hey guys!
I recently bought one of those cheap little amps and I immediately liked it but there are some common problems with it, so instead of fixing them, I'd like to rebuild this amp with better components! A friend of mine is a joiner and I also know an engineer who will help me with the dangerous work. I personally have had five years of electrical engineering in school and I also know the basics of soldering.
I'm trying to figure out which parts are used in the Champion 600 reissue.
my first two questions: are there only carbon film resistors used and which type of capacitors would you suggest me to use.
my goal is to get a very similar tone as the reissue, not like the 5F1 or any other tweed amp.
greetings from Austria!
rebuilding Fender champion 600 from scratch
Moderators: pompeiisneaks, Colossal
Re: rebuilding Fender champion 600 from scratch
okay I will stick to the carbon film resistors but what about the capacitors?
Re: rebuilding Fender champion 600 from scratch
Yes, 1/4 watt carbon film resistors throughout, but 12AX7 plates have 1/2 watt carbon film. Power supply dropping resistors and screen and cathode for the 6v6 are 2 watt metal oxide. Film caps in the signal path are generic looking red film caps (maybe panasonic?). Preamp cathode bypass caps are bennic. Treble cap in the tone stack is a blue generic looking ceramic.
Nothing magic about the parts, anything high quality will be a step in the right direction imo.
I'm modding one right now, but ran into some issues and probably need to make a post for some help with troubleshooting.
Good luck on your build!
-Dan
Nothing magic about the parts, anything high quality will be a step in the right direction imo.
I'm modding one right now, but ran into some issues and probably need to make a post for some help with troubleshooting.
Good luck on your build!
-Dan
Re: rebuilding Fender champion 600 from scratch
Use 1 watt resistors for signal/tone/plate/cathode/coupling (everything except power dropping resistors where you might need higher wattage). 1/4 watt resistors are fine for pedals, but they're SO SMALL and wimpy for decent, hand wired guitar amps.
I build and repair tube amps. http://amps.monkeymatic.com
Re: rebuilding Fender champion 600 from scratch
Thanks! that´s very useful.
I am thinking about an od mode with 8" speaker in a little bit bigger cabinet (like mojotone 5f1).
I am thinking about an od mode with 8" speaker in a little bit bigger cabinet (like mojotone 5f1).
Just out of curiosity
So, you're willing to gut a reissue to build about just the exact same amp out of it?
(I can't believe you plan to gut a vintage thing to build something which costs just a fraction of its price)
That can be a good plan but I truely wonder what issues you're planning to solve this way, because if you end up just re-using the chassis it may look as some waste, afterwards...
If I had one of those small practice amp I'd mostly just voice it to my taste and do with it as is. If that doesn't suit your need why not building your own boutique style amp from scratch, starting with good transformers?
Even if you're in the continental US, you will quickly spend a few hundred dollars of hardware, components, cab (incl. tolex & grillcloth), speaker, etc, anyway...
Also, I'm not sure that you'll have to bother with components quality/"period corectness"/mojo if you plan building a reissue. Metal and carbon film ones should be fine - except power dropping... )
(I can't believe you plan to gut a vintage thing to build something which costs just a fraction of its price)
That can be a good plan but I truely wonder what issues you're planning to solve this way, because if you end up just re-using the chassis it may look as some waste, afterwards...
If I had one of those small practice amp I'd mostly just voice it to my taste and do with it as is. If that doesn't suit your need why not building your own boutique style amp from scratch, starting with good transformers?
Even if you're in the continental US, you will quickly spend a few hundred dollars of hardware, components, cab (incl. tolex & grillcloth), speaker, etc, anyway...
Also, I'm not sure that you'll have to bother with components quality/"period corectness"/mojo if you plan building a reissue. Metal and carbon film ones should be fine - except power dropping... )
Re: rebuilding Fender champion 600 from scratch
yes I want a decent sounding amp with the tone of the reissue in mind without hum, but with the option for more punch 
the 8 inch speaker combined with some mods will make a much more versatile amp and still suitable for bedroom level. a self designed circuit would be great but this is my first project and I definitely need the template! The same circuit on a DIY board.
I will take some solid parts, better quality than the Champion 600 reissue components, all together for about 200 - 300 euro + 100 euro cabinet.
Which main and output transformers would you suggest?
the 8 inch speaker combined with some mods will make a much more versatile amp and still suitable for bedroom level. a self designed circuit would be great but this is my first project and I definitely need the template! The same circuit on a DIY board.I will take some solid parts, better quality than the Champion 600 reissue components, all together for about 200 - 300 euro + 100 euro cabinet.
Which main and output transformers would you suggest?
Re: rebuilding Fender champion 600 from scratch
Dismantling an amp, which starts to appear as a collectible item to keep just the chassis doesn't sound right to me, anyway...
To my taste a "decent" sounding amp starts with a better - not a bigger - speaker, and a less cheap output transformer (OT). Low (filter) capacitor values on the signal path can accomodate with the lack of bass response of the OT, which means that the speaker might not be the sole responsible for that - if this one of your concerns.
Moreover, 100€ a cab appears to me pretty optmistic. Tolex and grillcloth aren't cheap, while - in the mean time - the value of the outcome generally does not exceed that of its appearance...
