Hacking a Blackface Fender for Monster Gain, Blasphemous or Badass?
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- เผยแพร่เมื่อ 1 ต.ค. 2024
- RUSSIAN TRANSLATION: • Доработка лампового ба...
In this video, we will take an already heavily modified vintage Blackface Fender Bassman AB165 or AA165 head and turn it into a roaring, belching beast of the underworld. Is this blasphemy against God, nature, and all that's good, or is it acceptable and even necessary, like Shiva, who continually must destroy worlds to create new ones? You decide! Let me know in the comments...
Here is the other video of this amp where we solved a problem of red plating power tubes: • Red Plating Power Tube...
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Hey youtube, I'm the owner of this Bassman and am super happy with Brad's handiwork. Pre-mod, this amp would NOT break up at the volume levels I practice at and I really haven't found an OD pedal that I think sounds good with this amp. Initially, I hoped switching to 5881 tubes and biasing hotter would fix the issue but after learning that the amp was already (poorly?) modded when I bought it, I figured I'd let Brad make the best out of the situation. And he did. I got tons of compliments from the other bands we gigged with. It was one of the better shows we've played.
Before Brad did his thing and you were running with both channels jumpered out of phase how did it sound?
The best way I cant think to describe it was bland, but oddly full. Initially, I went through the normal channel but I left it at keyboardist's house and he played his rhodes with it jumpered. The next practice, I just left it jumpered to try to maintain that fuller sound but I wasn't happy with the tone, which was why I brought it to Brad.
That's awesome to hear, Russell! Bring it by any time you need work. You're always welcome. Also, just for the record...I watched this video back again and I believe I either cut out that part or failed to mention that the circuit ended up being closer to a AB165, meaning you WERE actually going through the 3 stages of gain before the PI. Totally m y bad for not mentioning that in the vid. Bottom line: you weren't playing OOP after all with channels jumped. But anyway, great to know it is working out.
Also Russell, if you get a chance, do a quick video with a Les Paul and link it here. I should have included a humbucker clip in the demo. I'd be interested to hear it with a Paul.
Just an FYI, if you're having trouble finding OD pedals that sound good with a Bassman, take a look at R.J. Ronquillo's YT channel sometime. He uses his BF Bassman about 80% of the time and uses tons of pedals with it. I'm much more of a Bandmaster guy than a Bassman guy, but I have to admit he almost always has a great tone.
Great video dude :-)
Much obliged, Rob. I appreciate you saying so. By the way, I enjoy your channel.
The Guitologist h
Well, Rob Chapman, the king of bought views says it's good so it must be... way to ruin a rare and beautiful bit of gear
Rob Chapman For the record, I like Rob and his channel. Good content on guitar stuff, presented in a fun, professional way, nothing like my train wreck of a channel. :)
Wow. If anybody is a nice down to earth guy, it's rob. Fame wouldn't get to his head even if he was the most famous musician. Your stupid comment about bought views makes me wonder if you are a troll or a pathetic jealous guy..
Pickup a SM57 so that everyone can hear the true glory you're creating in that shop ;)
As a former Fender warranty tech....I approve this message. Nice work. I love to watch people who care about what they are doing and provide exceptional customer service.
I got no problem with this kind of modification. The guy bought it, he can do what he wants. It's already been modded anyway.
These things are meant to be used to make music. If mods help you do it, go ahead. There's far too much cork-sniffery in all this stuff anyway. It's even worse with guitars. This is just physics-electricity doesn't know if it's going through a vintage paper in oil cap or a brand new one with dead on tolerances.
Those giant old blue caps do look cool, though. How much of a nerd do you have to be to think a certain kind of Cap looks "Cool"?
Agreed on the "cork sniffery".
Old oil paper cap should go to trash, they leaky and there is danger that they brake and it can damage tubes which expensive compared to new cap. You may like how it sounds but soon it could not make any sound at all.
There is no blasphemy in art. That thing has "the sound!"
I know all about gain stages. I eat a lot!
😂
I discovered this empty gain stage about 10 years ago on my silverface. The added the stage to the front of the bass channel and modded the stack more like marshall. Absolutely sweet. Might post a video of it
that overtones on the feedback and harmonics was lovely
I didnt understand a single word this guy said but it was sure damn interesting. good video.
th-cam.com/video/OrjmeGKoR1E/w-d-xo.html
Me too, but I love process. I have an old Bassman stashed away, early 70s, I played guitar and bass in to because Because I could afford one amp. It sounded fine with my playing.
