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Deleted member 148505
I can lift the resistors and put beads on the legs yes, it's gonna be hard to take out mosfet to put beads on their gates
Yes that's what I think too, solder resistor and ferrite bead in the air.
Okay, so I got the ferrite beads on the gate resistors, closest to mosfet, no difference, I noticed that the 0r3 resistors on positive rail heated up, so it's the 9240 that are the problem, also heard the indicator hissing, I poked around with a variable capacitor to ground and set in pf range, I was able to reduce oscillation but not eliminate it, heatsink is grounded in case you were wondering, what's the next logic thing to do?
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Deleted member 148505
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Deleted member 148505
I can try, but I just don't get why it's acting up, what is the function of c4 c5 . The other modules work fine just this one with other mosfet, would it help to increase value of gate resistor, make it less prone to oscillation, say 100 ohm?
C4-C5 is for bootstrap current source.
Can you put 100pf on base-collector of Q9 and Q10?
On SKA GB150D thread, some are experiencing oscillations when 10 ohms ground lift is placed on the circuit.
I will try your proposals as soon as I get some free time, I'm not one of the lucky who are forced to stay home because of corona.
Will theese implementations affect sound quality..?
I will check out that thread, been reading on biguns thread TGM7 he made a version of ska150 and he did also have oscillation trouble.
Will theese implementations affect sound quality..?
I will check out that thread, been reading on biguns thread TGM7 he made a version of ska150 and he did also have oscillation trouble.
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Deleted member 148505
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Deleted member 148505
Don't forget to mod the pcb on final version for 1D23A... the improvement is not negligeable versus 1D17A... for the same price !
Yes, the latest PCB has a footprint for 1D23A and DIP8 opamps.
Soft Start PCB Board - more info please !
Hi, is there discussion on your soft start circuit ? I'm looking to see if it would fit my needs.
I will be building a dual-monaural amp, probably with two 200VA transformers. From recent reading on diyaudio and elsewhere, I'd like to apply the following design specs:
Ideally, low power consumption (5v, mA circuit?)
Power to activate relay is digital (on/off vs. slow voltage rise)
Adjustable bypass delay (e.g., 100ms to 300ms)
Low cost (as fully assembled and in use) (under $30 per board?)
Thanks in advance,
Paul
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Soft Start / Power On Delay
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Hi, is there discussion on your soft start circuit ? I'm looking to see if it would fit my needs.
I will be building a dual-monaural amp, probably with two 200VA transformers. From recent reading on diyaudio and elsewhere, I'd like to apply the following design specs:
Ideally, low power consumption (5v, mA circuit?)
Power to activate relay is digital (on/off vs. slow voltage rise)
Adjustable bypass delay (e.g., 100ms to 300ms)
Low cost (as fully assembled and in use) (under $30 per board?)
Thanks in advance,
Paul
Hey JLesterP,
We've corresponded over email in the past, but I thought I would ask some questions here so others could benefit from the answers. A long while back I bought a pair of JLE-2000Ds for use as a subwoofer amp. I have a 1000va transformer with 2x55v secondaries. Speaker load will be a 4ohm subwoofer (likely 2ohm dual voice coils in series).
I am planning the input to the amp to be from a ADAU1701-based DSP (nanoDSP to be exact, a version of the FreeDSP project: https://www.diyaudio.com/forums/dig...ossover-suggestions-please-6.html#post4812991). This will take in a SE input from my preamp, perform the summing, LPF, and convert the signal to a differential signal to send to the amp.
I believe then with the differential signal, I can operate two modules bridged. Taking the non-inverted and inverted signals to separate JLE-2000D modules. Then taking the the + output from one module and - output for another and to my 4ohm speaker load. Does this sound correct?
My next question is will the 1000va transformer with 55v rails be sufficient to handle 2 bridged modules for a 4ohm load? What power handling should I expect in this setup? I'm planning on about 10mF capacitance for each rail, is this sufficient? Given the size of my transformer, would it be recommended to just go with a single module and SE input? I was hoping to be able to use a differential signal since the amp will be located across the room from my preamp.
Any other concerns with this setup? I noticed in the bridged diagram you sent me before there is a resistor in-line on the differential inputs, is that something that would be required?
Let me know what you think! It's always a joy to use your modules, your soft starts and speaker protect boards have become a mainstay in my amplifier builds and really looking forward to putting the JLE-2000D to use!
Thanks,
Greg
We've corresponded over email in the past, but I thought I would ask some questions here so others could benefit from the answers. A long while back I bought a pair of JLE-2000Ds for use as a subwoofer amp. I have a 1000va transformer with 2x55v secondaries. Speaker load will be a 4ohm subwoofer (likely 2ohm dual voice coils in series).
I am planning the input to the amp to be from a ADAU1701-based DSP (nanoDSP to be exact, a version of the FreeDSP project: https://www.diyaudio.com/forums/dig...ossover-suggestions-please-6.html#post4812991). This will take in a SE input from my preamp, perform the summing, LPF, and convert the signal to a differential signal to send to the amp.
I believe then with the differential signal, I can operate two modules bridged. Taking the non-inverted and inverted signals to separate JLE-2000D modules. Then taking the the + output from one module and - output for another and to my 4ohm speaker load. Does this sound correct?
My next question is will the 1000va transformer with 55v rails be sufficient to handle 2 bridged modules for a 4ohm load? What power handling should I expect in this setup? I'm planning on about 10mF capacitance for each rail, is this sufficient? Given the size of my transformer, would it be recommended to just go with a single module and SE input? I was hoping to be able to use a differential signal since the amp will be located across the room from my preamp.
Any other concerns with this setup? I noticed in the bridged diagram you sent me before there is a resistor in-line on the differential inputs, is that something that would be required?
Let me know what you think! It's always a joy to use your modules, your soft starts and speaker protect boards have become a mainstay in my amplifier builds and really looking forward to putting the JLE-2000D to use!
Thanks,
Greg
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