you got the same results with both boards? or is this with the board with signal problems?
with the know good board - if the voltage is that low what are you measuring "across" R22 R23 (those 1k ohms)?
with the know good board - if the voltage is that low what are you measuring "across" R22 R23 (those 1k ohms)?
yeah sometime i'll share my experience with an EV amp and current limiting but that would require that we all have appropriate drinks in our hands whether it be Italy, Canada,or the good ole USA
!
!😀 i like wine (obviously).
So, indianajo, nothing to be sorry about, that scheme would fool anybody.
On the good power board (A), without any load, i got:
7815
In +21
Out + 14.8
7915
In -21
Out - 15.0
The question is... Can i put the 0.6 ohm resistors now? I changed the lamp to 100w now. Strange, but they are available here in Italy (Europe?)..
So, indianajo, nothing to be sorry about, that scheme would fool anybody.
On the good power board (A), without any load, i got:
7815
In +21
Out + 14.8
7915
In -21
Out - 15.0
The question is... Can i put the 0.6 ohm resistors now? I changed the lamp to 100w now. Strange, but they are available here in Italy (Europe?)..
ok your doing it again!
yes put the 1 ohm resistors on the "bad board" in place.there more ground to cover and time for wine later!
yes put the 1 ohm resistors on the "bad board" in place.there more ground to cover and time for wine later!
Sorry man, you mean the 1 ohm resistors of the good board into the bad board?
Or the 0.6 ohm resistors i found at the local shop?
Or the 0.6 ohm resistors i found at the local shop?
the 0.6 from the shop (don't mess with the good board! that's -(minus) one tequila for you for even thinking like that)
Argh! But i learned to ask first before i burn something else..
So, with the 0.6 ohm resistors i got a slightly increased voltage, obviously:
7815
In 21.0
Out 14.87
7915
In -21.12
Out -15.18
If i plug the good pre board (B), the voltages do not change.
So, with the 0.6 ohm resistors i got a slightly increased voltage, obviously:
7815
In 21.0
Out 14.87
7915
In -21.12
Out -15.18
If i plug the good pre board (B), the voltages do not change.
well now let's see if we can sort out the bad board.
i might be absent here for a bit; snow to shovel and groceries to get ...etc..etc
at this point try both boards and see if you get signal through (you will need to hook up the speakers or any cheap drivers you've got laying around for this test.)
i'll check back soon.
i might be absent here for a bit; snow to shovel and groceries to get ...etc..etc
at this point try both boards and see if you get signal through (you will need to hook up the speakers or any cheap drivers you've got laying around for this test.)
i'll check back soon.
Ok man, i'll be here with a cheap speaker, waiting for instructions. Thanks so much, again.
And have fun with the snow.. 🙂
And have fun with the snow.. 🙂
That +- 15v with op amp board connected looks good. I would check the amp for DC out the speaker terminals, all four of them, before I hooked speakers to it. More than 0.2 VDC with no signal, I'd worry about it.
I was hiding from my amp project yesterday afternoon and evening, playing a computer game. Input transistor is reading base 0.4 v, emitter 0.4 v, collector, 0.3 v. That is not really possible with a good npn transistor. The transistor reads good with the DVM, one diode drop forwards (0.6 v) from base to both collector and emmiter. ???? Meanwhile the next transistor with no base drive is biasing an electrolytic cap to 72 v, on a new 50 v rated cap. I'm goning to violate a rule, yesterday I salvaged two 160 v rated e-caps out of an old terminal and TV power boards, to temporarily install while I debug this mess. Went to the grocery store too yesterday, **** cold and windy 6 miles on my bicycle. No snow here yet, though. -6 C here last night.
I was hiding from my amp project yesterday afternoon and evening, playing a computer game. Input transistor is reading base 0.4 v, emitter 0.4 v, collector, 0.3 v. That is not really possible with a good npn transistor. The transistor reads good with the DVM, one diode drop forwards (0.6 v) from base to both collector and emmiter. ???? Meanwhile the next transistor with no base drive is biasing an electrolytic cap to 72 v, on a new 50 v rated cap. I'm goning to violate a rule, yesterday I salvaged two 160 v rated e-caps out of an old terminal and TV power boards, to temporarily install while I debug this mess. Went to the grocery store too yesterday, **** cold and windy 6 miles on my bicycle. No snow here yet, though. -6 C here last night.
