I used the same chassis and donut Stereobob, been listening to it for several months many hours daily without a hiccup, amazing Amp. Don't know if you've monitored the bias after several hours warmup but I recently has to lower the bias as it was creeping dangerously high as the room temp (south Florida) increased in the afternoons. Was hitting .75 bias/1.6 amp with 58c on the sinks
Thats good information SimpleJim, I have also listened for many hours and the bias and DC offset have not moved. However It has been in the air conditioning set at 75 deg as I also live in Florida (Sebring). The magic number for the bias in my case seems to be .68V / 1.45A , any higher and it seems to lose some magic. I’m in Michigan now in a cottage with no air conditioning and its 90 deg today so I will hook up the meters when I turn it on again. Thanks
Barossi, my daughter made the vynal stickers on a cricut, I could ask her for the files.
Both the mono blocs are done and now playing in stereo. It’s a pretty good amp and sounds fabulous on my Klispch Fortes
A big thanks to @Nelson Pass for offering the design and @birdbox for the kit
A big thanks to @Nelson Pass for offering the design and @birdbox for the kit
Attachments
Need to get the VU meter driver pcb boards and finish the mono blocs. I am enjoying my music back now and its making my basement shake with Klipsch. I am still thinking which preamp will pair well with F5m as I have HPA1 clone, then I need to try FE22 and the JFET dispre line stage. I use a Audial Aya4 TDA1541 dac with Roon Nucleus core.
Thanks
Thanks
Sorry I missed thanking @Russellc for the give away of the kit. And thanks to those who suggested that I can use my pairs of 2SJ201/1530 FETs in this build and I am really enjoying it.
Its very hard to say in the summer but I am seriously thinking of building a monitor or bookshelf kind of speakers using Scan speak Reverlator drivers like the Rediscovery II kit. With my wood working skills not sure if I can accomplish.
From the amp building I need to put the Dispre jFET line stage into a chassis to give it a proper listen in my system. I have too many power amps, preamps in my home now and most of them sitting idle in the storage 🙂
Thanks
I'm not a wood worker either. Last speaker I built, the group buy had an option to sign up for pre CNC cut flat packs.
The various parts and panels used dowel pins. The CNC was very accurate, pins lining up great. Just glue and clamp.
If not for flat pack, I would still be waiting.
The various parts and panels used dowel pins. The CNC was very accurate, pins lining up great. Just glue and clamp.
If not for flat pack, I would still be waiting.
Oh yes I remember seeing your build pics of XRK's flat pack speakers. They look good and should be sounding good as well.
How interchangeable are the are the amp boards between the Aleph Jzm and F5m kits/builds?
I recently completed a “stock” AJzm build (ie, as per build guide using RThatcher’s PSU and Antek 4218 in 4U chassis).
It sounds great, but i am curious about the sound flavor of the F5m and its potential for driving a set of speakers that may often live well below 8ohms. Also, having another project in your back pocket never hurts.
The VDC out from my current PSU seems to match the needs of F5m, but i am not knowledgable enough to know if there are other factors involved that need to be considered.
Thoughts, questions?
Thanks in advance!
I recently completed a “stock” AJzm build (ie, as per build guide using RThatcher’s PSU and Antek 4218 in 4U chassis).
It sounds great, but i am curious about the sound flavor of the F5m and its potential for driving a set of speakers that may often live well below 8ohms. Also, having another project in your back pocket never hurts.
The VDC out from my current PSU seems to match the needs of F5m, but i am not knowledgable enough to know if there are other factors involved that need to be considered.
Thoughts, questions?
Thanks in advance!
Hook it up. Most of the first watt clones share the same power supply and rail voltages. Proceed with Aleph J start up protocol.
Case and heat sinks should be up to task, my F5m is in 3U 400mm chassis, which is supposed to be slightly more than 4U 300 that my AlephJ lives in
Russellc
Case and heat sinks should be up to task, my F5m is in 3U 400mm chassis, which is supposed to be slightly more than 4U 300 that my AlephJ lives in
Russellc
Whoops, start that up with F5m startup protocol! I'm thinking just the opposite, I have dual monio F5m, and was thinking of trading in the smaller new version of AlephJ in. I have a set of sinks for 3U 400 and bracket.That way I can keep the output devices mounted to heatsink.
Sorry with mix up!
Russellc
Sorry with mix up!
Russellc
Pick a nice chassis, sinks, transformer, flexible cap bank and go to town.
You can build design after design and spend very little. Or start a collection...
You can build design after design and spend very little. Or start a collection...
Maybe the Power supply, FE and OP should have a standardized interface?
Plug and play, dial in your voltage and go to camp?
My current set up includes a BA3B and dual bridged F4s.... Plus the preamp in front. Half way there, I guess?
Oh, and for sure plug and play LEDs.... Blue for Monday, Red for Tuesday.....
I suppose the end point might be a common chassis with plug and play cards. We did that in metrology all the time when I was into that business. And we managed to do that into video frequencies with no noise issues... just add $$$.
Plug and play, dial in your voltage and go to camp?
My current set up includes a BA3B and dual bridged F4s.... Plus the preamp in front. Half way there, I guess?
Oh, and for sure plug and play LEDs.... Blue for Monday, Red for Tuesday.....
I suppose the end point might be a common chassis with plug and play cards. We did that in metrology all the time when I was into that business. And we managed to do that into video frequencies with no noise issues... just add $$$.