Done-ish | '75 Fender Champ Pt 4
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- Опубликовано: 5 июн 2024
- Pending a few decisions the owner will make and the arrival of its new cabinet and speaker, the Champ is done.
And sounds quite nice if I do say so myself.
Previous videos on this amp are in the Vintage Fenders playlist.
My buddy Brad's video on a similar service done on a (much larger) Twin:
• Fender Silver Face Twi...
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These are things I get asked about a lot :
Amp Tech Gear Used :
Hakko FX-951 soldering station
Weller SPG 80L soldering iron (chassis work)
Rigol DS1054Z digital oscilloscope
Thsinde 18B+ digital multimeters
Kester 60/40 solder
Techspray #4 No-Clean Desoldering Braid
Below are things that make this channel possible that people don’t usually think about. If any of these companies want to send me new and wonderful toys, I’m open to that. I can’t take free stuff when it comes to the amps I review, etc, but for the stuff below, bribe away!
Microphones/Audio Equipment :
Guitar Amps : Royer R-10 Hot Rod and/or Shure SM57 (noted in videos)
Voiceover Bench : sE Audio sE8 (small diaphragm condenser)
Voiceover Streaming : Shure SM57 with shockmount and windscreen
Voiceover Mic Arms : Elgato Wave Mic arms
Guitar Mic Stand : Gator Frameworks short weighted base stand with boom
Mic Cables and Guitar Cables : Mogami/Neutrik
Mic pre : MOTU M2
DAW : Logic Pro II on MacBook Pro 16 running Sonoma 14.5
Plugins : No effects other than level matching/normalization unless a recording
specifically has reverb etc added in post (rare, various Waves plugins)
Monitors : Yamaha HS7s
Monitor Stands : Gator Frameworks Desktop Clamp-On Stands
Monitor Isolation Mounts : IsoAcoustics Iso-Puck Minis
Headphones : Beyerdynamic DT 770 Pro (main)
Headphones : Sony MDR-7506 (alternate)
Video Equipment :
Camera : Sony ZVE-10 with SmallRig Cage (main)
Lens : Sigma f2.8 18-50mm (main)
Lens : Sony ZVE10 kit lens (rarely used)
B Camera : Apple iPhone 13 Pro (rarely used)
Tripod : SmallRig 71” with SmallRig Fluid Video Head
Streaming Mount : Elgato Master Mount S with SmallRig Ballhead
Bench Light : SmallRig RC 120D
Bench Light Diffusor : SmallRig Lantern Softbox
Bench C-Stands (light and overhead camera) : Neewer Pro SS Heavy Duty
Streaming Light : SmallRig RC 120B
Streaming Diffusor : SmallRig Parabolic Softbox
Streaming Light Mount : SmallRig 148CM Wall Mount Boom with Triangle Base
Various Other Lights : Neewer LED Panels with Neewer Softboxes
Video Software :
Davinci Resolve 19
Phantom LUTs
Paul Leeming LUTs
Adobe Illustrator 28
Adobe Photoshop 25
Ecamm Live (streaming software) 
Видеоклипы
Thanks for the shout out, fella!
And beautiful work as always!
This is one of the most fun series Lyle has ever posted. Everybody loves fender champs!
Agreed!
I love 'em even more now after watching the series.
Australia is blessed to have Brad’s Guitar Garage! He does perfect work on some of the most haggard, destructively modded and most hopeless amps on the upside down parts of the world.
I still can’t figure out how he stands on his head all day and does such wonderful work.
Cliche Aussie jokes aside, He really is a master at rebuilding anything guitar electronics related.
…And Lyle…well, you can see his results here. Just fantastic work and has taught me a lot of new tricks.
For the mids resistor maybe use a CTS 250k pot that has a push-pull switch to enable either 15k or 7k to be selected
Normal position would be 15k
Pull out the bass knob and the additional 12k mid resistor in parallel with the 15k mids resistor will create a 7k mids configuration
It is transparent modification that works nicely
I like it better with the paralleled resistor, but nice either way!
Excellent work and demonstration as usual. (: All amp techs who charge money should have to completely rebuild a 70s Champ. Or even a dozen. A simple circuit offering so much in the way of flexibility (and possible modifications, sure) and a great insight into how so many more complicated amps work. So many good lessons on the importance of each element and how it all works together - as well as lead dress, component location, overly-long wires, consistent quality soldering, wax-impregnated eyelet boards, you name it. Not to mention properly and lovingly fixing a nearly 50-year-old vintage amp. Thanks for documenting this all. (:
Wow that resistor change was transformative. I personally like the 7k
That 15k in parallel reminded me of a BBE Sonic Stomp pedal. Like taking a blanket off of your speaker cab.
Nicely done Lyle! I'm soon going to rebuild my '78 Vibro Champ. I bought a parts kit from the Fender amp guy in Cali and asked him to include a 6.8k mid resistor, per your recommendation. Hearing it in the compressed RUclips world, I know I'll like the tone better than the stock 15k. I'm sticking with the 4ohm speaker and using a G8C from WGS.
