1. Yes, if you purchase the switch. I'm assuming if you didn't get the front power switch faceplate the kit does not come with that switch.
2. The rear switch is for stereo/mono RCA input only. The XLR connection is already balanced mono as is.
Borrowed from Jim (6L6):
Stereo single ended, use RCA connectors on both RCA jacks and attach L and R speaker to the respective speaker posts.
Monoblock XLR, use the XLR jack and take speaker output from the two black posts.
Monoblock RCA, use the Left RCA for input, leave the right empty, flip the switch up, and take speaker output from the two black posts.
2. The rear switch is for stereo/mono RCA input only. The XLR connection is already balanced mono as is.
Borrowed from Jim (6L6):
Stereo single ended, use RCA connectors on both RCA jacks and attach L and R speaker to the respective speaker posts.
Monoblock XLR, use the XLR jack and take speaker output from the two black posts.
Monoblock RCA, use the Left RCA for input, leave the right empty, flip the switch up, and take speaker output from the two black posts.
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XLR Connection Jack Mounting
Take a look at the v1.6 build pics for the XLR jack installation shots:
I've seen a couple of photos from at least one forum member where they've installed the jack so it's inside the enclosure and it appears flush from the outside, such as JeffreyD's build:
What are the pros / cons one way or the other? The flush mount looks neater to my eyes.
Take a look at the v1.6 build pics for the XLR jack installation shots:
I've seen a couple of photos from at least one forum member where they've installed the jack so it's inside the enclosure and it appears flush from the outside, such as JeffreyD's build:
What are the pros / cons one way or the other? The flush mount looks neater to my eyes.
Not sure I understand you correctly. Sounds like you want to use 2 x power supplies? Or do you you mean AFTER the CM's there will be separate +24VDC supplies - one for each channel?
The CM's will provide 100dB channel separation, IIRC. That is one of the reasons for using CM's in the first place.
I'm running my ACA (stereo) from one Meanwell SMPS through 2 x CM's mounted inside the amp chassis. And... it sounds like monoblocks, with excellent holographic imaging and focus; sonic features you won't get if there is cross-talk between channels.
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I think inside is much neater.
The reason some fit it from the outside is that the original XLR socket, shown in the build guide for V1.5, was a rectangular latching type and could only fit outside - so I guess people follow that instruction.
With the non latching 'round' type XLR, it will fit inside or out of course. Either is fine, there is no 'better' way.
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I will have a separate enclosure with AC to DC power supply, one 24VDC independent regulated supply for each ACA channel fed to 2 off power input connectors. From there feed to 2 separate CM pcb's and their output's ill then go to each channel of the ACA pcb's.
So entirely separate regulated DC supplies feeding separate CM's for each channel. Maybe over the top, but I have the hardware so may as well go for broke.
So entirely separate regulated DC supplies feeding separate CM's for each channel. Maybe over the top, but I have the hardware so may as well go for broke.
Stiil struggling with ACA 1.6
Guys,
I am still struggling with my ACA 1.6. The left channel plays fine, right channel gives much lower sound level.
Based on Alan4411's sample I have compared the voltages on both boards against his values. R9 and R10 are a little high against Alan's baseline, but they are in line with each other.
I do not see any obvious problems... Can anyone guide me what to check next, based on my measurements?
Thanks in advance,
Laurens
Guys,
I am still struggling with my ACA 1.6. The left channel plays fine, right channel gives much lower sound level.
Based on Alan4411's sample I have compared the voltages on both boards against his values. R9 and R10 are a little high against Alan's baseline, but they are in line with each other.
I do not see any obvious problems... Can anyone guide me what to check next, based on my measurements?
Thanks in advance,
Laurens
Attachments
Ok, understood. I was just pointing out that it is not necessary since you will be using Cm's. But if you have the hardware, then why not? 😀
Very quickly I would suggest you confirm the signal input voltages using a similar method to those I outlined to cRomer in his earlier posts. It takes seconds to do and eliminates all guess work
If the drilled hole in the backpanel is big enough for the XLR 'ring' on the front of the XLR plug, then I would put it on the inside. But it doesn't matter how you mount it.
Would that be Post #5599 on p.560?
I filed that little piece of guidance. It looked like a keeper. Thanks for those tips.
I think you have 90% proved that it is working ok.
I have a silly suggestion, swap the 2 boards over, does the fault follow the board or the location?
Pictures of the other board and internals of your amplifier, might help too.
Alan
If P1 is behaving the same as the good amp, I would think it is a AC (signal) problem. Everything on the schematic left side of C3, and right side of C1. Including signal wiring and connector mounting. All input and output plugs isolated from chassis as shown in the build guide?
Hi Mooly,
I just did your test.
Left channel 7.0 between posts, 0 on R11
Right channel 0.0 between posts, 0 on R11
When I turn the volume control right channel goes to 0.8
I just did your test.
Left channel 7.0 between posts, 0 on R11
Right channel 0.0 between posts, 0 on R11
When I turn the volume control right channel goes to 0.8
You need your meter on AC volts for this. If you have 7 volts volts rms between the speaker posts while playing that test tone then you should be seeing around 1.9 volts rms on the end of R11 that goes to the input socket. Measure the voltage on R11 from audio ground which is the RED speaker post.
Divide the output figure by the input figure and you get the voltage gain of the amp which is numerically around 3.7 (with no speakers attached).
If you have no AC voltage on R11 as shown then work back toward the RCA input sockets.
Divide the output figure by the input figure and you get the voltage gain of the amp which is numerically around 3.7 (with no speakers attached).
If you have no AC voltage on R11 as shown then work back toward the RCA input sockets.
Attachments
Hi aljordan
You'll find more info in post #5630, but here is an early picture of the two Cap Mx's before the heatsinks were anodized and the wiring got tidied up.
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Hi aljordan
You'll find more info in post #5630, but here is an early picture of the two Cap Mx's before the heatsinks were anodized and the wiring got tidied up.
![URL]](/community/proxy.php?image=http%3A%2F%2F%5BURL%5Dhttp%3A%2F%2Fwww.diyaudio.com%2Fforums%2Fattachments%2Fpass-labs%2F700258d1535493994-amp-camp-amp-aca-aca_cap_mx-med-jpg%5B%2FURL%5D&hash=b95ac11842d7efca1d3151cbb8cd6d64)
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Thanks. Are there any other benefits to this mod other than channel separation? I am wondering if there would be any reason to use a CM in a bridged mono configuration.
Well, as mentioned in post #5630, these two benefits still apply in a mono configuration:
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- A soft-start mechanism to slowly ramp up the current. (prevents strange noises and power on/off)
- It also provides a nice ripple reduction as a side benefit.
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