Fired up my A'J this afternoon and loving it. It is certainly the best of an F4 & F5 combined. warm like an F4 but powerful like an F5. A great combo for folks especially for Magnepan fans where power is needed without additional brightness.
Pairing this with Aikido 12vac tube preamp.......I don't wanna leave my man cave !!
Jim please quit with these build giudes... Too intoxicating
FYI I did add on C7 & C6 plus replaced R6 with jumper. Make sure R27 is set to 68K and R7 & R8 set to 1K. Then power up and follow Jim's most excellent guide.
Thank you once again
Neville
Pairing this with Aikido 12vac tube preamp.......I don't wanna leave my man cave !!
Jim please quit with these build giudes... Too intoxicating
FYI I did add on C7 & C6 plus replaced R6 with jumper. Make sure R27 is set to 68K and R7 & R8 set to 1K. Then power up and follow Jim's most excellent guide.
Thank you once again
Neville
Jim please quit with these build giudes... Too intoxicating
I take comments like that as a compliment!
It's a fantastic amp, congrats on a successful construction!!
Snuck home at lunch with some fuses. Amp came up and stayed stable with 5 amp fuses. The LED on the soft start board came on too, so I had put that together right to start with, it just did not a large cap to keep it lit.
I can't adjust it until tonight, but I'll try and get pics up this afternoon.
I can't adjust it until tonight, but I'll try and get pics up this afternoon.
Here are my photos to date. The box turns on and runs. I have yet to attach the front plate, but I have tested the switch on it hooked to the switch board, so you can see out the front of my box. The backplate is shown with the RCA and XLR connectors. The switches there point to the active jack. Actually the switch simply grounds out the neg input lead when it is pointed to the RCA jack.
I am just referencing my gallery here, so that when I add to it, the link will update automagically.
2014 Aleph J - My Photo Gallery
A big thank you to 6L6 for the thread, BobEllis and others for help along the way, and to all the DIYStore folks
I am just referencing my gallery here, so that when I add to it, the link will update automagically.
2014 Aleph J - My Photo Gallery
A big thank you to 6L6 for the thread, BobEllis and others for help along the way, and to all the DIYStore folks
Just Fantastic!
After the 30 minute warm up and setting the bias to 400mV, I had to take a listen. Amp went in my main system.
DIY fanless PC (Win7, JRiver 19 - JRemote on my iPhone)
Stello U3 (USB to SPDIF)
AudioNoteKits DAC 4.1 (balanced out)
Wyred4Sound STP-SE (RCA out, this is 15' cable to amp)
DIY AlephJ (DIY Canare Quad cables)
Zu Audio Essence speakers
Small room with decent treatments.
Blown away with the early results. Less gain than my 35 watt tubed amp, but easily fixed at the pre amp level.
Very dynamic and punchy. Great high and low extension. Perhaps a tad less low level punch than the ANK tubed amp, but very present. I definitely can tell the difference between the PP class AB amp, and the pure class A SE amp! Very clear and detailed compared to the tubed comparator.
Next on the list
1. Close up the amp, try 500mV bias
2. Get balanced XLR cables
3. Start on my DDDAC
4. Listen to some vinyl doing the first 3.
Thanks NP, And DIYAudio. One happy camper tonight.
After the 30 minute warm up and setting the bias to 400mV, I had to take a listen. Amp went in my main system.
DIY fanless PC (Win7, JRiver 19 - JRemote on my iPhone)
Stello U3 (USB to SPDIF)
AudioNoteKits DAC 4.1 (balanced out)
Wyred4Sound STP-SE (RCA out, this is 15' cable to amp)
DIY AlephJ (DIY Canare Quad cables)
Zu Audio Essence speakers
Small room with decent treatments.
Blown away with the early results. Less gain than my 35 watt tubed amp, but easily fixed at the pre amp level.
Very dynamic and punchy. Great high and low extension. Perhaps a tad less low level punch than the ANK tubed amp, but very present. I definitely can tell the difference between the PP class AB amp, and the pure class A SE amp! Very clear and detailed compared to the tubed comparator.
Next on the list
1. Close up the amp, try 500mV bias
2. Get balanced XLR cables
3. Start on my DDDAC
4. Listen to some vinyl doing the first 3.
Thanks NP, And DIYAudio. One happy camper tonight.
I finally resolved my hum issue last night, and I'm VERY happy with how the amp is sounding.
After a lot of work shortening cables etc, the root cause ended up being very simple: I had the RCA input ground wired to -IN rather than to GND on the Aleph board. Switching the wire over to GND completely resolved the hum issues.
Thanks everyone for all of the help through this project! On to the next one...
After a lot of work shortening cables etc, the root cause ended up being very simple: I had the RCA input ground wired to -IN rather than to GND on the Aleph board. Switching the wire over to GND completely resolved the hum issues.
Thanks everyone for all of the help through this project! On to the next one...
Noise in one channel
I have a low level hum and a occasional crackle noise coming from the left channel rt side is dead quiet. I have done the following to try and alleviate the noise but no luck.
Re-soliderd complete board
Replaced output fet's
Moved all wiring around
Replaced source resistors on ft side (now will bias to .4 ) only 3.5mv before.
Amp plays and sounds nice but spits some noise form L side every 20 sec. or so
Noise stays the same regardless of offset amount
I have a low level hum and a occasional crackle noise coming from the left channel rt side is dead quiet. I have done the following to try and alleviate the noise but no luck.
Re-soliderd complete board
Replaced output fet's
Moved all wiring around
Replaced source resistors on ft side (now will bias to .4 ) only 3.5mv before.
Amp plays and sounds nice but spits some noise form L side every 20 sec. or so
Noise stays the same regardless of offset amount
Attachments
Mounted the front panel, and the bottom, and ran the amp some tonight. Bias still at 400 mV. Chassis is lacking only to screw on the top panel.
Wonderful sound. A bit of quiet hum, symmetrically in my 97 db speakers.
Measured some temps at about an hour of some loud playing - 43 C was the hottest I found. I am using the 5U chassis, and the silpads. Tomorrow I'll increase the bias to 500mV, and repeat the session. Once that stabilizes, I'll repeat the bias, DC offset checks, and run temps again. I'll close it up permanent if all checks out. I ordered balanced XLR cables from Blue Jeans Cables to try balanced from my pre-amp.
Love the amp so far, it is truly as special as everyone says.
Wonderful sound. A bit of quiet hum, symmetrically in my 97 db speakers.
Measured some temps at about an hour of some loud playing - 43 C was the hottest I found. I am using the 5U chassis, and the silpads. Tomorrow I'll increase the bias to 500mV, and repeat the session. Once that stabilizes, I'll repeat the bias, DC offset checks, and run temps again. I'll close it up permanent if all checks out. I ordered balanced XLR cables from Blue Jeans Cables to try balanced from my pre-amp.
Love the amp so far, it is truly as special as everyone says.
Your non-twisted AC cables (and terminal block) are right by your left channel board and outputs. I was afraid to do that myself.
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I'am still having a issue with the L channel after finally getting the noise down I now can't get the offset below 28mv. It will now bias at .4 no problem but pot bottoms out at 28mv. I have tried several times to back off everything and start the process over but with the bias set to .35 and up offset stays high.
