It was those inductors and 10r resistors I was referring to. I'm still wading in deep water when it comes to circuits.
21193/4
Consider the low beta of the 21193/4 versus (all the rest) of the modern
30mhz fairchild/ON/ and Sanken outputs available.
While it might work , the (21194) 8-75 beta would be far short of the descent 75-200
offered by the modern devices.
An EF2 like this would struggle and possibly load the badger VAS.
This is why the Leach amp is an EF3 .
I can not believe the whole Sanken output lineup , and both the
whole ON/Fairchild lineup's are unavailable. Most 21'st century outputs
are the higher beta/30+ mhz types ??
OS
Consider the low beta of the 21193/4 versus (all the rest) of the modern
30mhz fairchild/ON/ and Sanken outputs available.
While it might work , the (21194) 8-75 beta would be far short of the descent 75-200
offered by the modern devices.
An EF2 like this would struggle and possibly load the badger VAS.
This is why the Leach amp is an EF3 .
I can not believe the whole Sanken output lineup , and both the
whole ON/Fairchild lineup's are unavailable. Most 21'st century outputs
are the higher beta/30+ mhz types ??
OS
HK uses this in some of their triples to reduce any HF local feedback.
I found decoupling the pre and driver (on the rails) much more effective.
The L/R that HK uses is very specific to the output device used. Rail decoupling
is not.
Newer HK's use rail decoupling (and basestoppers).
OS
Thanks OS, but it partially answered my question.
As I already figured it out, I will have to replace with other ones, just have to figure it out wich.
Can you recommend me the NJW ones?
Thanks
I don't have the technical expertise but I used NJW-0281/0302 in my Honey Badger and it sounds great. Be aware that the package has higher thermal resistance to the sink than MJLs and a smaller SOA. It might be an issue with low impedance speakers or sustained high power operations. I chose them during the output device draught a few years ago when the larger package devices weren't available. I've intended to replace them for years but haven't been willing to take my HB out of service long enough to do it even though I have several others. That should tell you something about the amp you're building.
Okay, I chose the NJW 0281/0302! 🙂
Just one more question: What is that 1,5 uH coil doing at the end of the amlifier, parallel to a 10 ohm resistor?
What would happen if it was a higher value? What if lower?
Thanks! 🙂
Just one more question: What is that 1,5 uH coil doing at the end of the amlifier, parallel to a 10 ohm resistor?
What would happen if it was a higher value? What if lower?
Thanks! 🙂
Exact value of the coil does not matter.
About 12 turns of 14 or 16 gauge (1.3 to 1.6mm) enameled magnet wire is OK.
About 12 turns of 14 or 16 gauge (1.3 to 1.6mm) enameled magnet wire is OK.
Like Still4given says, choose MJL4281/4302 or atleast NJW3281/1302, if you haven't already bought NJW 0281/0302.
regarding inductor, a very nice explanation can be found here: http://www.diyaudio.com/forums/chip-amps/194931-why-use-inductor-output-lm3886.html#post2678962
reg
prasi
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Fun. It says in the build guide that we should use 18 gauge. Any problems if it is 18 awg but have more winds (15)? In means of flowing current of course.
Thanks Prasi for the link!
Air Core Inductor Coil Inductance Calculator
1.5uH - 3uH , not too critical. I used 18ga X .75" D X 1" long (15 turns) =
2.35uH according to the above calculator.
A larger gauge would be less turns for same dimensions (16ga) - 12 turns
@ .75 X 1" would be the exact 1.5uH in the BOM.
Edit - wrap a "sharpie" with the wire .... @ .7" OD coil size.
OS
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did you read the link before asking your question? just google air core inductor calculator... i think you should use google search more with following text site:www.diyaudio.com, just a suggestion.
evanc had already posted an answer to your question. kindly ask questions about new doubts...
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I have read it, thanks, and my previous question contained the following segment: In means of current.
I was asking if the diameter of the inductor wire could bear the current flow on it, since everyone now is talking about 16 ga wires lately, not 18 ga ones. I tought I had missed something that changed the inductor wire diameter by the time.
I am really happy to have you guys and would never waste your time, nor would be rude, but I had to ask, since I'm a Mechanical engineer, not an electronic 🙂
Thanks for your kindness!
Good tip. I have been struggling with the internal search engine on a few occasions with topics I am sure are on here 🙂.
you are too modest, just ask questions after detailed study of the answers posted!... its all i meant, no harm done! i am mechanical engineer too with 17 years working on engines, with interest in audio...
enjoy your build!🙂
I was playing around in LTspice earlier and was wondering if somebody could explain why Ie - Q14 and Ie -Q15 are set up to have a "gap" going into the OPS. I would have guessed that they would cross over each other if I hadn't used spice to see this.
Thanks for any clarification.
Tim
Thanks for any clarification.
Tim
Attachments
The drivers are running class A. The "gap" is the driver not turning off.
How is your build coming? Are you making music yet?
How is your build coming? Are you making music yet?
Thanks 🙂 that makes sense! The build is on hold for a few more months probably. I have a lot done, but am in the middle of building my house, and getting ready for my first kid to be born!
I have the house wired now, so soon we will be insulating and sheeting in the walls!