The bass pot is a 1964 cts, I'm watching on a 65-inch tv ,lol God, i would L❤VE to be able to restore an old 5f6a or JTM. Good lord, you have my envy, Lyle !!
I also love it when an elegant result falls out of implementing simple rules consistently. It can evoke a strong sense of beauty in art and science…there is little difference, really.
Beautifully presented. Beautifully executed. As I progress in this hobby, I have learned that this level of quality requires only a slight increase in effort. Very satisfying.
Does your 1958 Bassman have *linear* volume pots? My 1960 5F6A does, and they're factory original, matching date codes. I've seen same in most later 5F6A along with the "non-scratchy" presence control circuit with a 25K pot.
Have no fear that when Lyle says he is going to "tape off" the unused heater-winding centertap, he means cover and insulate it with heatshrink tubing, not tape! 😉
@@joeltunnah , yup, I've seen that myself in a few old Fenders. Leo did a lot of things right but he was also a bit of a cheapskate businesswise and always looking to cut costs and labor time. Anyway, old fashioned masking tape has a tendency to dry up and glue itself in place, but electrical tape turns into a gummy gooey miss and unwraps itself when it gets warm. Neither are good electrical insulators.
The Mesa fanbois would ridicule me if I did a video without having one on the bench. Not that they understand the things I’ve said when I have had Mesas on the bench. And it’s unlikely I’ll be taking any more Mesas in. I’d rather focus on good amps from companies that don’t bend their customers over.
Who cares if it's "period-correct"? It's just a three-thousand-dollar amplifier that doesn't sound any better than some other new three-thousand-dollar amplifiers. It's not a million-dollar Ferrari, of which only a few were made and will never be reproduced. Of course, some obsessive-compulsive people need for them to be period-correct.🤦♂ I wouldn't drill holes in it though. All the other things can be brought back to original specs for the psychologically challenged to buy later.
I have a serious question about amps. I am going to build an amplifier with my grandson and I need to know which one to invest the time and money into. I've seen some kits but which one? My only requirement is that it can drive 2 - 12" speakers and can make Master of Puppets sound right. has to have what to me is badass distortion.
Why don't you look for vintage capacitors in the audio path ? It is possible to find Sprague 160P or 6PS or Sangamo 33-M or even the famous Blue molded . They sound incredibly better than modern metalized film. I'm in France and i've paid $$$ by ebay to buy these kind of caps but everybody tells me that my amps sound very good.
Because I disagree with the premise. I’ve done blind testing. I could put just about any cap I choose in this. And I’m entirely confident in these MKT1813s. And they’re pretty for those who hear with their eyes (not saying you do that). I do like the 6PS caps but I prefer radials for eyelet boards.
Nice work, but man, those old Fender eyelet boards are ugly, and the connections on the back... ugh. I know it's iconoclastic, but since it's already "player grade" I would have swapped it out for a turret board on standoffs, with all connections visible and accessible on top. One minor correction: the 68k input resistors are mixers, not "grid stoppers" which need to be physically on the socket pins. I'm sure you know that, but others may not.
They are only mixers if you use both inputs of a channel at once. If you use the lower gain input then they form a voltage divider and act as a grid stopper. If you use the higher gain input they (in parallel) are a grid stopper, though not perfectly located.
Looks exactly like one of my builds! Good to hear you’re using something other than the selenium rectifier as a terminal for the bias diode. I don’t know how, but I’ve seen them burnt up while not under any load. Maybe an internal short to the mounting hardware or something.
@@PsionicAudio, there's no electronics "get the funk out" operation that can compare to when a selenium rectifier burns up and vents it's stinky, toxic, rotten egg-adjacent fumes. The very first electronics repair I remember was replacing a filter cap and selenium rectifier in my dad's workshop radio when I was about 11. I don't even remember how I came to know what to do in order to fix it.