The Guy is Einstein... no joooke. 😐
As someone who's just getting their feet wet in amp building, this video is by far one of the most inspiring uploads I've watched in some time. Well done. Congratulations on the result but especially the diagnostics you performed along the way. Looking forward to incorporating some of your techniques when I move forward on my deluxe reverb build.
Good for you! Be unafraid to deviate from that schematic. Straight clones can be nice, but we don't learn as much as when we just think outside the schematic and go for it. Fucking up is a good thing when it leads to learning.
I discovered your channel at a couple of days ago and I'm really enjoying it. There arent many youtube channels with technical amp content. I have built a couple of effect pedals kits and have plans to build and amp by the end of this year. You are helping me understand amps circuits. Thanks!
Very cool, man. My advice on your first build, dont worry too much about making it neat. Think of it as an eternal platform for experimenting, and not a finished product. And dont use a kit! Also, think about some twist you want to try with an existing circuit, try to avoid straight cloning. That way you'll run into problems and have to solve them. A success is almost a failure, if you think about it. It only gets fun if it's broken. ;)
I would add a humble +1 to the advice of not buying a kit. I did a scratch build of a well-known circuit, the Champ 5F1 into an old solid state amp chassis and having to make build and layout decisions and trouble-shoot it myself rather than painting by the numbers was so much more instructive. My dad has a BF Vibrochamp, I've had a SF Vibrochamp and a Champ 600 so I wanted to hear what a fairly straight sounding tweed version would sound like, so built it as they did aside from leaving off the negative feedback. Working from a proven design/schematic came in handy when it didn't fire up right away, it was relatively easy to trace a known-good schematic.
Blackface Fender? Fender, that's racist. I'm an amp and I'm offended.
My wife said the same thing. :P
You mean "I'm ampfenderd!"
Did you just assume my Fender?! >:(
Well, you'd better not plug into any cabinets with Black widow speakers then.
DFW_Motorrad you would be offended because you are a SNOWFLAKE MILLENNIAL. BOOOO HOOOOO. my feelings are so delicate and need my mommy to kiss my booo boo. Crawl back to your hole you fatass snowflake. There should be a law against fat pigs riding motorcycles. Why do you even exist?
20:12 -- "Okay, hear that?" ...."that's Harley Davidson-isation"
baaaahahahahaha! You win the internet today, sir. I wonder if I can fit bigger pipes on this bad boy...
Really liked the sound of it when you finished it. Definitely has more gain than just about any bassman I’ve ever played. Blackface or tweed
I believe what you are working on is an AB165 that was taken back to an AA864. the AA165 label was used until they ran out however the AA165 circuit itself is SUPER rare. It was made for 1 month. that would explain the buss that you found disconnected and reused for the added gain stage. that originally had 2 200k feedback resistors mounted to it out of the phase inverter to the 6l6gc.
I laughed my ass of at the end :D
Congratulations!
Your Channel is finally getting what it deserves!
hahaha! Sold my soul for subs. :P
...but not really.
You, sir... are a magician for making that bassman sound so good.
would love to hear that thing into an open back 212 with Creambacks
I remember back in the 90s I went around to all the shops lookin for one of these. Ended up getting a mesa/boogie 50 cal. Mesa served its purpose but now I kinda wish I kept looking.
27:12 has that classic sound! I had a Marshall 2204 & 2203 that was modified a bit by a 'Fender" guy. Amazing amps!
For years I have been chasing the mods that Santana had on his Fender Twin reverbs from his golden era when he made his best music. Wasn't no Mesa on his early best stuff from the late 60s.
There's a software called "Tone Stack Calculator" that you can use to view the change in response for various tone controls.
I have it. It's called Duncan's Tone Stack Calculator: www.duncanamps.com/tsc/
Yep, that's the one! I've used it once to make a tone stack that could be switched between a Fender-ish to a Vox-ish stack, using a push-pul Bass potentiometer. All it did was add a couple capacitors in parallel to the ones in the circuit, to shift the Bass and Mid curves.
There's tons of stuff you can achieve by playing about with values.
Damn, I'm so tempted to find and old bassman and have you do this mod, both channels sound...perfect
Pretty interesting video, man. Thanks for sharing your knowledge in such an entertaining way.