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in northern ontario "snow" is a four letter word that is usually grouped with other four letter words!
indy's right (i hope that's not offensive me being informal) check that there's no dc on the outputs (no loads) if that's ok we can try to see if we get signal through.
indy's right (i hope that's not offensive me being informal) check that there's no dc on the outputs (no loads) if that's ok we can try to see if we get signal through.
Guys, you don't have to complain about cold if you live in the North. Go to Brasil or Cuba.
I would love to come in Us or Canada one day. Too bad i'm scared of flying more than 2 hours. God only knows how much i hate snow, fortunately it happens just once every 4-5 years i see that horrible white thing
Wonderful womens as well, in Brasil and Cuba. Ok, i stop it.
Little summit:
We have 2 power boards (let's call them so) and 2 pre boards.
A power board never had problems (i think, no clue for the opposite)
A pre board has signal problems (distorted sound, no lows etc)
B power board had problems with the rail we discussed so far. I replaced the protection resistors and now we got the rail slightly higher (resistors are smaller in resistance)
B pre board never had problems
This said, you ask me for DC on speaker out.
Obviously i tried any configuration, i would call it curiosity, Turk would call it impatience.. 😀
I could tell you any result for any configuration, but the results are pretty similar, so...
On tweet terminals i have between -0.6 and -1.2 mV (millivolts). On woofer between 42 and 51 mV (millivolts). On one configuration i actually got -40 mV. Don't think the sign is that important, but it's strange that i have just 1 negative and 3 positive value.
Volume and gain controls all shut down.
I know on hi fi amps you mostly have a trimmer in the board in which you can adjust it.
Anyway i think the result is ok, considering Indianajo wrote of 0.2 V, so 200 mV.
I assembled a couple of pa speakers on a box, very rude and crude stuff, but i wouldn't feel sorry if i would destroy them, so..
I would love to come in Us or Canada one day. Too bad i'm scared of flying more than 2 hours. God only knows how much i hate snow, fortunately it happens just once every 4-5 years i see that horrible white thing
Wonderful womens as well, in Brasil and Cuba. Ok, i stop it.
Little summit:
We have 2 power boards (let's call them so) and 2 pre boards.
A power board never had problems (i think, no clue for the opposite)
A pre board has signal problems (distorted sound, no lows etc)
B power board had problems with the rail we discussed so far. I replaced the protection resistors and now we got the rail slightly higher (resistors are smaller in resistance)
B pre board never had problems
This said, you ask me for DC on speaker out.
Obviously i tried any configuration, i would call it curiosity, Turk would call it impatience.. 😀
I could tell you any result for any configuration, but the results are pretty similar, so...
On tweet terminals i have between -0.6 and -1.2 mV (millivolts). On woofer between 42 and 51 mV (millivolts). On one configuration i actually got -40 mV. Don't think the sign is that important, but it's strange that i have just 1 negative and 3 positive value.
Volume and gain controls all shut down.
I know on hi fi amps you mostly have a trimmer in the board in which you can adjust it.
Anyway i think the result is ok, considering Indianajo wrote of 0.2 V, so 200 mV.
I assembled a couple of pa speakers on a box, very rude and crude stuff, but i wouldn't feel sorry if i would destroy them, so..
things should be safe if your still on the current limiter i could be wrong but i think the "bad" pre board was in the speaker with the "bad" supply lines (the "bad" pre could in fact be ok (just because the op-amps didn't have power there's all sorts of RC networks that would leak distorted audio to the amp) which is why i think we need to see if the preamp boards work.
Yeah, i'm ready to rock.
In tehe sense i would like to try it, wait for american permission!
In tehe sense i would like to try it, wait for american permission!
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C'mon Turk, give me the permission to try, please! Do me just this favour!
I'll give you the permission to drink, thereafter!
I'll give you the permission to drink, thereafter!
sorry i thought you where waiting for indianajo
i've been saying i think you should try it...so what are you waiting for a sign from God? (politics now religion! there's rules about that on this forum!)
i've been saying i think you should try it...so what are you waiting for a sign from God? (politics now religion! there's rules about that on this forum!)
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