Hello. New builder here with a few basic questions. I have most of the parts for an Aleph J except for the PCBs. It will be a dual mono block. While I'm waiting for the PCBs I've installed the transformers and rectifiers. Here are the questions:
1. I put the transformers at the back of the chassis. In posted build pictures I see transformers in just about every possible location. I read (I think) that they should be at the front away from the inputs. I could easily swap the rear panel to the other end if that would be better. Does it make a difference?
2. For push on connectors like those going from the transformers to the rectifiers, do the connectors need to be taken apart so you can make a solder connection or is crimping them OK? I tried taking the insulation off, soldering and getting the insulator to fit back over. It was pretty much a losing proposition.
1. I put the transformers at the back of the chassis. In posted build pictures I see transformers in just about every possible location. I read (I think) that they should be at the front away from the inputs. I could easily swap the rear panel to the other end if that would be better. Does it make a difference?
2. For push on connectors like those going from the transformers to the rectifiers, do the connectors need to be taken apart so you can make a solder connection or is crimping them OK? I tried taking the insulation off, soldering and getting the insulator to fit back over. It was pretty much a losing proposition.
Instruments work perfectly 🙂
Time to fine-tune...
As heatsinks are in the lower part of right temp scale, should I try to go higher with Iq?
What is sink temp right by the MOSFETs? Sink temp on top of sinks?View attachment 1029094
View attachment 1029095
Instruments work perfectly 🙂
View attachment 1029096
Time to fine-tune...
As heatsinks are in the lower part of right temp scale, should I try to go higher with Iq?
most important: what is the temp of the MOSFET cases, and and middle pin of the fets?
These readings will enable an assessment of heat transfer. Also, what is the current Iq? Drop 0v44? If so @ 23v5 rails an 1A6 Iq, each fet is dissipating 38 watts, not using Keratherm. Enough, most would say. And also: you sure you need more current? If speakers are happy, keeping amp in happyland before summers 50 degrees on sicily might be the best choice.
regards,
Baby V
Beautifully done! I love the amp gauges and front engraving, gels very nicely together.View attachment 1029094
View attachment 1029095
Instruments work perfectly 🙂
View attachment 1029096
Time to fine-tune...
As heatsinks are in the lower part of right temp scale, should I try to go higher with Iq?
I have a quick question, the next time you have the top off could you roughly measure the length and width of your CLC setup? Im trying to figure out if I could drop a similar setup into the Modushop monoblocks. Idea would be have a monoblock without heatsinks and dual mono power supply. Would shift your CLC setup all the way to the back, probably leave transformers vertical but rotated 90 degrees, and if there is room rectifiers behind the transformers. Could then add powercon connectors to separate amplifier monoblocks with the amplifier channels. I think the ZM boards elevated with chokes tucked under might fit.
Well, i like it 🙂View attachment 1029094
View attachment 1029095
Instruments work perfectly 🙂
View attachment 1029096
Time to fine-tune...
As heatsinks are in the lower part of right temp scale, should I try to go higher with Iq?
Cool?
Yes and No.
Warm Pass Class A and northern Sweden? A match made in heaven in teh Winter ❄️☃️❄️
Sweet and lovely minus 26C in them snowmobiling pictures, this year, just around the corner 🌴😎🌴
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The newly built light bulb tester. 70W + 30W halogen lamps. Classic 100W oldschool lamps is verboten unobtanium in my parts of the ”enviromental” friendly universe.
Well, im thinking watts is watts, and i really like the smell of halogen in the morning 😁👍
So. Well. If im thinking wrong. Just tell me 🙂
Well, im thinking watts is watts, and i really like the smell of halogen in the morning 😁👍
So. Well. If im thinking wrong. Just tell me 🙂
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New Builder here. Here are a couple of pictures of progress. This is as far as I can get without PCBs. Take a look and let me know if there are obvious errors or poor technique. The IEC is missing an inrush capacitor and a 3.3nf safety capacitor. I'm following Octopus technicus' chassis schematic (post 7711 from October 3, 2021.
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Looking good. A few comments. I’d move the bridges as close to center as possible. Remember goop under them, and tighten to 2nM-ish. No need for inrush NTC @ IEC, allready in place at connection blocks. Trannies could be closer to center. Remember to file off the anodization @ your chassis gnd points.
also, the right trannies secondaries pass right by the future location of your PCB. Put them on the center side of the tranny 🙂
Thanks Andynor. I'll probably get after these changes today. I don't know the nomenclature for "2nM-ish". Is that kind rule of a rule of thumb torque value? And what kind of goop is goop? Heat transfer paste? Also, I think I have just one more part to source and that is the the c2, c3 caps (220uf 35v 20% audio SILMIC II). For some reason I only bought 1 instead of 4 and now they seem to be out at Mouser and Digikey. I wasn't sure what subs to use since they either didn't specify "audio" and/or SILMIC II. I'm guessing that I'd want to get 4 of the exact same caps rather than mix with the one I already have?
