yup, lucky you. I didnt rework in mine, i still wait to get a new inductor. I may get it tomorrow or so.
I have my new caps and a new L-C filter cap too (4.7uf 250v, poly film cap). The original L-C filtering cap looks quite ridiculous, and could me damaged too.
Can you check something for me??
what is the impedance of your subs?? mine is 3.2 ohm. It should be more like 4 ohm as specified. I think it is damaged, but listening with it on a "better" amp, it sound like a brand new speaker.
I have my new caps and a new L-C filter cap too (4.7uf 250v, poly film cap). The original L-C filtering cap looks quite ridiculous, and could me damaged too.
Can you check something for me??
what is the impedance of your subs?? mine is 3.2 ohm. It should be more like 4 ohm as specified. I think it is damaged, but listening with it on a "better" amp, it sound like a brand new speaker.
Are you measuring the resistance with a multitester to come up with the 3.2 ohms? If so, a speaker's measured resistance is not the same as what the sticker impedance says. Most often it is lower, and that is due to the magnetic flux the voice coil moves about. 3.2 sounds about right for a 4 ohm speaker.
Do you have a cap checker at all? If not, it might be a worthy investment if you dabble in electronics somewhat often. They can be a lifesaver, especially in caps that the numbers have worn off.
The PSU caps that were bad on my 2 subs were quite obvious, just a simple check with a 60V power supply showed me that one cap in each sub was bad, since they didn't take any charge right away. The other was good in each one, but I never replace caps in a setup like this individually, only in pairs.
Time to go to the store and get some "Y" cables so I can hook all 3 up at once 😎
Jer
Do you have a cap checker at all? If not, it might be a worthy investment if you dabble in electronics somewhat often. They can be a lifesaver, especially in caps that the numbers have worn off.
The PSU caps that were bad on my 2 subs were quite obvious, just a simple check with a 60V power supply showed me that one cap in each sub was bad, since they didn't take any charge right away. The other was good in each one, but I never replace caps in a setup like this individually, only in pairs.
Time to go to the store and get some "Y" cables so I can hook all 3 up at once 😎
Jer
hi, yes i do have a cap tester, actualy it is a Marconi industrial inductance/capacitance tester. Quite a big unit. It is used for RF testing mostly, but i use it for almost all i can.
Yes it measure 3.2 ohm with a multimeter, i understand that it is a inductive load, and it measure more like 3.7- 3.8 ohm usualy in my experience, it is why i do ask about yours.
The cap i was talking about was the cap that is into the final stage with the indutor, not the power suply caps.
Yes it measure 3.2 ohm with a multimeter, i understand that it is a inductive load, and it measure more like 3.7- 3.8 ohm usualy in my experience, it is why i do ask about yours.
The cap i was talking about was the cap that is into the final stage with the indutor, not the power suply caps.
Oh, and i dont "dables" in electronics, it is my job.
go to astroflex.com...i have engineered almost everything electronic you see into this web page. No beginer.
Astroflex inc
go to astroflex.com...i have engineered almost everything electronic you see into this web page. No beginer.
Astroflex inc
Question
Is there sufficent hardware to support more than 200Hz sound. I mean can I use the little black box with out stage for class d amplifier for full audio range 20Hz-20KHz 🙂
Is there sufficent hardware to support more than 200Hz sound. I mean can I use the little black box with out stage for class d amplifier for full audio range 20Hz-20KHz 🙂
Hi,
I really wouldn't even consider it. This amp has a hard time surviving just at a ~100Khz switching frequency..... do yourself a favor and forget that idea. There are other options for a full range amp out there for you to look at.
Regards,
Chris
I really wouldn't even consider it. This amp has a hard time surviving just at a ~100Khz switching frequency..... do yourself a favor and forget that idea. There are other options for a full range amp out there for you to look at.
Regards,
Chris
ok, i have opened mine, i have removed all components to test them. the gates are ok.
the op amp seems to have gone the other side.
i think the vcc have been pumped so high and fast that the vcc to the opamp have taken it.
One of the mosfet also act wierd, i guess it is damaged as well.
Lets order new ones at digikey...
the op amp seems to have gone the other side.
i think the vcc have been pumped so high and fast that the vcc to the opamp have taken it.