@@PsionicAudio - Heheh. Son, I say Son (another ancient comedy reference) , yes I sometimes forget how old I am. When The Smothers Brothers did that routine I was repairing tube TVs and radios. I learned in a 2 period, twice a week High School Electronics Shop from an old Navy radioman thankfully hired on by my school. A few years later I had a Fender Authorized shop and by '72 added several others (Kustom, Plush, Vox, Ampeg, Mesa, Acoustic, etc.) many now defunct and all but forgotten. I mainly do one-off mods and design/builds now just 'cuz I love it. Nice to hear from you, Lyle. Love your channel and your meticulous work. It's the Real.
@@PsionicAudiono worries! Just wanted to make sure I’m on your list in some way, shape or form! The exploding inbox is a testament to your work! Thanks for the reply!
Your layout work is superb. Some very nice video that will come in handy and hopefully here in the near future to use on my Brother n Law's 1958 Fender Bassman. We have been threatening to go back in and replace all the electrolytics at a minimum since the day we resurrected it after a 20 year Rip Van WInkle nap 5 years ago. A previous owner of the amp was a professional bass player and gigged with a lot so we know there are most likely some weak links in it so it doesn't get fired up as often and babied at that when it does. I am a believer in full restoration and use rather than Keep it Original Museum Piece. What good is a Model T if you can't drive it? I just sent a links to my Bro n Law.
In my own amps I use preamp tube shields only in case of first stage or reverb recovery tubes, and often they don't need tube shields either. Grids of triodes are very much inside the structure of the tube and "shielded" by plate. Tube shield springs cause unwanted mechanical stress to glass envelope of tubes if there is no cushion (silicone or felt (like in case of Telefunken tape recorder EF86 tube)) between shield spring and tube.
I suspect that @jutukka(based on their name) is a Finn and has learned to utilize the traditional Finnish form of verbal and written communication which is utterly devoid of diplomacy, courtesy, and kindness. Please understand that they may actually be a warm human being. I've run into a few Finns in my life, and I find this particular quality to be challenging. On the other hand, mea maxima culpa. If I am wrong, or if I have injured anyone's feelings here, I apologize sincerely. Cheers, Alan Tomlinson
@@diegorhoenisch62 I don't understand this at all. I just told my personal approach to using tube shields, based on physical facts of glass as an amorphous solid. It was not anything else. I just cannot understand how it could be inappropriate. On subject, Page 8 Glass failures: www.worldradiohistory.com/BOOKSHELF-ARH/Technology/Technology-Vacuum-Tube/Getting-the-Most-Out-of-Vacuum-Tubes-Robert-B-Tomer-1960-(164-pages).pdf
Most amps have standby after the reservoir (first filter) node. This circuit has SB before the reservoir so the added cap is needed. Standby is not needed in this amp with the rectifier tube, but as it’s a valuable fairly rare amp I’m just restoring that part of the circuit too.
PS a rectifier (tube or solid state) has a higher DC output with a capacitive load than without, so there would have been a large voltage spike if the switch didn’t have that cap. There is still a spike as 100nF isn’t much of a load compared to 40uF, but it’s better than having a no-load state on the rectifier. Hard on the rectifier tube, too.
Watching on my newish computer monitor instead of phone tonight. Image looks as fresh as the amp restoration Lyle!! There is a “64 Bassman head and cab with webers down the street for sale. Would it sound anything like what your rebuilding?
Regarding the cap to ground on the standby switch, is that potentially dangerous? If it fails isn't it just like the "deathcap"? I must be missing something. Thanks!
The “death cap” has AC on it, often approaching the max AC rating of the cap used. This cap is rated for 630V DC, and will have @420-500VDC on it. So not really risky, and should it fail as a short it would simply trip the fuse, not make the chassis electrically live before the fuse (as the old polarity circuit can do).
Ceramic are too fragile for regular gigging . Well at least that has been my experience . Very good for high voltage if the pins are quality is they do not get shocked physically . Carter admin well there you go again good video again .
