Use 400VA 22v Antek per SLB monoblock for 24-25VDc under load. The next step down is too low. 25v works fine and gives you a few more watts than 24v.
300VA works but 400VA has less sag.
Oh wow 400VA? This is for a single chassis dual mono, so space and weight might become an issue at 2x400VA, but I’ll have to look into it more closely.
Would a 300VA with 25v secondaries put me at +/-24VDC under load?
Would a 300VA with 25v secondaries put me at +/-24VDC under load?
300VA 22Vac should still work if space is tight. Price difference is minimal between the two so if space permitting, always go up. I do use 400Va for a stereo amp so I know 300VA dual monoblock is fine.
Good to see the quick progress on the ALPHA 20 project.
And that test bench looks pretty impeccable too... 🙂
And that test bench looks pretty impeccable too... 🙂
Out of interest... what about neurochrome amps, 286/686? Any thoughs on their use or comparison in your experimental platform?
Stretchneck,
I have both the Neurochrome 286 and 686 but I have not compared them to the amp designs in the NPXP platform primarily because I like to compare similar amp topologies, one at a time. If you follow my reasoning I am currently going through the Aleph CCS output stage topologies, with the exception of the Alpha Nirvana which is inspired from Aleph but uses a totally different output stage CCS (it's the 'graduate' version of the Alpha 20).
What I will most likely do is compare single 'best' winner of the 4 designs (Aleph J, Aleph J Zen, Alpha 20 or Alpha Nirvana) to either the Modulus 286 or 686. Of course the Modulus 286 might be a more fair comparison at least from a power standpoint.
As you can imagine, it is somewhat challenging to be 'level headed' from a subjective standpoint. I have made sure that all these designs are around ~ 20dB gain however. So please take my words with a giant grain of salt!
All the best,
Anand.
P.S. I do apologize for the delays, I have had a few family emergencies to attend to and some vacation time to recuperate! Hopefully I will be back on schedule by the end of the month!
I have both the Neurochrome 286 and 686 but I have not compared them to the amp designs in the NPXP platform primarily because I like to compare similar amp topologies, one at a time. If you follow my reasoning I am currently going through the Aleph CCS output stage topologies, with the exception of the Alpha Nirvana which is inspired from Aleph but uses a totally different output stage CCS (it's the 'graduate' version of the Alpha 20).
What I will most likely do is compare single 'best' winner of the 4 designs (Aleph J, Aleph J Zen, Alpha 20 or Alpha Nirvana) to either the Modulus 286 or 686. Of course the Modulus 286 might be a more fair comparison at least from a power standpoint.
As you can imagine, it is somewhat challenging to be 'level headed' from a subjective standpoint. I have made sure that all these designs are around ~ 20dB gain however. So please take my words with a giant grain of salt!
All the best,
Anand.
P.S. I do apologize for the delays, I have had a few family emergencies to attend to and some vacation time to recuperate! Hopefully I will be back on schedule by the end of the month!
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Hi Anand - no problems a completely understandable approach. Your efforts are very interesting and appreciated.
I will be very interested in your subjective assessment against 686, if you ever get chance would be very interesting to know how they compare with regards to soundstage size, imaging precision and if each is comparatively bright, neutral or warm.
Thanks
I will be very interested in your subjective assessment against 686, if you ever get chance would be very interesting to know how they compare with regards to soundstage size, imaging precision and if each is comparatively bright, neutral or warm.
Thanks
Wait. Your Keysight DSOX1202G scope costs only $1000?! I may have to budget ASAP. Full stop.
Really nice work too!
Really nice work too!
i did not follow your full journey yet, but there are many other candidates along Papa's children that you can utilize same PSU
Single Ended territory : your Aleph J and if you love this then J2 can be your next build. F2J is also another beast
push pull candidates : M2 & F7
MauroPenasa GC that i build as 1st DIY amp as not contender to class A, it only serves me as woofer amplifier in my active setup
Gadut,
Yes indeed. I have about 20 variants, several in the M2 and F6 side, ZenMod varieties and there is UdNess as well.
Best,
Anand.
Yes indeed. I have about 20 variants, several in the M2 and F6 side, ZenMod varieties and there is UdNess as well.
Best,
Anand.
Nice work Anand, can you point me towards the final circuit with values you used for this Alpha 20 build, thanks.
Use the instructions here with the schematic here.
In the ALPHA thread above, they are posts 2780 (schematic) and 2789 (instructions/changes) to be exact.
Best,
Anand.
This thread has been quiet for some time.
Anand,
Hope all is well and you all had a wonderful Thanksgiving.
Anything been going on with the NPXP?
Anand,
Hope all is well and you all had a wonderful Thanksgiving.
Anything been going on with the NPXP?