Weird. Did this all the time with my twin. Never realized it was a cardinal sin lol
This almost makes me want to mod my 66 bassman. But I'm also kinda of a keep vintage stuff original kind of guy
I had a friend back in the early 80s who rearranged his Bandmaster Reverb to cascade the preamps at the stomp of a footswitch. Low budget Mesa Boogie :D.
I did that with a 1968 Princeton.
No holes drilled = not a hack job. Definitely enjoyed hearing more about the development of the mods as they happened. Did I somehow miss the resolution of the cathode biasing conversion? I have a '66 BF Bandmaster and don't need or want the headroom it has so have thought about going to cathode bias. I know it won't make it into a Deluxe or Princeton but a bit of tweed influence would be fun.
The owner and I discussed that and decided to go with the preamp mods first and later, if he still thinks the amp is too loud or needs earlier breakup, we'll re-bias the tubes for earlier breakup using the existing pot. And THEN maybe come back and think about cathode bias and 5881 tubes.
You may want to look at the resale value for that Bandmaster, then decide if it might be better to sell your amp & buy the one you really want. People used to modify blackface Bassman amps all the time because no one really liked them stock for either guitar or bass, and you could buy near-mint Bassman heads for $400 (retail). Now prices are going up, so...
I hear you but this was already gone through before I bought it back in 2001-2002, so 95% of the components on the board have been replaced, the transformers are all original though. So, changing a few things around in the circuit (no holes drilled, the chassis is perfect that way and will stay that way as long as I own it) wouldn't be hard to reverse if I were to want to sell it eventually.
Certainly reversible changes are no big deal. I was especially focused on your desire for lower headroom... You could get there with a master volume circuit (not insurmountable, but where do you mount it?). Or you could get there with an amp that makes less output power to begin with. If you're looking for the output tubes to distort first (big assumption on my part), even half-power may not be a big enough drop in headroom/volume.
A switch to cathode bias might only be a 20-40% reduction in output power, and heat in the output tubes & power transformer become a concern that must be addressed.
I'd recommend playing amps in the 10-15w range, and seeing if that is a volume level you're shooting for. If yes, it might yield some clarity on whether changing the Bandmaster's operation is the way to go, or if a different amp is the better answer.
It doesn't matter whether I or anyone else approves; it's your amp. But having tread this path before with my own amps, things usually worked better when I let an amp be what it is, and used a smaller amp when I really wanted less volume (just built a 1/3-watt amp for that very reason for playing around the house; still have the Pro Reverb, though).
Thanks for your thoughts, always good to hear from people that have been down that path.
I've recently finished scratch building a 5F1 circuit into a 1x12 combo cab, (what I've been using for the Bandmaster in recent times) and that does the (slightly) lower volume grind thing well, so I really don't "need" the Bandmaster to break up at lower volumes. I guess it's more of a desire to see what I can tweak on it and actually experience the changes vs just reading about them. I've no issue with component swapping since it's already been overly serviced, arguably but I don't see any point in doing a typical master volume since the pre-amp isn't exactly high gain anyway.
You're right in that it does what it does very well, and changing it to do another thing would inherently require a compromise in clean tone or the modded tone so why not just find another amp. I have another project to build out of an old PA amp, which will be 3x12AX7, 2xEL84s and somewhere between a JCM800, Marshall 18W and generic Orange front end and that will get VVR or a PPIMV.
A good OD pedal may be exactly what I need before I can get the EL84 amp designed and built and I'll probably pursue that avenue first as I have a Tubescreamer but I don't like how it works with my other sentimental piece of gear, '01 Gibson Explorer with Burstbuckers.
Thanks again for your thoughtful conversation!
i would have added the stage up front... JCM/d it.. still sounds great... i modded a bassman 70 to an AB165 /rev and boost control..
Badass would be my vote. The tone and sustain sound great to these ears.
Thanks Will.
You're very welcome. I happily look forward to more. :)
sweet vid man. I have an aa864 bassman but i'm afraid to mod it hehe maybe one day.
Nice vid, super informative, im surprised you dont have more subs.
Actually, I've gained about 3k subs in the past couple weeks for some reason. Maybe TH-cam finally figured out how awesome I am and started recommending my vids to people. :P
Yeah, your vids started showing up in my recommended and here I am. Probably has something to do with your vids being long.