@@PsionicAudio , "gold" plating is often no more than a marketing ploy or scam nowadays; a layer of gold only a few microns thick is indistinguishable from solid gold to the naked eye, but I've seen lots of cheap connectors where the plating underneath the "gold" flakes off easily when stressed or flexed. Is it even gold or merely some fake 1 carat alloy made to look like gold? Nickel is much tougher, a good conductor, and easy to solder to as long as it's clean.
I doubt it. Probably in the Triad catalog then in the Schumacher. But it’s possible he asked them to make 2 ohm versions of existing models. It would been so much more convenient for the rest of us if he’d used 16 ohm speakers for a 4 ohm load.
@@PsionicAudio It appears that Leo wanted to avoid series-parallel combinations in his 4x speaker cabinets, probably to avoid warranty repairs caused by having one blown speaker also disconnect another series-wired speaker from the system, and now you've got only two speakers left to handle full gig volume, leading to more blown speakers and possibly a blown output transformer...... Of course, it's easy enough to wire 4 speakers in series parallel in such a manner that when one speaker dies it doesn't automatically take a second speaker out of the circuit, but the fact that the Bassman has 4 separate output jacks seems to indicate he was worried about that type of scenario; Or perhaps it was a fail-safe for a speaker rattling at the gig and the musician could simply unplug The Wire to that 1 speaker that was causing a problem or perhaps it was a "show must go on" fail-safe for a bad speaker buzzing or rattling loudly at the gig, and the musician could simply unplug the wire to that one speaker that was causing a problem. I have some old Triad catalogues and I should look to see if they made transformers with 2 ohm secondary. I don't think I have any Schumacher catalogs......
That impeccably cleaned chassis would be a lovely surface for warming tiny sandwiches.😉
Why not? It had already been used for warming insects.
@@lewisgeyer1440 , great for a free protein snack!
The bass pot is a 1964 cts, I'm watching on a 65-inch tv ,lol
God, i would L❤VE to be able to restore an old 5f6a or JTM. Good lord, you have my envy, Lyle !!
A fantastic restoration from a real pro. Thanks.
BEE-YOU-TEE-FULL😃👍👍
Rotten Cotton is going to be the name of my next music group 😄
It could also be the nickname for someone who works in Congress.
I also love it when an elegant result falls out of implementing simple rules consistently. It can evoke a strong sense of beauty in art and science…there is little difference, really.
This series is a real treat! Thoroughly enjoyable and it's looking like a picture perfect example.
It makes me happy to see such attention to detail.
Beautifully presented. Beautifully executed. As I progress in this hobby, I have learned that this level of quality requires only a slight increase in effort. Very satisfying.
Does your 1958 Bassman have *linear* volume pots? My 1960 5F6A does, and they're factory original, matching date codes. I've seen same in most later 5F6A along with the "non-scratchy" presence control circuit with a 25K pot.
Yes it does.
Have no fear that when Lyle says he is going to "tape off" the unused heater-winding centertap, he means cover and insulate it with heatshrink tubing, not tape! 😉
Fender would have used masking tape and called it a day.
@@joeltunnah , yup, I've seen that myself in a few old Fenders. Leo did a lot of things right but he was also a bit of a cheapskate businesswise and always looking to cut costs and labor time. Anyway, old fashioned masking tape has a tendency to dry up and glue itself in place, but electrical tape turns into a gummy gooey miss and unwraps itself when it gets warm. Neither are good electrical insulators.
Masking tape? Hell, scotch tape! It was good enough in grade school...
Lyle you are a true artist. What would you charge for a two-week apprenticeship?
$12,452.73
Otherwise I would not have the time. But thanks.
You're the only tech who's opinion I wanted to hear about the new Gibson amps,especially the 5watt version.
I haven’t had one. But they look like a very bad joke. With very deceptive marketing (hand wired my ass).
