So, what does that look like, exactly, if I'm following the PSU build here on the forum (6L6) and building a single PSU, concurrent with the F5 build guide? Is that a power supply for each channel? So 2 PSUs? Educate me. And just a link if this has been discussed somewhere in detail.... so this doesn't go off of the ACA focus of this thread and we all get in trouble....
I've built 2 ACA's and am almost done with my F5.
The F5 PCB's are done sans transistors (need to be mounted to a water block that I'm still building before being soldered onto the boards). I wrapped up the PSU yesterday.
I spent way more time on the PSU than I did the amp. The F5 kit supplied by the diyAudio Store is so good, it makes it quite easy - paint by numbers, almost. The PSU boards are terrific, and there's a ton of documentation and help available, but I had to spend a lot of time with datasheets to cross-reference out of date spec'ed parts to currently available ones.
I learned a lot, and enjoyed myself. If you're into that, it's going to be great. If you're frustrated by looking up parts, PM me and I'll give you a jump start.
I just built an ACA from a full kit this weekend. The kit is very nicely put together and it was a pleasure to build. I used the recommended Cardas solder and I'll never use anything else again.
I've started listening to it and it sounds good. It's loud enough for me using 94db speakers in a large room. The heatsinks are at about 120 degrees with 75 degree ambient.
All in all, a great intro to class A for me.
I've started listening to it and it sounds good. It's loud enough for me using 94db speakers in a large room. The heatsinks are at about 120 degrees with 75 degree ambient.
All in all, a great intro to class A for me.
Probably the only "SheShed" that has an ACA! Hope she doesn't plan to play very loud. IMHO, the ACA and the Usher's wouldn't have been my first choice, however, at lower volumes, she should be fine.
I'm assuming she probably will use it as background listening, which would be perfect.
XLR Input Bridged - Buzzing
Hi, I finished putting together 2 ACA amps. What a wonderful sounding amp! I love it! I am however having an issue using the XLR input to use the 2 amps bridged. Basically, I hear a loud buzz from both amps through the speakers with a little sound in the background.
Whatever I messed up, I think I consistently messed up on both amps!
Any help is much appreciated! The amps work well and sound great if I use the white RCA inputs with the switch in the back flipped up.
Hi, I finished putting together 2 ACA amps. What a wonderful sounding amp! I love it! I am however having an issue using the XLR input to use the 2 amps bridged. Basically, I hear a loud buzz from both amps through the speakers with a little sound in the background.
Whatever I messed up, I think I consistently messed up on both amps!
Any help is much appreciated! The amps work well and sound great if I use the white RCA inputs with the switch in the back flipped up.
Hi, I finished putting together 2 ACA amps. What a wonderful sounding amp! I love it! I am however having an issue using the XLR input to use the 2 amps bridged. Basically, I hear a loud buzz from both amps through the speakers with a little sound in the background.
Whatever I messed up, I think I consistently messed up on both amps!
Any help is much appreciated! The amps work well and sound great if I use the white RCA inputs with the switch in the back flipped up.
Check the base plan:
I think you're off the mark slightly.
If that doesn't make sense. Take a photo of how you're set up and let's see what we can work up together.
A new ACA joins the club.
At the moment everything perfect. I have regulated the BIAS at 10vDC and except at the time of power-up, BIAS remains very stable.
I´m using a laptop PSU. "Dell" 130W (19.5V @ 6.7A).
I guess to everyone's surprise, instead speakers, I'm listening to some HD800 !!!! There are no noises of any kind and listening is quite pleasant. I only have a 10K pot between my DAC and the ACA.
I only have two observations to do:
A) I have a 250x70x35 heatsink on each channel, but I see that they get quite hot (I haven´t the definitive heatsinks).
I understand that 25°C above the temperature ambient would be normal. I have taken the temperature of the transistors after 30 minutes (with music and load) and they are around 60ºC and heatsink around 50ºC (the room temperature is about 27ºC). However, it remains stable but not pet friend
Should I lower the BIAS a little?
