It depends how you have wired it. If it takes the output of one channel and feeds it to the other channel input via the 39k (for bridged mode) then you will get out of phase mono if you have two speakers connected. You must remove that second channels other RCA input feed though.
If you have a low source impedance preamp etc feeding the ACA then that will effectively override the 39k and you would hear no difference.
If you have a low source impedance preamp etc feeding the ACA then that will effectively override the 39k and you would hear no difference.
It's built according to the build guide, using the B1 as a the pre, with two speakers connected - just like step 14 in the 1.8 build guide. All working as expected, no issues. Only asking because I noticed that the switch was not in the intended position - center - with no noticeable effect on the output.
Got mine on the 5th as well, MatthewPDX and I might have been the ones that the last ones till Q3.
I can say this! This is the first solid state amp I've owned since 2001 when I ditched my Counterpoint NPS-200. Since then, I've been all tube - 845 SE and a pair of Amity Clones I built and using relatively efficient speakers. Klipsch RF-3's for some time, and Snell J-II's for the past decade. I have Zu Dirty Weekends on Order for June!
This tiny amp is a real eye opener! I'm very glad I bought it. In many ways I feel like I've been fed my first free dosage of Smack or Crack and that somehow I'm going to be writing a check for an F8 or a XA25 at some point in the future.
I can say this! This is the first solid state amp I've owned since 2001 when I ditched my Counterpoint NPS-200. Since then, I've been all tube - 845 SE and a pair of Amity Clones I built and using relatively efficient speakers. Klipsch RF-3's for some time, and Snell J-II's for the past decade. I have Zu Dirty Weekends on Order for June!
This tiny amp is a real eye opener! I'm very glad I bought it. In many ways I feel like I've been fed my first free dosage of Smack or Crack and that somehow I'm going to be writing a check for an F8 or a XA25 at some point in the future.
Aleph P v.1.7
it can do bal-bal; bal-unbal; unbal-bal; if 1kohm attenuator at the output keep speaker connections short if running a tweeter section. Pass design. check out the older dedicated threads.
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yes, i am thinking smaller mosfets like the 2sk3565, and drain currents of 200ma, which @Vcc of 24v gives just 4.8 watts or 9.6 watt total stereo draw...
i can then make balanced inputs and or balanced outputs...
Hi Koja,
Do you know of a source for the Aleph P v1.7 boards that you can share? I know of one but other sources are welcomed.
~Chris
Do you know of a source for the Aleph P v1.7 boards that you can share? I know of one but other sources are welcomed.
~Chris
Built Two ACAs with rolled off highs - I'm stumped
Hello folks,
I built two version 1.8 ACAs from kits a couple of months ago. They sound great in the midrange except that everything sounds muffled compared to my other systems. The cymbals and the "sss" sounds are almost missing and way back in the background. I am driving these with a Nakamichi CA-5 preamp. I'm not sure what would be causing this based on the testing and measured frequency response graphs with an AP analyzer posted here for frequency response. I have read the entire thread for ACA and also the thread for the ACA with premium parts.
So, I ordered a second set of boards from diyaudio to make one of Tungsten Audio's recipe w/premium parts. I have all four boards populated with the new resistor and capacitor part values specified by Tungsten. I made one mistake this time and ordered and installed the wrong sk170 grade (GR) instead of (BL). Now I have the correct value and will install the correct one when my new desoldering tool gets here. I am going to post the progress of my latest build here, but I would like to find out what might be wrong with my first build that would roll off the high frequencies so severly. Any help is very much appreciated.
Hello folks,
I built two version 1.8 ACAs from kits a couple of months ago. They sound great in the midrange except that everything sounds muffled compared to my other systems. The cymbals and the "sss" sounds are almost missing and way back in the background. I am driving these with a Nakamichi CA-5 preamp. I'm not sure what would be causing this based on the testing and measured frequency response graphs with an AP analyzer posted here for frequency response. I have read the entire thread for ACA and also the thread for the ACA with premium parts.
So, I ordered a second set of boards from diyaudio to make one of Tungsten Audio's recipe w/premium parts. I have all four boards populated with the new resistor and capacitor part values specified by Tungsten. I made one mistake this time and ordered and installed the wrong sk170 grade (GR) instead of (BL). Now I have the correct value and will install the correct one when my new desoldering tool gets here. I am going to post the progress of my latest build here, but I would like to find out what might be wrong with my first build that would roll off the high frequencies so severly. Any help is very much appreciated.
Could it be that you wired or connected them 'in mirror' instead of identical and you are seeing a phase conflict? Have you tried a single AMP with a single speaker?
I have not tried it with a simple pot. What value would be suggested? I have a few Alps pots around.
I have tried the amps with two other preamps and one of those was in a different system altogether (speakers and sources). In this system, the preamp is an Emotiva PT-100. That system normally has an Emotiva BasX A-300 amplifier. When I replaced it with the ACA amps running bridged, it sounded like I stuffed cotton in my ears. Wierd. I will try reversing one of the speaker leads, but I really don't expect anything to change other than a loss of bass response. I can try them with a balanced preamp this weekend.
New ACA Build
Here are some photos the new build so far. I am using the part values suggested by Tungsten Audio. I have not implemented R16 - yet. I have not decided if I should increase the power supply past 24VDC. I picked up some IRFP140N transistors that I may try for Q1 & Q2 instead of the IRFP240. I have no idea what impact that will have on sound quality.
I welcome all recommendations to help make this latest build the best it can be.
Here are some photos the new build so far. I am using the part values suggested by Tungsten Audio. I have not implemented R16 - yet. I have not decided if I should increase the power supply past 24VDC. I picked up some IRFP140N transistors that I may try for Q1 & Q2 instead of the IRFP240. I have no idea what impact that will have on sound quality.
I welcome all recommendations to help make this latest build the best it can be.