@@PsionicAudio Well you could make an informative video about them from gut shots,no? Or would you rather judge one in person?
The Mesa fanbois would ridicule me if I did a video without having one on the bench. Not that they understand the things I’ve said when I have had Mesas on the bench.
And it’s unlikely I’ll be taking any more Mesas in. I’d rather focus on good amps from companies that don’t bend their customers over.
"Red right sounds political"?? It sounds nautical to me...."red right returning". How many sailors/boaters here??
Who cares if it's "period-correct"? It's just a three-thousand-dollar amplifier that doesn't sound any better than some other new three-thousand-dollar amplifiers. It's not a million-dollar Ferrari, of which only a few were made and will never be reproduced.
Of course, some obsessive-compulsive people need for them to be period-correct.🤦♂ I wouldn't drill holes in it though. All the other things can be brought back to original specs for the psychologically challenged to buy later.
I have a serious question about amps. I am going to build an amplifier with my grandson and I need to know which one to invest the time and money into. I've seen some kits but which one?
My only requirement is that it can drive 2 - 12" speakers and can make Master of Puppets sound right. has to have what to me is badass distortion.
@6:17 Well. I guess you'll just have to get yourself a TARDIS then.
Hey i live right outside Memphis. I was wondering about how much it would cost to shift the eq and increase gain on my orange ad200b?
Have you measured noise level with and without tube shields on V1, V2 and V3 and if so, was it lowered significantly when the shields were in place?
Absolutely stunning work Lyle, to tell the truth, I wouldn’t have expected anything less judging by your previous work you have posted. Cheers 🍻.
So is there a kit to make one of these somewhere? Eventually, I would like to make and amp, and I would love a Bassman with 4 celestion cream backs.
When you do the job properly, you effectively reap double rewards: Beauty... and Reliability!
I think Semi-Rotten Cotten is playing Glastonbury this year...
Fantastic detailed work that makes me happy, can't wait to see more.
"Vomitish" - Something that resembles, but is not quite vomit. 🤮
This episode is perfect. By that I mean the flow and content are perfectly balanced. This leaves a good taste and the want for more.
At 5:30...was Borat helping out?
Thats going to look amazing when done! Love it.
Thank you for sharing Sir.
Purdy wurk!
Incredible series! Great to see so many people here.
Video quality is superb
So beautiful! I am happy : )
Why don't you look for vintage capacitors in the audio path ? It is possible to find Sprague 160P or 6PS or Sangamo 33-M or even the famous Blue molded . They sound incredibly better than modern metalized film. I'm in France and i've paid $$$ by ebay to buy these kind of caps but everybody tells me that my amps sound very good.
Because I disagree with the premise. I’ve done blind testing.
I could put just about any cap I choose in this. And I’m entirely confident in these MKT1813s. And they’re pretty for those who hear with their eyes (not saying you do that).
I do like the 6PS caps but I prefer radials for eyelet boards.
Beautiful work!
I Luuuuvvv the domino!
This does make me happy to see. Thank you.
"...semi-rotten cotton"
Very nice work.
Bravo! You are an artist in the truest sense.
Nice work, but man, those old Fender eyelet boards are ugly, and the connections on the back... ugh.
I know it's iconoclastic, but since it's already "player grade" I would have swapped it out for a turret board on standoffs, with all connections visible and accessible on top.
One minor correction: the 68k input resistors are mixers, not "grid stoppers" which need to be physically on the socket pins. I'm sure you know that, but others may not.
They are only mixers if you use both inputs of a channel at once. If you use the lower gain input then they form a voltage divider and act as a grid stopper. If you use the higher gain input they (in parallel) are a grid stopper, though not perfectly located.
Looks exactly like one of my builds! Good to hear you’re using something other than the selenium rectifier as a terminal for the bias diode. I don’t know how, but I’ve seen them burnt up while not under any load. Maybe an internal short to the mounting hardware or something.