Same here. A few days ago your vids started showing up on my recommendations.
back in February I participated in a 4 session beginner's guide to tube amp circuitry with Gerald Weber of Kendrick Amps. At first I wasn't sure how much I absorbed but after watching your video I realized that I have a much better understanding than I thought. I really enjoyed this video and frankly that bassman sounded killer after you got done. You should document the circuit and maybe shop it out for a builder to replicate it in a new chassis. I think that would be an item people would be interested in buying.
BTW you have a lot of cool oddball guitars in your shop.
Great video and very detailed . Brad you make it look so easy i wish i had a 1/3 of the knowledge you have .
The fact that I'm doing it at all means it must be easy. :D
Said the genius.
Not genius, just tenacious.
Brad this summer i'm shipping you my mesa boogie mkiiC+ , i have your email and will send you some pictures and get your rates . I've never opened it up because i don't mess with electricity . I've had LIGHTING come through my house 4 times and the electrician i use can vouch for me .. lol Scary stuff ..
...."since this amp has already been, "MOLESTED", hahahahahahaha.....♥ that wording man!...ha!...
The problem with the Marshall tone stack is that tone stack's frequency response depends heavily on the impedance that's driving it. In a Marshall amp, the tone stack is driven by a follower, and the output impedance of the follower is a few hundred ohms at worse (and by "worse" I mean when low mu triodes are used, such as ECC83, 12AX7, 7025, 6N2P).
In a Fender amp, the tone stack is driven by a gain stage with an output impedance around 40k. So just changing the component values in the tone stack of a Fender to match the corresponding values in a Marshall will not result in a similar frequency response to that of a Marshall. This of course does not mean it can't sound ok.
An excellent point. Thanks for making it.
+kardRatzinger - Important point! and to which I'd like to add that static information, like interstage impedance and frequency response, is like a postcard of the Himalayas - 2D doesn't even approach the LIVE experience. What matters, especially to the player, is Dynamic Response - how it feels as well as sounds in a continuum, not a snapshot.. The Cathode Follower circuit is extremely important because it has Unity Gain and acts like a soft-knee limiter. Also because the entire Tweed tone circuit (and most best models from Marshall, HiWatt, Vox, and a dozen other venerable brands/models) comes AFTER the 2nd gain section and Volume control, overdriving that limiter and tone stack results in "squeezed up" bandwidth as well as attack which slowly recovers as signal decays results in a vocal effect that drives musicians to "talk" with their instrument. It can clean up when you turn down and slide smoothly into overdrive when signal increases either by turning up or just hitting the strings harder. If you just want a fuzz tone get one. If you long for a responsive musical instrument, explore Cathode Follower driven Tone Stacks.
well there's more resistances to ground on everything in that stack you notice and it's the followers distortion and not plate driven as well stages some tend go slightly colder, you can get monster distortion cold clip the hell out of the 2nd or 3rd stage and get everything else HOT sounds good...but I think it still sounds alittle still docile sterile and could play with feedback and it's still something like that...just go monster headroom and all gain allll hot running and clean then just run your choice of firestorm pedals up front, that's why I said might as well have some big clean ss/digital amp that's clean and filtered well and still sounds like what's running up front.
+JR - I don't understand why you are replying in this portion where we are discussing Cathode Follower driven tone stacks and Dynamic Response where a musician can travel between clean and distortion just from Guitar Volume Control or how hard or soft you attack the strings which has a tonal "squeeze" effect since it drives the Tone Stack, adding a whole dimension of vocal expressiveness. Extreme pedal (or preamp) overdrive is the antithesis of that. Also "distortion" is a misleading term when one is considering Cathode Followers since they are Unity Gain and have extremely low harmonic generation on their own. The concept of extreme preamp overdrive with ultra clean power section, especially of the "ss/digital" type, is completely out of place in this video which is for those that love what only tubes can offer and have an interest in whether hacking a 50 watt Blackface is a good thing or not. What you're talking about has some validity for some styles of players but not in this arena.
Oh it's no ill intent or Despair. But I know what I would do to it Lol, the follower seemed to have a somewhat audible "zingy" response and a lot fun in the highs and grins me the hell out lol...Plate driven now everything is really different it seems to of lacked a lot more of the harmonic content and excels at the low end.
