Thank you for the tip. I didn't even think about changing the temp for larger items like the RCA connectors. I planned on buying the Fire Metall Eutectic solder when I was buying the kit and all the soldering stuff, but solder was out of stock at the DIYStore. Instead, I decided to venture out and use silver solder, since I read that silver was supposed to be good for electronics. I also picked up some the 63/37 in 0.031" and 0.020" to encourage me to build more stuff in the future since I invested probably the cost of the amp in gear. There is a lot more involved here than just soldering RC car batteries together from like 25 years ago
Does anyone have firm convictions that more expensive silver solder sounds better? I’ve tried it in the past but compared to regular lead tin flux cored stuff it’s horrible to use even with temp controlled soldering iron. I do wonder if novice users would be better advised to use regular solder. I got beautiful shiny joints with flow right through the board and both ACA I built worked fist go. Upgrading the cables that come with the kit would have a bigger effect on the sound than the solder.
In English
I guessed right. Hahah I did notice the "cables" were pretty small gauge, but I noticed there was a temperature rating on them so didn't want to swap it out for any larger gauge automotive wires I had laying around. Also, I wasn't sure how it would affect anything sonically. I thought I had a decent wire stripper, but the 22 AWG didn't want to strip.
Okay, update time. I did the unthinkable and swapped to the other speaker (I honestly don't know how this one escaped me). Because they're active crossover via DSP, there's 3 pair of binding posts on the back of each speaker. Somehow, there's a pair of grounds that are shorted *inside* the speaker (may have rattled around or something at high SPL). I got reeeeally close to one of the 15" woofers, and the hum was present there, even though I only had the midrange plugged into the ACA. The ground loop went through the midrange, through the woofers, back to another amplifier (GFA 5800), out the input wiring, and completed a circuit at the DSP output ground bus (common ground for all six channels of amplification).
Time to open up the cabinets.
Ugh.
Time to open up the cabinets.
Ugh.
Hello,
today - just moments ago - I received my two kits which I will build for 2x15W bridged. I am really curious but also sure that they will sound great
Sadly, one kit came without transistors (silver bag). I hope that the store will find a solution.
Here is what came (minus cat).
Istvan
today - just moments ago - I received my two kits which I will build for 2x15W bridged. I am really curious but also sure that they will sound great
Sadly, one kit came without transistors (silver bag). I hope that the store will find a solution.
Here is what came (minus cat
).Istvan
Attachments
With a cat in your home, check under (and on top) of every piece of furniture and appliance. Mine always managed to store things under the oven. Then check every dark, hidden corner of your home. If you find your car keys from years ago, then that's even better. If all else fails, check the litter box... 
I'm sure the store will get you a set out ASAP. Make sure to e-mail them directly for fastest service.
Enjoy the build and the music!
I'm sure the store will get you a set out ASAP. Make sure to e-mail them directly for fastest service.
Enjoy the build and the music!
A small about of silver in tin/lead solder can make it eutectic with low melting point. That is the main purpose of the silver in leaded solder (according to my knowledge):
"SnPb36Ag2 phase with melting point at 179 °C".
I have read silver diluted in the "solder" does not make the conduction better. I think "audiophiles" thinks the opposite.....
"SnPb36Ag2 phase with melting point at 179 °C".
I have read silver diluted in the "solder" does not make the conduction better. I think "audiophiles" thinks the opposite.....
Maybe a stupid question, is there a remote chance that the silver bag contains the parts of BOTH amps? Maybe if you did it on a single order they combine your pieces to prevent more plastic waste?Hello,
today - just moments ago - I received my two kits which I will build for 2x15W bridged. I am really curious but also sure that they will sound great
Sadly, one kit came without transistors (silver bag). I hope that the store will find a solution.
Here is what came (minus cat
Istvan
That could depend... Others may have direct knowledge of the Hifiman HE-Adapter, but I don't. I'd like to see a schematic/wiring diagram. I could not find a user manual on their support page.
The first thing I would check for is continuity between the left and right speaker (black) terminals on the adapter. It's unlikely they're tied since they're using a 4-pin HP connector, but I would make sure. If they're not tied, then stop here, hook it up, and have fun.
If the the black terminals have very low resistance between them, then you'll need to be certain that you connect it properly to the ACA. Remember, red speaker terminals are GND (and tied together) on the ACA. Black are your speaker signal outputs. Don't short your ACA outputs. tl;dr - hook black (amp) to red (adapter). Phase will be inverted if you have to hook it up that way. Again, this only applies if there is very low resistance between the black terminals on the HE-adapter.
You may know this also but I'll mention it just in case since the 4-Pin XLR is normally used for balanced operation; you will not be using them balanced. So, make sure the switch on your ACA is set for normal 2-channel SE stereo.
It may be much ado about nothing, but those are the things I can think of that I would consider when using a product like that with the ACA.
It's likely not going to be the most quiet HP amplifier you've ever heard, but it may be very enjoyable.
Hope I got most of that right.
I'm sure others will chime in. Hopefully someone owns the HE adapter or knows the wiring.Happy listening!
If you don't already have one... my first comment is that since you're on a DIY site and building an ACA, you could very likely successfully build your own for <99USD. With this design, you're also (I think) reducing the damping factor of an amp that already has a fairly low damping factor. Again, I can't say that is an "issue" per se... that's up to you. Many people just wire them directly to their solid state amps.
