Satyrnine

I'm confused, aren't the split boards long and narrow, and designed to be stacked horizontally? Wouldn't vertical mount exacerbate the heat issue? Was thinking a single 3/8" copper plate as an interface between devices and sink would act as a great heat spreader, reducing the heat soak effect of the stack configuration.

Yes, I was thinking mains in the center, and out on each side towards each grlv. As far as the 4pdt, it'd come from the protect board to the 4pdt, and then I was thinking speaker wires tucked along top or bottom edge all the way back to the speaker outs on the same side as the 4pdt. The back panel shows speaker outs on right, but it has to be rotated obv vs the drawing so they'd actually be on the same side of chassis as the 4pdt. I was planning on braid shielding pretty much every wire to chassis as well, unless that's excessive. Edit: Here's the wiring mockup. Anything look problematic? Also, best solution for rear mounting a pot? First time doing so.

Alright, here's what I came up with. Any issue with proximity of IEC to CFA board on right, or the grlv to the bal/unbal outputs on front?

I was thinking I could either use a horizontal adjust trimpot or a remote trimpot, but others suggestions might mean a reconfig anyway. Thanks! This sounds like a good idea, I'm going to draw it up as you suggest. I laid it out as is just to minimize distance from IEC to trafos mostly, since I don't have a front power switch, it'd keep it all the mains lines nice and isolated. Unnecessary? The rear mounted pot near inputs also sounds great though, so that probably trumps the mains being isolated/short. I would only be driving small efficient nearfield desk monitors with this. I recall seeing others review it well for such use, am I off there? Thanks, will consider all this in new layout. In the last drawing I tried to keep them as close to bottom of sink as possible, but then as you say they are too close. Was hoping that direct-mounting the sand with a thick copper bar would help with the heat soak. I'll see what I can come up with. Thank you!

I haven’t either, just going by other peoples warnings I guess. I have a drill press I can use as a guide too. Maybe I’ll just mount direct if its not such a problem.

I'm hoping to mount output transistors flat to heatsink, although I realize this makes tapping mounting holes a rather arduous adventure. If I snap/jam a tap off in the heatsink, I'll have to move where I'm mounting boards, which would suck. I was considering a 1/4" thick by 2" bar of copper that I'd use as an interface. I'd lap both the bar and possibly the heatsink for a good joint and use some CPU thermal grease for a good thermal connection. A few big bolts to secure. Would use forming taps vs cutting taps since it's copper. Thoughts?

You're full of good ideas! Thank You! I love the adapter idea, will go that route. For rear panel XLR's, since it's less visible and I already have the jacks, I'm going to stick with they type I have. Will use the new style in the future for sure. For speaker terminals, I may keep the posts, as most of my speaker cables already have them. They aren't exposed metal at least, fully insulated, so less chance of shorting. Thanks again! One other question. I assume I want to isolate the unbal out jack ground from the chassis, right? The jack I have is a switchcraft metal barrel type. Should be able to isolate it without too much trouble with some kapton tape and fiber washers.

Alright, here it is updated with the recessed jack with hidden tapped holes, and the inputs and speaker outs spaced better to fill the space opened up by moving the grlvs.

I should clarify, because it's not clear, the stacked holes labeled just R and L are speaker jacks, not RCA jack holes. I didn't want them too close to either the inputs or the mains. Thoughts? RCA's would be the labeled SE input further to the sides. I do need to move the inputs further to the sides now that there's room to do so. Good call. I'm forgoing the bal/unbal board for now. (Had a hard time finding good input jfets, and Dukei suggested I try it without first) But yes, I'd run them around each side to the vol pot first, then off to CFA boards. Was planning well shielded Ag/ptfe for the runs fwiw. The SE inputs would be parallel to bal inputs. Flipping the switch grounds the neg boards inputs, and then you get SE output only. For the outputs, a 4pdt. Planned on running the speaker leads centered near the top of the chassis, or possibly back around each side of the trafos. Any input welcome! Wow, I think I'm going to convert to this actually, that's a far better look. Thank You! I wish they made a female version of this.

Alright, here's the new idea.

