Hacking a Blackface Fender for Monster Gain, Blasphemous or Badass?

[@rustygrant]

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.

[@ThePsprout]

Before Brad did his thing and you were running with both channels jumpered out of phase how did it sound?

[@rustygrant]

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.

[@TheGuitologist]

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.

[@TheGuitologist]

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.

[@wildbillhackett]

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.

[@mtchampion1831]

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.

[@SuprachargerMusic]

Pickup a SM57 so that everyone can hear the true glory you're creating in that shop ;)

[@davidhobbs624]

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

[@Nickpaflas]

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"?

[@TheGuitologist]

Agreed on the "cork sniffery".

[@dmitryhetman1509]

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.

[@MajicFreeman]

that overtones on the feedback and harmonics was lovely

[@RobChappers]

Great video dude :-)

[@TheGuitologist]

Much obliged, Rob. I appreciate you saying so. By the way, I enjoy your channel.

[@jkosh111]

The Guitologist h

[@mileswilliams1585]

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

[@TheGuitologist]

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. :)

[@MyRealName]

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..

[@superdriver777]

There is no blasphemy in art. That thing has "the sound!"

[@ylelevier]

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.

[@TheGuitologist]

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.

[@djordjeblaga7815]

I laughed my ass of at the end :D Congratulations! Your Channel is finally getting what it deserves!

[@TheGuitologist]

hahaha! Sold my soul for subs. :P ...but not really.

[@cky5117]

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!

[@TheGuitologist]

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. ;)

[@MarderExplorer]

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.

[@Tom-gv7hc]

I didnt understand a single word this guy said but it was sure damn interesting. good video.

[@TheGuitologist]

kzbin.info/www/bejne/haPNnph9gNSFZ6c

[@hugh-johnfleming289]

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.

[@thomasjohnson7735]

The Guy is Einstein... no joooke. 😐

[@jasonmcdaniel2325]

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.

[@songwriterjj6022]

I know all about gain stages. I eat a lot!

[@ZaneDalton]

😂

[@bayougtr]

27:12 has that classic sound! I had a Marshall 2204 & 2203 that was modified a bit by a 'Fender" guy. Amazing amps!

[@darrkstarg]

You, sir... are a magician for making that bassman sound so good.

[@mygabrielle7477]

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

[@toddjones5186]

the phase question. A radial bigshot has a phase inversion switch. Cheers Brad

[@kardRatzinger]

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.

[@TheGuitologist]

An excellent point. Thanks for making it.

[@enorbet2]

+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.

[@jspinks2388]

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.

[@enorbet2]

+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.

[@jspinks2388]

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.

[@KingDilph]

sweet vid man. I have an aa864 bassman but i'm afraid to mod it hehe maybe one day.

[@kevsnyder]

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.

[@mikewalker3337]

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.

[@Bleats_Sinodai]

There's a software called "Tone Stack Calculator" that you can use to view the change in response for various tone controls.

[@TheGuitologist]

I have it. It's called Duncan's Tone Stack Calculator: www.duncanamps.com/tsc/

[@Bleats_Sinodai]

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.

[@mickkennedy1344]

20:12 -- "Okay, hear that?" ...."that's Harley Davidson-isation"

[@TheGuitologist]

baaaahahahahaha! You win the internet today, sir. I wonder if I can fit bigger pipes on this bad boy...

[@89schofe]

I love the ambient static sound of an old fender when you mute the strings - you can feel it 😍

[@fernandom.7956]

you mean the little white noise that comes out of the speakers when you no play?

[@89schofe]

Fer365 I think so, it's like an ambient hum

[@MichaelLynMusic]

Great stuff brother.............love the tone and lots of fun!

[@mrsockmonkey1969]

would love to hear that thing into an open back 212 with Creambacks

[@luthiervandros]

The ol, “I need my amp for a gig tomorrow” ploy lol. I love that one. Brad, your techniques and choice of tools are a bit diff from mine, but I never fail to learn from you. Hope alls well.

