C3 polarity
I know I have seen the answer somewhere.
I am installing the caps now. I got to C3, the Mylar cap, and I can't remember is it polarized? If, how do you tell?
I know I have seen the answer somewhere.
I am installing the caps now. I got to C3, the Mylar cap, and I can't remember is it polarized? If, how do you tell?
Check Out Process
I finished my pcb and have everything mounted on a temporary breadboard. I have been looking for the checkout process for the SSE. Looked on Tubelab.com, and on this site. I must be using the wrong search terms. Where can I find the procedure?
I finished my pcb and have everything mounted on a temporary breadboard. I have been looking for the checkout process for the SSE. Looked on Tubelab.com, and on this site. I must be using the wrong search terms. Where can I find the procedure?
This is what I and a lot of other people have used in the past.
It is a checkout procedure posted on photobucket by Ty Bower.
I'm not sure how well the link still works but it tests the resistances through various paths on the schematics and voltages at different points.
http://www.diyaudio.com/forums/tubelab/158719-simple-se-checkout-dummies.html#post2051548
It is a checkout procedure posted on photobucket by Ty Bower.
I'm not sure how well the link still works but it tests the resistances through various paths on the schematics and voltages at different points.
http://www.diyaudio.com/forums/tubelab/158719-simple-se-checkout-dummies.html#post2051548
Fingers crossed for you Lee. A few (well quite a few) have been where you are now and it's a wonderful moment.
I want to thank everyone who helped me get that far and I'm sure I speak for a number of us.
Waiting to hear the good news Lee.
I want to thank everyone who helped me get that far and I'm sure I speak for a number of us.
Waiting to hear the good news Lee.
Finally checking out my amp. Using Ty's checkout regimen I obtained figures that left me questioning. V10 pin 3 was 9.886 ohms, pin 7 was 74.6, and pin 8 was 9.86. The power tube sockets both pin 5s were230.3, both pins 1 and 8 were 10.2. Is all okay and go ahead plug 're in, or does something warrant looking at? Thank you.
May or may not be a problem. Cathodes of the dual triode. There is an electrolytic capacitor bypassing the resistor. They have to be allowed to charge. It would read low while it is charging. After they have charged, it should be 220 ohms.
Grid of the triode. Should be 220K. Do you have a volume control installed?
Control grids of the power tubes. Do you by chance have an autoranging voltmeter? 220K is normal. 220 is off by a factor of 1000.
May or may not be a problem. Cathodes of the power tubes. There is an electrolytic capacitor bypassing the cathode resistors. They have to be allowed to charge. It would read low while it is charging. After they have charged, it should be whatever your cathode resistance is.
The pin 7 isn't right. I would re measure the others letting those caps charge, and make sure you have 220K resistors on the grids of the power tubes, and not 220 ohm resistors. You may have misread the color bands and swapped some resistors - it's easy to do, and we've all done it at one time or another.
Win W5JAG
We all do this as a learning experience right. Now I see the K on my meter. All the readings I used ground at T1. I do have an Alps blue velvet volume control. Aside from V10 pin 7 now reading 9.86 all other readings are the same. I left the meter leads on two to three minutes for caps to charge. Don't know if this makes a difference- PT is Allied 6k7vg, 0PTs are Edcor GSXE 15 8 5s, C11 and21 are Aurucaps .22uf /600 v, R 17 and 27 are Vishay 560 ohm 5w. Thank you w5jag!
I wasn't sure if it would help, I tried posting pics of my pcb. My post was denied. Something about security token. I am stuck. Would the pics help?
The readings of pin 2 and 7 of the 12at7 will be lower with the volume pot connected but should still read fairly high.
They should also read the same - mine both read 40K with the volume up full.
What does your pin 2 read?
I think you have a short at the volume pot or it may be connected wrongly.
Maybe you should wire it up without the volume pot and check you readings like that.
They should also read the same - mine both read 40K with the volume up full.
What does your pin 2 read?
I think you have a short at the volume pot or it may be connected wrongly.
Maybe you should wire it up without the volume pot and check you readings like that.
Although you should still get a reading of 100 ohms from the grid resistor.
You need to check around your R22 resistor.
You need to check around your R22 resistor.
I removed the board from test bed. Just pc board by its self. The current readings are: V2 pin 8 157.1k ohms, V10 pin 1 162+k ohms, pin 2 and 7 230.7 k ohms, pins 3 and 7 10.2 K ohms, V11 and 21 pins 1 and 8 10.2 k ohms, pins 5 230.7 k ohms. I haven't checked the volume control for shorts yet. I will. Any suggestions of what to check? Thank you for the help.
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Testing without Tubes
I believe I have read when the amp is powered up you should have speakers or something else connected. Does the same apply when testing with power on and have the tubes out?
I believe I have read when the amp is powered up you should have speakers or something else connected. Does the same apply when testing with power on and have the tubes out?
Tube Fit
Ahhhh. Went on vacation.
When I got back I checked grounds for the pcb. Ureka! The input I'm using is a 3.5 mm plug. It has four tabs, two channels, common and ground. I wrongly thought the ground would also work for pcb. Added connection. Now my checkout readings are right in line.
Proceeding to power checks. My probes won't fit in V10 socket holes- too big. I tried my tube and it is extremely tight. Like tube is over an eighth of an inch off socket. Is that okay?
( In the mean time I will use micro alligator clips on V10)
Ahhhh. Went on vacation.
When I got back I checked grounds for the pcb. Ureka! The input I'm using is a 3.5 mm plug. It has four tabs, two channels, common and ground. I wrongly thought the ground would also work for pcb. Added connection. Now my checkout readings are right in line.
Proceeding to power checks. My probes won't fit in V10 socket holes- too big. I tried my tube and it is extremely tight. Like tube is over an eighth of an inch off socket. Is that okay?
( In the mean time I will use micro alligator clips on V10)
Help
On to power testing.
I am using three meters. One old (1990s) Radioshackauto-ranging meter with a 400 vac limit.
One new GE 2524 digital 500vac, and one new Allison EM380 digital 600vac meter. Both from Walmart.
Preamp tube pins 4 and 5, and power tube pins 2 read 2.3 vac on the auto ranging meter, and 76.5 on the 200 scale from both other meters.?
On rectifier socket pins 4 and 6 both new meters read 419 on the high scale. Okay.
Rectifier pin 2 reads 1247 on the 500 meter and 13?? on the other.????
My wife was sautéing something in the kitchen- I thought it was the pcb. Maybe I could have. Everything Looks okay.
Meter?
On to power testing.
I am using three meters. One old (1990s) Radioshackauto-ranging meter with a 400 vac limit.
One new GE 2524 digital 500vac, and one new Allison EM380 digital 600vac meter. Both from Walmart.
Preamp tube pins 4 and 5, and power tube pins 2 read 2.3 vac on the auto ranging meter, and 76.5 on the 200 scale from both other meters.?
On rectifier socket pins 4 and 6 both new meters read 419 on the high scale. Okay.
Rectifier pin 2 reads 1247 on the 500 meter and 13?? on the other.????
My wife was sautéing something in the kitchen- I thought it was the pcb. Maybe I could have. Everything Looks okay.
Meter?