Semisouth Aleph J?

[andynor]

Yes I know. But lazy and short on time. Been scraping poo all day today, from MZM, Papa and Siegfried the chicken triplets

 

[andynor]

Back to seriousnezzez. This may be the best mod I have ever done! Thanks to MZM, Pa and Mike Mazzola

 

[RainfallSky]

Second channel is acting a bit weird need to investigate further. With bulb tester they are glowing not so bright and the bias I could dial to 300mv and offset to 50mV. But the negative rail led is not switching on. Also observation is that both the rails after powering up dropping to +/-9.9vdc

Strange. LEDs are independent of the circuit and only indicate that PSU is ON and correctly wired to the board.
Maybe negative LED is broken or accidentally reversed.
Try to isolate new channel and power it alone the same way you powered the first one.
Amp probably will not fully bias with both channels and bulb tester.

 

[manniraj]

Yes seems like the led is gone. Will replace it and test again. My readings of rail voltages dropping to 10vdc is actually on both the channels and it’s because of the bulb tester.

 

[andynor]

remove the tester as before anything else, and see if you have any issues at all… troublemachines all these testers.

 

[manniraj]

Ok replaced the led and all is good was able to set the bias to 350mv and offset 0.02mv after removing the bulb tester👍
Now need to listen to the music

 

[manniraj]

 

[TungstenAudio]

The makerbeam kit looks like a fun way to build a chassis. Fab yourself a nice backplate to hold the IEC power inlet, speaker terminals, RCA inputs and you’re in business.

I have no idea what is happening with the power wiring to those channel boards, or if the transformer shield wire (purple) is connected to chassis Ground. Hopefully those are sorted by now.

 

[manniraj]

@TungstenAudio this Antek trafo does not have any transformer shield wiring. The purple wiring is for the primary side switch I added. This is all temporary till I come up with the front/back panels. I am yet to do the psu wiring for the second channel.

Thanks

 

[manniraj]

Little more progress on the cabinet

 

[andynor]

R24 @ 1k8 not baaaaaad, gents.

 

[manniraj]

 

[manniraj]

Finally done and it’s playing music 👍
I may need to add a speaker protection module as the offset jumps above 1V when switched off and with FE22 having no caps do not want to risk my klipsch

 

[Toys4Boys]

Those rails look suspiciously like Salamander Synergy rails.

 

[poseidonsvoice]

@manniraj

Very nice work! I like the Makerbeam style with wooden fascia! The decorative finishing washers are a nice touch. Are you going to leave it topless or do you have a top panel design in the works as well?

Best,
Anand.

 

[ItsAllInMyHead]

Finally done and it’s playing music 👍

Awesome! Beautiful build.

I may need to add a speaker protection module as the offset jumps above 1V when switched off...

With or without a load?

 

[manniraj]

With or without a load?

Thank you @ItsAllInMyHead
Both with and without load and reading Papa original aleph that’s how it behaves and I will replace those thermistors with MJs soft start module

 

[manniraj]

Very nice work! I like the Makerbeam style with wooden fascia! The decorative finishing washers are a nice touch. Are you going to leave it topless or do you have a top panel design in the works as well

Thank you Anand for now don’t have anything planned for the top but thinking of transparent acrylic panel will look cool with all blue leds

 

[poseidonsvoice]

Just drill a few holes for some nice convection…Or raise the entire acrylic panel by a few mm and let the hot air seep out the edges…

Best,
Anand.

 

[TungstenAudio]

Speaker protection really isn’t necessary, and is not used in the commercial version of this amp as sold by First Watt.

It is difficult to add without degrading the performance of the amp.