The only Really Good Bassman head I ever worked on was the first one with the GZ34 rectifier, All the way good. All others need a push here and there to give up the goods, The best one I did, for playing bass, was a conversion over to The Gold Lion 🦁 KT88's a Mercury Magnetics blackface Twin Output transformer, and aux.filament trans. For the KT88's . Left the standard circuit pretty much , few Orange drops and also, I forgot! Got with Mesa Boogie and got some high quality 220 mfd. Main caps, friggin' amp on top of a 2x15" cab ! Headroom and tone!!!
this mod was awesome, sounds amazing!
Would you happen to have any pointer knobs for a Champ 30? In moving the movers broke the FX control knob and Fender doesn't have them nor does any body else.
In the 60's, we would run the ext. speaker out back into another input on our Fender amps. But note: you could only do this when a friend came over because thats the only time you would have TWO guitar cables.
Man! How did you not blow up your stuff?!
@@Aaron-zh4kj we nidged up carefully. Try it. Amazing distortion! Its fun to be 12.
@@RDYC So you're telling me you'd send the load from the power amp of an amp into the input of another amp?
Very good video with good theory lesson. You could have put the spare tube on the bass channel and then you would have has even# tubes ( no phase problems) also that would have had made more distorion before the tone stack, which sounds better.
I love the ambient static sound of an old fender when you mute the strings - you can feel it 😍
you mean the little white noise that comes out of the speakers when you no play?
Fer365 I think so, it's like an ambient hum
So can you use a jumper wire between the 2 channels, same as you can with the old Marshall plexis to get a way huge tone? Not to get more distorted but to go way huge? I am looking for the way hugest tone, right at the edge of distortion, like a Hendrix-Stevie Ray tone.. IS a 65 Basssman good for that? If not what amp would you recommend?
Best show on TH-cam!
That was a lotta mumbo jumbo to get through for a novice. But man what incredible natural sustain that amp has when combined with that Telecaster. I feel like I got punched in the face by Jimi Hendrix
Kind of wished I hadn't sold my 78 50 watt Bassman.
I could have been a better amp with a little tweaking from you.
I would have taken a look at it.
I think I sold it before we did that Sound City amp deal.
Did you ever do a video on the Sound City amp?
Really cool video and so interesting to see how you did that...thanks....
I think that is not quite a Marshall. That thing sounds more like a Dumble! Those sustaining notes are a work of art! Same old story, same old song and dance! Every one, me included, wishes they had hung on to their BF Bassmans. I plan building a AA165 or AB165. Got the parts, don't have the time, yet. I once worked on one that the customer used the bass instrument channel for bass ant the normal channel for a Farfisa compact deluxe organ. Whoa! Thankz
I bet the Farfisa sounds pretty good through it, actually.
This is incredible stuff by the way..I enjoyed trying to follow along and getting a sense of the kind of problem solving and frustrations that go along with it. Thanks for posting.
Wow. Sounds amazing! If that amp were around 20 or 30 years ago, it could have single handedly saved rock and roll.
so what did you do to stop the second channel from oscilating ?
Do you do any work on these amps just to sell them?
I like your videos, because you show all the in between, "WTF happened?" moments. Only thing I didn't quite follow on this, you started out talking about switching it to cathode bias, but then got wrapped up in the gain stages on the Normal channel, and I didn't see whether you did the cathode bias as well. EDIT: Never mind. I saw someone else asked that.
Thanks, man. Yeah, I left as is because everything was rocking so well with the other mods. Cathode biased 5881 would improve the breakup maybe slightly more, but it would be most felt in the feel and attack of the player, I think.
the phase question. A radial bigshot has a phase inversion switch. Cheers Brad
youve had nearly 1200 MORE subscribers since you filmed this!
Dont these amps sound awesome anyway? Why is it necessary to do all this modification stuff?
I love your approach. It's pretty similar to what I would have done, but modifying the bias was definitely a stroke of genius. Note taken. My first thought was to swap the 12at7 for a 12ax7 in the phase inverter, but this is probably the more usable approach.
When I saw the schematic my first thought was "wait... Where the hell is the cathode follower... I thought this was a bassman!", So I'm glad I'm not the only one bothered by an unused triode lol.
Bradley! your simply the Bomb my friend! you really knocked this one outa the park . Haliluja!!!. you got my vote big time and very deceint chopps too@!