2 Newton meters (should have bern Nm and not nM) of torque. Or just wing it, and tighten it lightly till it stops, and then a bit more. Remember split washer. Goop, yes, thermal paste. They get hot and can break over time. But details, it’ll probably survive anyways. But if you are a bit OCD, these details help sleep.
Nichicon Muse or Gold audio grade are fine replacements. But check octoparts.com. It’s like the Google of audio parts.
no worry in running higher voltage rated caps either. 35v is recommended minimum. You can also use 50 or 60v caps. I would personally not worry about using 25v either, my PSU caps are 25v and I sleep well, despite notoriuos OCD (no pun, biggie).
and yes, sure 4 alike caps. They are el cheapo anywz.
regards,
Andy
Hi Andy, Thanks for the guidance. I spent an hour looking for the 220uf caps. Checked for the Nichicon gold and Muse series. All back ordered in multiple voltages. I checked Mouser, Digikey and Octoparts. Did find this: https://www.mouser.com/ProductDetail/Wurth-Elektronik/860020775019?qs=0KOYDY2FL29ClCroqv7BnQ== but it isn't described as audio grade (maybe I just missed this or it doesn't matter for this cap). I'll get the paste. Hands and arms are dialed in when it comes to torque. "About right " is a personal specialty.
Digikey has the Silmic in 35V:
https://www.digikey.com/en/products...gTCBcDaIM4EsA2BbBBjABGMAGArgGaYDMArAG4gC6AvkA
Mouser has them in 50V:
https://www.mouser.com/ProductDetail/Elna/RFS-50V221MJ65?qs=HV/SjD3ivR8ZL2U%2BTEPuzA==
https://www.digikey.com/en/products...gTCBcDaIM4EsA2BbBBjABGMAGArgGaYDMArAG4gC6AvkA
Mouser has them in 50V:
https://www.mouser.com/ProductDetail/Elna/RFS-50V221MJ65?qs=HV/SjD3ivR8ZL2U%2BTEPuzA==
Thanks yet again!. Don't know how I missed the Elna- probably because I was over-focused on the Nichicon.
On a different subject, I'm kind of getting the infection for this stuff. It's got me thinking about building a preamp. I've searched the forums for preamp recommendations for the Aleph J and couldn't find anything specific . Not saying it's not there somewhere, I just couldn't find it. I looked at the BA-3 as preamp and the Wayne's BA2018 Linestage threads. Looks like there is enough support there for a newbie. Are either of those great with the Aleph J? My current plan is to use the preouts on my Outlaw 2160. From what I could discover it has 2.43 volts at the preouts (I'm above my pay grade here but I think I read that the preamp output voltage is important for amp matching.) The current speakers are Zaph SR71s (8 ohms, 85 db sensitivity). 15' x 15' x 8' listening space. If this post is more appropriate somewhere else please give a couple of suggestions and I'll happily move it.
On a different subject, I'm kind of getting the infection for this stuff. It's got me thinking about building a preamp. I've searched the forums for preamp recommendations for the Aleph J and couldn't find anything specific . Not saying it's not there somewhere, I just couldn't find it. I looked at the BA-3 as preamp and the Wayne's BA2018 Linestage threads. Looks like there is enough support there for a newbie. Are either of those great with the Aleph J? My current plan is to use the preouts on my Outlaw 2160. From what I could discover it has 2.43 volts at the preouts (I'm above my pay grade here but I think I read that the preamp output voltage is important for amp matching.) The current speakers are Zaph SR71s (8 ohms, 85 db sensitivity). 15' x 15' x 8' listening space. If this post is more appropriate somewhere else please give a couple of suggestions and I'll happily move it.
You’ve got plenty of drive at the pre-outs of the Outlaw to make your speakers sing, that will work beautifully.
Of course, you always want to build more stuff, I can report that BA2018 works wonderfully with AJ. (It’s also a pretty good headphone amp as well, that’s just a fun bonus.
Of course, you always want to build more stuff, I can report that BA2018 works wonderfully with AJ. (It’s also a pretty good headphone amp as well, that’s just a fun bonus.
I currently run my J with the B1 Korg Nutube. Plus is it comes in a full kit package, a comprehensive build guide, and comes together fast and easily. Not having to worry about chassis work and PSU is a big bonus if you want great sound for little effort.
it sings really beautifully, the best sound I have ever had. Will try my Wayne’s 2018 linestage with the current setup too, 6L6 just encouraged me to speed up that hookup 🙂
if you want low distortion, great dynamics and a dead honest linestage, and are willing to out in the hours, choose WLS 2018.
If you want tons of sugar (2nd harmonic distortion), a relaxed presentation that contributes with a bit of perfume to crappy recordings too, and a wonderfully warm but still clear presentation, and little work, choose B1 Korg Nutube 🙂
many options. I like these two. But the ACP+ is fantastic too. I mean, really fantastic. Less gain than both WLS and B1K, but single ended and wonderfully sprinkly sugary, and great bass and extension, and mids are wonderful. Long term solution deserves a chassis. I run it naked.
regards,
Andy