS an addendum to my wretched 'review':

Preface:
I had assumed all the readers here would know what I am talking about, and that is wrong of me, so I will further desribe the Hotplate, and what it does- more like a real review, eh? (DUH!!) :oops: :roll:

Introduction
The THD Hotplate series of products from THD Electronics are "attenuators"- a line of active load-boxes that are color-coded for various Ohm loads (purple for 8-ohm, blue for 16-ohm, and so forth), & they offer units from 16-ohms, clear down to 2.7 ohms. You buy the model for which rating your cabs have that you are running, or which speaker load your combo 'sees'. They are designed for tube amps up to 100 watts in output.

Since they are an active load-box for your amps, this power being absorbed if you will, gets transferred into heat, thus the moniker 'HOTPLATE'; and there is a fan inside the unit to further help cool the components and heatsink. "CAUTION HOT" is silk-screened on the unit for this very reason. However, I used it with both of my 50-watt Marshalls here at home before the gig ('75 JMP/EL34's, and '83 JCM800/6550's), cranking both of those critters wide open into the Hotplate, and neither made the Hotplate break a sweat- it remained cool to the touch; but I suspect using one of the 100 watt family of amps might change that in short order. They WILL get warm, it's simple physics.

USES:
"Why a Hotplate?"
I'm glad you asked! It simply allows you to further control the output of louder tube amps for more manageable applications (with a few extra perks thoughtfully thrown in), and gets you that nice tube sound at a more, ahem, 'civil' volume level. Any readers here that have dealt with older hi-wattage Marshalls, Hiwatts, Vox, Fender and other Non-Master Volume all-tube amps know how touchy the volume controls on these can be, and these amps need to be goosed a bit (not run at like .'5' of the knob's sweep..) to get the right tube tone out of them.

It is in this light, that I believe The HOTPLATE is virtually useless, and un-necessary for a solid-state amp, IMO.

The HOTPLATE is placed between the power amp and your speakers. It operates and, is powered soley from, the wattage you feed it from your amp.

THE REAL DIRT:
On the Front panel you have a knob that has steps of -0, -4, -8, -12, -16 (db reduction) and LOAD you can select. This reduces the volume output to your speakers accordingly. There are three switches (deep, bright, and bulb on or off) a small light bulb display that actually reduces noise, as well as tells you the unit is getting power (wattage) from you amp. You also have a 'db control' on the right that functions strictly when you have the HOTPLATE plate set at the -16db, which gives you a nice sweep of VOLUME between infinitiy and -16.

On the back panel, you have an "INPUT" jack (receiving a wattage from your speaker outputs of your amplifier) "LINE OUT", a knob for controlling your LINE OUT volume; and two SPEAKER OUT jacks, which will feed your speakers.
The unit is color- anodized very nicely, with black contrasting caps on each end, is well made, and has the feel and heft of a quality piece of gear.

Hook-up is simple: Take a speaker cable from your amp into the HOTPLATE's "input"; and then take another spkr. cable and plug it into one of the two "SPEAKER OUTPUTS" of the HOTPLATE, the other cable end into your cabinet. Done deal.

As mentioned above, the Hotplate has a "line out", in which you can take this post-pwr. amp signal and run it into a rack FX rig, a recording console, another amp, etc; and what makes this feature so nice is you can set the attenuation knob to "load", and this entirely shuts off the audio signal to your amp's speakers, so NOW you have an active load-box which will enable you to get those nice, creamy saturated tube tones at a totally controllable listening/recording level. (!)

Setting the attn. knob on -16db will get you the maximum reduced volume output level this attenuator offers, along with the variable volume control for this setting on the right side of the unit's front panel. As mentioned earlier in my first post, the -12 and -16 settings give you the most volume reduction, but they also flatten and compress the tone somewhat, so you have bright, and deep switches you can engage (on any of the db settings for that matter) to compensate, which works like a "loudness" button that are found on many home stereo/audio systems to boost these ends of the spectrum you ears don't hear as well when program material is reduced to a very low listening level.

Another consideration is the prospect of being able to EQ your tone post-EQ, if you are using the 'line out' signal into the aforementioned amp, recording console, etc. (Hello vintage amp users that don't want to mod your gear..like me; to get some modern FX and uses out of old tube amps) Now you CAN run your plexi un-modded, and still use that nice Lexicon you've had stashed and wished you could use for your guitar..(ta-da!) This also works well for more modern amps such as MESA, Soldano, Bogner, and the like with MV controls: you can open up the master now, and let those tubes breathe some much warmer tones.

