30 mv and 9 mv, that's pretty good, well within the usable range. Monitor the offset and the heatsink temps for an hour or so. You can hook up a signal source and check the output for AC signal, but don't hook up expensive spkrs to it yet.
Lookin good!
Lookin good!
when you get technical give the unambiguous technical units.
Your 30 & 9 become 30Vdc & 9Vdc or 30mVdc & 9mVdc
That's not good.
I'm going to ask again, are your trafo center taps hooked to the PS board ground?
I could see 30v if the fet grouping was turned off, but 9v is very strange.
I have to leave for a while, will be back later.
I'm going to ask again, are your trafo center taps hooked to the PS board ground?
I could see 30v if the fet grouping was turned off, but 9v is very strange.
I have to leave for a while, will be back later.
No Heat !
Bill ,
not sure what you mean by centre tap ? here is all the wiring in 4 photos .
I will give you a call later if its ok ... we can cover a lot of ground in a shorter
amount of time ....
I really appreciate the help of everyone with this cherry poppin !
still no reading on the 220 uf !
Rich
Bill ,
not sure what you mean by centre tap ? here is all the wiring in 4 photos .
I will give you a call later if its ok ... we can cover a lot of ground in a shorter
amount of time ....
I really appreciate the help of everyone with this cherry poppin !
still no reading on the 220 uf !
Rich
Attachments
I'm back.
Forgive me if I am wrong but you seem to have your amp board ground wires swapped. The supplies are totally separate for each amp board. All three wires must go to the same amp board.
Sure, you can call if you would like.
Forgive me if I am wrong but you seem to have your amp board ground wires swapped. The supplies are totally separate for each amp board. All three wires must go to the same amp board.
Sure, you can call if you would like.
Farnell are quite good Farnell United Kingdom | world-leading distributor of electronic and maintenance, repair and operations products.
Cricklewood electronics are good on price.
Future are good for cheap IRS parts.
Cheers
Thanks Nigel ,
I talked to Farnell today . There is no way around their MIN charge as an individual off the street wanting a part or parts mailed to a private address .
I ordered from Digikey ... they are superb - items will be here monday .
Rich
Thanks Nigel ,
I talked to Farnell today . There is no way around their MIN charge as an individual off the street wanting a part or parts mailed to a private address .
I ordered from Digikey ... they are superb - items will be here monday .
Rich
Nah !
Bill ,
I may have to resort to threats ..... . Im contemplating taking the thing apart and getting help to work through it all ...
What do you think ?
Rich
Bill ,
I may have to resort to threats ..... . Im contemplating taking the thing apart and getting help to work through it all ...
What do you think ?
Rich
Can you unbolt the heatsinks and remove them from the case. That would make things much easier to get to.
Also, email me the schematic you got with the boards.
Also, email me the schematic you got with the boards.
Crap !
I knew you were gonna say that . I can get to everything ,except the caps .
it makes sense though ... give me an hour . will be back for instructions
I knew you were gonna say that . I can get to everything ,except the caps .
it makes sense though ... give me an hour . will be back for instructions
It is imperative that we have the schematic for the boards unless you know what part does what. If you can get to everything it probably isn't necessary to dismantle it.
That's good enough. Give me a couple minutes to proof read it. I see 2 problems already if you used trimmers at R1 and R8. You're probably going to need to pull them. I'll get back.
It looks to be correct except for the addition of the trimmer pots. A lot of this is specific to your boards so we can do it here on the forum or through email.
I think the first thing to do is load test your power supplies with a 75 or 100W lightbulb unless you have a big 500 ohm resistor laying around. Rig up a tester, disconnect both amp boards, and hook the bulb up from ground to the rails, one at a time, and measure the voltage with the load attached. Once we know the PSs are capable we can proceed with the amps.
I think the first thing to do is load test your power supplies with a 75 or 100W lightbulb unless you have a big 500 ohm resistor laying around. Rig up a tester, disconnect both amp boards, and hook the bulb up from ground to the rails, one at a time, and measure the voltage with the load attached. Once we know the PSs are capable we can proceed with the amps.
I have tester made up ,but I only have a 60w bulb . Do I need to go to to store and buy
bigger ?
We can keep all this on here if there are no objections . A step by step record of the process may be useful to other virgins like myself .
Rich
Btw, there are no trimmers on my boards .
bigger ?
We can keep all this on here if there are no objections . A step by step record of the process may be useful to other virgins like myself .
Rich
Btw, there are no trimmers on my boards .
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I didn't see any trimmer pots in your previous pics so that's good, except for Rp2. R19 and Rp2 should add up to around 47k ohms. If you left the Rp2 space blank, the current source will bias up much too high.
I'm going to keep posting as I see things, don't get overwhelmed.
I'm going to keep posting as I see things, don't get overwhelmed.
Ok ,
I have no reference as R1, R9 etc . Im not confident following the schematic for this ,but I have just finished measuring everything on one amp board so we could count our way down from the output 10k + ,10k- ....
I have noted the values and what each component measures .
R
I have no reference as R1, R9 etc . Im not confident following the schematic for this ,but I have just finished measuring everything on one amp board so we could count our way down from the output 10k + ,10k- ....
I have noted the values and what each component measures .
R
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