tube rectifier

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guitarmike2107
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Re: tube rectifier

Post by guitarmike2107 »

Amberden wrote:what i'm trying to do is change the JCM800 around a lil bit to combine the great sound of analog like my jtm45 and have the punch of the jcm 800.
Changing the rectifier from silicon to tube doesn't make the amp sound analog, its always analog regardless of which device is used.
That say to say it is never digital.

My recommendation is to take it to an amp tech to do as you don't really seem to understand how everything works, i.e where your bias supply has to come from etc

You may also want to read the article on ampbooks.com, there is quite allot of differences between your jcm800 and jtm45 power amps
http://ampbooks.com/home/classic-circui ... power-amp/
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Amberden
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Re: tube rectifier

Post by Amberden »

the chassis is getting tossed out and i'm making my own. placement of parts in the schematic are pretty much just for reference
If it ain't broke don't fix it, mod it :)
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Amberden
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Re: tube rectifier

Post by Amberden »

guitarmike2107 wrote:
Amberden wrote:what i'm trying to do is change the JCM800 around a lil bit to combine the great sound of analog like my jtm45 and have the punch of the jcm 800.
Changing the rectifier from silicon to tube doesn't make the amp sound analog, its always analog regardless of which device is used.
That say to say it is never digital.

My recommendation is to take it to an amp tech to do as you don't really seem to understand how everything works, i.e where your bias supply has to come from etc

You may also want to read the article on ampbooks.com, there is quite allot of differences between your jcm800 and jtm45 power amps
http://ampbooks.com/home/classic-circui ... power-amp/
the bias supply will be running through the same circuit as the jcm 800. no changes need to be made to that.
If it ain't broke don't fix it, mod it :)
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Amberden
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Re: tube rectifier

Post by Amberden »

okay heres the revised idea with help from you folks.

keep in mind the chassis space limitations do not apply cuase i'm building one from scratch.
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If it ain't broke don't fix it, mod it :)
Jana
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Re: tube rectifier

Post by Jana »

The tube rectifier probably has the least to do with the "analog" sound of the JTM 45 as opposed to the punch of a 2204. This higher filter capacitance, the lower impedance of the OT, the EL34's and numerous other changes in the circuit all contribute to the 2204 punch. The JTM 45 has a much higher impedance OT, much lower PS filtering and different component values in the preamp.

It seems you are determined to use a tube rectifier. Nothing wrong with trying that. But just be aware that it might not be the magic bullet you are looking for.
Cliff Schecht
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Re: tube rectifier

Post by Cliff Schecht »

Also consider that if you put a choke after that tube rectifier then the choke is going to counteract the sag induced by the tube rectifier. If the choke is after the power amp plates (i.e. from the screens back) then when the plates draw a bunch of current you will get some sag just there but if the choke is before the plates then you really won't notice much sag at all (i.e. the rectifier would be pretty pointless).
Cliff Schecht - Circuit P.I.
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M Fowler
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Re: tube rectifier

Post by M Fowler »

I am not trying to piss on your parade but rather trying to understand something so be kind here.

You note this in your opening statement!
so my idea is to replace the diode driven rectifier in my marshall JCM 800 2204 to a tube driver one
Why would you take your 2204 apart when all you have to do is move one can cap insert tube socket and wire it all up.

I think KT66 has a nice plexi layout which uses tube rectifier he may want to share.

Mark
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Amberden
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Re: tube rectifier

Post by Amberden »

thanks for the suggestions guy i do really appreciate it. don't think i'm just blowing you off or being rude, thats not what i'm about.

this is only like one of 12 amps i own and I just picked the 2204 because i have 2 2203 that i'll be leaving alone.

nothing about the amp really matters in fact, its just a leaning tool as i see it. do things, experiment, learn. by the end of this amps life its gonna be toast i already know lol but its something to learn on and gather skills for feature builds.

guess i need to know is if i have the tube rec wiring in order
If it ain't broke don't fix it, mod it :)
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