Fender champ rebuild

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Spencerleehorton

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I think all this snow has made my brain MELT!!
I dont think I put the ct down to gnd!!
ct on two windings which I forgot.
Will rewire tomorrow and hopefully be back up and running.
Got some wood for the cabinet head, just need to find some metal for the chassis and a few other bits then put it all together.
 

Lee_M

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Won't there be quite a large jump in voltage when switching from the 5Y3 (full wave rectifier) to a diode bridge?
 

dmp

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Spencerleehorton said:
I'm trying to figure out a way where I could have the 5Y3 socket but also have a switch to switch between diode bridge or the 5Y3, is this possible?

Yes, you can, I did this in an amp build years ago. You must turn it off / standby before flipping it.

 

dmp

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Spencerleehorton said:
I think I'll just install the octal socket and use that for the diode bridge and at a later date look at switching it.

If I were to pick one or the other I would definitely pick the rectifier, but that's just my preference
 

Spencerleehorton

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Also I saw this article on in rush current and wondered whether this would be applicable to when using bridge diode over a rectifier tube?

https://circuitdigest.com/electronic-circuits/inrush-current-limiter-using-ntc

Or if there are any other solid state ways of ramping up the voltage and current similar to the way a valve works?

Just a thought!
 

Spencerleehorton

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Have built a chassis for this now and today I'm going to start the build of the current limiter and head cabinet for it, as its not going to be a combo.
Will post some pics later.
 

Spencerleehorton

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Here is the first scrappy version, I've also done some testing with finger joints but need some more practice and will probably setup the router and do it properly, but I do have a head cabinet but I think I'll use it for something else as my dims are a little out for this!!
 

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Spencerleehorton

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Just made a zero point system from two trem stoppers and a bit of wire.
Before when bending a string the other 5 strings would go out of tune about 100 cents, now with this they only go 10-20 cents.
I had them laying around so thought I'd give it a go
 

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Spencerleehorton

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I have built the head cab, glue needs to dry.
Have wired up the champ but just need to cut hole for IEC and wire that to on switch.
Then do star ground and check all connections.
Then if all looks good then i'll plug into current limiter and test!
 

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Tubetec

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I see the way you wired the diodes now ,
I desoldered an old tube base and fitted the diodes inside it , makes a really handy way to swap diode/tube rectifiers and save all the bother of HT switching arrangements. Course if you really want switchable rectification the Boogie dual rectifier does it fairly well , your still supposed to put the amp in standby though and hot switching tube rectifiers isnt good news either . Solid state rectified amps without standby switches I dont like at all , despite Hartleys treatise on the subject , vibrolux is a good example of tube rectified amp with a standby switch .
 

Tubetec

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Floating bridge on a strat its a joke no? ;D,
if you bust a string your gonna need to hand the guitar off to a roadie or maybe even a guitar tech .
A good buddy of mine who's a luthier always recomended a block of hardwood behind the bridge in the cavity , now you can only pitch up with the trem but in the event of a string break the rest of the strings hold tune , depends on playing style I guess .
 

Spencerleehorton

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I usually have a few guitars on hand at gigs so changing over isnt a problem, I dont seem to break many strings now with how I set them up and have a slightly better picking technique than I use to.
Not that I'm doing any gigs at the moment anyways!!! It's all studio work for the foreseeable future!!!
 

Spencerleehorton

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Tested the champ the day before yesterday and works great, have checked voltages and all seems in order.
There does seem to be a little hum when not plugged in or plugged in with volume off or volume on full and strings muted so I need to check where I've gone wrong!
Started to build wooden box for it.
 

Tubetec

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Remember you wont see the right DC voltage if theres no smoothing cap at the output of the bridge , Id also put somekind of current bleed resistor in there , just so you know a certain small amount of current is being drawn .
 
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