I'm going with aluminum panels, so they are 3mm aluminum. The steel are thinner though, obviously. I figure a 3U chassis isn't much bigger than two separate chassis though, no? The extra heatsink on the 3U for speaker use was my thoughts. The toroid cans are a single bolt, but the edge of the can is flush with the chassis, so any lateral force would be more distributed and less likely to bend the mounting plate, vs a "roundish" toroid without a can/cover. This is fantastic, thank you! I'll mock up the layout and see if it's feasible. If not, I'll change up the design. Many thanks for this! Edit: Yep, not going to work as I had it drawn. Thanks for saving me a lot of headache!

This is great, thanks Helium! You don't happen to have dimensions of the bracket do you? Edit: I may be able to determine dimensions from that top view by measuring off it and scaling. I may be able to make it work, considering I'll be cutting off the parts of the CFA boards where the transistors would typically lie, would give me some extra room. As Dukei said "it will be a tight fit, patience will be key" haha! I mainly wanted a better thermal connection from transistors to heatsink since I'll be driving speakers as well. Coming from IT, thermals are always on my mind, although maybe unneccessary in this situation. As far as the trafo mounting goes, I might add a plate under them for a bit of stiffening. Maybe drill a few more mounting holes in the bottom plate/brackets to connect it more securely. Only 4 bolts is indeed concerning. I just personally don't care for the looks of the steel bottom plate, although it would be very convenient that's for sure. Thanks for your help here!

I haven’t, thanks for the heads up, definitely the reason I posted here before finalizing/ordering. Thank You! That said, Dukei is the one who suggested it, sounding like it was possible. I’ll touch base with him on those concerns and either redesign or report back with a possible solution. As far as the steel floor chassis add on, this is good to know too. The trafo covers i ordered through antek are nice and beefy and support/clamp to the bottom plate around the edge of the cover as well as via the thicker/wider center support which maybe would prevent/reduce any rigidity related issues vs bare toroid? Def open to the add on support, but prefer not to if possible, if only for aesthetics. Since I’ll be assembling myself I don’t have to worry about shipping with trafos installed at least.

One side question: My understanding is that Nichicon MUSE/Fine Gold, or SIlmic/etc caps are inferior to power-supply specific caps for rails usage, no? Always thought they were for audio path/coupling use when needed, where an ultra low ESR, high mtbf hrs, and high temp (105c) cap is best for rails. I have just seen MUSE/FG/etc in places I'd usually choose a psu cap for. Am I off here?

Almost ready to start building my CFA2/3! Dual Mono, 2x GRLV, 4x CFA2 boards, and maybe a bal/unbal down the road. I plan to use this with my LCD-2's (orig), and my desk monitors via added speaker outs. I have all the components on hand but the chassis so far. Details: Dissipante 3U chassis. Mounting boards directly to heatsink. 2x Antek 100VA 30V trafos with steel covers MUR820 Ultra Fast diodes on daughterboards vs standard GBU4 package rectifiers for GRLV boards Goldpoint quad/balanced stepped attenuator KG Headphone Protector Board (just had a set made at Oshpark) Options for Bal and SE in Bal and Unbal outs (unbal out only works with se ins in CFA2 mode obv) Dale RN60 resistors throughout, Used Pars's BOM Here's what I have drawn up so far for Front/Rear panels I'm having made at Modushop, as well as internal layout plan thus far. Getting panels engraved/machined, with the "CFA" cut deeply at a bevel. Large circle where vol knob is is just a placeholder for the largest possible size knob. Dotted line around headphone/speaker switch is a rear recess since front panel is 10mm thick. Many Thanks to the infamous Dukei/Miroslav and Pars for guidance, as well as arteom from diyaudio for generously supplying boards, and of course the man himself for this awesome design.

https://drive.google.com/file/d/1wsVGv82qhTbcngFUPGC_LqT3Po8_XJVX/view?usp=share_link This is the headphone protect gerber you're looking for.

Anyone have CFA3, GRLV, or headphone protector boards available for sale? Thanks!

