PSU the same as for F5 but transformer 2x35VAC (or 2x36VAC) , change capacitors voltage accordingly i.e. 63V.
I am not quite sure but using the F5 PSU board and rising the xformers to 2x35V you must carefully look where you put your grounding point otherwise you could end with 100V......I am afraid!
or did I misunderstand something?
when you really take two 35V AC windings you had to separate the two branches so that ground is no more in the middle of the arrangement...
difficult to do with an F5 PSU board.....
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I am not quite sure but using the F5 PSU board and rising the xformers to 2x35V you must carefully look where you put your grounding point otherwise you could end with 100V......I am afraid!
or did I misunderstand something?
... but I'm sure.
A transformer with really two separate windings will work, but if the transformer is centertapped you will get twice output voltage if you connect the input to the pre amp or connect the GND of both channels together otherwise - trust me, C7 jumped right into my face!!!
cheers
Thorsten
Thank you Tp147.....!
Audio D, in the case you take the F5 PSU to get the 45V you have to use the minus tap as ground. So you have indeed around 45V between the new defined ground (-tap) and the +rail. And of course you let the "old" ground unused!
I did it sometimes but I always was in DANGER to use the ground connections marked on the board and take care if you have a thermistor CL60 or something like this on the pcb from the middle earth to chassis. I your case the thermistor has to be placed otherwise.
As a whole using the F5 PSU board for an F3 demands in my eyes to much attention to make no fault.....
Maybe you are an expert.....then all is possible.....
Audio D, in the case you take the F5 PSU to get the 45V you have to use the minus tap as ground. So you have indeed around 45V between the new defined ground (-tap) and the +rail. And of course you let the "old" ground unused!
I did it sometimes but I always was in DANGER to use the ground connections marked on the board and take care if you have a thermistor CL60 or something like this on the pcb from the middle earth to chassis. I your case the thermistor has to be placed otherwise.
As a whole using the F5 PSU board for an F3 demands in my eyes to much attention to make no fault.....
Maybe you are an expert.....then all is possible.....
You're absolutely right. I should have mentioned this also. I did PSU board myself.
Thanks
I have had a response from the man himself regarding the F3 power supply and he has advised me to used the information from the ZV9. so I will now need to look for this info or available PCbs
As it happens I was initially advised to build this Zen as a possible alternative to the F3, so too just confirm what is the relationship between Zen and First Watt amplifiers are they the same, just commercial and DIY names?
Audio-D
I have had a response from the man himself regarding the F3 power supply and he has advised me to used the information from the ZV9. so I will now need to look for this info or available PCbs
As it happens I was initially advised to build this Zen as a possible alternative to the F3, so too just confirm what is the relationship between Zen and First Watt amplifiers are they the same, just commercial and DIY names?
Audio-D
Not really.
The Zen amps were a series of DIY pieces that Nelson published, in DIY magazines as well as on the net, that were aimed at the DIY constructor, and were an experiment in different topologies that were easy to build, simple, and sounded great. The original premise was "what is the sound of one transistor" or a single gain-stage amp. This got expanded over the years, but it has always been the soul of the Zen series.
FirstWatt is a company of Nelson's that was made as a way to market amps that were different. The F4 is the best example of this, it is essentially a current buffer, it has no voltage gain, and needs a rather big signal to drive it. It then adds enough current to the line to drive speakers.
Most of the FirstWatt designs (not all) have been made available to the DIY community because, let's face it, Nelson is completely awesome and beyond cool.
The Zen amps were a series of DIY pieces that Nelson published, in DIY magazines as well as on the net, that were aimed at the DIY constructor, and were an experiment in different topologies that were easy to build, simple, and sounded great. The original premise was "what is the sound of one transistor" or a single gain-stage amp. This got expanded over the years, but it has always been the soul of the Zen series.
FirstWatt is a company of Nelson's that was made as a way to market amps that were different. The F4 is the best example of this, it is essentially a current buffer, it has no voltage gain, and needs a rather big signal to drive it. It then adds enough current to the line to drive speakers.
Most of the FirstWatt designs (not all) have been made available to the DIY community because, let's face it, Nelson is completely awesome and beyond cool.
F3 output cap mod
I am really intrigued by modifying the output caps on the F3. In my 3 way system (Seas W26, PHl 1120, Raven 2 I use a Marchand XM46 passive crossover with 12dB at 200Hz and 6dB at 6000Hz. A pair of Crown K1s are on the bottom end, a F3 on the mids and a Aleph 30 on the Ravens. I would really appreciate suggestions on possible caps to use in modifying the F3s output.
Thanks
Bob
I am really intrigued by modifying the output caps on the F3. In my 3 way system (Seas W26, PHl 1120, Raven 2 I use a Marchand XM46 passive crossover with 12dB at 200Hz and 6dB at 6000Hz. A pair of Crown K1s are on the bottom end, a F3 on the mids and a Aleph 30 on the Ravens. I would really appreciate suggestions on possible caps to use in modifying the F3s output.
Thanks
Bob
Hi Bob,
it depends on your speakers Z, 4R or 8R or perhaps 16R
You can calculate by yourself with Fg = 1 / (2 * Pi * Z * C) [ Z is speakers Z]
The best performance of the F3 is with the tweeter. But above 200Hz it would also be very OK!
Using high grade Audio caps as Elna Silmic II RFS or Nichicon is highly recommended.
I would stay with C10 at 220µF and C8 at 1µF KP cap and only change C1 from 15.000 to perhaps 470µF.
HTH & cheers
Thorsten
it depends on your speakers Z, 4R or 8R or perhaps 16R
You can calculate by yourself with Fg = 1 / (2 * Pi * Z * C) [ Z is speakers Z]
The best performance of the F3 is with the tweeter. But above 200Hz it would also be very OK!
Using high grade Audio caps as Elna Silmic II RFS or Nichicon is highly recommended.
I would stay with C10 at 220µF and C8 at 1µF KP cap and only change C1 from 15.000 to perhaps 470µF.
HTH & cheers
Thorsten
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The "best" mids from an F3 is via a BHC cap, especially the slit foils, but don't think they make anything like the values you're looking for - next possibility would be the Rifa peg124 (125?) and these are around (RS, etc) - to get the extra clarity for your PHLs (and the Ravens) you might consider changing the C3 to a 40 -> 50uF film cap (Sonicaps, okay) altho a bit of a squeeze. I haven't tried the Polymers - a better fit.
I wouldnt go with polymers for signal path really Bob, they tend to not have the greatest leakage (DC) spec, people also say they sound plasticy =)
Hey James!! i've got me infrared eye on you mate look after Bob here for me eh? hes good people
wouldnt something like the nichicon greenies with some scatterings of films do well here in AC? havent seen them mentioned much. been meaning to grab some slitfoils from audiocap, wanna go in on an order James?
Hey James!! i've got me infrared eye on you mate
look after Bob here for me eh? hes good peoplewouldnt something like the nichicon greenies with some scatterings of films do well here in AC? havent seen them mentioned much. been meaning to grab some slitfoils from audiocap, wanna go in on an order James?
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