[@kellen3818]

Damn, I'm so tempted to find and old bassman and have you do this mod, both channels sound...perfect

[@mrz80]

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.

[@MarkProffitt]

I did that with a 1968 Princeton.

[@danielsperry8114]

Great video and very detailed . Brad you make it look so easy i wish i had a 1/3 of the knowledge you have .

[@TheGuitologist]

The fact that I'm doing it at all means it must be easy. :D

[@douglaszolton8985]

Said the genius.

[@TheGuitologist]

Not genius, just tenacious.

[@danielsperry8114]

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 ..

[@wardpike]

Glorious!! Where is your shop located?

[@Will-dt3yg]

Badass would be my vote. The tone and sustain sound great to these ears.

[@TheGuitologist]

Thanks Will.

[@Will-dt3yg]

You're very welcome. I happily look forward to more. :)

[@thedonabides2218]

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.

[@GuernB2]

Nice vid, super informative, im surprised you dont have more subs.

[@TheGuitologist]

Actually, I've gained about 3k subs in the past couple weeks for some reason. Maybe KZbin finally figured out how awesome I am and started recommending my vids to people. :P

[@GuernB2]

Yeah, your vids started showing up in my recommended and here I am. Probably has something to do with your vids being long.

[@Todesnuss]

Same here. A few days ago your vids started showing up on my recommendations.

[@vmat1000]

Yow!!! Sounds great. Love the harmonic feedback on the 'M' channel and toothyness on the 'F' channel.

[@FabianLanfold]

Pretty interesting video, man. Thanks for sharing your knowledge in such an entertaining way.

[@redjetfirebird]

Sounds great and love you letting us see the whole process. I love that old National behind the Bassman too. Would love to have one of those.

[@MarderExplorer]

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.

[@TheGuitologist]

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.

[@brianingram2068]

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...

[@MarderExplorer]

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.

[@brianingram2068]

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).

[@MarderExplorer]

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!

[@felinekaiju4517]

Dude, I love the way it breaks up!!. I'll get back to watching the internals work. This world of amp modding is amazing, hence the reason I'm going back to finish high school and do electronic engineering. You're another inspiration for my path. Thanks dude!.

[@RDYC]

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.

[@Aaron-zh4kj]

Man! How did you not blow up your stuff?!

[@RDYC]

@@Aaron-zh4kj we nidged up carefully. Try it. Amazing distortion! Its fun to be 12.

[@Aaron-zh4kj]

@@RDYC So you're telling me you'd send the load from the power amp of an amp into the input of another amp?

[@wraith1977]

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!

[@dfw_motorrad1329]

Blackface Fender? Fender, that's racist. I'm an amp and I'm offended.

[@TheGuitologist]

My wife said the same thing. :P

[@chrismonaut]

You mean "I'm ampfenderd!"

[@TheCrimsonIdol987]

Did you just assume my Fender?! >:(

[@MrJohnnyDistortion]

Well, you'd better not plug into any cabinets with Black widow speakers then.

[@flukyreview9128]

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?

[@cassvirgillo3395]

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.

[@TheGuitologist]

haha! I remember that one. That Uncle Doug is a card.

[@epilespaulgoth367]

this mod was awesome, sounds amazing!

[@CB-ul2np]

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.

[@DalHap]

Best show on KZbin!

[@bitweisor8208]

No one lays it out there like Brad. He doesn't hide anything. What a great video & a great Mod. Not what anyone would expect from a Bassman. Great channel.

[@SpencerP96]

This almost makes me want to mod my 66 bassman. But I'm also kinda of a keep vintage stuff original kind of guy

[@letsleepingdogslie2492]

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!

[@SteveRieck-Music]

Wow. Sounds amazing! If that amp were around 20 or 30 years ago, it could have single handedly saved rock and roll.

[@jmgmarcus808]

You nailed it. I used to have a deluxe reverb with tubes you couldn't find in the last 20years. My local amp guy said it was the loudest Fender amp he had ever heard. Was modded before I bought it, the thing would levitate on a floor put past 5. Sounded unreal. Great job on this one.

