non-sparking said:
Hi Ralf, thanks. I think I'll go your route as well w/ the one 15KuF, it seems that is the way to go for the mystery C6 -
http://www.diyaudio.com/forums/showthread.php?postid=1286531#post1286531
Glad to see you got yours up and running I hope to join you soon.
Stan
I just got my F2 clone all hooked up and have ran into a couple of problems I was hoping someone might have some suggestions on. One of the amp boards is only showing ~1v between ground and the opposite side of the output caps (found when trying to bias). Changing the bias doesn't change anything. I've got a vague idea of where to check, but I figured it'd be better to ask someone a bit more experienced.
The other board biases fine, but I decided to make sure of the PS's output voltage before calling it done and found that the amp board was only receiving 20.2v. I decided to check the other side, and it's receiving ~23.2v. I went back to the power supply section and measure 23.6v coming from the bridge rectifier on that side and 22v on the side that biases correctly. The transformers outputs are both putting off roughly 19.5v ac. Should I try to replace both rectifiers to see if that fixes the situation? It seems there is a bigger drop in voltage on the side of the PS with the lower output.
I appreciate any suggestions I can get on this...and be gentle, this is my first point to point (done on proto-board)
The other board biases fine, but I decided to make sure of the PS's output voltage before calling it done and found that the amp board was only receiving 20.2v. I decided to check the other side, and it's receiving ~23.2v. I went back to the power supply section and measure 23.6v coming from the bridge rectifier on that side and 22v on the side that biases correctly. The transformers outputs are both putting off roughly 19.5v ac. Should I try to replace both rectifiers to see if that fixes the situation? It seems there is a bigger drop in voltage on the side of the PS with the lower output.
I appreciate any suggestions I can get on this...and be gentle, this is my first point to point (done on proto-board)
Not really.
While simulating the F2 i noticed a slight voltage dependence of the ccs.
I am living near an industrial area where mains often fluctuate by more than 5 percent. My first thought was a series regulation but remembered the Hiraga Monster supply with its big car batteries.
I like to experiment a bit beside the mainstream, and tried this kind of parallel regulation.
After the rectifier bridge i have made a C-R-SLA-R-C (+R-C on boards) for the F2.
Ripple figure and supply fluctuation are much better (10 and 16dB).
Ralf
While simulating the F2 i noticed a slight voltage dependence of the ccs.
I am living near an industrial area where mains often fluctuate by more than 5 percent. My first thought was a series regulation but remembered the Hiraga Monster supply with its big car batteries.
I like to experiment a bit beside the mainstream, and tried this kind of parallel regulation.
After the rectifier bridge i have made a C-R-SLA-R-C (+R-C on boards) for the F2.
Ripple figure and supply fluctuation are much better (10 and 16dB).
Ralf
.33ohm inductive resistors
hello,
I am taking the dive to build an F2, using it as a woofer amp in an Open Baffle per Dick Olshers recommendations.
I am looking for parts, but does anyone know of a qualified inductive resistor in the states? (preferably digi-key) Most are non-inductive,or try to be. Parts express has a Dayton DNR .33 part# 004-.33 is 'low inductive'
I am also confused about the C6 deal, would replacing c5-c6 with one a 30,000uf make sense here? They appear to be wired in series to me.
Thanks for any input. I plan on wiring point to point, unless someones got PCB's that work.
Thomas
hello,
I am taking the dive to build an F2, using it as a woofer amp in an Open Baffle per Dick Olshers recommendations.
I am looking for parts, but does anyone know of a qualified inductive resistor in the states? (preferably digi-key) Most are non-inductive,or try to be. Parts express has a Dayton DNR .33 part# 004-.33 is 'low inductive'
I am also confused about the C6 deal, would replacing c5-c6 with one a 30,000uf make sense here? They appear to be wired in series to me.
Thanks for any input. I plan on wiring point to point, unless someones got PCB's that work.
Thomas
Re: .33ohm inductive resistors
Don't worry about the inductance of the supply resistors.
C4 and C6 are in parallel, but this was merely an artifact of a circuit
that was altered after the PC artwork was delivered. You can use
any big single cap you like.
C5 and C6 are not in series.
mithomas said:
Don't worry about the inductance of the supply resistors.
C4 and C6 are in parallel, but this was merely an artifact of a circuit
that was altered after the PC artwork was delivered. You can use
any big single cap you like.
C5 and C6 are not in series.
More F2 construction questions
Yes I meant this and not C5....and not in series...
I plan on using 33,000uf at C4 as it's what I have around.
My only basic question that I think the answer is already out there, the F2, even with 2 FETS per channel, puts out 100W each side, so even though less FETS than F1, would still need a similiarly large heatsinks. (I realize it's not push pull) There are no voltamp deductions my basic math skills allows me to figure this out otherwise.
I have 4 12 X 6 X 1's, and 2 old Hafler DH-200 9 X 4.5 X 2 sinks. I assume the former would be okay, and the later not, but wanted to know what kind of heat others are getting from what size heat sink. 50C is the max target I assume measured on the heatsink, with the FETS not going more than 70C, I assume.
I also plan on using an external power supply, and assuming XLR umbilicals are acceptable.
Any feedback would be great.
Yes I meant this and not C5....and not in series...
I plan on using 33,000uf at C4 as it's what I have around.
My only basic question that I think the answer is already out there, the F2, even with 2 FETS per channel, puts out 100W each side, so even though less FETS than F1, would still need a similiarly large heatsinks. (I realize it's not push pull) There are no voltamp deductions my basic math skills allows me to figure this out otherwise.
I have 4 12 X 6 X 1's, and 2 old Hafler DH-200 9 X 4.5 X 2 sinks. I assume the former would be okay, and the later not, but wanted to know what kind of heat others are getting from what size heat sink. 50C is the max target I assume measured on the heatsink, with the FETS not going more than 70C, I assume.
I also plan on using an external power supply, and assuming XLR umbilicals are acceptable.
Any feedback would be great.