#1
hulllo UG modding people!

what mods could i possibly do to improve the champ? i dont want to change its tone at all, just improve it.
i heard putting a choke in it would help get rid of hum? what else is there?


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#3
Quote by hendriko
i dont want to change its tone at all, just improve it.




Adding a choke will change the tone (for the better, IMO).
#4
Quote by mr_hankey


Adding a choke will change the tone (for the better, IMO).

which is improving right

i just dont want someone coming here saying "do a VJr marshall mod" or something in the likes

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#5
Quote by mr_hankey
Adding a choke will change the tone (for the better, IMO).
Adding a choke between the output of the bridge and the first filter cap is a excellent addition. It has little effect on the output voltage and improves the filtering greatly. It also allows you do go much larger on the size of that first filter cap without beating the hell out of the diodes during the startup surge.


Quote by kurtlives91
I remember not so long ago there was a thread about about building amps or something and many Champ 600 mods were discussed.

Cant remeber the topic now.
You're probably thinking about this one:
Fender Champ 600 Mods?

A few interesting ideas were discussed there. A few were tried. Some weren't all that useful.

Another mod that will reduce hum would be to connect the 100 ohm resistors that are referencing the 6 Vac winding of the PT to ground, to the cathode of the 6V6 instead. We talked about this in the VibroChamp build thread and in the Epiphone Valve Junior resource thread .
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#7
^it sure does have a lot of hum, ill look into that

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#8
Quote by hendriko
^it sure does have a lot of hum, ill look into that

I really suggest the heater mod then.

My Vibro Champ has the mod and mine is dead quiet. I am also thinking about stepping up the filter caps to reduce hum. This may change your bass tone slightly though.

I also suggest stepping up the 6V6's cathode cap/resistor combo. Mr Hankey told me about this one. It preserves tube life and makes the amp run at optimum performance I believe. It does not change your tone.
#9
*writes on list*



would trimpots for the tone stack be a good idea? i dont wanna drill holes into that sweet chassis

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#10
Quote by hendriko
*writes on list*



would trimpots for the tone stack be a good idea? i dont wanna drill holes into that sweet chassis


Sure. I never change the settings on my Champ anyway; there is only one which sounds best!
#12
Quote by hendriko
would trimpots for the tone stack be a good idea? i dont wanna drill holes into that sweet chassis
Maybe. Read below.
Quote by mr_hankey
Sure. I never change the settings on my Champ anyway; there is only one which sounds best!
I guess it all depends on what your ears like compared to the frequency response of the speaker and guitar you're using. The preset tone stack in hendriko's might already be set exactly the way you or he think is best. Hard to say, really. With trimpots he might be able to dial in something he likes much better, or he might already be there.
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Quote by Jackal58
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Quote by SK8RDUDE411
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#13
^oh i think it has a too much bass, but ill see how that turns out with the 210 cab im gonna make


so how would i go on putting a choke like this in there?

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#14
Quote by hendriko
^oh i think it has a too much bass, but ill see how that turns out with the 210 cab im gonna make
Whether or not you put trimpots in for the other controls, you could put a bass control on the panel. You have 2 inputs, right? Do you need both of them? If you only have 1, you can use the other hole to mount the bass pot.

Quote by hendriko
so how would i go on putting a choke like this in there?
You'll need to examine the foil pattern on the printed board very carefully. You'll want to cut the foil to leave the anodes of D1/C12 and D2/C15 connected together, but separated from the part of the foil that connects C6, R11, and J4. Then connect the choke to each side of this break.
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#15
^so it would go between some of the already existing components? i dont have to take anything out?

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#16
^ Yes, exactly that regarding the choke.
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Quote by Jackal58
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Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#17
cool

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#18
umm, what i was just wondering - is it even possible to fit a choke in there

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#19
I don't know about the 600, but my silverface has plenty of space. The 600 is a bit smaller, but it should fit.
Last edited by mr_hankey at Apr 15, 2008,
#20
^ill try to find that out...it IS tight in there...

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#21
Quote by hendriko
^ill try to find that out...it IS tight in there...


You're looking at the back (bottom), right? I can't imagine there being much space inside the chassis.

Wait a minute...how about some pics? I don't think I've ever seen the inside of one of those.
#22
^of course, like where the trannies are is where im looking at

hold on for pichas


EDIT: here we are, here we are and here we go




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Last edited by hendriko at Apr 15, 2008,
#24
There's room, but most of it is toward the preamp tube.
Not really the best place to mount a choke.
Keep it toward the vicinity of the 6V6 and output transformer as much as possible.
And get a shield on that 12AX7! That will cut down some of the hum you complained about.
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Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#26
Quote by SomeoneYouKnew
There's room, but most of it is toward the preamp tube.
Not really the best place to mount a choke.
Keep it toward the vicinity of the 6V6 and output transformer as much as possible.
And get a shield on that 12AX7! That will cut down some of the hum you complained about.

thats exaclty what my problem was/is...its tight where the choke should go or where ive seen most chokes placed

there was a cover on there, the stores owner forgot to put it back on when he replaced my tubes (i got a svetlana 12ax7 though - the GE 5751 i bought seperately) - im gonna get a new one eventually though
the hums not because of that...its more like..power-line hum if ya know what i mean
e.g. - it wasnt quieter with the shield one


^green pilot light? for tone purposes?

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Quote by stevo_epi_SG_wo
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#27
Quote by hendriko
^green pilot light? for tone purposes?

Green sounds better than red.
#28
whys that?

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#29
would i be able to use an 8 ohm speaker with it?

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#31
^ The schematic doesn't show an 8 ohm tap.

Quote by mr_hankey
Cool. You should get a green pilot light, for tone purposes.
lol. That kinda reminded me of Randall Aiken's little tech advice on tolex colours and tone.
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Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#32
Quote by SomeoneYouKnew
^ The schematic doesn't show an 8 ohm tap.

the manual says its fine to use any value above 4 ohms though

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