Just picked up a 72 Champ yesterday. All original. The volume pot works but you can keep spinning it past the 1 and 10. Weird thing is turning the Treble down decreases the volume to almost 0. Even with the volume up. Going to start with replacing the Volume pot and go from there.
The wiring also has that green goo at both ends. I’ll be replacing that.
Thanks so much for the great content.
Sounds like a find. It would make me wonder if you can find a NOS matching pot, or something that looks like it belongs. I guess new production works as well.
so you can turn it up to 11… 😂
The pushed-in notch in the metal rear casing of volume and tone pots isn't merely a place to squirt control cleaner, it functions as a stop so the control can't rotate continuously. The rotating plastic disc that holds the wiper should have a protruding plastic tab that stops when it hits the notch in the metal case. The tab is probably broken off and rattling around in the control or inside the amp. The control might be repairable; nylon is difficult, almost impossible to glue but maybe you can melt a small nail or wire brad into the nylon disc with a soldering iron to function as a stop by hitting that metal notch. It's worth trying, and even if you fail you'll still learn something! 🙂
I guess I never saw inside a Silver face Champ. It looks like the same chassis, power switch, sideways tube sockets as my Musicmaster Bass amp. I am currently rebuilding it and adding a tube phase inverter. I also added chassis soldered grounds near the pots and jacks like on this Champ. This video was very helpful.
Thank you,
Funny that I have had several amps featuring a Fender tone stack with a middle pot. But I have noticed that I actually don't need an adjustable middle control at all because I tend to keep it in the same position anyways even almost independent of guitar or speaker used. And I have measured the optimal value and it means in my case around 7.5-8.5 kohm. That original solid 15k is usually absolutely too much for my ears. Going to much smaller values than about that sweet spot increases the load the plate of the driving stage which can be in certain circumstances seen easily as a distortion when feeding the input from sine wave gen.
Awesome neat work as usual 👊😎
Other factors such as B+ voltage, plate current, and actual load impedance, matter. But in general, 8k primary impedance is a better choice for a SE 6V6 and 5k is more appropriate for a SE 6L6.
great work Lyle, really enjoyed all your videos
So many options to get a signature sound.
Having just made a simple repair to a failed amp - transformer secondary fail, common fault on that model Marshall, I think a Champ might be a nice place to try building something from scratch!
Hopefully using some of the info gleaned from this channel to do it well!
Love it!. Building a vibro champ now (mojotone).
I was considering putting the 8 and 4 ohm taps on a switch.
I just may end up using the 8 and putting the 4 ohm tap on the resistor like you did here..
Job well done, time for coffee
"oh what a diff'rence, a resistor made. 15K little ohms..."
Ever think about putting together a recommended parts list for various amps? Or would this lead to “DIY nightmares”
I'm in the process of learning how tube amplifiers work and this video was, as always, very informative. However, I preferred the 15k mid resistor. Probably because of the more gain. You seemed to prefer the cleaner sound?
Aloha Lyle! Is the Owner going to bring new cab and speaker? If so, You going to test it with new cab?
All on order. It’ll be a bit.
Whoa, speak of the Devil. I have a '73 Champ that is still in very good condition. I've never played it. I've just been lugging it around and putting it in storage. A tech told me a few years ago that it looked to be in good shape. However the speaker cone is basically dust. Is it worth it to recone the original speaker for Original condition for possible re-sale, or should I just put an appropriate speaker in it's place, Webber, Jensen or whatever? Whether or not you reply, I still want to thank you for your channel. I'm learning a lot.
Thanks. The original speakers in these aren’t great. Get a new one.
@@PsionicAudio Wow, thank you. Will do!
I have had some techs tell me to put the hot wire from the mains cord go to the switch and then to go to the fuse, so the fuse & fuse holder won't be live. What is the first primary rule of safety regarding servicing anything electrical or electronic that plugs into a mains outlet? UNPLUG IT FIRST! I have had those Carling toggle switches short to ground.
Putting the switch first in line with the incoming hot lead won't turn off the voltage to the fuse if the wall outlet is wired backwards (nightclub electrical systems are notoriously dangerous). Anyway, I think perhaps America should use double-pole on-off switches like they do in Europe, so that both hot and neutral are disconnected when the switch is off.
Yup. Switches can short to chassis.
And the law is that any device like this must be fused first. Period.
That 15k in parallel reminded me of a BBE Sonic Stomp pedal. Like taking a blanket off of your speaker cab.
Big difference in tone from one change.
It would be cool to have that switchable...?😎👍👍
Yeah, Champs tend to be a bit midrangey and muddy for my taste; it sounded much better to me with the lower value mids resistor.
I'm in the process of learning how tube amplifiers work and this video was, as always, very informative. However, I preferred the 15k mid resistor. Probably because of the more gain. You seemed to prefer the cleaner sound?
I just wanted to do a little mini lesson on what a difference that one resistor makes, so players can be more informed about their amps.
Doesn’t matter what I prefer - this will be the client’s choice.
@@PsionicAudio, Most 8" speakers in a Champ are going to be somewhat mid-range heavy anyway, so I definitely preferred the paralleled, lower value resistors. It will be interesting to see what the customer prefers. Were you running this through your shop 4x10 or 4x12 cabinet?
2x12