Yeah, I don’t trust them.
@@PsionicAudio, there's no electronics "get the funk out" operation that can compare to when a selenium rectifier burns up and vents it's stinky, toxic, rotten egg-adjacent fumes. The very first electronics repair I remember was replacing a filter cap and selenium rectifier in my dad's workshop radio when I was about 11. I don't even remember how I came to know what to do in order to fix it.
Lyle and other old timers might get this... "Beware! There's pumas in the cravasses!"
I looked that up - that’s way before my time.
@@PsionicAudio - Heheh. Son, I say Son (another ancient comedy reference) , yes I sometimes forget how old I am. When The Smothers Brothers did that routine I was repairing tube TVs and radios. I learned in a 2 period, twice a week High School Electronics Shop from an old Navy radioman thankfully hired on by my school. A few years later I had a Fender Authorized shop and by '72 added several others (Kustom, Plush, Vox, Ampeg, Mesa, Acoustic, etc.) many now defunct and all but forgotten. I mainly do one-off mods and design/builds now just 'cuz I love it. Nice to hear from you, Lyle. Love your channel and your meticulous work. It's the Real.
Hey Lyle, how do I get in touch with you for a mod package to my AC30? I’ve emailed but haven’t heard back. Thanks man!
Sorry, please be patient. I’m a one man shop and I’m drowning in emails.
@@PsionicAudiono worries! Just wanted to make sure I’m on your list in some way, shape or form! The exploding inbox is a testament to your work! Thanks for the reply!
Beautiful work Lyle
Absolutely beautiful work.
Cheers,
Alan Tomlinson
Pure zen
Your layout work is superb. Some very nice video that will come in handy and hopefully here in the near future to use on my Brother n Law's 1958 Fender Bassman. We have been threatening to go back in and replace all the electrolytics at a minimum since the day we resurrected it after a 20 year Rip Van WInkle nap 5 years ago. A previous owner of the amp was a professional bass player and gigged with a lot so we know there are most likely some weak links in it so it doesn't get fired up as often and babied at that when it does. I am a believer in full restoration and use rather than Keep it Original Museum Piece. What good is a Model T if you can't drive it? I just sent a links to my Bro n Law.
#1!!!
Yay!!!
In my own amps I use preamp tube shields only in case of first stage or reverb recovery tubes, and often they don't need tube shields either. Grids of triodes are very much inside the structure of the tube and "shielded" by plate. Tube shield springs cause unwanted mechanical stress to glass envelope of tubes if there is no cushion (silicone or felt (like in case of Telefunken tape recorder EF86 tube)) between shield spring and tube.
They. Are. Removable.
@@PsionicAudio Thank God they are. 🤓
I suspect that @jutukka(based on their name) is a Finn and has learned to utilize the traditional Finnish form of verbal and written communication which is utterly devoid of diplomacy, courtesy, and kindness. Please understand that they may actually be a warm human being. I've run into a few Finns in my life, and I find this particular quality to be challenging. On the other hand, mea maxima culpa.
If I am wrong, or if I have injured anyone's feelings here, I apologize sincerely.
Cheers,
Alan Tomlinson
@@diegorhoenisch62 I don't understand this at all. I just told my personal approach to using tube shields, based on physical facts of glass as an amorphous solid. It was not anything else. I just cannot understand how it could be inappropriate.
On subject, Page 8 Glass failures:
www.worldradiohistory.com/BOOKSHELF-ARH/Technology/Technology-Vacuum-Tube/Getting-the-Most-Out-of-Vacuum-Tubes-Robert-B-Tomer-1960-(164-pages).pdf
@@diegorhoenisch62 that escalated quickly. smh
Impressive
how come all amps don't have a 47nf cap at the standby switch? Is this a common practice?
