Great timing. Today I am recapping my 2550 Silver Jubilee as I watch your video. Great tips on the ground connections and voltage differences across the screen resistors. I’m an electrical tech studying tube amps for the last few years. Thanks for the videos.
Incredible!!!...'71 is turret board ...my '73 100 watt is too, looks like that was last year, because all my '74's are printed circuit board. Easier to work on with pre '74 Marshall's. I kick myself for not buying a '72 50 watt Marshall Super Lead head for $500.00 back in the late 1990's!! $25.00..what!!! Makes me sick too lol!
Hey Lyle, about that Dremel burnishing bit, I use a red or green Scotch-Brite pads cut up in small circles. I use the same Dremel bit that the small cutting discs go on. A single pad would probably last you a year if that’s all you use it for. They don’t remove metal and you can get into anywhere with it.
Careful, Green definitely removes metal just very slowly. Red prolly does as well but the grey seems the most abrasive. The blue ones dont and that is why they can be used on pots and pans but I wouldnt recomend them for this application. Metal shop guys use scotchbright products to polish metal (Which works by removing metal).
"Magic eraser" pads will burnish metal; they're made from melamine (kitchen counter laminate!) that has been foamed with air and are surprisingly abrasive.
Try Nevr-Dull polishing wadding on the faceplate; it's the only thing I've found that you can use on a vintage McIntosh amp or receiver without removing the silkscreening.
Sorry if I missed the reason for this, but is it generally preferable to solder the grounds of the dual capacitors you were replacing to the chassis vs using a nut, compression washer and bolt to the chassis? If not, could you please explain? Thanks so much for all these great videos!
Disimilar metal junction that is how you make diodes. Trouble is it not in a control manner in this application or direction for the diode. Very nice practice shown here.
I TOTALLY LOST IT WHEN YOU MENTIONED "BRAD'S" CHANNEL LAST WEEK ! I FOLLOWED HIM BEFORE HE TURNED INTO A POLITICAL NIGHTMARE ! HIS WIFE BOOTED HIM FROM THE HOUSE AND HE LOST A TON OF SUBSCRIBERS ! IF HE DIDN'T HAVE TO WIPE HIS FACE EVERY 90 SECONDS HE WOULD APPEAR LIKE A NORMAL DUDE. WHAT A SHAME...THE DOOR CLOSED ON HIM AND OPENED FOR YOU ! THANK THE LORD YOU CAME ALONG !!! PLEASE DON'T START TELLING US ABOUT CONSPIRACY THEORIES ! YOU ROCK !
My [drummer] brother had bought the HW version of this amp [used] back in the late 80s along with it's optional 8x10 cab for our BASS player to use in our 'pick-up garage band'. Maybe for around a grand or so. Hey, he worked in the aerospace industry - he had scads of 'disposable' income. When we disbanded because well, 'life' happens, he sold that beauty a few years later. I think he recovered what he paid but I'll bet he could kick himself now for what THAT one is worth ! Anyway, I only mention it because those crappy input jacks and PC board mounted pots made me cringe! LoL
@@PsionicAudio Is there a way to test a cap electronically to see if its operating at spec? but you're right... if the car didn't need new tires or belts you probably wouldnt notice the change
Did Marshall put Glyptol or similar threadlocking lacquer on the bolts and nuts to lock them and prevent them from vibrating loose? That stuff causes corrosion on a hot environment such as a tube amp, and the corrosion at *the very end* of the grounding bolt of that second filter cap is somewhat suspicious.
Wombat, Hi my V2A preamp is 106,Volts and V2B is 240 Volts. My other two preamp Valves are about even on pin 1 and 6. Is it supposed to be like that? Thanks Nick
I've cleaned and reused mounting/grounding hardware on a vintage Fender, but if it was a more modern amp with a PCB board ike this Marshall I'd probably just change the hardware and ditch the slotted screw for a Philips, Pozidrive, or even a Torx or Allen- head bolt, something easier to hold in place with a screwdriver while you tighten the nut from the other side; and swap out the black oxide star washer for a shiny chrome or stainless one. Or, just solder the ground directly to the chassis.....either way, should we really care about mounting hardware originality in a modern amp with a PC board?
Great timing. Today I am recapping my 2550 Silver Jubilee as I watch your video. Great tips on the ground connections and voltage differences across the screen resistors. I’m an electrical tech studying tube amps for the last few years. Thanks for the videos.
Thanks for cheering me up! My friend bought a really nice 1971 Marshall 1987 at an auction yesterday for $25...I've felt sick all day lol
Incredible!!!...'71 is turret board ...my '73 100 watt is too, looks like that was last year, because all my '74's are printed circuit board. Easier to work on with pre '74 Marshall's. I kick myself for not buying a '72 50 watt Marshall Super Lead head for $500.00 back in the late 1990's!! $25.00..what!!! Makes me sick too lol!
I totally agree with your position on "flat-head" screws. There is no excuse for them to still exist.
That's a sweet sounding amp. And that tele really sounded good through it.
Audio sounds great!
Still enjoying your vids.