One of the mosfet also act wierd, i guess it is damaged as well.
Lets order new ones at digikey...
Hi Pat,
You said you smoked a lab supply testing it didn't you?
It's doubtful your lab supply would have enough capacitance in it to keep pumping under control, which explains why it would go up in smoke so fast.
Although, your op amp supplies are regulated, if the regulators aren't blown as well I would try to find another possibility as to why the op amp might have.
What did you get for an inductor anyway, does digikey have anything decent along those lines?
Regards,
Chris
You said you smoked a lab supply testing it didn't you?
It's doubtful your lab supply would have enough capacitance in it to keep pumping under control, which explains why it would go up in smoke so fast.
Although, your op amp supplies are regulated, if the regulators aren't blown as well I would try to find another possibility as to why the op amp might have.
What did you get for an inductor anyway, does digikey have anything decent along those lines?
Regards,
Chris
Oh yeaaaaah!!! Some lab supplies don't like to supply class-d amps driving low frequency (or even DC) into a load !!!
Regards
Charles
Yes, it was something like a lab supply, but nothing very acurate, and it was modified so it was at the end only a 50v ct transfo with 2x 10 000uf caps, no electronic regulation for this task. The op amp supply are regulated? would you say that a zener and some 100nf caps is something regulated ? there are no other components to regulate opamps. Id say "leveled" ...
I think for another possibility, while it was pumping to the hell, that the output of the amp was so bad and inductive that its been catched thru the resistor feedback and then fryed up the op amp by this feedback resistor?
Theres no million possibilities, input or ouput or rails. The output of the opamp is loaded by a very small cap so i doubt it could be the cause. Or to the end, some arcing ?
I think for another possibility, while it was pumping to the hell, that the output of the amp was so bad and inductive that its been catched thru the resistor feedback and then fryed up the op amp by this feedback resistor?
Theres no million possibilities, input or ouput or rails. The output of the opamp is loaded by a very small cap so i doubt it could be the cause. Or to the end, some arcing ?
oh, and yes, Digikey got some cool inductor, look under Miller inductors.
I use one of those into my IR based amp, and it works marvelously.
They have anough values for any kind of design.
I use one of those into my IR based amp, and it works marvelously.
They have anough values for any kind of design.
Thanks Pat,
Excellent, that'll be a big help for me I didn't think they had any, I will look into them.
Good luck with your amp, keep posted.
Chris
Excellent, that'll be a big help for me I didn't think they had any, I will look into them.
Good luck with your amp, keep posted.
Chris
all of those are power inductor, toroidal, with high curent ratings.
