I have a 5U case and I'm more disappointed that one MOSFET is too close to the edge of the heat sink.
Happens to me all the time.
Did you purchased from the diyaudio.com store?
Are you saying the heat sink is drilled and tapped incorrectly?
Do you have a picture?
Did you check the orientation of the heat sinks? Try to reverse the orientation.
Last edited:
Yes.
Yes.
See Post 1400. You can see the hole does not line up.
4 holes are out by around 1.5mm enough so the board cant be mounted. The PCB holes will need to be drilled out to make them larger to compensate.
I don't have these cases, but it seems the holes originally for F5 would
be better for the mosfets. Unfortunately then you will need
new holes for the standoffs. 🙁
Dennis
It would be hard to say who is at fault the board maker or the case maker without making precise measurements. Really not worth bothering with because it is a small easily fixed problem. I do not mind one of the mounts on the other side of the board being left off but it is needed on the transformer side.
Has anyone tried this with the 4U case? I think 6L6's build of F-6 was in the 4U case.... My 5u fits the BA-3 boards perfectly. 6L6's Aleph J build was in the 5U case, and I dont see any mention of him having a problem.
As the 4U is plenty sufficient for the F-6, I am going to use it. Sounds like, unless 6L6 didnt mention it, that it lines up with f-6 boards fine?
What say you 6L6...or anyone having completed F-6 in 4U case? Seems odd that this is a standard pattern heatsinks and boards are supposed to be at...
Russellc
As the 4U is plenty sufficient for the F-6, I am going to use it. Sounds like, unless 6L6 didnt mention it, that it lines up with f-6 boards fine?
What say you 6L6...or anyone having completed F-6 in 4U case? Seems odd that this is a standard pattern heatsinks and boards are supposed to be at...
Russellc
The build guide example was built in a 4U. Works great!
If there is an alignment issue in a 5U, the first thing I'd do is look to verify that the heatsink pairs are as close as possible, if they are a bit wonky on their mountings, the UMS pattern would be out of alignment... most likely too wide.
That said, I have not myself tried mounting the F6 PCB in a 5U.
If there is an alignment issue in a 5U, the first thing I'd do is look to verify that the heatsink pairs are as close as possible, if they are a bit wonky on their mountings, the UMS pattern would be out of alignment... most likely too wide.
That said, I have not myself tried mounting the F6 PCB in a 5U.
Yes I just checked his build guide, for F-6 he used the 4U case. Pics seem to show perfect alignment, so it sounds like some 5U cases are off? Since I am still waiting for my cases from DIY store to be restocked, my F-6 boards are not yet mounted.
When I get home I will hold them up against some spare BA-3 complementary output boards. If they line up, I think it shows some 5U heatsinks are mis drilled, If they dont then the boards must be off....which doesnt make sense.
Russellc
When I get home I will hold them up against some spare BA-3 complementary output boards. If they line up, I think it shows some 5U heatsinks are mis drilled, If they dont then the boards must be off....which doesnt make sense.
Russellc
I just build an F6 in a 4U case and everything fits and aligns perfectly, even managed to (barely) squeeze a dual mono 400VA in a 4U case. I posted a picture not too long ago.
Thanks...well, then the 5U cases at some point must be off....I will compare my F-6 boards to BA-3 boards when I get home.
2Picodumbs, have you compared the measurements of your heatsinks to the standard pattern layout?
Thanks again,
Russellc
replace Z1,2 ?
Hello, I am thinking if it is a good idea to replace zenerdiodes Z1 & 2 with TL431 and some resistors. Is it any idea and will that improve the F6 amp ?
/ Tord
Hello, I am thinking if it is a good idea to replace zenerdiodes Z1 & 2 with TL431 and some resistors. Is it any idea and will that improve the F6 amp ?
/ Tord
Sure, NP does that himself in some of his other amps. I'm also doing that in my F6.
Just give them enough current to work properly.
Last edited:
One side of case mounts up ok, the other side is out of alignment.
I'll check pcbs against F4 and BA3 output boards.
see first Papasony amp article for example
Devil is in details , and fun is spotting all his horns
