F5 with 2SK2013/2SJ313

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True, and they've been saying that longer than you can imagine.
 

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Hi JethroTull,

I really liked your first few albums, but somewhere in the middle of "Thick as
a Brick" it started to pall for me. Thanks anyway.

:cool:


At my 50th birthday (sadly quite a couple of years ago) my children bestowed me a ticket to a Jethro Tull concert in my home town.

It was funny – they only played their old songs from the mid of the Sixties (“… the times when we had the Blues…”).

Near the end of the concert Ian Anderson announced “And now we are going to play a new song”. It was “My Sunday Feelings” from their 1968 debut album…
 
Hi Georg,

The pcbs arrived safely - nice job, very neat.

About the regulator components - some options and to see what you had in mind for the pcbs ....

Simple ones: BC 546 -> BC 548B, TL 431 -> ML431, 1n4007 -> SF14, Z12 = 12v?

Now, the 1uF - I added legs to a Wima 1uF SMD6560 and this will neatly fit

Now, the output 10uF cap - the only one I could fit is the Epcos B32522, or maybe the B32562, both Polyesters. Can "off board" larger PolyPropylines be used instead?

The thin holes for the 33uF 'lytic -> only my stock Panasonics FA series fit these holes, but smallest value is 220uF/25v, or 100uF/50v - can easily redrill holes to fit Nichicon Muse 33uF/50 volt, etc...

What did you intend for all of these and are any, or all, critical to the performance/sound

The IN, OUT, GND pads are input and seem too close fit terminal blocks and okay for the 1/4" (6mm) Faston spades, yes?

Incidently, where did you have the central 0 Volt point for the amp to be located? at the Reg GND points?

I know a few of these queries are quite trite, but it saves time if original design intentions are known.

ps: Is the 39uF/25v cap on the amp pcb intended to be a SMD Polymer cap?
 
Hi Georg,

The pcbs arrived safely - nice job, very neat.

About the regulator components - some options and to see what you had in mind for the pcbs ....

Simple ones: BC 546 -> BC 548B, TL 431 -> ML431, 1n4007 -> SF14, Z12 = 12v?

Now, the 1uF - I added legs to a Wima 1uF SMD6560 and this will neatly fit

Now, the output 10uF cap - the only one I could fit is the Epcos B32522, or maybe the B32562, both Polyesters. Can "off board" larger PolyPropylines be used instead?

The thin holes for the 33uF 'lytic -> only my stock Panasonics FA series fit these holes, but smallest value is 220uF/25v, or 100uF/50v - can easily redrill holes to fit Nichicon Muse 33uF/50 volt, etc...

What did you intend for all of these and are any, or all, critical to the performance/sound

The IN, OUT, GND pads are input and seem too close fit terminal blocks and okay for the 1/4" (6mm) Faston spades, yes?

Incidently, where did you have the central 0 Volt point for the amp to be located? at the Reg GND points?

I know a few of these queries are quite trite, but it saves time if original design intentions are known.

ps: Is the 39uF/25v cap on the amp pcb intended to be a SMD Polymer cap?


Hi James,

Thanks for the compliment.

The Zeners on the regulator boards should be around half the value of the desired Vout, i.e. 9.1V ... 12V. The current limiters at the MOSFET Sources ~ 6.2V.

1µ and 10µ are Epcos MKT: https://www.buerklin.com/datenblaetter/D102770_TD.pdf?ch=24487. Off-board devices are possible, of course, though not an elegant solution... .

100p an 150p are Wima FKP02: https://www.buerklin.com/datenblaetter/D102380_TD.pdf?ch=33680

.051/4W (or .047/4W) are Vitrohm KN 350-8. They form low pass filters together with the 10µ caps to prevent the circuits from HF oscillation.

The Source Rs of the MOSFETs on the amp boards are Fukushima MPC70 2W (9mm spacing).

The absolute value of the 33µ capacitors is not critical at all. Their proof voltage should be 40V minimum, however.

The 39µ/25V SMD caps are super low esr NIPPON CHEMI-CON PXA Series.

