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Author Topic: Gain delay with Warm Hi Gain voicing  (Read 17369 times)

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rnolan

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Re: Gain delay with Warm Hi Gain voicing
« Reply #15 on: Time Format »

Hey Harley, you may be onto something here  :dunno: , the 12AT7 needs/wants much higher current than 12AX7, the MP2 circuit is designed for 12AX7s and the 10 tube "voices" are created by manipulating a bunch of variables and (some eq) so current draw will be a factor.  The lower gain is probably not as big a deal (hey not that I'm an eggspurt here, MJMP and others may be able to edify us more). A 12AU7 may be a better choice if you want to turn the gain down a bit ?, IIRC they are lower current than 12AT7 and lower gain than 12AX7.  While I haven't tried using 2 different 12A?7 tubes in my MP2, I think the MP1 circuit (particularly with MDRT as it delivers significantly more herbivours) may be more tolerant. Of course the other way is to use 12AX7s (and not necessarily the same brand/type) and wind back the OD/drive setting(s) if you want to clean it up a bit.

But I think you and I are on the same page liking/recommending long plate 12AX7s for the MP2 as they seem to suit the MP2 circuit.
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Harley Hexxe

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Re: Gain delay with Warm Hi Gain voicing
« Reply #16 on: Time Format »

@ MJMP,
    I know it isn't a big difference, but it might be enough after a long enough period of time.

@ Richard,
   Yes, we are on the same page with the MP-2. I'd rather not try to downplay the gain it comes with, and just let it work the way it was meant to, and use it primarily for the modern amp sounds. The MP-1 and the Classic can give me all the vintage tones I'm looking for, so why try to make the MP-2 do the same thing?  :crazy:
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rnolan

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Re: Gain delay with Warm Hi Gain voicing
« Reply #17 on: Time Format »

I'm starting to envisage a guit rack that has all 3 preamps (need to get a classic now LoL) for just that reason. And I'm really happy I've picked up 2 MP1s (one for live rack one for studio (I can use the MP2 cab sims for the studio MP1 by going into the MP2s FX returns, I tried this before with Mikes MP1, works a treat)).  But obviously not everyone can afford one of each.  I was really happy with my MP1 tones back in the day (and miss them a bit), and also happy with the MP2 when I moved onto it, a classic I will get someday  :dunno: and maybe use an MB1 for cleans ??  Hey MJMP, there's an option to try for clean tones  :thumb-up: . While I didn't linger long I tried a guitar through MB1 and it sounded great for cleans, food for thought...
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MarshallJMP

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Re: Gain delay with Warm Hi Gain voicing
« Reply #18 on: Time Format »

Yeah didn't think of that, using the MB-1 for cleans, well I could try it out.

I would not use a 12AU7 in the mp-2, that's going to be worse.You won't be able to bias it correctly, and the same goes to some extend also for the 12AT7.
The MP-2 has some sort of bias circuit between each half tube, maybe it's got something to do with that.
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rnolan

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Re: Gain delay with Warm Hi Gain voicing
« Reply #19 on: Time Format »

Thanks MJMP, that's good to know and I suspect you may be right about the bias between the triodes.  Then best is stay with 12AX7s, not necessarily the same model/brand (although that's my preference), and just adjust your OD/drive settings.  Also try the in between voicings, and hey there are 10 voices!.

As I said I didn't linger long using MB1 for cleans but it had lots of promise, definitely worth a try, it sounded good on humbuckers, tamed them quite nicely, I was politely impressed from a quick trial and swore to come back to it...
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MarshallJMP

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Re: Gain delay with Warm Hi Gain voicing
« Reply #20 on: Time Format »

Only the MP-2 has this bias circuit, they were planning on also using it on the MP-1 plus but in the end didn't use it. Now the whole MP-1 plus idea didn't came so...
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Rawk777

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Re: Gain delay with Warm Hi Gain voicing
« Reply #21 on: Time Format »

Could you do some kind of tutorial to show how to bias the mp2 correctly? I'd be glad if this could fix my drive delay issue :).
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MarshallJMP

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Re: Gain delay with Warm Hi Gain voicing
« Reply #22 on: Time Format »

I had a few problems with one of the bias circuits but it always resulted in distortion on the clean channels, so I don't think it has got something to do with the bias circuit.
Are all your clean sounds clean?
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vansinn

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Re: Gain delay with Warm Hi Gain voicing
« Reply #23 on: Time Format »

Those bias circuits have another function  besides providing (programmable IIRC) bias, but about this, I'll have to dig out old discussions about this with Rand (analog designer at ADA and former member in here).
At least, I don't see them having anything to do with the problems discussed here, maybe unless some components are DOA.
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Rawk777

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Re: Gain delay with Warm Hi Gain voicing
« Reply #24 on: Time Format »

I have a bit of dirt on the clean channels if the drive is at 100%, but that seems normal to me.

EDIT:
The 3 clean voicings (1-Crystal Clean, 2-Spanky Clean, 3-Fat Clean) are a lot louder than the other ones (4-10).
« Last Edit: Time Format by Rawk777 »
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Rawk777

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Re: Gain delay with Warm Hi Gain voicing
« Reply #25 on: Time Format »

I think the problem is with Voicing 4 (vintage brown), 6 (dynamic vintage) and 8 (dynamic high gain).

I just did a couple more tests to see what is going on, and this is what I get:

No problems
  • If I exclude voicings 4,6,8, I can go from any voicing to any voicing without any problems.
  • I can go from any voicing to voicing 4,6,8 without any problems.
  • I can go from voicing 4,6,8 to voicing 4,6,8 without any problems.

Problems
  • If I go from voicing 4,6,8 to any voicing other than 4,6,8, I experience gain delay, (even on clean channels).

Dante, do you get the same results?
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rnolan

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Re: Gain delay with Warm Hi Gain voicing
« Reply #26 on: Time Format »

Wow, that's a curly one  :dunno: . When I get back home this week I'll play around a see if I get similar results.  I've never used voice 4, 6 or 8, just voice 1, 5, 9 & 10.
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vansinn

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Re: Gain delay with Warm Hi Gain voicing
« Reply #27 on: Time Format »

Well, over the years, I've used all voicings, and don't remember these issues (though, one or two voicings have had delays, just in an isolated way).

This is over my head - though, as a start, I shall with vigor suggest replacing all electrolytic capacitors..
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MarshallJMP

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Re: Gain delay with Warm Hi Gain voicing
« Reply #28 on: Time Format »

This seems to be more either a switching problem or there are also 2 vactrols in there for some tone shifting.

I wrote all 10 voicings vs fet switching down years ago,I'll look it up and see if there's something in common with those 3 voicings.
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Dante

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Re: Gain delay with Warm Hi Gain voicing
« Reply #29 on: Time Format »

I think the problem is with Voicing 4 (vintage brown), 6 (dynamic vintage) and 8 (dynamic high gain).

I just did a couple more tests to see what is going on, and this is what I get:

No problems
  • If I exclude voicings 4,6,8, I can go from any voicing to any voicing without any problems.
  • I can go from any voicing to voicing 4,6,8 without any problems.
  • I can go from voicing 4,6,8 to voicing 4,6,8 without any problems.

Problems
  • If I go from voicing 4,6,8 to any voicing other than 4,6,8, I experience gain delay, (even on clean channels).

Dante, do you get the same results?

Not sure, but I can't wait to try  :thumb-up:
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