Updated Schematic - V2.5.4
Hopefully this is the last one.
Updated as noted
Hi stuartmp
Now the base of Q3 and Q4 are connected to Vcc
Best regards
rephil
Hopefully this is the last one.
Updated as noted
Thanks stuartmp for creating updated and easy to see schematic. Your note about cascode voltage reference shows the zener option using 15K at R19. I'm pretty sure I have 68K for R19 with zener D3 option. I don't see this in the build guide but it has been several years since I built it. Should I change R19 to 15K?
A few people including myself experienced oscillation on start up.
This was found to be the current through the zener was not high enough.
You can do some more reading here.
AN008 - How to Use Zener Diodes
And
AN007 - High Power Zener Diode
Basically you need to have about 20% of the zeners current handling capacity going through it to get a stable output.
The 15k is based on 65v rails and may need to change depending on your supply rails. Search back for my posts and you'll find more info to.
Thanks for the info. I looked back to post 4132 and found the discussion. Will definitely look at what I have for D3 zener. Its been several years since building the HB and I've always had a tiny audible "hiss" with this amp. Back to the workbench, as soon as I finish one more thing....
I used these for the 0.22R at r43-r48 (need 12 of em to fill both boards)
https://www.mouser.com/ProductDetail/Vishay-Dale/CPF3R22000GNB14?qs=Uu2yXFAsHaw1J3r8JX1RDQ==
and for the 2.2R at r37-r42 I used this (again, need 12 to fill both boards.)
https://www.mouser.com/ProductDetail/Panasonic/ERX-1SJ2R2?qs=gQQ/pDEpiRKnmJUyrvVwng==
These have worked fine in my second HB build for months now with daily use.
https://www.mouser.com/ProductDetail/Vishay-Dale/CPF3R22000GNB14?qs=Uu2yXFAsHaw1J3r8JX1RDQ==
and for the 2.2R at r37-r42 I used this (again, need 12 to fill both boards.)
https://www.mouser.com/ProductDetail/Panasonic/ERX-1SJ2R2?qs=gQQ/pDEpiRKnmJUyrvVwng==
These have worked fine in my second HB build for months now with daily use.
THis work for the .22R ?
http://www.farnell.com/datasheets/2866553.pdf
Is it a negative for wire-wound because of induction?
http://www.farnell.com/datasheets/2866553.pdf
Is it a negative for wire-wound because of induction?
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diyAB Amp The "Honey Badger" build thread
I always use metal oxide ones,
Search MOSX5CR22J on mouser. Only time I have a problem it was from a wire wound so I stay away from them. Changes to a MOX and oscillation went away.
MOX should be cheaper too.
Edit: I use 3w parts most of the time and never had a power issue that wasn’t caused by some other part going bad.
I always use metal oxide ones,
Search MOSX5CR22J on mouser. Only time I have a problem it was from a wire wound so I stay away from them. Changes to a MOX and oscillation went away.
MOX should be cheaper too.
Edit: I use 3w parts most of the time and never had a power issue that wasn’t caused by some other part going bad.
There is a guy who called me up to buy a used amp, which I ended up not selling, it was a Denon poa-2200. I ended up turning it into a honey badger amp. Somehow, the guy called me again, and I talked him into trying his hand at building a honey badger out of a Denon like mine, and I'll be damned if he didn't go out and buy a used Denon amp, and order the honey badger boards. The other night, after installing the circled jumper, having no electronics experience, but being a capable dude, he wrapped up his build and got both boards up and running. I helped a bit over the phone and with bom. Pretty fun. If you want a simple build, the Denon poa2200 and probably a couple other similar models, make an excellent platform. Heatsink is perfect size, power supply is perfect size, and blah blah, here is one side of his amp...
Just wanted to share this fun story.
Just wanted to share this fun story.
Attachments
Okay, my first class AB... I'm going to use the DIY Store UPS. My question is since this AB, do we exclude the ripple filter or CRC of the supply? In other words, excluding R1-R8 and shorting them?
Then we just use the bleeders, LED Rs and our input and output snubbers.... Do I have this right?
@Bullit Thanks for the part number. Hey, they found Steve's original Stang! Hit me with a PM if ya want to chat about it.
JT
Then we just use the bleeders, LED Rs and our input and output snubbers.... Do I have this right?
@Bullit Thanks for the part number. Hey, they found Steve's original Stang! Hit me with a PM if ya want to chat about it.
JT
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Yep. No CLC or CRC since the current is not constant as with a Class-A. The variable current of an AB amp would cause a variable voltage drop across the R (or L), thus modulating the rail voltage with the audio signal.