Nice job and tech info, and practical replacements of those caps..Great sounds..Ed..uk..😀
Hey Lyle, about that Dremel burnishing bit, I use a red or green Scotch-Brite pads cut up in small circles. I use the same Dremel bit that the small cutting discs go on.
A single pad would probably last you a year if that’s all you use it for. They don’t remove metal and you can get into anywhere with it.
Careful, Green definitely removes metal just very slowly. Red prolly does as well but the grey seems the most abrasive. The blue ones dont and that is why they can be used on pots and pans but I wouldnt recomend them for this application. Metal shop guys use scotchbright products to polish metal (Which works by removing metal).
"Magic eraser" pads will burnish metal; they're made from melamine (kitchen counter laminate!) that has been foamed with air and are surprisingly abrasive.
Try Nevr-Dull polishing wadding on the faceplate; it's the only thing I've found that you can use on a vintage McIntosh amp or receiver without removing the silkscreening.
Sorry if I missed the reason for this, but is it generally preferable to solder the grounds of the dual capacitors you were replacing to the chassis vs using a nut, compression washer and bolt to the chassis? If not, could you please explain? Thanks so much for all these great videos!
Disimilar metal junction that is how you make diodes. Trouble is it not in a control manner in this application or direction for the diode. Very nice practice shown here.
I TOTALLY LOST IT WHEN YOU MENTIONED "BRAD'S" CHANNEL LAST WEEK !
I FOLLOWED HIM BEFORE HE TURNED INTO A POLITICAL NIGHTMARE !
HIS WIFE BOOTED HIM FROM THE HOUSE AND HE LOST A TON OF SUBSCRIBERS !
IF HE DIDN'T HAVE TO WIPE HIS FACE EVERY 90 SECONDS HE WOULD APPEAR LIKE A NORMAL DUDE. WHAT A SHAME...THE DOOR CLOSED ON HIM AND OPENED FOR YOU !
THANK THE LORD YOU CAME ALONG !!!
PLEASE DON'T START TELLING US ABOUT CONSPIRACY THEORIES !
YOU ROCK !
No, no, I meant the good Brad! Brad's Guitar Garage, not the other Brad.
Yep. Very different Brad’s. I highly recommend Brad’s gear garage. I just wish he would walk away from Fake Book and focus on RUclips.
A lot of good people went goofy during these wacky times unfortunately. Some came back others not so much. That’s why I’m here too!
My [drummer] brother had bought the HW version of this amp [used] back in the late 80s along with it's optional 8x10 cab for our BASS player to use in our 'pick-up garage band'. Maybe for around a grand or so. Hey, he worked in the aerospace industry - he had scads of 'disposable' income. When we disbanded because well, 'life' happens, he sold that beauty a few years later. I think he recovered what he paid but I'll bet he could kick himself now for what THAT one is worth ! Anyway, I only mention it because those crappy input jacks and PC board mounted pots made me cringe! LoL
Sounds awesome...
The devil’s in the details, often overlooked. That’s how one reaches the title of Wizard. There’s some smoke for your ego, but Sincere.
Aside from the noise, that thing sounds good. Have you worked on the reissue?
Just one. Tin whiskers in a 16mm pot. Not a real RI.
Would have loved to hear a before and after demo to see if the cap change actually made a change/improvement to the tone..
That's like asking if cars drive better with new tires and belts.
@@PsionicAudio Is there a way to test a cap electronically to see if its operating at spec? but you're right... if the car didn't need new tires or belts you probably wouldnt notice the change
Did Marshall put Glyptol or similar threadlocking lacquer on the bolts and nuts to lock them and prevent them from vibrating loose? That stuff causes corrosion on a hot environment such as a tube amp, and the corrosion at *the very end* of the grounding bolt of that second filter cap is somewhat suspicious.
Nah, just black paint.
Wombat, Hi my V2A preamp is 106,Volts and V2B is 240 Volts. My other two preamp Valves are about even on pin 1 and 6. Is it supposed to be like that? Thanks Nick
Yes.
SOLDAPULT!!! YAY!
How hot do you run your iron?
700 usually. A bit more for eyelets, hotter for lead-free.
@@PsionicAudio Thanks. I've been running a little cold, time to jack up the temperature. Got a 5F6 Bassman to go through.
My OCD really wanted you to center that filter cap in the chassis hole... 🙄
Funny, I thought I wonder if I’ll be able to see the LED clipping diodes and boom, there there are to the right
I know only too well that those compression washers can fall into a portal to another dimension never to be seen again. ha-ha-ha
They reappear as coat-hangers in your closet.
I've cleaned and reused mounting/grounding hardware on a vintage Fender, but if it was a more modern amp with a PCB board ike this Marshall I'd probably just change the hardware and ditch the slotted screw for a Philips, Pozidrive, or even a Torx or Allen- head bolt, something easier to hold in place with a screwdriver while you tighten the nut from the other side; and swap out the black oxide star washer for a shiny chrome or stainless one. Or, just solder the ground directly to the chassis.....either way, should we really care about mounting hardware originality in a modern amp with a PC board?
The value of these '87 SJs continues to increase, so I need to keep everything as original as possible.
Chassis/wiring looks nothing like the current "silver jubilee" in production.