Argh, I misspoke. At one point I said Leo chose the bright cap value for roundwounds but I clearly meant to say he chose the value for flatwounds. I didn’t mean to sound like I was contradicting myself.
I caught it and anyone paying attention would have known what you meant. Otherwise, thank you for being the only amp tec to be able to explain why the bright cap was set at an unusable value, or unusable in today's world. Omgosh that makes so much sense. Thanks again! splendid video and videos.
Maybe one day… How about the much overlooked, though maybe not any better sounding, ‘94 Twin Amp? Not as much a vintage design, but similar in some ways circuit-wise to AB763 without all the circuit switching, extra-drive, inserts, mix and amp I/O scheme. Sorry, forgot about the Jan ‘22 post.
COULD NOT AGREE MORE. I sent a link and told my buddy I learned as much about amps from my one week marathoning Psionic as I had in the 20 years since I started playing guitar.
Fantastic video - thank you so much. I recently inherited a Twin Reverb from the late seventies and it only partially works so this is very helpful in understanding how it's supposed tk work. Fender's designs from back then aren't the most intuitive.
GREATEST Vintage Fender video ever. So grateful to have good information all here in one place. For most it takes YEARS to learn/understand all this stuff (if ever). This video is a huge service to the vintage guitar amp community. Thank you, Lyle & congrats on 25k! 🏆
You have taught me to solder and desolder correctly, how to spot bad factory solder, recognizing burns on a board . Thanks from a six string front sider, and congtats! Keep that AMSR voice Brandy Smooth.
Your channels growth is well deserved. One of the best amp techs/builders out there and a great educator, providing a most valuable service to the community. Well done Lyle!
I just want to say you do a great job for beginners to understand these things such as the voltage issue with no load and the standby switch. That was eloquently said in this video as well as the ground lift reference. I started 12 years ago building amps as an industrial and commercial well trained electrician and struggled for years learning things. When you started comming out with these videos I had considered doing something simular. When I saw how you were doing this and that you see and have way more experience with different amps than I do(mine is a hobby not primary work). You do such a Fine job at this and speaking about these things, I say kudos, let the pros teach. Kudos
Thank you so much. Your vids are not only very informative but your presentation, voice is excellent for these instructional/info rich vids. Learning so much about fender. I have a 77 or 78 fender twin, had it since 1998 and I’m still learning about it.
Lol, large companies are generally risk averse. I'm sure there is a safety Nazi lawyer having a panic attack over these videos. Besides, keeping people ignorant about circuits probably means more money for them.
Lots of good info! For whatever reason I like “input 2” a lot - I use it a lot. Now I know that input is maybe a little more different from input 1 than I thought. I feel a little vindicated - like, oh, it IS actually different.
Was playing a newly Rehabbed roadhouse with a beautiful fresh stage. Lots of noise from my Silver DR and the PA. We knew we had a ground situation but could not find it. Every amp was properly 3 wire plugged etc. Well time to go noise or not so I walked up to the Mic and ended up in the drums on my back. Pretty blue fire. I thought somebody had decked me. I had grounded the PA system one hand on the strings one on the mic. Don;t know how I didn't die. Found out no grounds on the new wiring for the stage. We ran a ground cable and got back up there. Played 4 hours with a welt on my lip that kept getting bigger. Moral is that ground thing is no joke son!
After the ground switch has been disconnected, the death cap removed, a grounded cord installed properly, and the power input wiring is CORRECT, then you can repurpose the ground switch to become a pentode/triode switch which will give your amp a reduced power mode. I recommend that over and above a negative feedback switch.
I do not, nor will likely ever, own a vintage Fender amp. Yet I find this, and really all your videos, endlessly fascinating. Keep up the good work...on both the amps and the channel!
Amazing detail you remind me of a guy named Jim Kelly that makes amps here in Orange County… or used too , another guy with complete understanding and practical history knowledge 🤙🏽
I just put one of those Warehouse speakers in my Princeton reissue to replace the Cannabis Rex it came with. Seems to have less output, but far better tone. Closer to what you'd expect from a Fender. Broke it in a bit with several plays of Mahler's 5th Symphony.
