That is what my notes report. I just reversed my DMM leads and now read 325.3 mV DCV. But I should see 750mV on start up.
Is that because I've limited the voltage to 30DCV for this test?
Is that because I've limited the voltage to 30DCV for this test?
Just went thru the 17. initial Power Up and again measuring off of TP107/108 I get +318.3mV. The target is 750mV. Since I'm using the Rigol DC supply constraining the voltage to 30V, I assume that is why I only get 318mV.
Following 17.1 all the other metrics are on the money or close when I bias R109, but again, I can only get to 1.266V vs. target of 1.45V.
I guess I'm ready to move on to step 18, 19 and 20. Powering Up Output Transistors?
If I'm missing something it would be helpful to know that I'm on the right track or something needs to be fixed before I proceed.
Thanks
Following 17.1 all the other metrics are on the money or close when I bias R109, but again, I can only get to 1.266V vs. target of 1.45V.
I guess I'm ready to move on to step 18, 19 and 20. Powering Up Output Transistors?
If I'm missing something it would be helpful to know that I'm on the right track or something needs to be fixed before I proceed.
Thanks
Attachments
I set it to the Rigol's max of 30DCV per the instructions on page 38 of the guide or 2nd paragraph of section 16.
The point being to minimize the risk of burning the boards if something is amiss. That's my understanding.
Or at this point do I turn to the Cobra PSU and unleash the full 64DCV's?
The point being to minimize the risk of burning the boards if something is amiss. That's my understanding.
Or at this point do I turn to the Cobra PSU and unleash the full 64DCV's?
Re : TP107 and 108, its mainly due to the 30V rails. I believe the build guide may have an error here where the value was documented with full rail voltage. OR more likely, it may have been when the Bias Circuitry was changed, resulting in a different initial set up value, and the Guide hasnt been updated here.
Back to everything else:
So long as those negative values are just DMM meter lead errors, you should be good to progress to install output transistors. Dont forget to remove the temporary parallel resistor on R17 and J103.
Back to everything else:
So long as those negative values are just DMM meter lead errors, you should be good to progress to install output transistors. Dont forget to remove the temporary parallel resistor on R17 and J103.
Are the sanken 2sa1859a\2sc4883a strong enough to drive 4 pairs of mjl4291ag/mjl4302ag in the ef3-4 at 64vdc ? anyone have any input would be greatly appreciated Thank You
What about KSA1220A/KSC2690A?
These have the highest Ic at +/-100V of all transistors mentioned in the BOM and also are the fastest.
These have the highest Ic at +/-100V of all transistors mentioned in the BOM and also are the fastest.
I don't see the KSA1220A/KSC2690A pair mentioned in the BOM as drivers. The 2sa1859a\2sc4883a could be used looking at the BOM, but if you don't want to risk it, you could use the MJx15032/33 pair. Not very fast though...
No doubt the sankens are the faster part I have the mje15034/5 in my current wolverine the heatsinks barely get warm even when pushed. I have always been a fan of the sanken MT200 series of bipolar some of the best audio bipolars ever made they could take a beating too I hope Sanken under rated the figures like they did on those . I think 2 amps should be plenty I'm going to go for it. Thank you to everyone for input
For Q13 i found 20 pieces of 2sa2682y original NEC parts that i bought 20 years ago I measured the HFE with a cheap mega328 tester and they were all over 200 hfe most in the 230 range try buying anything todau TO-126 with that kind of gain. The Jaɔanese made bipolars were the best i have seen i stashed 2sc3423 and 2sa1360 when they were marked EOL.The parts coming out of chinatin plated steel leads not copper even onsemi ksa992 fta was steel samɛles I got from them everything not SMD the fiture of through hole parts is grim at best
Yes, after I posted the question of wire size I remembered Daniel's video, Wiring Your Amplifier. There's a lot of good stuff in there. I'm going to use silver coated stranded copper 14 AWG with PTFE insulation if my source still has it.
Many thanks mainframe99,
John
ksa1220a is obsolete so I guess that's the reason for not mentioning it in BOM as it has better specs than 2sa1837 and at higher voltages has better specs than any other driver transistor mentioned in BOM. I do not like mje150xx transistors as these are slow while drivers should be fast. I'll probably use KSA/KSC in my EF3-4. In my EF3-3 I'm using 2sa1859a/sc4883a. Haven't yet put these finished boards into the enclosure as my PS is not yet finished.
I don't see the KSA1220A/KSC2690A pair mentioned in the BOM as drivers. The 2sa1859a\2sc4883a could be used looking at the BOM, but if you don't want to risk it, you could use the MJx15032/33 pair. Not very fast
I don't see the KSA1220A/KSC2690A pair mentioned in the BOM as drivers. The 2sa1859a\2sc4883a could be used looking at the BOM, but if you don't want to risk it, you could use the MJx15032/33 pair. Not very fast
Hello, just introducing myself here. Just getting started on my Wolverine amp build. Really enjoying the project so far, thanks to everyone who developed this amp and for all of the fantastic documentation. Below is an image of my planned build, also a quick snapshot of where I am with the input stage, just finished the resistors. 🙂
You are about have the equivalent of a "benchmark AB2" (Google it) . actually the Wolverine beats it.
"benchmark" uses a 1200W SMPS that is integrated - only difference. Benchmark does 1-2ppm , Wolverine can go sub ppm.
Price is the big difference. Benchmark goes for $3500 !
DIY rules !
OS
Benchmark AHB2 uses a small auxiliary amp to inject the inverted distortion into the output aka "feed forward", as well as GNFB (Probably a bit beyond DIYA at this stage) and still can't top wolverine. While its a very nice design, I'll stick with wolverine for the next 10 or so years I'd say 😎