Is R17 0805? R17 is dissipating 200mW to 250mW depending on the rail voltage. This part needs to be rated at 1/3W or 1/2W which would be 1206 or 1210 size.
Base of Q13 needs to be to tied to collector of Q3 not the emitter. Well at least on the schematic.
On the schematic
Q5, Q6, Q12 are PNP they need to be NPN.
Q1.1 is drawn as NPN it needs to PNP
Q5, Q6, Q12 are PNP they need to be NPN.
Q1.1 is drawn as NPN it needs to PNP
A second set of eyes on the schematics are handy!
All resistors are 1206, but I'll make R17 a 2512 if it's dissipating that much current. I missed the cap and Q12 swap on the latest schematic.
I think there's a bug in the latest version of Diptrace. It keeps picking different libraries for a couple of the transistors like Q1, Q5 and Q6. I've fixed that a couple times already. I need to sort that out before anything goes to the board house.
Are there any other suggestions for dual input transistors? The one I've chosen works great but it's SC-70, top heavy device that likes to flip over in the oven. I'd like to find something that's easier to hand solder.
All resistors are 1206, but I'll make R17 a 2512 if it's dissipating that much current. I missed the cap and Q12 swap on the latest schematic.
I think there's a bug in the latest version of Diptrace. It keeps picking different libraries for a couple of the transistors like Q1, Q5 and Q6. I've fixed that a couple times already. I need to sort that out before anything goes to the board house.
Are there any other suggestions for dual input transistors? The one I've chosen works great but it's SC-70, top heavy device that likes to flip over in the oven. I'd like to find something that's easier to hand solder.
How much current does U2 draw? Because if it draws more than 4.5mA-5mA Q16 and Q20 are going to smoke. If that's
the case Q16 and Q20 should be SOT-223, the current parts can only dissipate 250mW at 50°C.
the case Q16 and Q20 should be SOT-223, the current parts can only dissipate 250mW at 50°C.
I'm not sure what U2 actually draws, but rule of thumb is 10mA for an op amp. I just went with what Pete had on his schematic. I think it might be a good idea to move the +/-12V regulation to the output board to free up some space for the through hole version. I can use larger devices there. Lots of room under the input board.
It looks like the LT1001 will draw worst case ~90mW across +/-15V, so 3mA per LT1001 we have two of them and that's assuming they are driving a high impedance load. Q16 and Q20 would let out the magic smoke for sure if we keep the current parts so 10mA is a good estimate.
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If each op-amp is drawing 10mA then 2x=20mA total which is 1W of dissipation on Q16 and Q20!
I am going to baseline sprint 6.0 and I will go all the way. boss man want's it'
Could you , as a 2'nd party to assure that I don't make mistakes that I made on the
current version ??
My time is finite , I will give this forum my ultimate before this happens.
OS
I sold bossman on something like the NS-OPS.
I won't copy any of Vz's stuff , I'll sprint it. All through-hole.
If you could just be a 2'nd party to any error I make in this endeavor.
You are the layout master. I have studied Vzaudio.
I am impressed. Really.
PS - I'm not doing any any of the non-switching , just MY EF3.
OS
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Hi everyone. I'm late to the party again!
Just a thought,
One of the choices I was making while beginning assembly my V2.4 Badger was to use a thermal bus bar across the OPS transistors. It wasn't because of efficiency, or necessity. It was so I could have somewhere to mount Q13.
The 5U deluxe UMS chassis, uses 2 lengths of heatsink, with a join directly in the center. so the options are to either use a thermal bar, and mount Q13 to it, or drill a new hole and tap it out(but it will have to be offset from center, reducing accuracy I'd assume).
Just a thought. I'd guess a few other builders will use the 5U.
Just a thought,
One of the choices I was making while beginning assembly my V2.4 Badger was to use a thermal bus bar across the OPS transistors. It wasn't because of efficiency, or necessity. It was so I could have somewhere to mount Q13.
The 5U deluxe UMS chassis, uses 2 lengths of heatsink, with a join directly in the center. so the options are to either use a thermal bar, and mount Q13 to it, or drill a new hole and tap it out(but it will have to be offset from center, reducing accuracy I'd assume).
Just a thought. I'd guess a few other builders will use the 5U.
I'm planning to do a 2ch honeybadger next. But that one will be in a 3U400mm chassis. I'm going to fit a piece of 3 or 4mm aluminium across the heatsink joint. and mount Q13 to that piece.
AudioSan,
Do you plan on thermally bonding the strip to the sinks, and just drilling through both of it dead center?
Do you plan on thermally bonding the strip to the sinks, and just drilling through both of it dead center?