+barry christiansen thanks Barry
the amp looked so clean I would've restore it to original specifications and sold it
Exactly or not. Keep it yourself and let its value steadily appreciate. Jam on it, but do not put it in harms way such as a bar or band practice with clumsy people who might damage its appearance. The bassman/ marshall sound can be duplicated easy by buying one of many, many "kits" out there!!!!
what I wouldn't give to have a tech like you here in Jacksonville. sadly, since our last guy went all crack filled an' shortrly after completely dead, we've been out of luck. But that's not all - you're a damn fine guitarist! Are you playing? have a band? don't hold out!
Peter Snyder is the best in Jax Fl area. I no longer live there but he worked on my amps about a year ago. He does the amp work for Mockshop. Check him out!
I didint think you could do that Wow!.....crazy!
And thus...the most amazing Fender Bassman tone EVER! Bravo.
Bass Guitar,,,and,,,Electric Guitar?,,,in One Amp,,,,oh firstime i saw these kind of Amp,,,,,,
What was already modified before and what exactly did you do to it?
How could it ever be sacrilegious to apply modern perspectives to a commercial product from years gone by that was made in a cost-effective way, presumably with no secret mystical incantations whatsoever in the production pipeline?
too right robi, if leo fender could only see this now
i`m sure he`d be more than happy with such mods,
he didn`t make museum pieces ,after all, or fossils,
his amplifiers are the groundworks,
Great Amp...sounds alot like Jimi at the 12th fret...you did an awesome job mate! PEACE
Yow!!! Sounds great. Love the harmonic feedback on the 'M' channel and toothyness on the 'F' channel.
dayum. you are a genius that sounds amazing.
What about a 1970s silver face bassman or twin. I believe John Mayer has one modded like this next to his Dumbles.
Man, if I had one of these I would do a Fender Rivera era conversion mod to this. Look up Rivera Fender's before he ventured built Rivera amplification.
Hope this isn't the wrong place to task, but I have a question for ya. I bought a new, hand-wired amp which is like a deluxe reverb clone basically. I was a little dissapointed that the noise floor is higher than I thought an expensive, handwired amp should be, like white noise. Playing loud it doesnt matter, but quiet passages its noticeable. I don't know what causes the "ssshhhh" white noise in amps. Could it be the carbon comp resistors? Tubes don't in themselves make noise, do they? Do metal film etc resistors sound as good to you as carbon comp ?
Lots of ways noise can be introduced...poor shielding, bad ground schemes, poor lead dress, and even tubes can introduce noise. try switching out your V1 tube with another tube, or swap V1 with another tube in the amp and see if it changes at all.
Transformers can also have a big influence on sound. I am now playing through a red plate amp kind of dumble like sound . Thanks for the great video
Had a blackface Bassman once....loved the bass channel as it was....put channel switching in it....was a great rig!
This video just indirectly taught me the difference between Class A and Class AB by causing an "Aha!" moment when discussing signal phase through the tubes. Thanks!
Beautiful sound man! Congrats
sir you should do a POD download of your programmes for audio, very intresting stuff
First thing when I saw this is "WTF is jumpering the #2 inputs supposed to do?"
You can gain up an amp by jumping channels.
Before there was a master volume that's how we had to do it.
i just watched all off this... understanding next to nothing lol. it was very interesting and i loved the first tone that you played at the end. i can get a simmilar tone out of my peavey bandit running a suhr shiba drive wide open in to it (see my video).
freaking awesome video man... wish i understood more of it.
The great think about the pursuit of tone is there are many destinations and even more paths to get to those destinations.
Sounds Awesome! What did you charge for the mods?
It sounds just amazing. Perfect!
Can you make me functional again since 40 jears damaged movement ?
My 74 blackface “musicmann HD130 breathes FIRE 🔥 WHEN YOU PUSH ONE CHANNEL WITH THE SECOND...
Btw my music man has a tube preamp circuit
It sounds good but sounds extremely compressed. Some re-voicing the of the preamp to take out the bass would help. Nice and organic sounding though.
At 20:18...cap to grid on gain stage needs voltage divider to cut signal and piss grid stopper???10kat grid.maybe smaller cath cap? .22 for less bass gain..writing while watching LOL..you probably caught this
Hi Brad, There was a piece missing on the Tube chart, that amp should be heading to the Dump, kidding, from an Uncle Doug video on a Pristine Fender Champ time capsule. Excellent videos, learning a lot from you, Thankyou. All the Best, C.
haha! I remember that one. That Uncle Doug is a card.
Did realize how good of a player you are until I saw the end. Nice brad!
Sounds like my modded Showman. It sounds way better than my modded JMP.
This is the way to go for gain. IMO
A bit disappointing that you don't show what exactly you did to that second channel to make it scream like that. Ok you put in that extra gain stage --that was taken out before? if so there was no problem jumpering the channels. This video starts with a working amp... you explain what you are going to do... do a mod FAIL, another FAIL. Then cut to the final walkthrough...
Did you eventually change the bias network?
Awesome vid. I'd love to see an sm57 and 421 on vids like these, to really capture the beautiful work you do.
I'm surprised what you made out of it tonewise Great work!
My first rig was a 65 Showman which I ran through an 8X10 Marshall hotdog cabinet. It had been "MESA BOOGIED"; i.e. the channels were rewired together in series and a master vol was installed, so the cascading gain was MIND BLOWINGLY beyond even a dimed up channel jumpered JMP. The amp was given to me by my uncle back in 78 when I was 16. He was a working musician (keyboard player) who got it from his guitar player at the time who modded it. Instead of jumpering the channels in parallel, he wired it in series so it was essentially a nascent Mesa Boogie. This is not an exaggeration - the gain on that amp was so outrageously good it was somewhere between a 100 Watt Marshall superlead and Eddie Van Halen's legendary tone from his first album. When I heard Van Halen for the first time, I actually thought he was using the same rig LOL. No, it didn't quite nail Eddie's tone but it got darn close.
The original lead dress of one or both of the inputs, from the series resistors to their respective grids, seemed pretty messed up. I redid what was needed to make it look better, and only wanted a single channel. I bet a lot of people just go ahead and do the same to theirs. This eliminated the main cause of the parasitic oscillations, for which extra (wonky) circuitry was added. It was a detriment to the tone & playability of those amps, and I was able to rewire the output stage to eliminate a handful of those components. My AB165 amp can finally breathe.
Yep, all the feedback chokes them off. This one had most of that removed before I got here, or it was never there.
I know almost nothing, about electronics and the internal workings of amps, but I would really love to delve into it. My goal is to build my own amp. Can you give me any recommendations on where to start? I was thinking about reading the RCA Tube Manual and going from there.
hey man Brad is your name? If you even read this.. What exactly had already been done to this Bassman an then u furthered the modding by doing (?) , it's got an awesome tone.. I'm going to be playing at a studio soon that has a blackface Bassman. was going to play through there Twin Reverb but this is making me reconsider
This is probably a bad idea, but with my MusicMan 210 130 I bypassed the reverb tank and used the Rev knob for extra overdrive. Like it needed it, but that was back in the day.
Add a Variac transformer Inside the chassis for about $160 and have a cold beer while you play the amp breaking at very low volumes. Problem solved as I did to someone who wanted his amp to break are very low volumes. Now he controls how much break he gets.
A Tech that wails! Robin Trower Live! I think I passed out a couple of times when you were retracing your steps! LOL Just when I thought it was safe to go back on the stage! You are step above the rest sir! I have a bassman 50 watt with a 2/15 cab and guitar players love this amp! Thanks again, great video!
Fucking awesome. That normal channel was the tits. And the gain was sweet on the dirty channel. Your playing was blazing my saddles, bro.
I have been playing for about 35 years, dont know a thing about wiring, but you make it so interesting and easy to follow. You are the FIRST TH-camR that I Have subscribed AND hit the bell for. I know I wont regret that decision. Keep up the great work. Cheers. Jay Brown "The Metalhead of Comedy".
I haven't used a Tube Amp all that much since 2009 i could count on one hand how many time i used my Tube Amps since 2009..the past 9 years i have really been into my Marshall MG 100FX 2X12 stock with celestion speakers..bought it back in 2009 and never really looked back on the Tube Amps since..also have a VOX Valve Tronix..2009 Also and i have a Line6 Spider IV 75 watt stock with 1x12 celestion speaker 2010..i haven't had one single issue with any of them..all 3 Amps are brilliant..and can not say that about my Tube Amps..
I've had many Fender basements keep in mind I play bass through them including an original 59 Tweed just love the sound of these things with the breakup that I get especially on for Atlas I just acquired another basement 50 the sound is so sweet but you just pointed something out to me and I never even realized it and the reason why jumpering the channels with the phase issue now I understand why and it made a lot of sense and I didn't even realize that the base channel was the hotter channel keep in mind I play bass positively bridge pickup dominant so I guess you could understand the style that I'm into nevertheless thank you....