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I know, tl;dr Question on using an IR thermometer on these. When I aim at the to92 flats, since these are in rows of 4, it seems like the far end device measures hotter than the others, and temp increases as I go down the row. Shooting them from the top results in more even but somewhat lower temps. I think the thermo is picking up more than the one device when going for the flats down the row. Thoughts? Sent from my iPhone using Tapatalk

What Nate said. Have the Honda dealer check the charging system and if they don't find anything wrong there, see if they can determine if there is some drain on the battery when the car is off. 3 batteries in 3 years is way excessive. I would have expected 1 battery to last at least that long. Many batteries are really made by the same manufacturer. I've been using the Everstart Maxx from Walmart in our cars for a few years and they have been economical and reliable. And I normally shudder at the thought of going there (Mobil One and the batteries is about it). Reading some of the Honda sites, the 51R is the recommended larger battery to go in there. Batteries such as the Walmart Everstart Maxx have a 60 month warranty, and they replace the battery outright for the first 3 years, then prorate after that.

Wow! and ^ this

Nothing that would really generate any heat around that, and I was checking temps around the board anyhow. There are 3-4 others at 50C or more, some in the 30s. This was all done at approximately the same time with the amp having run for an hour or so. Board 1 NPN device ID hFE temp °C Vr Ie ohms PNP device ID hFE temp °C Vr Ie ohms Q22 10 293.3 39 0.2926 14.64 R44 19.991 Q24 45 293.3 52 0.2916 14.59 R47 19.989 Q21 32 293.1 39 0.2996 15.00 R45 19.978 Q23 18 293.1 46 0.3004 15.03 R46 19.985 Q16 44 93.0 45 0.2998 14.99 R40 19.999 Q17 64 293.0 44 0.2995 14.98 R43 19.992 Q12 8 292.8 40 0.2936 14.69 R32 19.982 Q14 30 292.7 42 0.2949 14.75 R37 19.996 NPN device ID hFE temp °C Vr Ie ohms PNP device ID hFE temp °C Vr Ie ohms Q11 74 278.9 35 0.2933 14.68 R35 19.983 Q13 11 278.8 55 0.2897 14.50 R36 19.980 Q15 40 279.1 35 0.2929 14.67 R41 19.970 Q18 31 279.4 47 0.2989 14.96 R42 19.982 Q19 5 279.4 45 0.2896 14.50 R51 19.973 Q25 39 279.5 49 0.2944 14.74 R48 19.969 Q20 86 279.6 47 0.2865 14.34 R50 19.982 Q26 90 279.6 38 0.2893 14.49 R49 19.968 bias VR39 1.7420 VR39 1.7420 Board 2 NPN device ID hFE temp °C Vr Ie ohms PNP device ID hFE temp °C Vr Ie ohms Q22 20 298.6 31 0.2879 14.42 R44 19.965 Q24 93 298.6 50 0.2813 14.08 R47 19.983 Q21 53 298.4 36 0.2883 14.43 R45 19.981 Q23 60 298.4 50 0.2807 14.06 R46 19.969 Q16 55 298.1 42 0.2875 14.39 R40 19.979 Q17 25 298.4 44 0.2905 14.54 R43 19.983 Q12 62 297.2 45 0.2839 14.21 R32 19.973 Q14 76 297.2 42 0.2867 14.36 R37 19.963 NPN device ID hFE temp °C Vr Ie ohms PNP device ID hFE temp °C Vr Ie ohms Q11 88 282.2 30 0.2834 14.19 R35 19.968 Q13 55 282.3 55 0.2819 14.12 R36 19.963 Q15 7 282.6 36 0.2869 14.36 R41 19.975 Q18 99 282.5 48 0.2862 14.32 R42 19.980 Q19 85 282.8 43 0.2862 14.31 R51 20.004 Q25 56 282.6 40 0.2860 14.33 R48 19.965 Q20 64 283.3 46 0.2814 14.09 R50 19.975 Q26 49 283.3 37 0.2831 14.16 R49 19.986 bias VR38 1.7344 VR38 1.7380

^ It's only 16 pins The right size tip and a good solder sucker and you're home free... Sent from my iPhone using Tapatalk