Digikey catalogue page
M1292-ND 2100HT-151-H INDUCTOR TOROID 150UH 15% HORIZ J W Miller Magnetics 55 3.66000
1 -
M1299-ND 2200HT-120-H INDUCTOR TOROID 12UH 15% HORIZ J W Miller Magnetics 93 3.98000
1 -
M1300-ND 2200HT-180-H INDUCTOR TOROID 18UH 15% HORIZ J W Miller Magnetics 98 4.07000
1 -
M1303-ND 2200HT-560-H INDUCTOR TOROID 56UH 15% HORIZ J W Miller Magnetics 162 3.64000
1 -
M1305-ND 2200HT-101-H INDUCTOR TOROID 100UH 15% HORIZ J W Miller Magnetics 81 3.68000
1 -
M1307-ND 2200HT-271-H INDUCTOR TOROID 270UH 15% HORIZ J W Miller Magnetics 95 3.80000
1 -
M1310-ND 2200HT-220-V INDUCTOR TOROID 22UH 15% VERT J W Miller Magnetics 100 4.07000
1 -
M1313-ND 2300HT-100-H INDUCTOR TOROID 10UH 15% HORIZ J W Miller Magnetics 120 5.17000
1 -
M1286-ND 2100HT-150-H INDUCTOR TOROID 15UH 15% HORIZ J W Miller Magnetics 80 3.34000
1 -
M1297-ND 2100HT-101-V INDUCTOR TOROID 100UH 15% VERT J W Miller Magnetics 117 3.56000
1 -
M1298-ND 2200HT-100-H INDUCTOR TOROID 10UH 15% HORIZ J W Miller Magnetics 86 3.98000
1 -
M1302-ND 2200HT-390-H INDUCTOR TOROID 39UH 15% HORIZ J W Miller Magnetics 192 3.56000
1 -
M1304-ND 2200HT-820-H INDUCTOR TOROID 82UH 15% HORIZ J W Miller Magnetics 82 3.64000
1 -
M1309-ND 2200HT-100-V INDUCTOR TOROID 10UH 15% VERT J W Miller Magnetics 147 3.98000
1 -
M1315-ND 2300HT-220-H INDUCTOR TOROID 22UH 15% HORIZ J W Miller Magnetics 74 5.48000
1 -
M1320-ND 2300HT-151-H INDUCTOR TOROID 150UH 15% HORIZ J W Miller Magnetics 98 5.64000
1 -
M1321-ND 2300HT-221-H INDUCTOR TOROID 220UH 15% HORIZ J W Miller Magnetics 87 5.68000
1 -
M1326-ND 2300HT-220-V INDUCTOR TOROID 22UH 15% VERT J W Miller Magnetics 114 5.48000
1 -
M1285-ND 2100HT-100-H INDUCTOR TOROID 10UH 15% HORIZ J W Miller Magnetics 488 3.34000
1 -
M1293-ND 2100HT-221-H INDUCTOR TOROID 220UH 15% HORIZ J W Miller Magnetics 133 3.80000
1 -
M1295-ND 2100HT-220-V INDUCTOR TOROID 22UH 15% VERT J W Miller Magnetics 74 3.34000
1 -
M1301-ND 2200HT-270-H INDUCTOR TOROID 27UH 15% HORIZ J W Miller Magnetics 70 4.07000
1 -
M1308-ND 2200HT-391-H INDUCTOR TOROID 390UH 15% HORIZ J W Miller Magnetics 94 3.88000
1 -
M1324-ND 2300HT-561-H INDUCTOR TOROID 560UH 15% HORIZ J W Miller Magnetics 96 5.84000
1 -
M1325-ND 2300HT-100-V INDUCTOR TOROID 10UH 15% VERT J W Miller Magnetics 102 5.17000
1
M1329-ND 2300HT-221-V INDUCTOR TOROID 220UH 15% VERT J W Miller Magnetics 45 3.80000
1 -
M1330-ND 2300HT-471-V INDUCTOR TOROID 470UH 15% VERT J W Miller Magnetics 41 5.80000
1 -
M1287-ND 2100HT-220-H INDUCTOR TOROID 22UH 15% HORIZ J W Miller Magnetics 95 3.34000
1 -
M1288-ND 2100HT-330-H INDUCTOR TOROID 33UH 15% HORIZ J W Miller Magnetics 98 3.43000
1 -
M1289-ND 2100HT-470-H INDUCTOR TOROID 47UH 15% HORIZ J W Miller Magnetics 138 3.47000
1 -
M1290-ND 2100HT-680-H INDUCTOR TOROID 68UH 15% HORIZ J W Miller Magnetics 70 3.52000
1 -
M1291-ND 2100HT-101-H INDUCTOR TOROID 100UH 15% HORIZ J W Miller Magnetics 202 3.56000
1 -
M1294-ND 2100HT-100-V INDUCTOR TOROID 10UH 15% VERT J W Miller Magnetics 58 3.34000