You are becoming the AvE of amp repair. I mean that as about the highest compliment I can give. Thanks for lettings us peek over your shoulder and telling us what you do and why. 😎👍
I literally just built a trainwreck expess, and when i fired it up, i plugged into the ext jack by mistake and was scratching my head for an amount of time that im too ashamed to admit ! Hahahah
It's worth noting that the silverface models that did come with a grounded plug still retained the three way ground switch, rendering it unsafe if that gets switched from the grounded position. I found that out the hard way recently while running two amps in stereo.
@@shckltnebay Fender didn't start using grounded mains until around 1970. The amp I was using was a late 70s Princeton Reverb with the red three prong plug and a three position ground switch.
@@jimmyjoefine I miss read your post, Silverface started in 1967 I thought you said SF came with grounded cords, are you saying the death cap failed in a closed state and made a path for power to chassis?
Congrats on 25K. It wasn't long ago you reached 10K. I've been with you since you were in the low thousands and have learned a lot from watching nearly all of your videos. I even gained the confidence to re-cap my 1968 Bassman, 1969 Super Reverb and 1977 Deluxe Reverb. I've also learned to stay away from the insides of my 1976 Super Twin Reverb. That thing scares me, lol.
I watched this video again this morning and when you showed the Super Reverb, my eyes were glued to the dings and dents on the bottom of the control panel, lol. I would have that thing removed and clamped up between 2 pieces of steel. I use c-clamps and work on one section at a time.
This is singlehandedly (is that a word?) the best channel on youtube if you're a guitar/amp-nerd like me. Very calm and pedagogical approach. Congrats!
I loved this in depth explanation! A lot in the beginning I already knew but explaining the front panel in depth was informative and enjoyable! Thank you and keep up the great work!
Congrats on 25k! Well deserved. The knowledge you share so freely is a generous and kind act. I own an AC-15 clone that you modded for the previous owner and it’s superb, my favorite amp. I’m looking for a Princeton and once I find one, even though there are competent techs nearer to me, I plan to ship it to you for your tone and reliability upgrades. Not even considering anyone else. Thanks again for a great, informative channel!
Congratulations, Lyle! I learned a long time ago not to play my guitar through my Twin Reverb in bare feet. It came with a grounded plug but somehow when my buddy turned on his Ampeg amp the next time I pressed one of my effects pedal I found myself doing the spaz dance of electrocution. He switched his ground switch and the problem went away. Always wore socks and sneakers after that just for peace of mind.
I've been dipping into your channel for a while and just stumbled across this incredible video. Some of this goes over my head (I admit!) but the level of detail and explanations you give is seemingly unparalleled on RU-vid, as far as I can tell. I just bought a little Pro Junior IV and I'm really enjoying it so far. It had a bit of hum at first but I pulled the back off and pushed the ribbons down and away from the cabling which appears to have reduced the hum a bit. It's about all I'm qualified to do, but I really enjoy the way you walk through all the components, design and operation (and faults!) in your videos. Cheers from Brighton, UK.
This is amazing! thank you so much! Some things to mention - as high your set volume control the bright switch have less effect, in twin reverb in volume 6,5 it almost sound identical like it when in off position. If you have master volume fender - trun in to 10 and it will be the same as no master volume fender amp.
Thought I'd already subbed, I have now. The first two and a half minutes had my jaw hitting the desk - never realised how much of a deathtrap early amps were...
Hi Lyle. Congrats on the 25K subscribers - you deserve it! 😃 One question for you: Have you ever considered using the hole from the bypassed polarity switch to mount an H.T. Fuse - like on a Marshall or many other european amps? If the owners let me, I always do this when restoring old Fenders. And I do believe this has saved at least a few of them from "letting out holy smoke" over the years and limited the damage to just a blown fuse. Thanks for all your good work - keep up the spirit!👍😀
My understanding of the 1 and 2 input jacks on both channels, is that 1 was designed for single coil Fender guitars and 2 was for Gibson-like guitars with humbuckers. The bright switch or bright channel was to compensate for the darkness of humbuckers if they needed to be brightened up. I started using Fender amps in 1966, and had a little 1950s five watts tube tweed amp for my initial practice amp. My Dad had picked it up somewhere for $5, ha. It broke up into dirty/overdrive/distortion/whatever a lot, possibly because I over drove it on the volume or it needed new tubes/caps, ha. At the time I was more into clean so did not realize it was good for overdriven lead solos, and was mostly practicing rhythm guitar with chords in the beginning.
