you said you had C1 shorted. wouldnt the grid resistor be the part tha was shorted. If that grid resistor is missing, you would have oscillation issues.
first time bought from ebay j109 they were fakes, after that I bought these...hope they are not fake cause I`ll never ever buy this kind of things from ebay
1.never twist GDS (ECB) wires for any output
2.keep them shortest you can
3.include gate res ditto on gate pin
4.be sure that your parts are genuine ; if you doubt - testing routine out of circ is simple
5.if one channel is working - swapping parts ( take care to label them , to not mix if they're matched ) between channels isn't most insane idea in last 10 years
6.if your head is boiling - leave it for few days ; ride a bike , drink wine , communicate with children or even wife
😉
2.keep them shortest you can
3.include gate res ditto on gate pin
4.be sure that your parts are genuine ; if you doubt - testing routine out of circ is simple
5.if one channel is working - swapping parts ( take care to label them , to not mix if they're matched ) between channels isn't most insane idea in last 10 years
6.if your head is boiling - leave it for few days ; ride a bike , drink wine , communicate with children or even wife
😉
Attachments
well dead quiet here for a while...
btw what is the maximum bias I could go with at 12V rails and 3.5ohms minimum speaker impedance ?
btw what is the maximum bias I could go with at 12V rails and 3.5ohms minimum speaker impedance ?
As I prepare to start the testing on my plain vanilla A-J, I have a couple of questions.
1, Is there a best target temperature for the heatsinks? ...perhaps one at which the IRFP240s sound best? [I will be able to adjust heat sink airflow and will have a front panel temp readout]
2, To get up and running without alot of fuss, is it advisable to install any trimmers rather than all fixed resistors? If yes, where? [I measured all the resistors and they are all extremely close to spec, but this is my first class A project. I don't really know what to expect when I crank up the variac!]
TiA!
1, Is there a best target temperature for the heatsinks? ...perhaps one at which the IRFP240s sound best? [I will be able to adjust heat sink airflow and will have a front panel temp readout]
2, To get up and running without alot of fuss, is it advisable to install any trimmers rather than all fixed resistors? If yes, where? [I measured all the resistors and they are all extremely close to spec, but this is my first class A project. I don't really know what to expect when I crank up the variac!]
TiA!