5F1 Champ vs. 5F2A vs. GA-5 Circuits

Based on your experience, please share your opinions regarding the merits of these three circuits.

For example, IMHO, the tone control of the 5F2A does not make a huge difference over the tone-control-less 5F1. Others may feel that it does.

Other differences between these two old Fender Circuits include bigger and more filtering in the 5F2A.

This is something that is very easy to address when building a 5F1. Adding more and better filtering is typical.

For example, I provide bigger filter caps in the 5F1 kits that I sell.

OTOH, it is neither easy nor practical to put a tone control pot on a 5F1. There isn't sufficient space on the chassis face to put one.

Now, I have figured out how to put a GA-5 circuit on a 5F1 Board with no modifications to the standard 5F1 board.

I have not built the GA-5 circuit yet, but I plan to do one soon.

Some say that the GA-5 circuit is an improvement over the 5F1.

If anyone can share their opinion on this, that would be interesting also.

Despite there similarities, I think the 5F2A feels much more refined. I have always attributed that to the losses in the tone control. For the record, refined does not mean better.

Which GA-5 are you interested in? I think there at least 2 maybe 3 different amps with that designation. And here again, improvements over the Champ are in the ear of the beholder,

Since I've been assisting for the past 2 months, we've repaired the old mid 50's ga5t skylark (the white one) a 60's ga5 (black tolex) and I've built my champ kit from u! (I have a 70s Princeton reverb but I know that doesn't count really.)
As maybe expected, the 50's sounded the best of the three hands down. It was in very decent shape with original speaker and tubes. Broke up about 1/2 way with a strat. The distortion was sweet and not overly compressed. The best though is that @ low clean volume it still had a great mid sparkle and was not anemic.
The 60's after fixing to stock sounded really weak and anemic/ lifeless til half way, but even the distortion quality wasn't too thrilling. The customer agreed and it was modded to the fender musicmaster bass circuit, which helped some but still the amp wasn't special by any means (very much IMO!!!)
Lastly, there's my champ, which sounds fine and raw, but just is not vintage sounding. But it has a 10" speaker, new tubes and a sturdy new cab, which I'm sure contribute to that.
Of course the best is my Princeton reverb...(esp with my new alnico spkr!)

I know you've got all the goods, it'd be fun if you made all three circuits using same parts and ran them into an external speaker!! I'd love to hear some sound samples of that.

The 5F1 is a beauty for sure, but I like tone controls and the 5F2A tone control is king.

Now this is my observation only as I asked the same question you did

I have a 61 GA-5 that I have just restored along with a 57 Champ similarly serviced (both - 5Y3, 6V6 and 12AX7 all NOS tubes). I didn't swap speakers (as they are different impedances) what I found was that the GA-5 sounded sweeter to me running a range of instruments from a 335 to Tele to Strat (all 3 from the respective customs shop).

Again this is only an observation and I have also toyed with the idea of a GA-5 build on a 5F1 board - interesting thread

Thanks to all for your input.

http://img854.imageshack.us/img854/9774/ga5q.jpg
By boothillamps (http://profile.imageshack.us/user/boothillamps) at 2012-03-20
Here be the schematic for the GA-5 I'm discussing. It is easily built on an unmodded 5F1 turret board.

I'm gonna build one very soon.

...there's my champ, which sounds fine and raw, but just is not vintage sounding. But it has a 10" speaker, new tubes and a sturdy new cab, which I'm sure contribute to that.

Try some vintage tubes. Though I suppose you've tried different tubes. Perhaps a lower gain preamp tube would be good. I'll send you a 12AU7.

I forgot I did put an old coke bottle RCA 5y3, but the 12ax7 is new. You don't need to send one!! Thank you though that's very nice :)
I'm excited to see how your ga5 kit turns out. Do you have any leads on cabinets? Or is it too unpopular (compared to the champ).
Also, what about the tremolo circuit? That'd make for a cool slightly more challenging first build kit!
Ps. That's a cool schematic! Has good peripheral info. Why does it look like the 12ax7 heaters go to ground?

http://www.tdpri.com/forum/amp-central-station/267624-fender-champ-5c1-wiring-power-transformer-question.html

andy, take a look at this thread about old heater wiring.

Interesting thank you! I wish I wasn't so new to it all when we had the old Skylark in for repair.
Now I'm very curious re: your kit.

220k plates, 2.2k cathodes. Dude's lucky number was 22.

Need two pairs of dice to roll that.

Don't forget the V1a grid leak.


http://www.tdpri.com/forum/amp-central-station/267624-fender-champ-5c1-wiring-power-transformer-question.html

andy, take a look at this thread about old heater wiring.

Ah, a trip down memory lane.

Peter had an Alamo Model 3 (pretty much a Champ) he couldn 't figure out. He sent it to me and I sent him two 5C1 cabinets I had kickin' around.

I still have a couple 5C1 cabinets.

Channeling Leo Fender: Leo made sure he built enough for everyone. :grin:

.

muchxs, what is the difference between your 5C1 cab and a your 5F1 Cab? Chassis cut-out is the same is it not?

BTW, your cabs are very nice.

muchxs, what is the difference between your 5C1 cab and a your 5F1 Cab? Chassis cut-out is the same is it not?

BTW, your cabs are very nice.

A 5C1 is the transitional amp ('53 or so) between the Champion and the later narrow panel amps. It uses the Champion style chassis which is very different from from the late '50s Champs.

Confusion arises when people build "5C1" circuits on a 5F1 chassis. It's easy to build a GA-5 (change four resistors) or even a Silvertone 1471 on a 5F1 chassis. If it's a 5F1 chassis it goes in a 5F1 cabinet. Yeah, I have a few of those...

Pic is a "5C1" cabinet in black. TDPRI member Peter.Sawtelles built up a 5C1 in that cabinet. I never saw the finished amp. Peter, are you out there?

It's a "5C1" but obviously very far from "stock".

Here are a couple recent favorites. The blue one is a chunky Alex W replica. It's a 5F1 with a viintage 12", obviously it's four resistors away from being a "GA-5". Next pic contrasts the big guy with a stock sized cabinet. Finally, I've been using a Gibson style fixed lower rear cleat from the get-go. I do it when I feel like it, not every cabinet gets one.