I didn't had intention to sound harsh, just stressed a need to always try to be precise and methodical, not primary in explanations (that's the second), but primary in execution of every step of building an amp (or whatever)
that way , you are not just going to have longer building experience
, but every step is going to be most likely more successful, thus entire experience more fulfilling
I sorta learned that in heat of the battle - doing electronic work for living, so sometimes forcing myself to go slower, just to have as result that work is done faster, in the end
point is - every tiny step must be done most thoroughly, and then slow becomes most effective
huh - I'm sounding way too clever now- time to sleep
🙂
that way , you are not just going to have longer building experience
, but every step is going to be most likely more successful, thus entire experience more fulfillingI sorta learned that in heat of the battle - doing electronic work for living, so sometimes forcing myself to go slower, just to have as result that work is done faster, in the end
point is - every tiny step must be done most thoroughly, and then slow becomes most effective
huh - I'm sounding way too clever now- time to sleep
🙂
I didn't had intention to sound harsh, just stressed a need to always try to be precise and methodical, not primary in explanations (that's the second), but primary in execution of every step of building an amp (or whatever)
that way , you are not just going to have longer building experience
I sorta learned that in heat of the battle - doing electronic work for living, so sometimes forcing myself to go slower, just to have as result that work is done faster, in the end
point is - every tiny step must be done most thoroughly, and then slow becomes most effective
huh - I'm sounding way too clever now- time to sleep
🙂
No issue at all. I am happy to learn.
Slow can be fast (overall), I get it. Similar to other things like driving on a track
Echoing Benmah: Good temperatures here for ClassA amps - 1C
I spent some time letting the amp get up to temperature while changing offset. Iq for both channels is about 1.7A
From being off overnight, the output offset start out at -75mV for left and -200mV for right. When I check after 20 minutes, it is in the single digits mV for both left and right. After an hour or so, they still move around say +/- 10 mV.
Is this ok ?
From being off overnight, the output offset start out at -75mV for left and -200mV for right. When I check after 20 minutes, it is in the single digits mV for both left and right. After an hour or so, they still move around say +/- 10 mV.
Is this ok ?
I have around 100mV difference in offset at cold vs thermal equilibrium. Also see a little bit of flutter (never more than 10mV) if I watch offset for a while. I think it’s completely normal, and comparable to other amps I’ve built.
Thanks everyone.
It sounds excellent. No careful listening yet. It seems like live recordings have better ambience than before.
Iron Pre is happy with Babelfish 2J
😀
It sounds excellent. No careful listening yet. It seems like live recordings have better ambience than before.
Iron Pre is happy with Babelfish 2J
😀
In comparison to an Acurus 200x3 (level matched with my phone), many songs were similar, no clear winner. These two songs were outstanding on babelfish 2j.
Ingrid Michaelson - Breakable
Kasper Bjorke - Lies
Thanks again ZM
Ingrid Michaelson - Breakable
Kasper Bjorke - Lies
Thanks again ZM
Yes, I realize it isn't a fair comparison, it is what I had available.
Pioneer SP-FS51-LR Floorstanding Speakers Pair
https://www.pioneerelectronics.com/...P-BS21-LR_SP-C21_SP-FS51-LR Owners Manual.pdf
From this doc: 6 ohms, 87dB
well, not best of tools for comparison, but when you give that info, that's just the praise for Babelfish J2
Babelfish J2 moving into its new home. 5U 400 deluxe with dual Antek 4222 toroids, SLB power supply boards, diyA soft start and XRK SSR speaker protection boards.
I noticed when taking the boards out of the previous chassis the screws holding the boards in place had significantly loosened. I think this explains the dc drift I was experiencing while trying to adjust everything when I first built this amp. Hoping I won’t see this happen now that I’ve added lock washers and tightened things up properly.
I noticed when taking the boards out of the previous chassis the screws holding the boards in place had significantly loosened. I think this explains the dc drift I was experiencing while trying to adjust everything when I first built this amp. Hoping I won’t see this happen now that I’ve added lock washers and tightened things up properly.
Attachments
I have one channel up and running again on the SLB PSU. Power supply ripple is virtually non-existent. We'll see how this translates to noise/hum once I hook them up to my speakers again. So far, very impressed.
Cooking the channel I have hooked up last night, P102 is maxing out Iq at 708mV after temp equilibrium is reached. Following ZM's post #437, I will plan on swapping out R123 for 510ohms (or 499R since I think I have those on hand). I will probably swap out R118 for DC offset adjustment (have 1.05K on hand) while I have the boards out. I'll report back once I have that done and cooked. 😀
FYI, I have SJEP120R063's down with the recommended .68R/1R resistor revision.
Cooking the channel I have hooked up last night, P102 is maxing out Iq at 708mV after temp equilibrium is reached. Following ZM's post #437, I will plan on swapping out R123 for 510ohms (or 499R since I think I have those on hand). I will probably swap out R118 for DC offset adjustment (have 1.05K on hand) while I have the boards out. I'll report back once I have that done and cooked. 😀
FYI, I have SJEP120R063's down with the recommended .68R/1R resistor revision.
that amp is for Sissies
Still loving it 🙂
Currently listening to November Rain on Polk LSi15s
4 ohms, 88 dB but so sweet
I realized Semisouth down R118 is only 270R so I swapped for 499R. And R123 I swapped for 510R as prescribed. Didn’t quite work out. I can only get Iq up to about 775mV. Offset won’t go below 435mV with pot maxed out. Doh! Thinking I should put R118 back to 270R and leave R123 at 510R?