1 -
M1306-ND 2200HT-181-H INDUCTOR TOROID 180UH 15% HORIZ J W Miller Magnetics 100 3.76000
1 -
M1312-ND 2200HT-221-V INDUCTOR TOROID 220UH 15% VERT J W Miller Magnetics 36 3.80000
1 -
M1314-ND 2300HT-150-H INDUCTOR TOROID 15UH 15% HORIZ J W Miller Magnetics 136 5.25000
1 -
M1316-ND 2300HT-330-H INDUCTOR TOROID 33UH 15% HORIZ J W Miller Magnetics 137 5.52000
1 -
M1317-ND 2300HT-470-H INDUCTOR TOROID 47UH 15% HORIZ J W Miller Magnetics 65 5.56000
1 -
M1318-ND 2300HT-680-H INDUCTOR TOROID 68UH 15% HORIZ J W Miller Magnetics 36 5.60000
1 -
M1319-ND 2300HT-101-H INDUCTOR TOROID 100UH 15% HORIZ J W Miller Magnetics 70 5.60000
1 -
M1322-ND 2300HT-331-H INDUCTOR TOROID 330UH 15% HORIZ J W Miller Magnetics 94 5.76000
1 -
M1323-ND 2300HT-471-H INDUCTOR TOROID 470UH 15% HORIZ J W Miller Magnetics 89 5.80000
1 -
M1328-ND 2300HT-101-V INDUCTOR TOROID 100UH 15% VERT J W Miller Magnetics 88 3.68000
1
Digikey catalogue page
M1292-ND 2100HT-151-H INDUCTOR TOROID 150UH 15% HORIZ J W Miller Magnetics 55 3.66000
1 -
M1299-ND 2200HT-120-H INDUCTOR TOROID 12UH 15% HORIZ J W Miller Magnetics 93 3.98000
1 -
M1300-ND 2200HT-180-H INDUCTOR TOROID 18UH 15% HORIZ J W Miller Magnetics 98 4.07000
1 -
M1303-ND 2200HT-560-H INDUCTOR TOROID 56UH 15% HORIZ J W Miller Magnetics 162 3.64000
1 -
M1305-ND 2200HT-101-H INDUCTOR TOROID 100UH 15% HORIZ J W Miller Magnetics 81 3.68000
1 -
M1307-ND 2200HT-271-H INDUCTOR TOROID 270UH 15% HORIZ J W Miller Magnetics 95 3.80000
1 -
M1310-ND 2200HT-220-V INDUCTOR TOROID 22UH 15% VERT J W Miller Magnetics 100 4.07000
1 -
M1313-ND 2300HT-100-H INDUCTOR TOROID 10UH 15% HORIZ J W Miller Magnetics 120 5.17000
1 -
M1286-ND 2100HT-150-H INDUCTOR TOROID 15UH 15% HORIZ J W Miller Magnetics 80 3.34000
1 -
M1297-ND 2100HT-101-V INDUCTOR TOROID 100UH 15% VERT J W Miller Magnetics 117 3.56000
1 -
M1298-ND 2200HT-100-H INDUCTOR TOROID 10UH 15% HORIZ J W Miller Magnetics 86 3.98000
1 -
M1302-ND 2200HT-390-H INDUCTOR TOROID 39UH 15% HORIZ J W Miller Magnetics 192 3.56000
1 -
M1304-ND 2200HT-820-H INDUCTOR TOROID 82UH 15% HORIZ J W Miller Magnetics 82 3.64000
1 -
M1309-ND 2200HT-100-V INDUCTOR TOROID 10UH 15% VERT J W Miller Magnetics 147 3.98000
1 -
M1315-ND 2300HT-220-H INDUCTOR TOROID 22UH 15% HORIZ J W Miller Magnetics 74 5.48000
1 -
M1320-ND 2300HT-151-H INDUCTOR TOROID 150UH 15% HORIZ J W Miller Magnetics 98 5.64000
1 -
M1321-ND 2300HT-221-H INDUCTOR TOROID 220UH 15% HORIZ J W Miller Magnetics 87 5.68000
1 -
M1326-ND 2300HT-220-V INDUCTOR TOROID 22UH 15% VERT J W Miller Magnetics 114 5.48000
1 -
M1285-ND 2100HT-100-H INDUCTOR TOROID 10UH 15% HORIZ J W Miller Magnetics 488 3.34000
1 -
M1293-ND 2100HT-221-H INDUCTOR TOROID 220UH 15% HORIZ J W Miller Magnetics 133 3.80000
1 -
M1295-ND 2100HT-220-V INDUCTOR TOROID 22UH 15% VERT J W Miller Magnetics 74 3.34000
1 -
M1301-ND 2200HT-270-H INDUCTOR TOROID 27UH 15% HORIZ J W Miller Magnetics 70 4.07000
1 -
M1308-ND 2200HT-391-H INDUCTOR TOROID 390UH 15% HORIZ J W Miller Magnetics 94 3.88000
