use a champion 600 reissue to build a 5F1

[nokaster]

i can buy a champion 600 reissue really cheap and was wondering if this would be a good choice to get parts and hardware for my 5F1 build.

especially the transformers in the 600. are they any good?
the switch, the pilot light assembly etc...

i've been playing the champion 600 through my 3 x 10 inch speakers at 2.6 ohm and it sounds huge.

so i'm convinced i'll build a proper 5F1. economically, using parts from the 600 would be cheaper than buying 2 tranfos (and other maybe re-usable hardware).

you could say i should keep connecting the 600 to the speakers, but i really wanna build a 5F1.

[tubeswell]

Might be more hassle than its worth. Check out the 5F1 schematic and the Champion 600 schematic, I bet they are pretty similar (except that the Champion 600 is diode-rectified and laid out on a PCB and probably uses crappier resistors and caps than what you might put into a 5F1 ).

But wot the hey? - as long as you can fit all the bits in PTP-style, or on a turret/eyelet board (which you will have to score), go for it. If using the 600 PT and OT, you probably are restricted to having it diode-rectified, because there will be no 5V rectifier winding on the PT. Apart from the possible 'saving' on the PT and OT, I doubt it will cost you less tho, especially if you are going to fork out for decent caps, pots(s), resistors and sockets and other miscellaneous paraphenalia. Why not build a 5F2A instead and end up with a tone control as well?

[Mandopicker]

I turned my Champ into a 5F1 and added a few upgrades and it is an amazing little amp.

Transformers...Output is OK- but I replaced anyway...Power transformer-needed to be changed cause I wanted a Tube rectifier.

FYI: The Champion 600 is more like a 60's or 70's Champ, but with fixed value resistors for the tone stack as opposed to the Bass and Treble knobs.

Do a search on this site and you will see photos of mine experiment.

Added a 6" Weber Alnico, and it is amazing.

Wouldn't even think of using a bigger speaker, though just plug one in as an external speaker and you got the best of all worlds.

If its cheap, buy it. The cabinet and chassis are worth plenty as a foundation to a real killer amp.

Good luck and have fun.

[Howlin' Mad Mac]

I've turned several Champion 600's into 5F1's now... the transformers are crappy but they'll work just fine if you use 1N4007 diodes for rectifier but if you want to add 5Y3 tube rectifier you'll need to replace the PT as the stock one don't have 5v secondary. You will also need a 1M pot, a new input jack & pilot light assembly (the stock one is chrome plated plastic & uses an led) plus you'll need a good tapered reamer or Dremel to enlarge the hole for the pilot light. I'd also grab a new noval socket, octal socket, a piece of tag board, some eyelets & a 5F1 set of caps & resistors. Personally I'd say scrap the whole idea... Champion 600's even after rebuilt are still pretty crappy IMHO... I'd unload that puppy on Craigslist & use the money to buy a better SE amp like a Vox AC4TV or better yet a VHT Special 6.

[Mandopicker]

Everyone is entitled to their opinion, of course, but that should not deter the inspired DIYer to have a little fun and learn something in the process. Besides, who said making amps from scratch was essentially an affordable proposition anyway?

As for me...the process of rebuilding my 600 gave me lots of knowledge for many other far more complicated designs than just the extremely simple 5F1, not to mention a cool small amp that really does sound good in the end. Compared to my other projects and larger amplifiers, my neighbors are certainly happy enough when the inspiration to play comes at irregular hours and I choose to use the 600.

With an unbiased mindset or maybe a little biased as I actually did it (and spoken to all DIYers), you would be surprised at the tone that can be had from a well built amp and a good alnico 6" speaker. Not every amp needs a 12" speaker...IMHO...better yet, just plug it into anything you want and the possibilities are endless assuming the right kind of transformers were used from the beginning.

Just a thought...but it seems to me the SP 6 just might have been inspired in many ways from studying the 600 and rebuilding it.. I'm also pretty sure that both amps are made in the same factory in China anyway. One for Fender and one for (the new) VHT.

That said, anyone can just buy an amp and miss out on the learning process of building something from scratch...but where is the fun in that?