You can also see a few posts on Head-Fi if you'd like to do further work. I'd build one and see if I like it. If the price to convenience ratio is good for you to buy the retail version, no judgement from me.
The wiring is a bit obscured in the picture, but to my eyes:
L+ to pin 1 (OK)
L- to pin 2 (OK)
R+ to pin 3 (OK)
R- to Pin 4(OK)
That's a standard, but if it were me... I'd open mine up and take a look just for fun.
If you want to build one mostly like theirs, here is a parts list.
2 - 10R resistors (10W will work. Looks like they've used +- 5%. Just provides a resistive load to the amp - may be good for tube amps) Non-inductive would be nice.
2 - 25R resistors (2W will work. Looks like they've used +- 0.1% which is nice since it's in series with the signal and attenuates the signal).
1 - 4-pin female XLR
2 - Red Speaker Terminals
2 - Black Speaker Terminals
Some wire
Chassis of your choice
I think I got most of that correct. Someone with sharper eyes and more knowledge may chime in to point out any errors.
tl;dr - I'd build one. If you build or buy one like the one in the pic, hook it up to your ACA just as you would a pair of speakers (black to black and red to red) and enjoy your music. You can even flip them (black to red) without worry of shorting your outputs to see if inverting the phase makes you happy or not.
Edited for not enough caffeine typo.
With this design, you're also (I think) reducing the damping factor of an amp that already has a fairly low damping factor. Again, I can't say that is an "issue" per se... that's up to you. Many people just wire them directly to their solid state amps.You can also see a few posts on Head-Fi if you'd like to do further work. I'd build one and see if I like it. If the price to convenience ratio is good for you to buy the retail version, no judgement from me.
The wiring is a bit obscured in the picture, but to my eyes:
L+ to pin 1 (OK)
L- to pin 2 (OK)
R+ to pin 3 (OK)
R- to Pin 4(OK)
That's a standard, but if it were me... I'd open mine up and take a look just for fun.
If you want to build one mostly like theirs, here is a parts list.
2 - 10R resistors (10W will work. Looks like they've used +- 5%. Just provides a resistive load to the amp - may be good for tube amps) Non-inductive would be nice.
2 - 25R resistors (2W will work. Looks like they've used +- 0.1% which is nice since it's in series with the signal and attenuates the signal).
1 - 4-pin female XLR
2 - Red Speaker Terminals
2 - Black Speaker Terminals
Some wire
Chassis of your choice
I think I got most of that correct.
Someone with sharper eyes and more knowledge may chime in to point out any errors.tl;dr - I'd build one. If you build or buy one like the one in the pic, hook it up to your ACA just as you would a pair of speakers (black to black and red to red) and enjoy your music. You can even flip them (black to red) without worry of shorting your outputs to see if inverting the phase makes you happy or not.
Edited for not enough caffeine typo.
Last edited:
Re:
Thanks again, that was very quick response.
Actually I only built Broskie's BFC preamp once, that project let me leave the chassis part to someone.
But If i need to, i will buy a drill tool kit from this time!
I know beginning is difficult always.
And since you told me it should not be a problem using it as a headphone amplifier, i will attach he6se directly to or building something like HE-adapter.
Also i ordered ACA today before it gone.
I will try what you told me and see how much those changes affect the sound.
Best regards,
Kim
Thanks again, that was very quick response.
Actually I only built Broskie's BFC preamp once, that project let me leave the chassis part to someone.
But If i need to, i will buy a drill tool kit from this time!
I know beginning is difficult always.
And since you told me it should not be a problem using it as a headphone amplifier, i will attach he6se directly to or building something like HE-adapter.
Also i ordered ACA today before it gone.
I will try what you told me and see how much those changes affect the sound.
Best regards,
Kim
Hello,
today - just moments ago - I received my two kits which I will build for 2x15W bridged. I am really curious but also sure that they will sound great
Sadly, one kit came without transistors (silver bag). I hope that the store will find a solution.
Here is what came (minus cat
Istvan
Mine arrived missing components as well. Had to order them online from someone here in Ireland. Great sounding amps but some quality control needed
had a few hours up my sleeve so hooked the ACA V1.8 up to the Oscilloscope, ACA now has about 80 hours on it now.
Ran a 1kHz signal in, set the DC offsets so both the + and - peaks on each channel was as perfect as my eyes allow, it resulted in a 0.05V offset difference between the channels.
I then reduced both offset voltages by ~0.6% to help open the soundstage. Its sounding damn nice I must say.. think there's more room yet >~0.6% to play with, a balancing act.
Anyway question, could this 0.05V difference between channels result in a channel phase misalignment? How do I test with the scope to confirm this please?
I have math functions on the scope. I'm assuming I need to split the input between channels then compare the outputs.
Any reason a simple "Y" splitter feeding the inputs from the generator would effect the outcome?
Ran a 1kHz signal in, set the DC offsets so both the + and - peaks on each channel was as perfect as my eyes allow, it resulted in a 0.05V offset difference between the channels.
I then reduced both offset voltages by ~0.6% to help open the soundstage. Its sounding damn nice I must say.. think there's more room yet >~0.6% to play with, a balancing act.
Anyway question, could this 0.05V difference between channels result in a channel phase misalignment? How do I test with the scope to confirm this please?
I have math functions on the scope. I'm assuming I need to split the input between channels then compare the outputs.
Any reason a simple "Y" splitter feeding the inputs from the generator would effect the outcome?
Last edited: