If you just move the PCBs without changing any wiring, that won’t change anything. The PCBs are identical, which side they are on is immaterial. The input wiring and output wiring is the only thing that matters.
That said, I’m not entirely sure what you are describing, could you post a couple photos?
That said, I’m not entirely sure what you are describing, could you post a couple photos?
Thanks 6L6.
It might be my imagination, but it seemed to take a lot longer this time to set the bias to 12v it seemed to jump about a lot.
Also, when I turn the power on (having left the test leads on the boards, I noticed that initially the voltage jumps up to around 16v, then descends to about 10.5v and slowly creeps back to 12v after about 45 seconds, is this normal? In truth I didn't check to see if this happened on the first ACA I built.
Same model of Meanwell psu used on this amp.
It might be my imagination, but it seemed to take a lot longer this time to set the bias to 12v it seemed to jump about a lot.
Also, when I turn the power on (having left the test leads on the boards, I noticed that initially the voltage jumps up to around 16v, then descends to about 10.5v and slowly creeps back to 12v after about 45 seconds, is this normal? In truth I didn't check to see if this happened on the first ACA I built.
Same model of Meanwell psu used on this amp.
Normal. Things take a bit of time to settle in on power up.
As for jumpyness on setting the DC point, you may have a not solid connection somewhere, or perhaps it’s just that the amp takes a bit of time to react to the changes, and you are trying to have it change too fast? Make a change in pot position, wait for it to settle, make another change, let it settle. It does not track the pot immediately.
As for jumpyness on setting the DC point, you may have a not solid connection somewhere, or perhaps it’s just that the amp takes a bit of time to react to the changes, and you are trying to have it change too fast? Make a change in pot position, wait for it to settle, make another change, let it settle. It does not track the pot immediately.
They are just "channel on" indicators. They are not within the audio signal nor are they used to control current or voltage. So you can pick them to fit your aesthetic needs:
- most people use two of the same color
- most people use the blue ones because this is a NelsonPass design
- you can use two reds with no problem if that is more to your tastes
- you can have one red and one blue, if you think it looks better, but I believe it could be confusing as to what each color means. Both represent the same concept: the channel is on and receiving electricity.
I'd go for same color, whichever you choose.
Best regards,
Rafa.
- most people use two of the same color
- most people use the blue ones because this is a NelsonPass design
- you can use two reds with no problem if that is more to your tastes
- you can have one red and one blue, if you think it looks better, but I believe it could be confusing as to what each color means. Both represent the same concept: the channel is on and receiving electricity.
I'd go for same color, whichever you choose.
Best regards,
Rafa.
LEDs
Late to the party and just getting around to assembling my balanced bridged monoblocks.
This is a niggly little thing. I had my heart set on those cool blue LEDs, then found I have 3 blue and 5 red. I'll just pick a few up at a local electronics store, which lists these: CREE BLUE LED 5MM 4100MCD VF=3.2VDC IF=20MA CREE5-BLU. Anything special about the ones in the kit? I measured 'em, they are 5mm.
On another note, when I got to the wiring & assembly stage, I found build thread posts #173 and #175 by Anand to be very helpful. These were comments on which wires to use where and a general assembly process. And of course the only reason I got that far was because of that really nice guide by 6L6. Thanks to you both. May want to consider incorporating posts #173 and #175 into the guide? Just a thought.
Late to the party and just getting around to assembling my balanced bridged monoblocks.
This is a niggly little thing. I had my heart set on those cool blue LEDs, then found I have 3 blue and 5 red. I'll just pick a few up at a local electronics store, which lists these: CREE BLUE LED 5MM 4100MCD VF=3.2VDC IF=20MA CREE5-BLU. Anything special about the ones in the kit? I measured 'em, they are 5mm.
On another note, when I got to the wiring & assembly stage, I found build thread posts #173 and #175 by Anand to be very helpful. These were comments on which wires to use where and a general assembly process. And of course the only reason I got that far was because of that really nice guide by 6L6. Thanks to you both. May want to consider incorporating posts #173 and #175 into the guide? Just a thought.
We Have Lift Off
Got the first one up and going on it's maiden voyage. Sitting here on top of it's little brothers. Robbed their setup to run a quick test. I'm always amazed when I flip that switch and get wonderful sound instead of puffs of smoke.....
This one does not have the manners of it's little brothers, it farts lightly on startup. I'm sure the family will be amused.
Got the first one up and going on it's maiden voyage. Sitting here on top of it's little brothers. Robbed their setup to run a quick test. I'm always amazed when I flip that switch and get wonderful sound instead of puffs of smoke.....
This one does not have the manners of it's little brothers, it farts lightly on startup. I'm sure the family will be amused.
Attachments
I went ahead and bought 5 of these blue Cree LEDs. Got some extras, they're cheap. Used one to replace the missing blue one from my kit, and used the three blue ones from the kit. The naked eye normally can't see the difference between the new one and the other three. But I can tell the difference, and when I take a picture at certain angles it really shows up as different. I should have just used 4 new ones, and that way I would have been assured they were all the same.
Not a big deal, just a note to be aware that all blue LEDs are not the same. If I get bored and ambitious one day I might switch them out so they are all the same.
I was just bumming around the ACA thread to see if anybody needs help and along comes your thank you note!
Thanks!
I tell newbies and seasoned diy'ers all the time: "It's not about the destination, because for diy'ers there is none, it's about the journey."
I'm sure somebody famously intelligent and modest coined a similar phrase, like the Dalai Lama...so best to listen to those guys!
Best,
Anand.
Got the first one up and going on it's maiden voyage. Sitting here on top of it's little brothers. Robbed their setup to run a quick test. I'm always amazed when I flip that switch and get wonderful sound instead of puffs of smoke.....
This one does not have the manners of it's little brothers, it farts lightly on startup. I'm sure the family will be amused.
Yes, but it's a musical fart.
So true, Mazeppa, so true.
I have noticed that my MF'ers (that's Musical Farters, of course) only do it in stereo mode. In bridged mode, they hold it, very quiet on start-up.
If you miss those cute little noises, parallel mono mode will bring them back.
I have a pair of low 86 dB efficiency 4 ohm speakers that are made up of a standard driver that crosses over to a BG quasi ribbon dipole panel at 200 or 250 hz. The panel takes the rest of the range. I've only ever driven these speakers with fairly high powered mono amps.
Yesterday I got the idea to drive the low frequency drivers with a stereo M2, and use the ACA 1.6 amps in parallel mono mode on the panels, as the ribbon is a non-reactive stable 4 ohm load.
I can't believe how good it sounds.
I have a pair of low 86 dB efficiency 4 ohm speakers that are made up of a standard driver that crosses over to a BG quasi ribbon dipole panel at 200 or 250 hz. The panel takes the rest of the range. I've only ever driven these speakers with fairly high powered mono amps.
Yesterday I got the idea to drive the low frequency drivers with a stereo M2, and use the ACA 1.6 amps in parallel mono mode on the panels, as the ribbon is a non-reactive stable 4 ohm load.
I can't believe how good it sounds.
So true, Mazeppa, so true.
I have noticed that my MF'ers (that's Musical Farters, of course) only do it in stereo mode. In bridged mode, they hold it, very quiet on start-up.