[Howlin' Mad Mac]

Sorry Mandopicker... I didn't meant to ruffle anyone's feathers but then again I can tend to come off as abrasive sometimes and you are quite right of course. I too learned a great deal tearing apart Champion 600's & rebuilding them to greater potential. Also sitting on the shelf at the local GC they're much cheaper than most of the other low-watt tube amps. Still there are certain elements of Fender's pint-sized offering that leave me a little cold... the cabinet is too small which makes it sound very "boxy" (Also only a 6" speaker... what's up with that? Even the original had an 8" speaker.) & I really find that chrome-plated plastic pseudo amp jewel to be extra "cheesy" (C'mon now, wouldn't you have gladly forked over an extra 5 or 10 bucks for a real pilot light?) & last I can't imagine why they chose to go with that awful heavy tan fabric grille cloth that chokes every bit of nuance that tinny little speaker can muster right out of it. But I digress, if this little amp is one's gateway to higher knowledge regarding all things iron & glass, taking one's tonal nirvana into their own hands, so to speak, is a very, very good thing. Nor did I wish to convey that mere purchase of one of the other low-watt offerings that one need not open up that magic little box, find out what makes it tick & do your very best to vastly improve upon what lies beneath... I just wanted to impart my two cents worth & again IMO from one who owns both a Fender Champion 600 (I paid $199.00 for mine as I purchased before Fender dropped the price to $149.00) & a Vox AC4TV8 (purchased for $179.00 at local GC on closeout) for close to the same dollar the Vox offering offers a more musical OTB sound & a built-in attenuator (which if you take a look is simple, ingenious & something you can easily incorporate into almost any low-watt design around) but better styling & build quality (& it's built in Vietnam.) Finally, regarding the VHT 6 watt models I can't say whether or not their inspiration came from the venerable Fender Champ 5F1 or not, as it may well could've but then again you've got a two triode gain stage pre amp feeding a tetrode or pentode SE power stage & a power supply so apart from a few tweaks here & there all the various low-watt offerings are at heart basically the same as how else are you going to accomplish that? (Take a good look at the 5F1 schematic & compare it to various recommended "hobbyist audio projects" using 12A_7 dual-triodes & 6V6 tetrodes in the old tube manuals & you'll find Leo wasn't having a moment of great inspiration, that's just how you do it.) That said I am very impressed with the fact VHT's are hand-wired "tag board" fashion with real jacks, pot (not the sealed in plastic pc board mount kind) & pilot light (don't actually own one but I've seen inside photos & it looks like the real McCoy or at least a better copy) making them so much more inviting & encouraging for the novice to peer inside, tweak & experiment & for that I say kudos to VHT! Again though, no offense just offering up my unasked for "two cents" so just ignore me... as my girlfriend will tell ya I'm an ornery ol' fart anyway LOL.

[Mandopicker]

No need to be sorry, Howlin'...I'm cool. I just think that sometimes the amp gets a bad wrap. I really do enjoy mine when I do not need to or want to go big. Every amp has its moment, in my book...certainly those in my collection.

Anyway, my comments were more to the point of addressing the original question from Nokaster...I believe that it is worth it to do mods if you got the time, the money to dig in and the desire to make the amp sound like you want it to. To your point, no question there are great amps out there ready made. Those you suggested... as well as others. At that price point, I wouldn't expect all the best parts, but they will be good amps in general.

What I meant by comparing schematics was for you to compare the Champ 600 schematic (not the 5F1) to the VHT Special 6 schematic...you will see the similarities. Any of the things you mentioned can easily be done to the Champ 600 with a few parts and knowledge. Change the plate resistors to 220K, lift the tone stack for the boost function, add a pentode/triode switch, bigger OT trans, plug it into a 12" speaker cab and you are 90% there. Also the pilot lights are the same...led based, cheap plastic. Like I said...same factory. Though, easy to change for sure.

Plus the Champ 600 is so cute! Just consider it a "head" with a simple speaker attached for those cold quiet evenings pickin' on your tele. Anyway..no need to beat the horse.

Regarding 6" speakers in an original Champ 600: It was definitley used for this amp back in the late 1940's early 50's. (Tweed) The Champ 800 (Looking like the reissue), and later the Champ, had the 8" as far as my research tells me.

Amp Guide » Fender*Champion 600
Amp Guide » Fender*Champion 800

I was actually told a story one time why the 6" was used...can't confirm it is true, but it was from someone who knew Leo in the old days. (I grew up in Fullerton.) Anyway, story goes that Leo ordered a bunch or 8" speakers and ended up receiving an large shipment of 6" speakers instead. Waste not want not! Hearing other stories of Leo's frugality, it wouldn't surprise me at all if it was true. Or if it was false, either way...6" they were.

So, again, that's what we are here for...to help each other out. Share knowledge and insight, but most of all, to encourage the CAREFUL and SAFE exploration of tube amp technology. After all, everybody deserves good tone.

Peace!

[steve_rolfeca]

Sorry for jumping on this thread a little late...

How vintage-accurate a 5F1 does the OP want to achieve?

After spending a lot of $$$ to get a Marsh 5E3 kit sounding like a "real" Tweed Deluxe, I'm a little gun-shy about this sort of thing. Don't get me wrong, the kit sounded very nice right out of the box, but not in a vintage way. The sound was more Blackface than Tweed- I had over 400 volts on the B+, and it was much louder/brighter/crunchier than expected. I eventually got it sounding great, thanks to a new PT from Mission Amplifiers, a Weber speaker, tube changes, etc. But in the end, I spent enough to have simply bought a used Victoria 2112.

