This video shows the conversion of a fender Champion 20 solidstate amp to a Champ Amp AA764 handwired tubeamp. It also shows a few beneficial modifications You will find a sound demo here : • Champ Amp AA764 Clone ...
You read my mind! I just got an EG solid state practice amp that’s about the same size. I plan on building a champ in the chassis with a ten inch speaker.
I would have liked to hear a sound demo, also hearing the effect of the NFB and tone stack bypass switches. You are a very accomplished player, I checked out your blues duo videos, fabulous stuff.
Lovely work, I did something similar a few years ago with my Frontman 15R and built a Tweed Princeton into it with a few mods. Great little undercover amps
I am tempted to build one of these. I built a micro deluxe as detailed on Rob Robinette's website. Very pleased as a home practice amp but now need a small, light but slightly louder amp to play at local music groups. A mic input plus line in and instrument input to run guitar and drum machine, poss two channels. :-)
Genuine Fender chipboard with it's amazing sound deadening tone-removal qualities and vintage-like weight increase... You can't just go out and acquire such features (?) ...well I doesn't thimk you can (Always enjoy your vids BTW)
I did the same thing with my grandpa but we made mine into a mini Fender 65 reverb style amp I have a RCA 12AU7 tube for the preamp I prefer cleans and the other tube is a 6V6 and the spring reverb tank I bought on eBay My style is more like Luther Perkins when I play I play classic country and Rockabilly and blues I don't use pedals and the speaker is a 8inch Jensen C8R I get that late 60s Luther Perkins tone I also use flatwound strings I took out the gain knob so it's just volume mids treble bass single reverb knob and I took out the FX select and the the white button is now a bright switch and I added a classic tube amp on off switch we took out the PCB board it's now hand-wired point to point like back then And I also turned a Fender frontman into a mini 1952 style Bassman style tube amp it's also got 12AU7 tube in the preamp I have a 6L6 tube 6inch custom bass guitar speaker to fit in the amp
@@martinstubeampworkbench2299 yessir I'm 21 years old my grandpa is 68 that man is the most hard-working guy there is even when he's not working on electronics and woodworking me and him work outside fixing other things like chicken coops for example typical country boy stuff howdy from North Carolina
Hi, didn’t you have to change the power and output transformers? Also, where did you get the faceplates? The point to point looks top notch btw.. Also, where did you get a tube chart? The outcome looks great and I’m sure it sounds great too. Just curious if you don’t mind, how much did it cost to convert it not including your time? Every video of yours really impresses me with your knowledge and attention to detail.. I sure hope the algorithms that suggest videos to people picks up on your channel because you deserve it. Be well, Tom
Hey Tom, yes I changed the transformers. Transformers from a solid state amplifier won‘t work for tubes. The faceplate was a little bit tricky. I designed it on my computer, put it on an USB stick and went to a printshop. They printed it on a selfsticking foil, made to cover cars. It is very reliable. I spent around 250 bucks for the conversion. But don’t forget the fun building an amp. AND by the way: thanks a lot for your kind word. I appreciate that.
The original capacitors were obviously overheated by high-frequency ripple coming from the switching power supply. A common problem with many many solidstate devices nowadays since almost everything uses switching supplies. You can't use cheap capacitors on that type of design and expect them to last.
This is great! Thanks so much for sharing. I'm an amateur builder and have assembled a Princeton kit, but would love to try something like this, though the point to point is a bit intimidating! Nice work! Did you design the circuit yourself?
Thank you for your kind comment. I agree, that it’s easier to use an eyletboard. Point to point is a challenge, when you do it the first time, but you benefit having a quieter amp, less hiss and hum, because of less wires. The circuit is pretty much stock, except the mods, I tried to explain in the video. Using the Champion 20 chassis wasn’t a problem, because the faceplate has a lot of holes. Some of them I had to widen, for example the one for the pilot light. If you consider building a champ from the scratch, go for a 10“ speaker. 8“ always lacks in the bass response.