Congratulation and Thank You I have a hand full of Fender amps yet as much as I love watching you work I have never done anything other than tightening the screws and nuts. Heres to 50K!!
A truly awesome video. I’ve been playing these amps for about 20 years and you answered so many common questions - some of which I was still asking myself (now I know what the death cap is!). Thanks very much. Also, in recent years, in line with wide and narrow panel tweeds, I’ve started calling this era black panel and silver panel because of some of the obviously negative connotations that go with calling anything black panel. I noticed early in the video when describing the front of the amp you said “the black panel doesn’t reflect light the same way the silver panel does”. I’ve been mocked for changing my nomenclature but it seems that calling them black/silver panel is really no big deal and actually quite intuitive.
Thank you for this video inparticular.I recently acquired a 1974-75 Twin Reverb(1st year of master volume).I really was clueless of everything you covered with this amplifier.I hope you get a a Roland JC-120 to do a video on one day.Thanks again.
I think the speaker chassis provides some degree of shielding to the reverb tank connections, making the circuit slightly quieter when factory oriented.
Congrats on 25K!! I've been learning and enjoying your channel a lot lately. Your knowledge of theory coupled with experience is such a source and we are fortunate that you take the time to film these repairs and provide explanation. Especially amongst a sea of trolls! Question: when converting to 3 prong, what is your thought of running the hot to the switch first, then the fuse? Physically, the shorter paths are fuse then switch, but just curious if it mattered or if there was benefit to either way
Thanks! Fuse first as switches can burn. A 2-4A fuse in the amp will fail before the switch can really burn. But if you are trusting to the 10-15A circuit breaker on the wall supply that switch can start a fire inside the amp before the circuit breaker opens.
The audio taper pot *fix* to better control the reverb is something I want done to my Deluxe clone, which is very well made and sounds great. Breath too hard near the reverb knob and all of a sudden I'm in a surf band lol. Thanks for that piece of advice. What the builder did that I really like is make the vibrato like in a brown Deluxe which not only doesn't click, but has a really soft quality to it that I think is superior to the vibrato in the blackface and beyond. Not sure why Fender changed that beautiful sounding brown series vibrato...
Champs, & Princeton Reverbs had (almost) NO changes at all. If memory serves 50 volts higher B+ from the PT's HT in the CBS Champ vs the blackface Leo, and 1 resistor & the rectifier tube for the P Verbs. Champ speakers varied too. Some were alnico & some were ceramic.
In my opinion, a hardwired (rather than switched) bright cap can be a nuisance at times. It can be useful in some situations, since the further clockwise the volume control is rotated, the less effect it has. But that's not always a good thing.
Really enjoyed this, Lyle, and congrats (again!) on passing the 25K subs threshold. 🎉🙌 Question/suggestion for future video: you mentioned Baxandall tone control in guitar amps. I've read about it, seen some confusing things (e.g. in the Peter Baxandall entry in Wikipedia), have a vague sense that it makes the treble/bass interaction more significant for midrange, feel like it might be a good thing ... but don't really understand it, nor what amps (you mention Ampeg) have featured it. If the mood strikes, and the gear is handy, would love to have your treatment on this. I'm confident it would be illuminating. 🙂 So grateful for your channel!
Great video, Lyle. So much good basic info without the bullshit. BTW, I have a low power tweed Twin clone made by Achillies (yes, that's how they spell it) from Melbourne, Australia. It's got two 5U4GB rectifier valves. It's insane: 6 amps on the 5 V secondary! 😬
recommended nos tubes for blackface fenders; mullard i63 at v1 will give a low mid boost at the normal channel, great for single coils or overdrive. and ge 12ax7wa at v2 for the vibrato channel for a great clean tone with p90's or humbuckers.
Excellent video! Learned many things and in a relatively short video! Looking forward to upcoming content! Also, what is the 2nd input for the channels used for active pickups or something to reduce input gain? Thanks again!
Thank you very much. This was so much great info. I want a fender amp but don’t know which. Used to have a 1966 blackface Super Reverb which sounded amazing but got cancer and had to sell all my studio stuff. I want lighter and quieter but with that beautiful sweet spot. For some reason I’m leaning towards a Princeton Reverb but which one? Pretty sure I want a 12” speaker but don’t know enough to know why? Just heard a guitar playing say 10” are plinky and 12” compress a bit more and are smoother.
