Champion 600 Upgrades

[voided3]

I agree that this little amp is what it is, but I can't help trying to make something better.

Yeah, that's my outlook on a lot of gear. Especially since the speakers for these are so cheap, why not try a few? Aren't they only $15-25?

[abraxas]

Originally Posted by tonfarbe

What about the Jensen Mod 6"?
http://www.tubedepot.com/sp-jen-mod6-15.html
They are pretty cheap and from what I heard (they are not available in Germany) the Mod series sounds pretty good.

Oh, yes, they are available in Germany:

http://www.tube-town.net/ttstore/pro...W---4-Ohm.html

[ibobunot]

Boys and their toys....

That day in 1967, when Dowd came to the studio to meet Cream, He was not expecting to see a trio of roadies setting up massive stacks of Marshall amps and a double-bass drum kit. “I thought to myself, ‘Three guys need all of this?’”

And that's why Dowd was stunned the next time he got to work with Clapton, on the “Layla” session, at Criteria Studios in Miami. Walking into the studio, Dowd was braced for another stack of Marshalls, perhaps even more of them than on the Cream sessions. Instead, he found Clapton playing quietly through a tiny Fender Champ amp. The contrast was startling, and as Dowd puts it, “If someone had walked into the studio that day during a take and their shoes squeaked, it would have blown the take.”

--Tom Dowd--

[dadm]

It took me a day to get used to it. It's not at all clear and bright like the old vibro-champs. Now I like it. It's not too loud or distorted-The just right. Doesn't disturb the people next door. The tubes were poor had to replace them in 6 months.

[BarnesTO]

Same here....different than my Vibro Champ....not better, not worse, just different. Took me a little time to get used to it, but now I really like it. I changed the tubes out a week or two after I picked it up last June, and have considered actually eBaying my VC to buy a Swart....

[cacibi]

Okay - I just tried to get the back off this thing and it seems like it's glued on! Unscrewed what look to be the four mounting screws on the back - and it's not budging. Feels like it's gonna break before it comes off......anyone taken this thing off and have some tips they want to share?

[BarnesTO]

Hmm....mine came right off, might have had a little goop in there though? Same goes for the preamp tube....some kinda black goop hloding the cover on. Just be gentle!

[voided3]

Mine was a royal pain to get off too. Just keep tugging at it...

[cacibi]

Originally Posted by voided3

Mine was a royal pain to get off too. Just keep tugging at it...

Thanks - did manage to get it off - although it was creaking like it was going to snap in two before it gave way.

[Richdonald]

Is this thing even smaller than the tweed champ?

[BrianF]

Originally Posted by Richdonald

Is this thing even smaller than the tweed champ?

yes...by about an inch all the way around

[B Vance]

Originally Posted by cacibi

Alright - had a few days to live with the Champ....overall, very pleased. Do not like the overdrive sound at all - sounds like a bad fuzz pedal, so speaker and maybe tube replacement will be in order. I'm getting some 'sizzle' sounds out of the speaker after it warms up....sounds like bacon cooking but without the delicious smell. If it had the smell, I'd probably leave it alone

Thinking of going with the 6" Weber Alnico replacement speaker, Tung-Sol 6V6GT power tube, and a Jan Phillips 5751 for the preamp. Seems like the preamp stage needs to be tamed a little bit in this amp.

The JAN 5751 should tame the over-the-top gain. At 90% the gain of a standard 12ax7 it may be just the ticket. I'm interested to see how this works for you.

[Brent Hutto]

When Fender says they've upped the gain in the new Champ 600 versus the classic one, how much are they talking about. Is the low-gain input on the new one somewhere in the ballpark of the original?

I seem to recall seeing somewhere that the low-gain input on the new Champ produces a voltage gain of around 130 or so. Anyone know how that compares to a vintage Champ?

[Talmir]

Originally Posted by Brent Hutto

When Fender says they've upped the gain in the new Champ 600 versus the classic one, how much are they talking about. Is the low-gain input on the new one somewhere in the ballpark of the original?

I seem to recall seeing somewhere that the low-gain input on the new Champ produces a voltage gain of around 130 or so. Anyone know how that compares to a vintage Champ?

It seems to depend upon which tubes you´re using in the amp. I tried putting electro harmonix tubes in mine. It pretty much killed all sound and made both low and high channels sound very much exactly the same. But now I´ve changed over to JJ´s and while the clean channel is, well, pretty clean except when you go up to and over volume 10, the high gain channel is nice and crunchy.

[Walker]

Originally Posted by Talmir

It seems to depend upon which tubes you´re using in the amp. I tried putting electro harmonix tubes in mine. It pretty much killed all sound and made both low and high channels sound very much exactly the same. But now I´ve changed over to JJ´s and while the clean channel is, well, pretty clean except when you go up to and over volume 10, the high gain channel is nice and crunchy.

Having said that, what was the difference like with the original tubes?

[Talmir]

The original tubes had a slight difference.. Not too much tho. Kinda similar both in high and low gain channel. (But I hear it differs from champ to champ). But they´re ultra-cheap no name chinese tubes that have an extremely high failure rate.. So its advisable to switch them asap.

[Brent Hutto]

talmir,

When you changed to JJ pre- and power-amp tubes, was the pre-amp still of type 12AX7 (nominal gain 100) or some other type?

Just this evening I swapped an old 12AT7WA/6201 (nominal gain 60) into my Champ 600 and the low input stays clean as a whistle even at 12 on the volume, although the whole combo sounds pretty boxy and compressed once I get to 11-12. The high input has to get up to 9 or a bit lower to start distorting and even then it's just a raw edge to the tone rather than a fizzy and/or splattery breakup as with the original Chinese 12AX7A. But once again it's getting unpleasantly boxy sounding before arriving at any obvious distortion.

My initial impression is that the 12AT7 also shifted the EQ balance of the amp toward the treble a bit. But that's hard to judge without a real A/B comparison, which isn't practical when you have to root around in there and swap a vacuum tube in and out. It may just have tightened the bass up somewhat and that sounds like a brighter balance (such bass as there is with a 6" speaker anyway).

[Talmir]

It was a 12ax7

[Twangbanger]

I just bit the bullet and joined the club. Mine will be a modder's nightmare.
First get rid of that horrible, way too thick, grill cloth. That sucks up allot of the sound, just turn them around and listen to the back of these. Sweet!
Then I'm gonna bypass the preset tone stack and change out the tubes. Maybe some orange drop caps and carbon comp resistors.

[BrianF]

Originally Posted by Twangbanger

I just bit the bullet and joined the club. Mine will be a modder's nightmare.
First get rid of that horrible, way too thick, grill cloth. That sucks up allot of the sound, just turn them around and listen to the back of these. Sweet!
Then I'm gonna bypass the preset tone stack and change out the tubes. Maybe some orange drop caps and carbon comp resistors.

Why not just remove the entire front baffle (leave the hole there for cord access) and turn the amp around and build a new baffle that mounts to the back. An added benefit of this is now the controls are in the 'front'