Amps

[Jead72]

Thanks - the forum update is awful!!! Hard to figure out anything. I think I had to reply to a previous post in order to get a barebones text window. Seems like a step back to me.

[brunoserrano86]

Hello.

I want to make an active loop to my JCA20H and I want to know if the power transformer have enough power to supply 6.3V to the heaters of 2 new 12AX7

Anyone knows this?

Sorry about my english, I'm Brazilian.

[Soulcrusher_X]

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brunoserrano86 wrote:

Hello.

I want to make an active loop to my JCA20H and I want to know if the power transformer have enough power to supply 6.3V to the heaters of 2 new 12AX7

Anyone knows this?

Sorry about my english, I'm Brazilian.

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Is there a sticker on the side of the power transformer? I thought I read a while back that it should be able to supply another tube. Why would you need two 12AX7s?

[Soulcrusher_X]

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macheted01 wrote:
Alright, I have my JCA20H and loving it. I might go for a little more clean headroom, but I still am more interested in the FX Loop. Have not heard back from anybody on it. Would like to know what the best approach for the loop was? Thanks.

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What kind of loop do you want? Solid State or Tube-buffered? Solid State kit from Mojotone apparently works really well, and if I'm correct, is the same one on the 20HV. A guy I was helping mod his 20H on the SeymourDuncan forum said he installed the mojotone kit fairly easily.

[brunoserrano86]

Sorry, i got confused with the schematics, it`s just one 12AX7. I will check if have some label in the transformer.

[brunoserrano86]

the label in the PT shows 6.3V 2A.  How much current the heater of one 12AX7 consume? anyone knows?

[Bodiex1]

Hey guys, I've had my JCA20h for about a year now and its a great amp, only mods I've done is replaced the stock tubes with JJ power tubes and a blend of preamp tubes.  This may be something no one is interested in sharing, but I would like my amp to be more "vintage" sounding, maybe a little less gain.  Looked at the new 20hv, but I think I could have mine modded cheaper than buying a new amp.  Has anyone ever done this, looking for kinda a early marshall kinda flavor, any suggestions?  Thanks.

[audiosalvage64]

While checking ground to OT red wire, I get 500 volts.  Then switching to mA, from red to blue or brown I get 0.  If I change to Amperes setting I get .4, what gives?

[Soulcrusher_X]

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Bodiex1 wrote:

Hey guys, I've had my JCA20h for about a year now and its a great amp, only mods I've done is replaced the stock tubes with JJ power tubes and a blend of preamp tubes.  This may be something no one is interested in sharing, but I would like my amp to be more "vintage" sounding, maybe a little less gain.  Looked at the new 20hv, but I think I could have mine modded cheaper than buying a new amp.  Has anyone ever done this, looking for kinda a early marshall kinda flavor, any suggestions?  Thanks.

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What kind of early Marshall flavor? Plexi? 800?

[Soulcrusher_X]

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audiosalvage64 wrote:

While checking ground to OT red wire, I get 500 volts.  Then switching to mA, from red to blue or brown I get 0.  If I change to Amperes setting I get .4, what gives?

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Happened to a buddy of mine. Tried to bias his tubes and kept getting weird readings. Turns out his meter was no good. Didn't blow the fuse in yours, by chance?

[Bodiex1]

More early Marshall, actually just sent the amp off to BFG Amplification for some upgrades, so we'll see how it goes. 

[audiosalvage64]

No, I tried two meters with same results.  I'm returning the amp for a new one.

[malhomme]

Hi to all

I am (or rather hoped) to be a new member of the community. I bought second hand a JC20H received yesterday. I have the 2x12 baffle on it's way too. I am a french guitar player and have a few clips there My soundcloud page

Unfortunately, not exactly what I expected from the videos and sound clips here... The amp is making a loud buzz making it impossible to use clean, and it produces a weird clipping noise used solo with gain past 12 o' clock. My first take is I may have to change all tubes for a start, they may have been damaged in the delivery process (the amp was badly protected).

I am very interested in all mods alound here.  Something lie the brown sound is appealing to me. AS well as a sort o two channel mod with  clean channel. And as well an effect loop. All these make quite a lot... I will have to choose I guess.... I have yet to finish reading all 64 pages of the topic...

[sparks61]

I have bought this FX-Loop and put it into my JCA20H! All I can say is that it doesn't get any better! This Loop is fantastic. I have also build in a Footswitch to switch the FX-Loop on and off!

http://www.tube-town.net/ttstore/product_info.php/language/en/info/p5992_Kit-Tube-FX-Loop-6112.html