Roo2 I'll bet that Aleph J looks Amazing in dim lighting with all those pretty blue LEDs coming through the perforated case!
Dennis,
Well, I knew from using caps with multiple pins in my BAF 50W amp that only the pin directly across from the negative pin is active, and the rest of the pins are for mounting only. So I keyed in on the cap connections. That one cap was essentially not connected.
But I am happy that it worked for Eric. Troubleshooting can be so frustrating.
Ben
Well, I knew from using caps with multiple pins in my BAF 50W amp that only the pin directly across from the negative pin is active, and the rest of the pins are for mounting only. So I keyed in on the cap connections. That one cap was essentially not connected.
But I am happy that it worked for Eric. Troubleshooting can be so frustrating.
Ben
After a couple days of burn-in, Aleph J is really singing! Marked improvement over Aleph 30, especially in lower end response. And suuuuper quiet. Still a hard comparison thus far, as the Aleph 30 had 20 years of play time.
Hi Eric. Not copper. I bought uncoated perforated mild steel sheet. Pickled it with vinegar. Sprayed it with a solution of hydrogen peroxide, vinegar and salt. Voila! Instant oxidation (rust😉)! Rinsed, dried and sprayed on some polyurethane to stabilise the nice powdery red rust.
Pass DIY Addict
Joined 2000
Paid Member
Congrats, codyt!
Roo2: Clever implementation! I like the look!
Without the kick from Ben, I probably would have kept focusing on the PCB... Funny how you get blind to things. Now that I understand the problem, other behavior is becoming more clear. I did notice some time ago that when I powered the Aleph-J off, the positive rail was being drawn down much faster than the negative rail. The LEDs on the PSU board told this story. I didn't understand why, since each rail pulls the same measured current. I never put these two behaviors together, though.
This fix is just in time, too. In the colder winter months, I trade out the cooler running MoFo amp for the hotter running Aleph-J.
Roo2: Clever implementation! I like the look!
Without the kick from Ben, I probably would have kept focusing on the PCB... Funny how you get blind to things. Now that I understand the problem, other behavior is becoming more clear. I did notice some time ago that when I powered the Aleph-J off, the positive rail was being drawn down much faster than the negative rail. The LEDs on the PSU board told this story. I didn't understand why, since each rail pulls the same measured current. I never put these two behaviors together, though.
This fix is just in time, too. In the colder winter months, I trade out the cooler running MoFo amp for the hotter running Aleph-J.
I happened to have one of these around (2000pf) - would it work in the meantime? MOV-20D201K Bourns Inc. | Circuit Protection | DigiKey
Have been listening to my Aleph J for about a year and I'm really happy with it, this thread was invaluable, thanks for all of your knowledge! If you were to recommend your favorite speaker to pair with the AJ what would it be? I'm currently listening through a pair of two ways with Seas drivers that I built a few years back but I'm looking for another DIY project. Any suggestions?
Pass DIY Addict
Joined 2000
Paid Member
Just a public service announcement: remember to readjust your DC offset after any changes to your PSU 😉
@pggriff
Speakers Worthy of Pass Amps?
Some examples of what people are using in here. Most are high ish efficiency examples but a couple of pages back someone mentioned some 86dB that they loved. Depending on your listening level that may be fine. I think 6l6 might have mentioned one or two of the Troels designs, possibly the DTQWT?
Speakers Worthy of Pass Amps?
Some examples of what people are using in here. Most are high ish efficiency examples but a couple of pages back someone mentioned some 86dB that they loved. Depending on your listening level that may be fine. I think 6l6 might have mentioned one or two of the Troels designs, possibly the DTQWT?
The Open Source Monkey Coffin might fit your needs. It's a long thread, but these loudspeakers were designed explicitly for "weak" amps like the ACA or similar "weak" amps, and they sound pretty nice to my ears.
Is till have problem with my Aleph J. When powering off the positive LED goes out immediately while the negative’s LED lingers +30 seconds, is this normal?
I disconnected the motor run capacitors and with shorted input the powering off swap sound is still there but smaller. No swop sound without input shorted but a bopp sound. There is also a small static sparkle in right channel. I have carefully looked over all joints.
I would appreciate some guides how to troubleshooting.
I disconnected the motor run capacitors and with shorted input the powering off swap sound is still there but smaller. No swop sound without input shorted but a bopp sound. There is also a small static sparkle in right channel. I have carefully looked over all joints.
I would appreciate some guides how to troubleshooting.
Sov - my V- LEDs also stay on until the bleeders pull the capacitance down. Power down also produces a very light speaker bump. Based on my experience with a Pass-built Aleph 30, I considered both of those to be normal. Not sure about the sparkle in right channel.
Last edited:
I am going to convert my m2x into aleph J, I got the jfets and aleph j boards. Parts will order from mouser.
Does any one know a good source for matched IRFP240, preferably in europe?
Does any one know a good source for matched IRFP240, preferably in europe?
Thanks codyt, that is reassuring. Perhaps more reflowing is the remedy for static.
The remaining issue is the loud “swoap” sound when powering off if connected to preamp.
Other wise the amp sounds good.
The remaining issue is the loud “swoap” sound when powering off if connected to preamp.
Other wise the amp sounds good.