HRM and non-HRM...best of both worlds?

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Fischerman
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HRM and non-HRM...best of both worlds?

Post by Fischerman »

It occurred to me that if one were to build an ODS with the D'Lator built-in...that you might be able to use the non-HRM circuit but then add a tonestack after the cathode follower Send stage that switches IN/OUT when you switch from clean to OD. Then you'd likely have to attenuate the signal (post Send stage...same place as the tone stack) when on the clean channel to account for the tone stack loss when in OD. Anybody tried such a thing? Any caveats I'm overlooking? Would the typical HRM/Marshall stack likely be best or some other stack (like maybe Baxandall)?
llemtt
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Re: HRM and non-HRM...best of both worlds?

Post by llemtt »

I thought about that but never tried.

Wouldn't it be better to connect a 3 band parametric eq in the loop instead? I saw that Presonus sell one model for little more that 100$ and I'am willing to try asap.

Teo
Fischerman
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Re: HRM and non-HRM...best of both worlds?

Post by Fischerman »

Yes you could use something in the loop but I wanted something that would auto-engage when in OD and auto-OFF when in clean.
phalanges
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Re: HRM and non-HRM...best of both worlds?

Post by phalanges »

With a Ground Control and GCX or their ilk you could engage OD and the EQ effect at the same time but it would have to take the place of your passive footswitch.
Last edited by phalanges on Thu Jul 10, 2008 12:18 am, edited 1 time in total.
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Luthierwnc
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Re: HRM and non-HRM...best of both worlds?

Post by Luthierwnc »

Glaswerks has a proprietary version of a dual use unit.

My own take is it would be much easier to just bring two heads. For a worthwhile gig you should bring a back-up anyway. Plus, with all the fiddling, obsessing and tweaking we do, you know you're going to get a preamp tube that sounds better in one than the other or some cap that is just right in one amp and way too bright in the different configuration.

I floated a thread a month or two ago about switch boxes for this and got a recommendation for a two head/one cab switcher:

https://tubeamparchive.com/viewtopic.ph ... ght=#55164

I've got a 50 HRM with an internal D'lator using KT66's and Marshall iron and a 50 watt 80's grail type with 6L6's and Fender-style iron. If I don't take them both, one will be lonely ;-) Skip
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briane
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Re: HRM and non-HRM...best of both worlds?

Post by briane »

Yes you could use something in the loop but I wanted something that would auto-engage when in OD and auto-OFF when in clean.
I'm a bit confused. HRM only affects the OD channel, clean is same as it always was.....So technically the design already does this.

I have put a switchable HRM in an amp, the only caveat is to have a separate master volume on the HRM( HRM switch also changes master volume controls). The HRM has a lot less gain, so the separate master allows volume levels to be matched between the separate modes. Another relay and now the HRM is footswitchable.

I wonder...Is your goal to put a HRM on the clean channel? There's no reason why eq could not be added to the dumbleator, but I suspect HAD just figured it was not needed.
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Fischerman
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Re: HRM and non-HRM...best of both worlds?

Post by Fischerman »

I'm a bit confused. HRM only affects the OD channel, clean is same as it always was.....So technically the design already does this.

I have put a switchable HRM in an amp, the only caveat is to have a separate master volume on the HRM( HRM switch also changes master volume controls). The HRM has a lot less gain, so the separate master allows volume levels to be matched between the separate modes. Another relay and now the HRM is footswitchable.

I wonder...Is your goal to put a HRM on the clean channel? There's no reason why eq could not be added to the dumbleator, but I suspect HAD just figured it was not needed.
I know what the design does but I'm thinking of something different. HRM tone is a different tone than non-HRM tone (as you know). What I'm thinking about is the non-HRM tone but with a post-OD EQ. As soon as you add the HRM stack it's not...non-HRM. This stack would be after the Send stage and would function essentially like an EQ pedal (of sorts) in the loop...but it would auto-engage when in OD and auto-OFF when in clean. And the loop would still work as usual (except for a loss in gain which there seems to be plenty of anyway...so it can be recovered).

And definitely not wanting to add HRM to the clean.
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Luthierwnc
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Re: HRM and non-HRM...best of both worlds?

Post by Luthierwnc »

Is the LNFB on the switch too?

sh
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heisthl
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Re: HRM and non-HRM...best of both worlds?

Post by heisthl »

You woulds have to switch a lot more than the tone stack - LNFB, entrance values snubbers etc. Anything less would be a compromise, also OK but not a clone.
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Fischerman
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Re: HRM and non-HRM...best of both worlds?

Post by Fischerman »

I hadn't thought about the LNFB but I don't see why you'd have to do anything there. Same with the snubbers although since there is a post-OD stack maybe the snubber wouldn't be necessary on one or both triodes of V2.
You woulds have to switch a lot more than the tone stack - LNFB, entrance values snubbers etc. Anything less would be a compromise, also OK but not a clone.
Yea I know there would have to be some tweeks...and I'm not going for a clone (I never do). I'll probably never try it...it was just a thought.
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