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I'm certainly no authority but I would guess that you could run the ACA as cool as you want. Cooler seems to me better from a reliability standpoint. As for how a cooler junction temperature would affect the quality of the sound, perhaps you could try different temperatures and let us know how you think it changes the sound quality. In Nelson's article on finding the sweet spot, he mentioned temperature as one of the variables that can be manipulated I the quest for better sound. If you vary your sink temperature by changing the Peltier current or by some other means you should be able to run some interesting tests. Very interesting idea!
I made an experiment tonight. Since I do not fully trust in my passive crossover designing skills, I wanted to biamp, with the F-5 amp for midbass and the old ACA for the even more efficient mids and tweeter drivers, where I still have passive crossovers (BW -12dB).
Time for testing! I cringed. I asked my girlfriend and she said "Don't ask me, I am as spoiled as you." Clearly this did not turn out as expected, as the F-5 is SO superior to the ACA, it is ridiculous. Fun build though! Simple and fun. No thoughts like "Am I now going to die from my own stupidity?", like with the F-5 build.
Time for testing! I cringed. I asked my girlfriend and she said "Don't ask me, I am as spoiled as you." Clearly this did not turn out as expected, as the F-5 is SO superior to the ACA, it is ridiculous. Fun build though! Simple and fun. No thoughts like "Am I now going to die from my own stupidity?", like with the F-5 build.
On another thread I was asking about incorporating a buffered line out in a headamp to control the ACAs. The design I was thinking of was using a 12bh7 off the plate of the driver tube , but the gain will be way too much.
I would like to use something besides just a volume pot. Would the Mesmerize boards be a good route to put in front of the ACAs?
I've got my eyes on a 9 pin Aikido to mate with an F4 if I really dig the ACAs, fwiw.
I would like to use something besides just a volume pot. Would the Mesmerize boards be a good route to put in front of the ACAs?
I've got my eyes on a 9 pin Aikido to mate with an F4 if I really dig the ACAs, fwiw.
Yep. My concern was the overall gain into the ACA's. If I remember correctly it's about 25 dB with an output impedance of around 20 kΩ if taken directly off the driver plate with no 12BH7 buffer and 600Ω off the cathode of the 12b4. in the particular configuration I sent you I'm not sure what the gain would be (I'm guessing somewhere around 14dB). It's been a long time since I've calculated things like that.
So would the Mesmerize be a better choice in this instance?
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Yes, it's the DC version with spots for relays and such. Good to know about the combo!
Sachin, you may want to replace the adapter with a larger capacity one like this. AC Adapter Charger Power PSU FOR IBM Lenovo Thinkcentre M57 M57P M58 M58P A61E | eBay 6.3 amp capacity. They are large units designed for small workstations rather than laptops. cheers.