This video needs more love. It's quite a demonstration of the common issues when un-stuffing an old amp and making it gig-ready for years to come. All the meat and potatoes issues are covered, from dying caps & crappy earths to valve bases and drifting carbon comp resistors.
Hello! Just a quick question, why did you wire the ground on the chassis using some solder instead of putting a spade on the top right bolt of the transformer? Thx for the videos i'm watching all of it
Using transformer hardware for ground terminal mounting is unreliable. Fasteners used for dual purposes can become loose over time, resulting in unreliable connections to ground.
Hi there. Please don't take this the wrong way but I believe you are supposed to remove the nuts on the transformer and mount the transformer with them. It should sit flush not on nuts. That's why hammond doesn't give you extra nuts to mount with. Just say'n nice video
I'm surprised you left the heater wiring "stock", with the chassis used as the return for the 6 volt heater supply. Upgrading to twisted pairs for the heaters, and using the 6 volt centertap ---- or an artificial version, with resistors, perhaps even biased up from the 6V6 cathode ---- lowers the hum level. Champs, being single-ended and without the common-mode hum cancellation inherent to a push-pull circuit, can use all the help they can get!
You mention not using the 47 uf on the first power node off the 5Y3. So instead of the can cap values of 40/20/20 as shown on the schematic are you installing the caps 22/47/22? Did I understand that correctly and can you elaborate on the reason please sir.
That is correct. The maximum direct capacitance a 5Y3 should see is 32uf. I probably could have put a 33uf on the first node, but the diameter of them is excessive at that voltage rating and the hum was low enough to be barely audible.
I've heard that from champions in the states. They may be winding them to 110v spec which would be pretty silly. I've found that when they say 240v they mean it though. Many others say 240v when it's really wound for 230v and we have similar problems in that case.
@@BradsGuitarGarage Thank you Sir :) Oh going back to the prev episode on the Vibro Champ, noticed the CE cap issue. I tried those in some pro audio builds, completely unreliable. Had no problems with the JJs but maybe I was lucky (so far! haha). Anyhow, thanks again!
See if you can find some replacement power cords for vacuum cleaners; they're usually very tough and very flexible. Probably much longer than you really need, but you can make the cord for the amplifier 10 or even 12 feet long if you like! Can you find them in a 3 wire grounded version? Most vacuums here in the States are diubkegrounded now and only use 2 wire cords, but your codes are stricter, so .... I used to use vacuum cleaner cords for replacements on some of my power tools.
Beautiful work!
Your de-soldering iron is awesome.I sure wish I had one!!!! I'm still using the good old soldier sucker...
This video needs more love. It's quite a demonstration of the common issues when un-stuffing an old amp and making it gig-ready for years to come. All the meat and potatoes issues are covered, from dying caps & crappy earths to valve bases and drifting carbon comp resistors.
Cheers, she sounds sweet!
I prefer IEC sockets.
Hello! Just a quick question, why did you wire the ground on the chassis using some solder instead of putting a spade on the top right bolt of the transformer? Thx for the videos i'm watching all of it
Using transformer hardware for ground terminal mounting is unreliable.
Fasteners used for dual purposes can become loose over time, resulting in unreliable connections to ground.
@@BradsGuitarGarage ok thanks
Hi there. Please don't take this the wrong way but I believe you are supposed to remove the nuts on the transformer and mount the transformer with them. It should sit flush not on nuts. That's why hammond doesn't give you extra nuts to mount with. Just say'n nice video
So interesting. Shame i never took education seriously. Bathroom was my "major" grade 7-11.2.
Amp sounds great. Great job on the repair
I'm surprised you left the heater wiring "stock", with the chassis used as the return for the 6 volt heater supply. Upgrading to twisted pairs for the heaters, and using the 6 volt centertap ---- or an artificial version, with resistors, perhaps even biased up from the 6V6 cathode ---- lowers the hum level. Champs, being single-ended and without the common-mode hum cancellation inherent to a push-pull circuit, can use all the help they can get!
I contemplated that, but the hum was barely audible with your head against the cabinet, so I left it stock. Budget was also a consideration.
You mention not using the 47 uf on the first power node off the 5Y3. So instead of the can cap values of 40/20/20 as shown on the schematic are you installing the caps 22/47/22? Did I understand that correctly and can you elaborate on the reason please sir.
That is correct. The maximum direct capacitance a 5Y3 should see is 32uf. I probably could have put a 33uf on the first node, but the diameter of them is excessive at that voltage rating and the hum was low enough to be barely audible.
Wow! I have nothing but trouble using Hammond transformers. The voltage is usually 30+ volts high on the HT at 117vac line.
I've heard that from champions in the states. They may be winding them to 110v spec which would be pretty silly.
I've found that when they say 240v they mean it though.
Many others say 240v when it's really wound for 230v and we have similar problems in that case.
Hey, any recommendation for big solder iron in terms of wattage? 100W sounds reasonable? Thanks Brad!
The Weller 80W ones are more than adequate.
@@BradsGuitarGarage Thank you Sir :) Oh going back to the prev episode on the Vibro Champ, noticed the CE cap issue. I tried those in some pro audio builds, completely unreliable. Had no problems with the JJs but maybe I was lucky (so far! haha). Anyhow, thanks again!
Ebay has 1.00 dollar cords US. They are computer power cables. They work for 120 volt.
Brad, what happened to your beard! I just ran across this video and find the "Brad Clean Shaven" look rather disturbing ;-)
See if you can find some replacement power cords for vacuum cleaners; they're usually very tough and very flexible. Probably much longer than you really need, but you can make the cord for the amplifier 10 or even 12 feet long if you like! Can you find them in a 3 wire grounded version? Most vacuums here in the States are diubkegrounded now and only use 2 wire cords, but your codes are stricter, so ....
I used to use vacuum cleaner cords for replacements on some of my power tools.
I tend to save those for hostage situations.