If the OP just wants to mess around with a Champ-ish circuit and can get the donor amp cheap enough, it could be a nice little project. Gotta be careful about parts costs, though. If he wants to go all the way with a tube rectified repro 5F1, he'll end up throwing out the PT and the board, changing the tube sockets, etc. At that point, he won't have much of the donor Champion 600 left.

Another thing to consider, is that cheap PC-board based amps can be a pain to modify. I've done up a couple of Vox AC4TV's for friends. They sounded great in the end, but the process was very time-consuming compared to working on the eyelet-board VHT Special 6 that I just picked up.

I don't know where the OP is at, but this is especially true if his soldering skills are limited. When you're already working in crowded conditions, there are few things more hair-raising for a beginner than watching a pad or a trace curl up off the board after applying too much heat or pressure. Also, it's just plain annoying to have to keep pulling the chassis apart in order to flip the board over when changing components.

I would make some of the same arguments regarding the VHT. Sure, it's got classic eyelet board construction with all components on the top side of the board, it has a nice roomy chassis, and would make a nice basis for a hot-rodded Champ-style circuit.

But the emphasis would have to be on hot-rodded. With those huge transformers and a solid-state rectifier (plus a 10" speaker if he buys the combo), it's going to have a different tone and breakup characteristics, compared to a period-accurate 5F1.

[Mandopicker]

Regarding dropping voltage...On a number of occassions, Bruce has suggested using a few zener diodes attached to the HV CT to ground. This is very effective at dropping a reasonable amount of voltage...enough to get it in the range of vintage voltages. I think the zeners cost...maybe $.25 each. A couple 12v 5 watters might just do it with a modern Tweed Champ Transformer.

(Thanks for that suggestion Bruce! It has worked like a charm for me.)

[tubeswell]

Regarding dropping voltage...On a number of occassions, Bruce has suggested using a few zener diodes attached to the HV CT to ground. This is very effective at dropping a reasonable amount of voltage...enough to get it in the range of vintage voltages. I think the zeners cost...maybe $.25 each. A couple 12v 5 watters might just do it with a modern Tweed Champ Transformer.

(Thanks for that suggestion Bruce! It has worked like a charm for me.)

Meee tooo - on a number of occassions

[Howlin' Mad Mac]

Yeah, you're quite right there... the tone from a VHT 6 would not be that of a Tweed Champ but then again neither would a project built from a Champion 600. To turn one into a true 5F1 with all the vintage vibe/mojo would require new transformers (PT at minimum), replacement of the SS rectifier with a 5Y3, additional octal tube socket, caps, resistors, pot, input jacks, pilot light, fuse holder, speaker and tagboard (which you would have to layout and fabricate as well.) Also if you really are after as close to the tone of an original 5F1 you would need to tweak supply voltages and while I can't swear to this but in confirmation of the vintage building community at large would also require fabrication of a pine cabinet with box joints. Personally if someone's gonna get that picky they'd be better off just getting a Tweed Champ kit or building from scratch and even then voltages will need to be adjusted to compensate for modern transformers/tubes. As I think most of us all know... you can do it right or you can do it cheap but you can't do it right and cheap.

[Howlin' Mad Mac]

Ya that's a pretty cool idea. I've always used a power resistor before the reservoir when I've needed to bring voltage in line but using zeners is an elegant solution. How would you do that with a stock Champion 600 PT that don't have a HT CT? Can you create one like using a pair of resistors like with the heater winding?

[tubeswell]

Ya that's a pretty cool idea. I've always used a power resistor before the reservoir when I've needed to bring voltage in line but using zeners is an elegant solution. How would you do that with a stock Champion 600 PT that don't have a HT CT? Can you create one like using a pair of resistors like with the heater winding?

If you have a FW bridge rectifier, the zener goes on the 'ground-side' of the bridge, cathode (banded end) pointing to ground

[steve_rolfeca]

Regarding dropping voltage...On a number of occassions, Bruce has suggested using a few zener diodes attached to the HV CT to ground. This is very effective at dropping a reasonable amount of voltage...enough to get it in the range of vintage voltages. I think the zeners cost...maybe $.25 each. A couple 12v 5 watters might just do it with a modern Tweed Champ Transformer.

(Thanks for that suggestion Bruce! It has worked like a charm for me.)

Sorry for the thread hijack, but I tried the zener trick with my 5E3, and dropping the voltages certainly helped the tone. But not as much as one of Bruce's low-voltage PT's. The dynamic behaviour was much, much better after the transformer swap.

It's funny, I would have expected more sag and a less brittle sound from the little Mojo transformer than from the much larger Mission PT. I've been playing with tubes for about twenty years now, and it seems like the more I learn, the less I know