(if you're not a famous artist in the business...
)
So, I will likely follow this thread and I hope that you won't end up in frustration, once dissipated the joy of having achieved the project and built a sounding amp: in my book a 6.5" replacement speaker and a beefier OT would me a more valuable expense with respect to several points, the one mentionned above and also retaining (more than) the value of the amp - at a least expense.
To reply to your question, I'll probably go with the stock power transformer but your choice for the OT depends much on your location. In France, I'd probably with the Hammond tranny for 8W single ended amps.
Depending on where you live and more info about the circuit - including measured voltages maybe, others will probably suggest more interesting options but this one seems pretty failsafe to me. Check the dimensions, anyway.
To my taste a "decent" sounding amp starts with a better - not a bigger - speaker, and a less cheap output transformer (OT). Low (filter) capacitor values on the signal path can accomodate with the lack of bass response of the OT, which means that the speaker might not be the sole responsible for that - if this one of your concerns.
Moreover, 100€ a cab appears to me pretty optmistic. Tolex and grillcloth aren't cheap, while - in the mean time - the value of the outcome generally does not exceed that of its appearance...
(if you're not a famous artist in the business...
)So, I will likely follow this thread and I hope that you won't end up in frustration, once dissipated the joy of having achieved the project and built a sounding amp: in my book a 6.5" replacement speaker and a beefier OT would me a more valuable expense with respect to several points, the one mentionned above and also retaining (more than) the value of the amp - at a least expense.
To reply to your question, I'll probably go with the stock power transformer but your choice for the OT depends much on your location. In France, I'd probably with the Hammond tranny for 8W single ended amps.
Depending on where you live and more info about the circuit - including measured voltages maybe, others will probably suggest more interesting options but this one seems pretty failsafe to me. Check the dimensions, anyway.
Re: rebuilding Fender champion 600 from scratch
I've owned my champion 600 for about 10 years now. I bought it specifically because of the tiny speaker since I was moving to a small apartment in a high rise for a year during school. I've swapped the tubes in mine, which made a minor improvement. I also swapped the speaker and changed to proper grill cloth. This made a HUGE difference. So, I agree with ChopSauce. I put in a Jensen Mod speaker. Worth every penny.
The stock circuit is just a blackface circuit with TMB in fixed positions. If you already have a similar amp, you may consider doing something else or not if that's what you like. Good luck!
On resistor size, if you are making your own board then you should go 1 watt as mentioned above. On the pcb I am not sure you could fit bigger than 1/2 watt without standing them up.
-Dan
The stock circuit is just a blackface circuit with TMB in fixed positions. If you already have a similar amp, you may consider doing something else or not if that's what you like. Good luck!
On resistor size, if you are making your own board then you should go 1 watt as mentioned above. On the pcb I am not sure you could fit bigger than 1/2 watt without standing them up.
-Dan
Re: rebuilding Fender champion 600 from scratch
I will take the AA764 Circuit and make a blackface champ! many useful parts , infos available and less work.
I´d like to have a clean switch with similar settings like the Champ 600. I read there are some resistors added to the AA764 circuit to reduce gain for the champion 600. Is it possible to add these with minor effort? (switch or potentiometer)
Thanks for the useful response so far!
I´d like to have a clean switch with similar settings like the Champ 600. I read there are some resistors added to the AA764 circuit to reduce gain for the champion 600. Is it possible to add these with minor effort? (switch or potentiometer)
Thanks for the useful response so far!
Re: rebuilding Fender champion 600 from scratch
I don't know really but (just too) many things are possible. That is just a matter of expense, either money, either your time. Maybe both...
Whatever you'll be doing finally, this will be great oppotunity to learn and start in the matter than makes us meet here, but if you intend building a blackface champ, you might as well end up not even using the chassis...
Did you considered starting with the schematic of the Champ 600 (just post it) and (very) slightly re-designing the circuit according to your taste...
One last thing, before the discussion starts to be pretty technical and will be better just reading what wrote more experienced members of the forum:
- yet I am not a great amp builder, I have been customising almost any kind of things around me: furnitures, houses, cars, motorcycles, etc, and afterwards, I feel like any attempt I had to go "against" the nature of the thing was mostly wasted. This is the first reason why I so much insisted for you take it as the little practice amp it is. The second reason is I like its design very much and I'd only change its grillcoth - in addition to what was discussed - if I had one.
Have fun, anyway...
(I'm just jealous...
)
Whatever you'll be doing finally, this will be great oppotunity to learn and start in the matter than makes us meet here, but if you intend building a blackface champ, you might as well end up not even using the chassis...
Did you considered starting with the schematic of the Champ 600 (just post it) and (very) slightly re-designing the circuit according to your taste...
One last thing, before the discussion starts to be pretty technical and will be better just reading what wrote more experienced members of the forum:
- yet I am not a great amp builder, I have been customising almost any kind of things around me: furnitures, houses, cars, motorcycles, etc, and afterwards, I feel like any attempt I had to go "against" the nature of the thing was mostly wasted. This is the first reason why I so much insisted for you take it as the little practice amp it is. The second reason is I like its design very much and I'd only change its grillcoth - in addition to what was discussed - if I had one.
Have fun, anyway...
(I'm just jealous...
)