Chops,
Here's a diagram to assist you in tracing out the circuit. Just connect the wires. Either print it out and draw the wires, or draw the wires in some pic editor on the computer. Your choice.
Draw in the Octal keys so we know where pin 1 is, I can't see them in the photo.
..Todd
Here's a diagram to assist you in tracing out the circuit. Just connect the wires. Either print it out and draw the wires, or draw the wires in some pic editor on the computer. Your choice.
Draw in the Octal keys so we know where pin 1 is, I can't see them in the photo.
..Todd
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I think you were right with CLC, Ian444. It looks like there is a choke in the photos.
Yes, you're right there. On second take, it looks like the first 2 green resistors are screen grid resistors.
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Oh, I thought you measured one cathode resistor to be 244 ohms and the other to be 199 ohms?
Yes, the left channel pair reads 244 ohms and the right channel pair reads 199 ohms. Each pair in each channel shares one resistor.
Chops,
Here's a diagram to assist you in tracing out the circuit. Just connect the wires. Either print it out and draw the wires, or draw the wires in some pic editor on the computer. Your choice.
Draw in the Octal keys so we know where pin 1 is, I can't see them in the photo.
..Todd
WOW! Thanks Todd!
Depending on how I feel tonight when I get home (around 9pm), I may start working on this diagram. Been working some long days lately so it's been a bit rough and I'm usually exhausted when I get home, but we'll see.
Thanks again Todd, I really appreciate it!
Just got home a little while ago and decided I'm not going to attempt to do this diagram until the weekend when I get home a couple hours sooner.
On a different note, I just tried placing another coke bottle 5U4G along with the original coke bottle 5U4G and they both fit side by side. So when I find a good pair, I'll buy them and put them in. Those smooth plates seem to be perfectly silent when sitting right next to the amp. No rattles or nothing. Sorry, I know it doesn't effect the performance or sound, but it's just something that kind of bugs me. Silly I'm sure to most of you.
On a different note, I just tried placing another coke bottle 5U4G along with the original coke bottle 5U4G and they both fit side by side. So when I find a good pair, I'll buy them and put them in. Those smooth plates seem to be perfectly silent when sitting right next to the amp. No rattles or nothing. Sorry, I know it doesn't effect the performance or sound, but it's just something that kind of bugs me. Silly I'm sure to most of you.
I have a used coke bottle 5U4G if you need one. It's branded Admiral and says Made In Canada (which means anything you want). I don't imagine I'll ever use it. I have plenty of 5U4's if I do need one. I don't know if it's any good, but the getters (top and bottom) look great. Cost of shipping.
..Todd
..Todd
I have a used coke bottle 5U4G if you need one. It's branded Admiral and says Made In Canada (which means anything you want). I don't imagine I'll ever use it. I have plenty of 5U4's if I do need one. I don't know if it's any good, but the getters (top and bottom) look great. Cost of shipping.
..Todd
LOL! A day late and a buck short... Thanks for the offer, but right after I posted here, I went browsing around on eBay and purchased both an Admiral and NOS Philco. According to the seller, on his BK 707 the Admiral measures 80/80 and the Philco measures 90/90.
I've just found this thread and I may be able to help a little. I started a blog to keep track of what I was doing and it includes some schematics that you may find useful I found the schematics somewhere but I can't remember where.
Baldwin 40 watt amplifier
If you click on the pictures or schematics you can see a larger version and if you click again it gets even larger.
I'm curious whether the second amp which includes a pedal amp as well as a manual amp could be used as a stereo amp. The output transformers are different in size, though it looks like they would be much the same feeding 8 ohm speakers.
ray
Baldwin 40 watt amplifier
If you click on the pictures or schematics you can see a larger version and if you click again it gets even larger.
I'm curious whether the second amp which includes a pedal amp as well as a manual amp could be used as a stereo amp. The output transformers are different in size, though it looks like they would be much the same feeding 8 ohm speakers.
ray
That schematic on ratbagp's blog explains a thing or two. The amp was originally built assuming different output tubes for each channel. Replacing the output transformer and tubes got you most of the way to a 'stereo' amp, but the cathode resistors are different enough still to make your output tubes run with a different bias current, and probably a bit different grid bias voltage in operation. Swapping out that 200 Ohm cathode resistor to 250 ohm to match the other channel will make them operate identically.
Not sure if the difference is really worth the hassle though. I'll defer to the veterans on that issue.
..Todd
Not sure if the difference is really worth the hassle though. I'll defer to the veterans on that issue.
..Todd
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