[@gmmakesmehurl]

Weird. Did this all the time with my twin. Never realized it was a cardinal sin lol

[@walterkasper467]

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

[@audiotechlabs4650]

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

[@TheGuitologist]

I bet the Farfisa sounds pretty good through it, actually.

[@NERDOFUNK]

Great Amp...sounds alot like Jimi at the 12th fret...you did an awesome job mate! PEACE

[@richardturk7162]

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.

[@TheGuitologist]

I would have taken a look at it.

[@richardturk7162]

I think I sold it before we did that Sound City amp deal. Did you ever do a video on the Sound City amp?

[@abradfordajb]

Well, i wouldn't know how to rate your "blasphemous-ness", but i'll say that you indeed created a super "Badass" amp mod ! Super flexible, with the two channels giving out beautiful clean-to-crunch/juicy tone (ch 1), and that over-the-top crunch in ch 2, esp. driving that 4x12 cab. MAN, what a sound :-O rgds

[@barrychristiansen4579]

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@!

[@TheGuitologist]

+barry christiansen thanks Barry

[@innovate1983]

Wonderful job. The break up on that is super lush, and whatever you’ve done has given that amp some real smack. Great!!

[@michaelcraig9449]

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?

[@timbeaton5045]

Wow, must be learning something after all. As soon as you showed the different channels phase characteristic, i immediately thought of using the unused half of the 7025 as a phase inverter. As i replied to one of your others videos., we all can learn a lot from this channel. Have mailed links to your stuff to several friends who are tube (or for us in the UK, Valve!) amp fans. Keep up the good work!

[@BillBowyer1971]

New to Tube Amp Repair, I enjoyed this learning experience. Glad to subscribe to your videos. Bill from Indiana.

[@jerrymorganjr]

Did realize how good of a player you are until I saw the end. Nice brad!

[@GuitarHeavenPL]

I'm surprised what you made out of it tonewise Great work!

[@gryzor]

You may or may not understand exactly everything that this person is talking about, but this may be one of the most informative channels I've come across in a very long time.

[@RiptideMusicOfficial]

Props for the PROPER reference to Shiva in the description, from a Hindu subscriber

[@michaelcraig9449]

What was already modified before and what exactly did you do to it?

[@andrewarbogast9313]

That reminds me of a Dumble! Very nice! The notes soar and morph throughout the sustain. The feedback tone was even toasty.

[@marinkino]

Beautiful sound man! Congrats

[@seanerik7339]

HOLYMOTLEY.....sweet singing sustain.....LOVE the OD rather than a distortion situation

[@randolphpatterson5061]

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.

[@TheGuitologist]

Yep, all the feedback chokes them off. This one had most of that removed before I got here, or it was never there.

[@matieupizil424]

Nice man, killer modifications. Getting some great early Billy Gibbons tones there, I really dig it. Thanks again for all the great vids and helping us along with our own projects. Inspiring stuff man

[@TheGuitologist]

Thanks, Matieu.

[@DreamWeaver3112]

Very cool vid. I really enjoyed how you demo'd the results of your labor @ the end. Awsome.

[@jatin7361]

Very interesting video. I appreciate the fact that you include your mistakes and how you trace your steps until you get it right. Most of these type of videos are "highlight reels" that only show the creator's flawless genius. Lastly, that hum you hear during the demonstration portion is likely the sound of Leo Fender spinning in his grave after seeing what was done to his creation. :)) Jokes aside, thanks for making these vids and sharing.

[@mattmckennamusic4934]

Way to spread the news! Sounds great! Here in So Cal because of the sheer number of baseman amps floating around because of proximity to Fullerton, we’ve been hacking up Bassman amps into gain monsters since the 1970s. While most famously done by billy Zoom of X, this was the go to for 80s California punk bands. DI bassist and Divided by 13 Amps principal Frederic Tacconne has a spectacular mod for these, adding a stage to the Bass channel to give a fuzzy Gibbons style high gain tone. Well done sharing and great playing. Bassman, yes!!