1 -
M1324-ND 2300HT-561-H INDUCTOR TOROID 560UH 15% HORIZ J W Miller Magnetics 96 5.84000
1 -
M1325-ND 2300HT-100-V INDUCTOR TOROID 10UH 15% VERT J W Miller Magnetics 102 5.17000
1
M1329-ND 2300HT-221-V INDUCTOR TOROID 220UH 15% VERT J W Miller Magnetics 45 3.80000
1 -
M1330-ND 2300HT-471-V INDUCTOR TOROID 470UH 15% VERT J W Miller Magnetics 41 5.80000
1 -
M1287-ND 2100HT-220-H INDUCTOR TOROID 22UH 15% HORIZ J W Miller Magnetics 95 3.34000
1 -
M1288-ND 2100HT-330-H INDUCTOR TOROID 33UH 15% HORIZ J W Miller Magnetics 98 3.43000
1 -
M1289-ND 2100HT-470-H INDUCTOR TOROID 47UH 15% HORIZ J W Miller Magnetics 138 3.47000
1 -
M1290-ND 2100HT-680-H INDUCTOR TOROID 68UH 15% HORIZ J W Miller Magnetics 70 3.52000
1 -
M1291-ND 2100HT-101-H INDUCTOR TOROID 100UH 15% HORIZ J W Miller Magnetics 202 3.56000
1 -
M1294-ND 2100HT-100-V INDUCTOR TOROID 10UH 15% VERT J W Miller Magnetics 58 3.34000
1 -
M1306-ND 2200HT-181-H INDUCTOR TOROID 180UH 15% HORIZ J W Miller Magnetics 100 3.76000
1 -
M1312-ND 2200HT-221-V INDUCTOR TOROID 220UH 15% VERT J W Miller Magnetics 36 3.80000
1 -
M1314-ND 2300HT-150-H INDUCTOR TOROID 15UH 15% HORIZ J W Miller Magnetics 136 5.25000
1 -
M1316-ND 2300HT-330-H INDUCTOR TOROID 33UH 15% HORIZ J W Miller Magnetics 137 5.52000
1 -
M1317-ND 2300HT-470-H INDUCTOR TOROID 47UH 15% HORIZ J W Miller Magnetics 65 5.56000
1 -
M1318-ND 2300HT-680-H INDUCTOR TOROID 68UH 15% HORIZ J W Miller Magnetics 36 5.60000
1 -
M1319-ND 2300HT-101-H INDUCTOR TOROID 100UH 15% HORIZ J W Miller Magnetics 70 5.60000
1 -
M1322-ND 2300HT-331-H INDUCTOR TOROID 330UH 15% HORIZ J W Miller Magnetics 94 5.76000
1 -
M1323-ND 2300HT-471-H INDUCTOR TOROID 470UH 15% HORIZ J W Miller Magnetics 89 5.80000
1 -
M1328-ND 2300HT-101-V INDUCTOR TOROID 100UH 15% VERT J W Miller Magnetics 88 3.68000
1
I'm going to get two of these Mnf.# 2300HT-150-H "mystery core" ones.
I checked the JW Miller site and there's very little extra information on them. So, since you say you've used them in your IR amp, I'll get em anyway, but if you had to guess as to the core material, what do you suppose it could be, just out of curiosity.
Hey check this link out I found the other day:
http://xtronics.com/kits/ccode.htm
Remember the cap code conversation? Check out Table 1, I didn't know about that little trick use of the #'s 8 and 9 as multipliers.
Seems like a great site for cap codes all around.
Cheers
I checked the JW Miller site and there's very little extra information on them. So, since you say you've used them in your IR amp, I'll get em anyway, but if you had to guess as to the core material, what do you suppose it could be, just out of curiosity.
Hey check this link out I found the other day:
http://xtronics.com/kits/ccode.htm
Remember the cap code conversation? Check out Table 1, I didn't know about that little trick use of the #'s 8 and 9 as multipliers.
Seems like a great site for cap codes all around.
Cheers
Hi, thanks for the link for the caps, very good.
