Fender Champion 600 mod help...

[olddawg]

As mentioned above. Why did you remove filter caps? That is probably the source of your hum. You need to understand how a power supply works and what filter caps do. Also be aware that even this little amp can kill you. Again. Put the amp back stock. When it is working correctly, implement one mod at a time. Only then will you know the source of your problems.

[CroakerSmoker]

As mentioned above. Why did you remove filter caps? That is probably the source of your hum. You need to understand how a power supply works and what filter caps do. Also be aware that even this little amp can kill you. Again. Put the amp back stock. When it is working correctly, implement one mod at a time. Only then will you know the source of your problems.

I should have been more clear in the previous post. I was going to Change the value of three of the four filter caps. I left them stock because I didn't have the parts. So as far as filtering goes, the Amp is stock. An as you said earlier about the amp possibly killing me, I am pretty careful about those caps. What is the best method for discharging the caps btw? Resistor? Meter? Since they are large 450v 47uF caps I'm sure you can't just arc them with a screwdriver...

[Jazz P Bass]

You can safely use a 1K/ 2 watt resistor.
B+ -1K R - Chassis ground.
Don't forget to remove it when you do power up

[eschertron]

I wanted to try changing this value (to original spec of 100k) to see if it would fix the problem. This solved my original volume problem and I get alot more gain than I was getting. I'm still getting the hum from the amp and it gets louder as i turn up. I don't know what it is so far...

I'm glad you've got the amp working again, please keep me posted on your progress! As far as the hum issue goes, search the forum with the keyword 'hum' and I'm sure you'll get a lot of good background discussion on the topic...probably a lot more than you'll want to digest in one sitting! My champion 600 hums a bit too, and while I haven't tried any mods yet to reduce it, I am sure there are basic techniques that you'll come across. I'd like to know what you find that works for this amp, fer sure!

[soundguruman]

Or just plug a $40 Bad Monkey OD pedal on the input. And by all means put it back to original first.

Your solid state overdrive pedal is blasphemy. Bless him James Marshall, for he has sinned.

[J M Fahey]

Your solid state overdrive pedal is blasphemy. Bless him James Marshall, for he has sinned.

Just tell that to Jimi Hendrix and his Fuzz Face or SRV and his Tube Screamer or a Zillion others

[olddawg]

Your solid state overdrive pedal is blasphemy. Bless him James Marshall, for he has sinned.

I love my Bad Monkey (TS with a tone control) and my old Rat, lol. I used to be a purist. I mentioned the BM because it is the best bang for the buck OD available, IMHO. Albeit a little hissy.

[wmupat79]

I have the same amp and I did a little work to it, but my amp works just fine. I like the sound of this amp for my acoustic electrics more than anything else, and I'd like to gig it to our smaller acoustic shows, but I'd like to ad an output line to run it straight into our PA. Can I just run that straight off the jack that goes to the speaker? I know this is an old thread and sort of off topic, but I figured to post it here where people seem to know the amp well. Thank you for your time.

[Jazz P Bass]

but I'd like to ad an output line to run it straight into our PA. Can I just run that straight off the jack that goes to the speaker? .

That is a recipe for disaster!

The voltage that goes to the speaker is way too high to send to a PA or a mixer.

You need a voltage divider to knock down the voltage to a respectable level.

[wmupat79]

ha, yeah that's kind of what I was afraid of. That's why I never make a change unless I find information on it somewhere or ask. Any way to find out what the voltage should be reduced to?

[eschertron]

That is a recipe for disaster!

The voltage that goes to the speaker is way too high to send to a PA or a mixer.

You need a voltage divider to knock down the voltage to a respectable level.

+1. Not only would the signal be way too hot for the input of your mixer, you could damage the amp, if I read you right about using the jack for a DI instead of feeding the speaker. the output transformer really wants to see the 4 Ohm-ish impedance of the speaker. The high impedance of a mixer input would be bad.

Having said that, you could insert an adapter (Y-splitter, I'm thinking) and with the proper circuit interface, your idea would work. There are other discussions on this forum about making DI outputs in parallel with the speaker out. A little searching might reveal them.

If you really want the amp to be silent when you play, you could use a 4 Ohm 10W or bigger power resistor (I think the one I have on my bench is 25W) instead of the speaker. The amp still needs to drive the speaker load impedance (resistance) in order to function correctly. Hope that helps!

[wmupat79]

oh, I didn't mean mean to use the speaker jack straight into the PA. I meant could I take the signal going to the speaker jack and take it into an output jack. I was going to use an output circuit similar to what's on a small 15 watt solidstate amp I have. I don't want to cut out it's speaker, I want to hear the amp onstage, and also have an output jack to run to the PA. I could always put a mic in-front of the speaker, but I don't always prefer that way when playing in a pub. Thanks to everyone for the advice. I am taking some electronics courses now, but not much is taught in the way of tube amps these days.

[eschertron]

So you will be OK with that idea, but find a way to drop the signal voltage. It might be as simple as a 100k to 1M volume pot. Hunt a little and you will find some discussions here.

[Jazz P Bass]

The Marshall DI circuit would work.

http://www.marshallschematics.com/sc...50_revised.zip

[wmupat79]

I will try that out, thank you very much for your help.