[@marsmediapro]

Awesome work, Brad! Now I am scratching my head, wondering if you could tackle a few amp issues for me- I have a Silvertone 1483, a Kalamazoo Model 2, and an Electra PS-20D, all in need of repairs... ???

[@carterpochynok4874]

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.

[@TEENSLUTPUNKBAND]

I'M NOT EVEN A FAN OF THE TELECASTER SOUND! BUT THE WAY YOU SET THIS AMP UP IS AWESOME! keep rocking that idea

[@frankscassi4960]

In my opinion your work is blasphemous, but ain't that what Rock and Roll is all about? Amazing job, man!

[@chucklambert7283]

dayum. you are a genius that sounds amazing.

[@billneill7567]

Just got around to seeing this video. I absolutely love the tones you got with this!! The ultimate 2 channel amp with Fender clean and a Marshall dirty channel. Sounds killer!!!!

[@Vrdavila67]

Sorry for the heart break Fender purists but this amp now sounds like it should. Good job man💪🏽🎼🎸🎼🔊

[@green323turbo]

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.

[@bayougtr]

I have just hit the stage where I see similarities of this Bassman and my 2204. Thanks Brad.

[@diceman220]

Awesome, screamer.. Very nice. I have a 1967 Black face Fender Twin Reverb I bought it new and would love to have him go through it and clean it up . Not sure where he is located. I'm in CT. He does some great work. Bob

[@ragnarviews]

Awesome job. A Fender channel and a Marshall channel in the same amp. The best of both worlds

[@yadabotbingo]

I've got a tricked out Dual Showman that was Boogie-ized by a Mesa Boogie tech/ GIT professor. The work done on this amp was a project with the student, the professional jazz musician I got it from. He used it for several years as a gig amp, but went with a lighter solid state amp and digital effects to dial in his sound. That was early eighties. It just sat around so he decided to part with it. This thing has push pulls all over it, on both the channel volumes, the trebles, and on the master volume knobs. They act as saturation/overdrive adjustments. There's a crazy amount of sound options/variations (exponential variables) and quite a learning curve. Great studio amp, but a bit to much fussy fiddlin' and a heavy beast for a steady gigging workhorse. Truely unique sounds and huge range of character though, from crunch, fuzzy, shhh mudd, clean, bright n twangy. It even does weird stuff like playing with just reverb, no volume just the reberb echo. Oh yeah, has vibrato too. Totally, a one of a kind.

[@IbervilleMusic]

Since it had already been modded, I really don't see any problem. And that tone, man. wow. New subscriber here! great content!

[@michaeldeas1969]

Don't believe the ewetoob analytics, this is the shit we love to see! Love ya little brother!

[@leehodge2415]

very happy to have found your channel. thx for being awesome.

[@stevefearon9337]

Best real world explanation of phase.... man I love this channel, even with all the crazy shite going on in the world, just chilling with a good guy running schematics and pointing at electronics. . 🙏

[@pauldavis6356]

Moding a classic amp, how dare you. Carry on, my friend - you do excellent work.

[@dooleyfan]

Someone this knowledgeable about amps and circuits who can also shred like that? That's just not fair. Great video! An inspiration.

[@TheGuitologist]

Thanks for the comment!

[@skycarl]

Pretty slick Brad. Great run through on the different circuits and what you did. Thanks pal.

[@TheGuitologist]

Thanks, Carl. I appreciate you always taking time to comment and let me know how Im doing.

[@giulioluzzardi7632]

Nice one, great work. You are and artist.It actually sounds like Fender amp should. You have an ear for tone and technical skill though I am certain theres some Magyk involved. Fantastic Man!!

[@julesl6910]

I really enjoyed this one, excellent documentation of your approach to problem solving. And man you made that one mean machine it sounds fantastic.

[@1thommyberlin]

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!

[@jaredheld2672]

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!

[@ralphups7782]

sir you should do a POD download of your programmes for audio, very intresting stuff

[@johnmac9002]

Just sick man what great tone!!! Where do I sign up for my stock AB165 to be modified ????