Point being- This is a very powerful tool for both live use AND recording.

You might say, "but hey, my amp is only 30 watts". Okay- Maybe it's only 18w, or ten...or less. That's fine, there is a place for a hotplate in these applications, too. You know how loud 30 watts of tube power (either class A or A/B) can be; 18w, too. And if you are recording with these smaller amps, you still have the option of diming the amp into the hotplate if you wish, and/or taking a line out into the console (this also works live, too)

Conclusion:
When you start looking at the potential and options for use; this unit gets pretty important for the pro or semi-pro guitarist who is a tube amp user; let alone the players that play and/or record at home, but are tired of getting complaints about volume. I believe the suggested retail price is $349, but realistic 'street price' (and on EBAY) on this piece NEW, avgs between $269-$279 (US). This gem offers more bang for the buck than it's demure facade might imply.

Yes, you can have your cake, and eat it too!

Now maybe the gibberish I wrote in my 1st post may have some real meaning...

[Teleguy]

Hey thanks for sharing.

Sounds like it solves the usual problem.
I may look into one.
Nice write up. Makes sense I can understand.

[Crunchyriff]

My apologies for the first un-informative post; and for 8 edits (!) of my real review!! :oops:

Next time I'll use WORD2003 for composition, and post it when it's 'presentable'.

My bad....

[stephen]

Very nice! Good informative piece!

[Old Believer]

Hey Crunchy,

I figured out where you were going with post one. Post two was a rock solid review of a product. Thanks a lot.

[randy_mc]

We've changed the platform at church (its a 3500 seat sanctuary). So, after finally getting the sound right, I have to start all over again. Last Sunday, the Metro was placed behind the big curtain at the back wall, and surrounded by baffles, then mic'ed.

The tones through the mains were great.
The tones through the monitors (to me) were dry.

Maybe I could use one of these. Does it do well even with pedals (overdrive, fuzz, vibe, and delay) ahead of the preamp? Do the lows stay tight and clear, and do the highs stay defined as though the unit were not in use?

Have you ever tried a Palmer PGA, or one of their direct boxes?

Randy

[kewlpack]

One of the guys I jam with on Fridays uses a hot plate 100% of the time with his JCM 2000. In my opinion it loses the low end and squashes the tone quite a bit. It does allow you to drive the tubes hard at low volumes, but it comes at a price - paid in tone. :?

I would avoid an attenuator if I could. I understand that most 50/100w heads need it for low volume stuff though.

Good luck!
~A~

[dmock66]

I'll bring back this older thread -

I too have the 8 ohm Hot Plate. I just recently decided to remove it from my rig for two reasons -

1) I wanted to simplify and this was a point I decided to experiment with
2) I found it was just another variable in my tone - to try to get as few pieces between my guitar and speaker as possible. As this has several EQ type options (Bright and Deep switches, variable levels of attenuation) I elected to pull it out.

I have an Ernie Ball volume pedal at the end of my pedal board. After a few weeks I determined that it does a wonderful job of truly allowing me to go without the Hot Plate. I've been "sans Plate" for about a month now and am wondering if I should eBay it - but I have to say that for the time I used it I did like what it allowed me to do. I get the sneaking suspicion that is one of those "wish I hadn't sold THAT" pieces of gear so I'm going to hold on to it. It does have it's purpose. I can't push a 40 watt 1x12 tub combo past 1.5 on the clean channel - and that bothers me some - but not enough to put the attenuator back in the mix. If I were playing somewhat bigger places and could be at 4+ volume and -8db or less attenuation, it would be better - but I can't do that in my environment so having the amp at 1.5 and not going much past 80 - 85% of my volume pedal is a better option for me.

I do believe the Hot Plate is a good piece of equipment and it does allow you to get a good "tube burn" without peeling paint off the walls. If I had a 100 watt amp or needed to dime a Plexi to make it sound good it would be different - but with a 40 watt 1x12 it's not quite as effective.

Just my experience.

David

[dmock66]

Just as an additional thought -

The Hot Plate can also be set as "Load", which I tried using it in this setting connecting it to the second speaker send of my amp. This resulted in a lower overall volume output from my amp, and also it slightly reduce the gain from my amp's gain channel. I know it seems a little odd to use it like this, but if you're just a little bit too loud, you can use it this was in addition to putting it in your signal path, which does alter your tone and effect the EQ of your signal.

Just my observations.
David