B) I had to do a ground loop breaker (10R // 0,1uF cap) from the PSU/amp ground to IEC ground. In the final assembly I will have to review the ground scheme.
Now I will start making the chassis, although the temperature of the heatsinks has me a little worried. Maybe I opt for a chassis somewhat larger than the original.
At the moment everything perfect. I have regulated the BIAS at 10vDC and except at the time of power-up, BIAS remains very stable.
I´m using a laptop PSU. "Dell" 130W (19.5V @ 6.7A).
I guess to everyone's surprise, instead speakers, I'm listening to some HD800 !!!!
There are no noises of any kind and listening is quite pleasant. I only have a 10K pot between my DAC and the ACA.I only have two observations to do:
A) I have a 250x70x35 heatsink on each channel, but I see that they get quite hot (I haven´t the definitive heatsinks).
I understand that 25°C above the temperature ambient would be normal. I have taken the temperature of the transistors after 30 minutes (with music and load) and they are around 60ºC and heatsink around 50ºC (the room temperature is about 27ºC). However, it remains stable but not pet friend
Should I lower the BIAS a little?
B) I had to do a ground loop breaker (10R // 0,1uF cap) from the PSU/amp ground to IEC ground. In the final assembly I will have to review the ground scheme.
Now I will start making the chassis, although the temperature of the heatsinks has me a little worried. Maybe I opt for a chassis somewhat larger than the original.
Thank you for your comments 6L6. Now I am more relaxed
Yes, this "bug" sounds great. I sincerely expected to have more problems with headphones but it has not required any modification. Plug and play.
I had doubts about the supply voltage but I think I´ll definitely leave it with 19.3vDC. My goal was to make it sound with headphones, use with speakers is not my priority.
Yes, this "bug" sounds great. I sincerely expected to have more problems with headphones but it has not required any modification. Plug and play.
I had doubts about the supply voltage but I think I´ll definitely leave it with 19.3vDC. My goal was to make it sound with headphones, use with speakers is not my priority.
So I figured out the issue. Basically, one of the amps did not have a wire connection from the Left Black speaker connection to the center of the RCA Mono/Stereo Selector switch. My guess is that introduced some sort of a DC loop in the both channels of my pre-amp that then sounded like a buzz in both channels.
Thanks so much for your help and suggestion around checking the base plan for all the jacks in the back!
Enjoying the awesome sound. Paired the 2 ACA amps with ADS L-1230 speakers that claim to have 94db efficiency. So the 16 watts go a long way!
Thanks so much for your help and suggestion around checking the base plan for all the jacks in the back!
Enjoying the awesome sound. Paired the 2 ACA amps with ADS L-1230 speakers that claim to have 94db efficiency. So the 16 watts go a long way!
Check the base plan:
I think you're off the mark slightly.
If that doesn't make sense. Take a photo of how you're set up and let's see what we can work up together.
So just for fun I bought the ACA kit a couple days ago. I'm actually a vacuum tube guy. But I thought, what the heck! So without reading 777 posts, is there a commonly accepted list of upgrades I should consider as I build it? I'm assuming small by pass caps on the output caps. Other simple mods that make a good improvement? Thanks!
Yes... look for ACA w Premium parts thread, if the below link doesn’t work
ACA amp with premium parts
I am really enjoying my pair of ACAs. I assume and sorry I am lazy to search this mammoth thread - I assume there is an additional circuit that could be added to remove the start-up and shut down sounds?
Also, what alternatives have people used for the power lights? The blue LEDs are really bright and I would like to use something that is much more subtle. Ideally even non-lighted indicator of some sort? I was thinking of even a linear actuator for a mechanical indicator but anything I have searched up on that would be more expensive than I care for.
Also, what alternatives have people used for the power lights? The blue LEDs are really bright and I would like to use something that is much more subtle. Ideally even non-lighted indicator of some sort? I was thinking of even a linear actuator for a mechanical indicator but anything I have searched up on that would be more expensive than I care for.