6505+ Hotplate

Completed amps from Fender, Orange, Hiwatt, Vox, etc.

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FL6
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6505+ Hotplate

Post by FL6 » Mon Feb 13, 2006 4:09 pm

I recently purchased a 6505+ amp head and did some experimenting with a THD Hotplate.

The thing is, there is no real discernable difference in the tone of the amp with or without the hotplate.

Without the hotplate, I have my pre-gain at 5, and my post at 3.5.
This is pretty loud, does fine in my band.

And with the hotplate, I have my pre-gain at 4 and my post at 8. The bulbs are lit on the hotplate so it's doing it's job, and the amp has to be working hard. But the tone is really quite similar.

Shouldn't there be a big difference in these 2 settings?
Or is this kind of result sometimes normal depending on the amp.

Thanks.
Or could it be the speaker cab that's not responding correctly.

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Skoora
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Post by Skoora » Mon Feb 13, 2006 5:38 pm

On many high gain (preamp gain) amps there power section is designed to be very clean and have as much headroom as possible to accommodate the level of saturation coming out of the preamp. IMO using a Hotplate on any high gain preamp type amp is a waste of time. On a 6 knob MV Marshalls, Oranges or Hiwatts it makes sense as they're not as gainy as a 5150 style amp but it gives you the kind of breakup that works for leads but you might find too hairy for rhythm work (except on the Hiwatt).
On any high gain pre-design amp the best bet is to always play with the preamp gain as low as you can get away with for the best dynamics and articulation. The power tubes should be made to work but you'll have a hard time getting them to contribute in a positive way if they're breaking up too with all that sizzle coming from the front end.

Ultimately it depends on what you want....

Guest

Post by Guest » Tue Feb 14, 2006 3:20 pm

ok, I know what you mean.
That seems to make sense.
I just figured Ed would've made something more with this original Marshall in mind, or at least part of it.

Billy Batz
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Post by Billy Batz » Tue Feb 14, 2006 3:37 pm

Skoora wrote:On many high gain (preamp gain) amps there power section is designed to be very clean and have as much headroom as possible to accommodate the level of saturation coming out of the preamp. IMO using a Hotplate on any high gain preamp type amp is a waste of time. On a 6 knob MV Marshalls, Oranges or Hiwatts it makes sense as they're not as gainy as a 5150 style amp but it gives you the kind of breakup that works for leads but you might find too hairy for rhythm work (except on the Hiwatt).
On any high gain pre-design amp the best bet is to always play with the preamp gain as low as you can get away with for the best dynamics and articulation. The power tubes should be made to work but you'll have a hard time getting them to contribute in a positive way if they're breaking up too with all that sizzle coming from the front end.

Ultimately it depends on what you want....
Having the master on 10 and the gain knob on 2-4, depending on the amp, gets me a pretty decent Super-Lead type amp impersenation on every hi gain amp Ive owned. SLO, 2203, XTC, Legacy, the beat goes on... They still didnt have anything on my Marshalls. But they did cop that sound to a degree that makes it worthwhile for some to get an attenuator with a high gain amp. In any other situation with high gain amps I agree with you. With most, with the preamp knob above 3 or 4 the sound is horrible witht he master dimed. Id say if you have the pre-gain up higher then after about 7 on the master, depending ont he amp, it just falls apart.

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MacGaden
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Post by MacGaden » Tue Feb 14, 2006 5:23 pm

These amps are fixed bias, and are biased very cold. So your powertubes aren´t really sweating...

Look here: http://www.metroamp.com/forum/viewtopic ... ght=peavey

It´s a thread about adding a bias adjustement to the 5150. Should be the same for yours.
MacG.

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