Most amps have standby after the reservoir (first filter) node. This circuit has SB before the reservoir so the added cap is needed. Standby is not needed in this amp with the rectifier tube, but as it’s a valuable fairly rare amp I’m just restoring that part of the circuit too.
PS a rectifier (tube or solid state) has a higher DC output with a capacitive load than without, so there would have been a large voltage spike if the switch didn’t have that cap.
There is still a spike as 100nF isn’t much of a load compared to 40uF, but it’s better than having a no-load state on the rectifier. Hard on the rectifier tube, too.
@@PsionicAudio Thanks for the reply and knowledge!
Mahalo Lyle! Yes, I agree. Nice and orderly.
Giving us something all to strive for ! ❤
Excellent as always. Thanks.
Watching on my newish computer monitor instead of phone tonight. Image looks as fresh as the amp restoration Lyle!! There is a “64 Bassman head and cab with webers down the street for sale. Would it sound anything like what your rebuilding?
The ‘64 model is a very different amp, but cool in its own way. Thanks.
Regarding the cap to ground on the standby switch, is that potentially dangerous? If it fails isn't it just like the "deathcap"? I must be missing something. Thanks!
The “death cap” has AC on it, often approaching the max AC rating of the cap used. This cap is rated for 630V DC, and will have @420-500VDC on it.
So not really risky, and should it fail as a short it would simply trip the fuse, not make the chassis electrically live before the fuse (as the old polarity circuit can do).
Well done sir. Looks great!
Stunning !!
Wow!
Ceramic are too fragile for regular gigging . Well at least that has been my experience . Very good for high voltage if the pins are quality is they do not get shocked physically . Carter admin well there you go again good video again .
These were much higher quality ceramics than you usually find, but phenolic/micalex is my preference.
@@PsionicAudio , "gold" plating is often no more than a marketing ploy or scam nowadays; a layer of gold only a few microns thick is indistinguishable from solid gold to the naked eye, but I've seen lots of cheap connectors where the plating underneath the "gold" flakes off easily when stressed or flexed. Is it even gold or merely some fake 1 carat alloy made to look like gold? Nickel is much tougher, a good conductor, and easy to solder to as long as it's clean.
👍👍
The difference between when that amp first came in and where it is at now is extremely stark and amazing!
Excellent choices and rationale for your handling of this restoration. Hope to see some description of impedance match logic of 4 speakers.
Thanks. Not much to say on that. There are four 8 ohm speakers in parallel making a 2 ohm load.
@@PsionicAudio , did Leo have those transformers custom-made for a 2 ohm load?
I doubt it. Probably in the Triad catalog then in the Schumacher. But it’s possible he asked them to make 2 ohm versions of existing models.
It would been so much more convenient for the rest of us if he’d used 16 ohm speakers for a 4 ohm load.
@@PsionicAudio It appears that Leo wanted to avoid series-parallel combinations in his 4x speaker cabinets, probably to avoid warranty repairs caused by having one blown speaker also disconnect another series-wired speaker from the system, and now you've got only two speakers left to handle full gig volume, leading to more blown speakers and possibly a blown output transformer...... Of course, it's easy enough to wire 4 speakers in series parallel in such a manner that when one speaker dies it doesn't automatically take a second speaker out of the circuit, but the fact that the Bassman has 4 separate output jacks seems to indicate he was worried about that type of scenario; Or perhaps it was a fail-safe for a speaker rattling at the gig and the musician could simply unplug The Wire to that 1 speaker that was causing a problem or perhaps it was a "show must go on" fail-safe for a bad speaker buzzing or rattling loudly at the gig, and the musician could simply unplug the wire to that one speaker that was causing a problem.
I have some old Triad catalogues and I should look to see if they made transformers with 2 ohm secondary. I don't think I have any Schumacher catalogs......
Maybe I missed it, did you say you cleaned it? 🙃
I think I might have. Accidentally.
Absolutely love the attention to the smallest details. Your customers get better than new equipment retuned to them.
sweet . Cheers