@@martinstubeampworkbench2299 thank you Martin! I appreciate your comment. It sounds like you used the stock circuit and did mods as noted in the video. I'll listen again to see what I can gather. I read adding a master to this circuit is sometimes problematic, but it doesn't seem like your experience! Great tip on speaker size as well. Yes, a 10 inch it is! 😁
@@trbr1799 Hey Trbr1. Yes I was using the stock circuit. A Mastervolume is not a big deal in a single ended amp. Using a 1 meg pot, connect lug no. 3 with the coupling capacitor that runs from pin 6 of the preamp tube. Connect lug no. 2 ( middle lug ) with the gritstopper resistor which runs from pin 5 of the output tube. Lug no. 1 goes straight to ground. That’s it. With the volume pot all the way up, you get some nice saturation and you can dial in the loudness with the mv. Though you still wońt have a high gain amp! But a Blackface is sounding best, when it’s clean anyhow. Take care!
@@martinstubeampworkbench2299 thank you for taking the time to respond. I appreciate it! I'll look into this as an option since I really like the idea of a master volume. 😁 Appreciated, sir!
I have a Super Champ X2 head with a most likely dead power XFMR (from a 'fall-over' -no continuity on the primary windings) and I'm trying to decide whether to just fix it or get "creative"... Any suggestions? ...Cheerios
Sounds great. What brand and model power transformer did you use for this build? And do you recommend any specific supplier for the other components? Really appreciate you sharing your mods as well. Very insightful. If you have any separate webpage for personal contact, please share.
Hi John, the power transformer was a Hammond 290 CAX, the output transformer a Hammond 1750 C. If you want to go for an 8 or 16 ohm speaker, you should use a 1760 C. It makes no sense to recommend a specific supplier, because I am located in Germany. But I ´m shure you will find a supplier in the internet. I have no website for my ampshop yet. Since I started building and repairing amps, I’m pretty busy. The word is getting around and I neither have time, nor need to take care of an official website. Might be something for the future. Thank you for your interest.
@@johngilson2227 Hey John ! Good luck and have fun. One last advice: if you build this thing from the scratch, go for a 10“ speaker. Sound way better! Greetings from Germany
Thanks a lot! I designed the faceplate on my computer. It was a bit tricky and took some time to make it fit to all the pots and jacks. When I was shure, that it´ll fit , I put it on an usb stick, took it to a printshop. These guys printed it on a selfsticking foil, that is made to cover cars and trucks. A very reliable and long lasting way to reproduce the look of Fender ( or others, like my Supro/National build) faceplates. Greetings from Germany
Well, the champion 40 has a bigger cabinet, a 12“ speaker and a bigger chassis, right? A good starting point to convert it to a 6g2 Princeton (brownface circuit) or if this is too complicated for your skills, go for a Vibrochamp . Just two more knobs and a few components. Both amps have a wonderful clean tone and a great tremolo. By the way, I recently had a Silverface Vibrochamp on my bench. If you are interested, I’m going to release a video about it within the next few days on my channel. Have fun!
And the funny thing is, they always keep saying that modern electronics is more reliable than valve electronics, as you can see that's clearly not the case at all as shown in this video.
Sorry, but there's nothing in this video that proves valve electronics are more reliable than modern (solid-state) electronics. Although the filter caps appeared defective, we have no way of knowing what really happened, since the amp was not even inspected or tested before being trashed 🙄
They don’t put any effort into analog solid state amps nowadays (except for a few companies like Orange, Quilter, Roland…), but from the mid 80s to late 90s Marshal and Fender made outstanding solid state amps. I have a Fender Sidekick 25 from around 1990 that is still going strong. Hasn’t yet any needed servicing or maintenance. My four 60s tube amps all need some work that I’ve been putting off because it’s going to be hundreds of dollars, maybe over a thousand to get done.
It's not the technology but how it's used....Modern Electronics are much better when used properly....These cheap SS Amps are built to price and churned out so Fenders fault for making cheap shitty products....Not just Fender either....Plus this wasn't a 'conversion', he just used the Cab to house something else not really a conversion is it!
Great build. I do like point to point, but aren’t you concerned about the caps basically being supported at the ends of the leads? I didn’t see any support under some of them, and I would worry about vibration causing the leads to possibly break. Just an observation. I like the mods you did. What do you think about adding tremolo? Without looking at tube specs, I wonder if the power transformer would need to be upsized? Would you have space for the extra components? Thanx, great project. I love seeing tube amp monsters being created or replacing solid state.
Hey Dave. Thanks for your interest. In an short video like this, I can not show or discuss every detail. But I supported the HT caps with zipties at the terminalstrips. These guys don’t go nowhere! Of course I could not repurpose the champion PT. I had to replace it. A tremolo is a great idea. I made a Supro clone a few years ago, with a tremolo. Sounds fantastic. Greetings!