Is it OK to mix PNP with a higher rated NPN? Or do I need to stick with exact complimentary? Is it frowned upon to make a separate post asking if anyone has any here, or should it be kept to this thread? Fake? https://www.ebay.com/itm/282183443413?hash=item41b371a3d5:g:jP4AAOSwzaJX39va&amdata=enc%3AAQAHAAAA4GNkEAQg%2FjOoJrNbKOJ3YaRLeg52WKNNfGrDBY1l0slSvaMPH7MJnW0I64%2BTbeD8jMBQA7QT8cpwRskwq6CyyplgPfiDufQl%2FrUnMqnLqmnfzXg2RGmvEQLiiyOxbQNl6PJtUwMpn0LnxgFdd1PePd9BZEego1aQXXGc9plAwLjbD2hZlILkhLpPoNwUdd12DNpWDURBcvdYhllWIOqHXyTo96mvEFNcP9dNhfEvlamuJXv%2BWCcwuBXfCqPNlw4%2BuaMu1dDnqylObWBvWi40C85rrpfcJERfX4fuS5jB%2BF%2Fm|tkp%3ABFBMnIXUtsxh

Fantastic, thanks Pars!

I'm looking to build a Gilmore CFA3 and GRLV, anyone have boards available? Also, some sand is out of stock. Does anyone have the following, or know if the following subs will be OK: CFA3: MJF15030G: Can I sub MJE15028G? It has 120v C-E voltage vs 150v of the orig, and I'd need shoulder washers/isolation washers. PZTA56 Can I sub DPLS4140E-13 ? GRLV: MJW21194G Can't find a decent sub here. Thoughts? DN2540N3-G Can I sub DN2540N3-G-P003 Seems the same. Confirmed OPA134, I assume I can sub the SMD version with an adapter board, but the SMD version is out of stock too... Other good subs? OPA228? opa228 Confirmed Transformers: These three were recommended. Any reason to pick one over the other? The 30v 1.67A one is considerably smaller, still "enough"? 30V vs 24V practical differences? https://www.mouser.com/ProductDetail/553-VPT24-4170 https://www.mouser.com/ProductDetail/553-VPT30-3330 https://www.mouser.com/ProductDetail/553-VPT30-1670 Many thanks!

Will do! Thanks!

Excellent! Thank you! The split boards sound interesting, maybe try a tube input. Hmm.... CFA3 sounds ideal, since not all sources/cans will always be balanced. When you say "Kevin did some boards" how would a guy go about getting gerbers or such for that? I found his Google Drive full of schems, but didn't see much for the cfa3, or the split boards. Just message him? Sorry, new here. Thanks!!

Hello, new here. Hoping to build a Kevin Gilmore CFA3, and looking for a set of boards. Anyone have spares? Thanks!

I should add I realize I don't NEED a Dynahi for LCD-2's low impedance, but my bud has said that it's a fantastic pairing regardless, and will let me try higher imp cans later on. My Darkvoice mods (usually ideal for 600ohm cans) were all about making it work for lower imp cans. 5998a output tube, higher B+, drastically increased output cap value, etc. Attached are pics of the Dynahi I biased/balanced for my bud.

Wow! This is exactly what I'm looking for! Thank you! Those google drive links are a treasure trove! My friend suggested I look into the CFA3 as well. Is there a similar thread for the CFA3? I definitely did some searches for "Kevin Gilmore Dynahi" and didn't find that thread you linked, so I appreciate any guidance there. I'm definitely not a scalper or such, just a hobbyist. My main area of work is custom guitar/bass tube amps and effects pedals for musicians, but I dabble in hifi. I have a heavily modded Darkvoice 336se, Schiit Vali2, and some mid level Schiit Dacs, and LCD-2's. Some heavily modded Adcom power amps as well. As soon as I heard my friends Dynahi, I knew I had to upgrade. Planning on a balanced DAC as well. Finding someone with a set of known good boards seems ideal, but I've had good luck with Oshpark, a domestic board maker. I'd likely use them if I have to make my own, never had an issue with their work fortunately. I've designed a few pcb's as well, but for relatively simple stuff vs a dynahi. Good to know there's good mods here. Really makes or breaks a community, and seems like this one is great! Thanks for the warm welcome!