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Author Topic: Lower gain 12A*7s?  (Read 3544 times)

Dr. Stein

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Lower gain 12A*7s?
« on: December 15, 2010, 02:12:58 PM »
I've been getting on pretty well with my Laney (LC15R) recently so I'm thinking I'm going to invest a bit in it and get it revalved. What I'm wondering is how safe it is to replace preamp 12AX7s (propably V1) with a lower gain alternative, and what would be the best option. AT's I've heard can cause problems, so maybe AY's?

What I'm looking for is basically for the amp to stay clean longer, I use fairly high output pickups so it starts breaking up significantly by about 2 on the gain control, and since I mostly use it for cleans that makes it a bit awkward to dial sometimes.

HTH AMPS

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Re: Lower gain 12A*7s?
« Reply #1 on: December 15, 2010, 03:52:49 PM »
you could try a 5751 or a 12AY7, but if you only use it for cleans, then you might be better off having a tech look at it to reduce the gain of the amp so you have more clean headroom - i.e. optimise it for cleans.


HTH AMPS

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Re: Lower gain 12A*7s?
« Reply #2 on: December 15, 2010, 04:03:52 PM »
actually, looking at the schematic, its just a 2203/2204 Marshall preamp mated to a lower wattage output stage (15w, 2x EL84).

if you want this for cleans, I'd take it to a tech and get it modded so that you take the second gain stage out of circuit via a switch so you can have the stock tones, and also lower gain 'plexi' tones.

shouldn't run you any more than a ton.

MDV

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Re: Lower gain 12A*7s?
« Reply #3 on: December 15, 2010, 04:06:30 PM »
I was going to say 5751, but couldnt quite remember if I was talking shite or not :lol:

Dr. Stein

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Re: Lower gain 12A*7s?
« Reply #4 on: December 15, 2010, 07:29:30 PM »
actually, looking at the schematic, its just a 2203/2204 Marshall preamp mated to a lower wattage output stage (15w, 2x EL84).

if you want this for cleans, I'd take it to a tech and get it modded so that you take the second gain stage out of circuit via a switch so you can have the stock tones, and also lower gain 'plexi' tones.

shouldn't run you any more than a ton.

That's a thought actually. How would the gain control work in that case? Does it control both gain stages?

Even if I had a schematic I don't think I'd have a clue what it meant :lol:

Thanks man

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Re: Lower gain 12A*7s?
« Reply #5 on: December 16, 2010, 10:46:01 AM »
actually, looking at the schematic, its just a 2203/2204 Marshall preamp mated to a lower wattage output stage (15w, 2x EL84).

if you want this for cleans, I'd take it to a tech and get it modded so that you take the second gain stage out of circuit via a switch so you can have the stock tones, and also lower gain 'plexi' tones.

shouldn't run you any more than a ton.

That's a thought actually. How would the gain control work in that case? Does it control both gain stages?

Even if I had a schematic I don't think I'd have a clue what it meant :lol:

Thanks man

the gain control would work in the same way as it does now, just you'd have plexi or JCM800 (stock) tones.

its not a big deal, just rearranging a few things and bypassing the second gain stage.