I would think that the attenuation is the important thing here, not the actual resistance. I could be wrong however The one shown looks to be pretty good, particularly for a cheap pot. Not sure if Justin will weigh in here as he used these for some time in his amps. Sent from my iPhone using Tapatalk

^ this belongs in the golden reference thread, not here. Question: do individual devices run hotter at specific bias than others at the same bias/current? All of my devices (MPSW06/56) are matched by hFE to the best of my ability. Vbe was consistent as well as Ib when matching (monitoring Ib and Ic). Since getting an IR thermometer and looking at temps, I have a couple of devices running at 55C (Q13 on both boards, interesting). Both are running at similar current to neighboring devices and the R value is within 0.02 ohms of others. hFE is also very close. I thought by measuring all of the R values and drop across them that I would see something out of the ordinary for the devices running warmer, but I'm not seeing anything. I'll probably just drop the bias resistors down to 255R for now and revisit when I case the amp to ensure that temps aren't over 50C or so. Any advice on when temp would be a problem appreciated as well. Current is verging on 15mA; these two are running at 14.8 or so (don't have access to data right now). These are thru hole boards also. Sent from my iPhone using Tapatalk

I thought it was in there. See attached. GR LV BOM_Sep26.xls

^ Thanks George, just realized my mistake. Carry on

What do you want the BOM for? The Dynalo Mk2 (this thread) or the GRLV (a different thread)? The respective BOMs are posted in their thread... Sent from my iPhone using Tapatalk

Yep, just saw this. RIP Carrie Fisher. Sent from my iPhone using Tapatalk

I'm not sure how to feel about that Sent from my iPhone using Tapatalk

Oops, nm, misread. Carry on

The ones in the BOM are what is needed. I use Schottkys because I believe that they induce less switching noise. The GRLV is very well protected against diode switching noise, so I don't know whether they actually help in this case. I couldn't see anything on my scope when looking at them, but I might not know what to look for and I certainly don't have access to a screen room. I don't know what you are talking about in your last sentence. Sent from my iPhone using Tapatalk

These weren't the devices that I got from you, but the ones that I had in there. Yours are matched very well. I just haven't brought myself to use them yet Sent from my iPhone using Tapatalk

Glad to hear that you are healing well Steve! Sent from my iPhone using Tapatalk

Some posts regarding lower voltages. I would think that the 10V LT1021 reference and 9.1V zeners should be OK for the 12/15 and definitely the 18V you were thinking about, but don't know for sure on the 12V. BTW, you can buy the LT1021 directly from Linear at a lower price, but only worth it if you are buying several. When I was testing mine with a 24-26V transformer on a variac, it was regulating at 20V output down to around 18Vac input, a bit lower (17.9Vac). I wound up using the Antec 20V 520 transformer and it is working fine, and running at around 44C on the pass transistors powering an SS dynalo.

Yet again... RIP George M

Happy Birthday Ric!

But... But... But... Those aren't Oyaide! I assume you have 20A wiring/breaker as well? And agree regarding Decora. Always interesting to see what you are up to; like the Pass phono as well above.

Yes, I don't think that anyone got theirs working. Pretty large GB as well, so kinda surprising. I thought that luvdunhill had his working earlier in the thread, but I think not. As for using a ferrite bead for this, would it replace the gate stopper, go in series with it, or? I do have some ferrite beads like these.

Happy Birthday Ken!

Spent some time reading the build thread (and rubbing salt in old wounds I had seen or had the T2 thread pointed out back then, and tried larger gate stoppers at that point with no luck. After re-reading that thread, I'm not going to continue doing anything with these.

Sorry, it was in the group buy thread. Also he mentioned that R1 and R3 should be 422 ohms, not 402. I got my Dynalo all back up and running, offset dialed in, GRLV. Listening, it sounds very good. I can't tell if it sounds better than it did with the sigma22; I think so but going from memory. I also had found that I had miswired the switch I use for SE->BAL input; it had left the - input floating when in SE mode, so I corrected that. Flipping back and forth, I couldn't tell any difference. Might have to actually listen to this with balanced in one of these days, if I can get my XLRs back from my son

Very cool, thank Kevin!