The pads are 1/4" (6.35mm) Faston spades (5mm spacing). It might be necessary to redrill the holes depending on their makers. Just solder them on both sides of the boards. The IN pads are 1.2mm solder nails.

The central 0V points are the grounding points at the capacitor banks, where all grounds meet, except of the IN GND which are directly lead from the RCA ports to the amp boards. I recommend to have a load capacitance of at least +- 44.000µ per channel before the regulator boards and the same buffer capacitances at the regulators' outputs.

Best regards,
Georg
 

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Thanks Georg, that just about cover everything including the B32522 10oF caps - I use the 1uF version of these (1uF/63v B32529) as bipass caps a lot - I think Elfa has the 10uF ones - not so sure about the Fukashimas, but can get the equivalents okay.

A query about the raw supply filter caps - you mention a 40,000uF per rail/ch - can this be a C-R-C of 10,000 - 0.1R - 20,000uF.

Also, from the above ...
load capacitance of at least +- 44.000µ per channel before the regulator boards and the same buffer capacitances at the regulators' outputs.

Does this mean another 40,000uF on the output of the Rag, on the amp's supply lines (after the regulator) too?
 
Thanks Georg, that just about cover everything including the B32522 10oF caps - I use the 1uF version of these (1uF/63v B32529) as bipass caps a lot - I think Elfa has the 10uF ones - not so sure about the Fukashimas, but can get the equivalents okay.

A query about the raw supply filter caps - you mention a 40,000uF per rail/ch - can this be a C-R-C of 10,000 - 0.1R - 20,000uF.

Also, from the above ...
load capacitance of at least +- 44.000µ per channel before the regulator boards and the same buffer capacitances at the regulators' outputs.

Does this mean another 40,000uF on the output of the Rag, on the amp's supply lines (after the regulator) too?


Yes. See the picture of my supply boards (two channels shown). I use BCcomponents 47,000µ/40V (051 57473). There are also available 22.000µ (051 57223) and 33,000µ (051 57333) with equal 40mm diameter.

The first section is CRC, the second the buffer capacitance after the regulators. The bypass caps are Roederstein or Wima or Siemens 2.2µ MKC or MKP (22.5mm spacing).
 
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Ah, sorry Georg - I now had a good look at the pcb and see the flexibility of the cap sizes designed into it - foot in mouth troubles!

Present design is BYV diodes into 2 x 4,700uF Nichicon GT - 0.1R/3W Dale SMD - 12,000uF Elna for Audio -> Basic Fet Cmultiplier -> 6,800uF Nichicon SuperThru -> amp (1uF Epcos bipass caps) for 8 Ohm load.

Nothing like the cap sized you have designed - have to look into this.

Mixed results with Choke filters for me, Andrew - I can't seem to get the Duncan design to work right for me with the C-L-C setup, even with #14 wire and flat Theile profile.
 
Hi Georg,
The PCBs look great !
And long... perfect for my 40cm long heatsinks :)

You used a 4x CRC PS, like a dual mono configuration.
I'll keep mine a little simpler, a common PS for both channels but separate regulators:
one 500VA, two bridges(+and-), two CLC and then the four regulators.
Almost the same PS as in my regular F5 but with the extra regulators.

One question: what's the heat dissipation of the regulators ?
So I can calculate if I need additional heatsinks or I can put them on the same heatsink as the toshiba mosfets.

Regards,
Danny
 
Hi Georg,
The PCBs look great !
And long... perfect for my 40cm long heatsinks :)

You used a 4x CRC PS, like a dual mono configuration.
I'll keep mine a little simpler, a common PS for both channels but separate regulators:
one 500VA, two bridges(+and-), two CLC and then the four regulators.
Almost the same PS as in my regular F5 but with the extra regulators.

One question: what's the heat dissipation of the regulators ?
So I can calculate if I need additional heatsinks or I can put them on the same heatsink as the toshiba mosfets.

Regards,
Danny


Hi Danny,

Given a transformer with 2*22V secondaries, the regulator MOSFETs will dissapate ~ 20W each per rail and channel ((22V*square root 2 - 20V Vout)*2A). That is a minimum total of 80W for a Stereo amp.

Regards,
Georg
 
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