Sometimes if I need to see the bottom of a PCB, I can shine a bright pinpoint LED light around the sides or up through one of the valve holes and you can see the shadows of the bottom traces.
..spend more time playing Music through the amps rather than tweeking endlessly is "The" best advice as well as " "Keep it simple" . Good to see all these different designs and why they sound the way they do so Thankyou for that. All I know is that a new set of strings can change the sound coming from the amp for the better or even worse ?!?!
Woo new build, love it! Glad Im not the only one who is a fan of Cornford they always floated my boat. I have long since used Kemper as my amp but my profile is a Cornford MK50 II amp, sounds great.. dosnt weigh a ton!
UK voltage.. I recently repaired a Marshall AS50D - replaced the power transformer. It's a UK model and the xformer is would for 230V which is why they're a common failure point. Transformer was £23 delivered from Marshall so no big deal but I'd have liked to source an appropriate 240V one for peace of mind. Anything I could find was prohibitively expensive though.
It's strange, all the blackface fenders with series caps have the 220k resistors as do the standard silverface ones. But I have seen a 135w ultra linear twin reverb without the resistors, very strange, but fender appear to have left them out.
@@jasonsansome5579 Money. With the 135 Watt ultralinear amp the resistors would be a higher wattage rating and cost more and caps had much better tolorances by the time the 135 & 185 Watt Fender amps came along. Bipolar or non-polarized electrolytic caps are merely just two electrolytic caps wired back to back negative to negative, and they don't have any balancing resistors. An axial 100 volt 10 uF non-polarized cap is just two 50 volt 20 uF caps wired - to - and suffed into an aluminum sleeve with the rubber releif caps on each end. Radial non polar caps are still just two cap in one can wired - to -. They don't use balancing resistors either. My R&D power supply has to use 3 totem polled caps to achieve a 1200 volt rating, and the balancing resistors are about a $1000 50 watt industrial resistor assembly, but capacitors when that was made had terrilble tolerances. The tolerances are much tighter now.
Just a dumb question from an electronic illiterate, what is, if any, possible differences in tone or percieved dynamics from ,say, an american amp ( originally designed for 120 volts) even with appropriate power transformer windings. Point being, the perceived sound the amp is designed to produce could be affected by being listend to from the local wall voltage,... or could it? Maybe if designed for UK or NZ it could have something that makes a small change in sound, or is it just maths in voltage conversion at the power transformer and just imagination? I'm aware that wall voltage fluctuates anyway, and this seems to make the amp sound a little different, I think, but this is hard to test in an A/B type comparison as well, so could just be the sound of different rooms or ( guitar string) conditions so is hard to assess. So is everything down to transformer maths, or is their subtle differences in locations of design with lower voltages?
Great episode Chris, Maybe you covered it already but what temperature are you soldering at, and I noticed you don’t appear to use a flux, or as a novice am I missing something?
Thanks Chris great work
Sometimes if I need to see the bottom of a PCB, I can shine a bright pinpoint LED light around the sides or up through one of the valve holes and you can see the shadows of the bottom traces.
Yup, tried that, it’s too opaque
..spend more time playing Music through the amps rather than tweeking endlessly is "The" best advice as well as " "Keep it simple" . Good to see all these different designs and why they sound the way they do so Thankyou for that. All I know is that a new set of strings can change the sound coming from the amp for the better or even worse ?!?!
thanks for the input i will dive into it!!
Best repair channel. Cheers!
Woo new build, love it! Glad Im not the only one who is a fan of Cornford they always floated my boat. I have long since used Kemper as my amp but my profile is a Cornford MK50 II amp, sounds great.. dosnt weigh a ton!
UK voltage.. I recently repaired a Marshall AS50D - replaced the power transformer. It's a UK model and the xformer is would for 230V which is why they're a common failure point. Transformer was £23 delivered from Marshall so no big deal but I'd have liked to source an appropriate 240V one for peace of mind. Anything I could find was prohibitively expensive though.
Sounding more like your old self, Chris. Hope you’re feeling better too.
Did i miss something, I would've thought there would be 220k strapping resistors on the capacitors that are wired in series on the pro reverb.
Hi Chris, For your designs, what software do you use to make your schematics? Cheers, Don
DIYLC
Hi Chris. Really enjoying the time lapse portions, any chance of hearing some Benny Hill to accompany the next one, 🤞🤞
Hi Chris, I have never seen you use a variac. Have I missed it , or is it just not part of your regular toolkit? Great channel, thanks!
On the fender cap job; no voltege balancing resistors alongside the serial caps of the first reservoir?
It's strange, all the blackface fenders with series caps have the 220k resistors as do the standard silverface ones. But I have seen a 135w ultra linear twin reverb without the resistors, very strange, but fender appear to have left them out.
@@jasonsansome5579 Money. With the 135 Watt ultralinear amp the resistors would be a higher wattage rating and cost more and caps had much better tolorances by the time the 135 & 185 Watt Fender amps came along. Bipolar or non-polarized electrolytic caps are merely just two electrolytic caps wired back to back negative to negative, and they don't have any balancing resistors. An axial 100 volt 10 uF non-polarized cap is just two 50 volt 20 uF caps wired - to - and suffed into an aluminum sleeve with the rubber releif caps on each end. Radial non polar caps are still just two cap in one can wired - to -. They don't use balancing resistors either. My R&D power supply has to use 3 totem polled caps to achieve a 1200 volt rating, and the balancing resistors are about a $1000 50 watt industrial resistor assembly, but capacitors when that was made had terrilble tolerances. The tolerances are much tighter now.
Watch Sunday’s video to find out 👍
Just a dumb question from an electronic illiterate, what is, if any, possible differences in tone or percieved dynamics from ,say, an american amp ( originally designed for 120 volts) even with appropriate power transformer windings. Point being, the perceived sound the amp is designed to produce could be affected by being listend to from the local wall voltage,... or could it? Maybe if designed for UK or NZ it could have something that makes a small change in sound, or is it just maths in voltage conversion at the power transformer and just imagination? I'm aware that wall voltage fluctuates anyway, and this seems to make the amp sound a little different, I think, but this is hard to test in an A/B type comparison as well, so could just be the sound of different rooms or ( guitar string) conditions so is hard to assess. So is everything down to transformer maths, or is their subtle differences in locations of design with lower voltages?
Where did you send that vox transformer to get rewound? And what did it cost? Have a -66 ac30 with a new ot but still have the og bad one
Great episode Chris,
Maybe you covered it already but what temperature are you soldering at, and I noticed you don’t appear to use a flux, or as a novice am I missing something?
60w iron @ 363°C with 3.2mm chisel tips. The solder has a flux core 👍
Sounds like your emails are going into Hook Amps spam folder ?
Just ring them?