If i look at the inductance i have, it looks like plain ferrite core. It have some brown paint on its edge, and it is mostly charcoal black. I know there is several parameters for the ferrite material such as impedance at freq, permeability,...cant get them.
At least, i know for sure that the one i have into the IR redesign works perfeclty.
If i look at the inductance i have, it looks like plain ferrite core. It have some brown paint on its edge, and it is mostly charcoal black. I know there is several parameters for the ferrite material such as impedance at freq, permeability,...cant get them.
At least, i know for sure that the one i have into the IR redesign works perfeclty.
Hi, i think i have found some source of bug into this amp.
The preamp section was latching up +vcc sometimes, without any reasons, i searched and searched...until it was evident: mosfet Q1 was bad, sending its gate signal to the -input of the opamp, and then latching up everything else after. Ive been able to simulate it and it is this poor litle mosfet that was giving some pops pops. how can this be?. This mosfet is used only for the muting section. I did replace it and then no more latch up.
Its the very first part into this sub amp that tested bad, and intermitently.
Any tought on these kind of problems with small signal mosfets?
tia.
The preamp section was latching up +vcc sometimes, without any reasons, i searched and searched...until it was evident: mosfet Q1 was bad, sending its gate signal to the -input of the opamp, and then latching up everything else after. Ive been able to simulate it and it is this poor litle mosfet that was giving some pops pops. how can this be?. This mosfet is used only for the muting section. I did replace it and then no more latch up.
Its the very first part into this sub amp that tested bad, and intermitently.
Any tought on these kind of problems with small signal mosfets?
tia.
Attachments
Hi. I have rebuild it all. It works ok and have survived some crash test.
One thing i have discovered, the shift level at the output of the op amp to the first gate IS the weak point.
I have also added a small board wich reads the actual dc offset, and the vcc rails, so if it stuck or start to pump too much, it can disable the woofer output by the means of a relay, and can also shut down the amp by the SD signal. So turn on/off is controled by a relay to the sub, and potential problem with the relay and total shut down with the SD.
Also, when it is muted, i have added a circuitry that disable the oscillation by the SD thing too. So, when it is at rest with no signal, muted, it is mostly all disabled. So it stays totaly cold when not used. No more chances that it could blow while we are sleeping.
I think that should be it for this thing. Next step is to trash.
**SD is the shut down of the amp, it disable the signal to the power mosfet, making them both OFF.
One thing i have discovered, the shift level at the output of the op amp to the first gate IS the weak point.
I have also added a small board wich reads the actual dc offset, and the vcc rails, so if it stuck or start to pump too much, it can disable the woofer output by the means of a relay, and can also shut down the amp by the SD signal. So turn on/off is controled by a relay to the sub, and potential problem with the relay and total shut down with the SD.
Also, when it is muted, i have added a circuitry that disable the oscillation by the SD thing too. So, when it is at rest with no signal, muted, it is mostly all disabled. So it stays totaly cold when not used. No more chances that it could blow while we are sleeping.
I think that should be it for this thing. Next step is to trash.
**SD is the shut down of the amp, it disable the signal to the power mosfet, making them both OFF.
replacement amp ???
Hi all
I am new here but have read the 22 pages of this post on this JBL PB12 amp issues. Why I appricate all of the efforts and hours you guys have put into this. Is there any one out there where we can just buy an decent inexpensive complete replacement amp and slide into the hole where the old amp was.
thanks 😕 😕
Hi all
I am new here but have read the 22 pages of this post on this JBL PB12 amp issues. Why I appricate all of the efforts and hours you guys have put into this. Is there any one out there where we can just buy an decent inexpensive complete replacement amp and slide into the hole where the old amp was.
thanks 😕 😕
Hi !
Unfortunately, i cant sell parts for the PB12, or any module that can go in it as a replacement, i simply dont encourage anyone to spend time or cash in those, even if some of us have repaired them.
You might consider a plate amp, as one already suggested me.
cheers.
Unfortunately, i cant sell parts for the PB12, or any module that can go in it as a replacement, i simply dont encourage anyone to spend time or cash in those, even if some of us have repaired them.
You might consider a plate amp, as one already suggested me.
cheers.