lzybztrd
Yup....but making sure to drink plenty of coffee first! Not sure to tell if relay working, right now on off is at variac some distance from board.
Using scientific wild a$$ guess method I set multimeter to ohms, measure all output after relays. All 0 except one I meant to turn on, so soon we will know...one more volume pot. (used 50k mono pieces)
Oh, BTW, all measurement still as left last time.
Russellc
if you can't hear relay when connecting pin 1 to 3 ( or 2 to 4 , or 2 to 3) , you can check things with DVM across diode parallel to relay coil
(I know - if you presoldered those pins, relay will click on softly while powering up entire thingie )
(I know - if you presoldered those pins, relay will click on softly while powering up entire thingie )
OK, I have old phone with spotify for test. Hooked up to inputs for
testing, not hooked up to amp. I suppose if working I should detect some tiny voltage on outputs, where off set was measured.
Russellc
testing, not hooked up to amp. I suppose if working I should detect some tiny voltage on outputs, where off set was measured.
Russellc
AC? I figured when I measure DC offset on power amp, I can zero (or as close as possible) but when music playing suddenly it begins to dance a bit.
Using that "logic" I figured that if I am measuring offset with music playing on this piece, it may show a little, but I am measuring DC. There is .5 mv on output of relay #1 and zero if I measure pads of other relays. It does not dance...just sits at .5
What should I measure? I think I will take it to mystery lab, hook it up to JBL mule power amp and older speaks and see what happens.
Russellc
measure DC offset without signal
if you have signal , you can measure just AC
if you insist on measuring DC with signal present , both you and your meter will be confused
been there, done that, still enjoying immensely when remembering any of my precioussssss moments
if you have signal , you can measure just AC
if you insist on measuring DC with signal present , both you and your meter will be confused
been there, done that, still enjoying immensely when remembering any of my precioussssss moments
I'm certainly not above leaving this sissy contraption as is, but hardly cat creature proof!
Russellc
Russellc
While waiting chassis from Italy, I will start collecting Power supply caps, rectifiers and transformers for dual mono SissySit amp. And a deluxe U5 chassis...and a better volume pot for this Iron pre.
Russellc
Russellc
Seemed to work fine with JBL6230 "mule amp" but when hooked up to M2 as soon as M2 came up, hums like crazy. It is just layed out on a board...must need chassis ground, but ItsAllinmyhead's worked like this. Looking it over. Put Wayne's 2018 BA line stage back and it plays fine.
Russellc
Russellc
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gimme pic exactly in humming arrangement
few please
there can be several reasons, but it can work even case-less without problem
funniest example - Pa's own Iron Pumpkin , called Plankey
it had some faint hummm in SE mode, simply because Pa gave me a pair of nastiest Donuts ever made at that side of Ocean
I can bet that he even didn't replace them later ....... Plankey collecting dust on some shelf top
edit: without waiting for pics - it must be issue with arrangement of Safety Gnd and Audio GND
either connect them or disconnect them (contrary to present situation) and it 'll stop humming
of course that I prefer all Audio GNDs connected to Safety GND , either through 15R NTC or last fashion - bridge+cap+NTC
few please
there can be several reasons, but it can work even case-less without problem
funniest example - Pa's own Iron Pumpkin , called Plankey
it had some faint hummm in SE mode, simply because Pa gave me a pair of nastiest Donuts ever made at that side of Ocean
I can bet that he even didn't replace them later ....... Plankey collecting dust on some shelf top
edit: without waiting for pics - it must be issue with arrangement of Safety Gnd and Audio GND
either connect them or disconnect them (contrary to present situation) and it 'll stop humming
of course that I prefer all Audio GNDs connected to Safety GND , either through 15R NTC or last fashion - bridge+cap+NTC
Last edited:
gimme pic exactly in humming arrangement
few please
there can be several reasons, but it can work even case-less without problem
funniest example - Pa's own Iron Pumpkin , called Plankey
it had some faint hummm in SE mode, simply because Pa gave me a pair of nastiest Donuts ever made at that side of Ocean
I can bet that he even didn't replace them later ....... Plankey collecting dust on some shelf top
edit: without waiting for pics - it must be issue with arrangement of Safety Gnd and Audio GND
either connect them or disconnect them (contrary to present situation) and it 'll stop humming
of course that I prefer all Audio GNDs connected to Safety GND , either through 15R NTC or last fashion - bridge+cap+NTC
Since I upgraded my computer to windows 10, I cant upload pics. They load in the box, hit upload and it goes away but does not attach. I will have to sort that out. Going to try putting sim card from camera in reader and see if that works.
If you check #569, mine is laid out just like this for checking it out before boxed up. So basically nothing is grounded...odd thing with JBL 6230 mule amp, nary a hum. Put M2 in chain and big 60hz hum. It is laid out just like his is in post #569
I may have to wait for chassis before I can go further so to have proper ground. I have no idea how Itsallinmyhead pulled it off.
Russellc
either you have signal xformers in close proximity with some Big Donut, or your setup is lacking in grounding
first you can test with some moving, second with simple croc shortie put between chassis pad and mid pin on IEC
hoping that two other IEC pins are heatshrinked 🙂
first you can test with some moving, second with simple croc shortie put between chassis pad and mid pin on IEC
hoping that two other IEC pins are heatshrinked 🙂
Going to try to do it with phone....wiring is electrical nightmare. Transformer AC inputs are bolted to large barrier strip. Power cord to that, then to variac.
I probably need a chassis. In #569, I see a wire coming off his input plug IEC part. Maybe this is a ground wire?
This was just temp setup to hear it.
I probably need a chassis. In #569, I see a wire coming off his input plug IEC part. Maybe this is a ground wire?
This was just temp setup to hear it.
