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WTB: F4 PCB boards

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On Components:

Peter what are your lessons learned so far from your other projects? I understand you designed the board to accept Caddock Mk132...is this your recoemndation ? Would a 200R as a "grid-stopper" as well fine for the F4 instead of the 150R in the original schematic ? Recommendations for the 220 uF ? Blackgate / Cerafine / Silmic ? Or a Foil like an MKT ?
 
I received your payment and adjusted your order.

As to the parts, I didn't test anything for Zv9, just used whatever performed well in my chip amps. So for PS I used Nichicons 15,000µF 63V KG Super Through which are presently on special at Percy Audio at $16.95 each. Power resistors were Mills 5W, all shunt and feedbacj resistors Caddock MK132, for series resistors I prefer nude Vishays, but if they seem too expensive or hard to get Caddocks will work well too (one might even consider Rikens). I'm not sure what was the reson to use smaller values for grid stoppers in later versions of F4 , it's best to ask Mr. Pass.

Small electrolytic caps were BG N, however, they may not always work for everybody: depending on personal preference or rest of the system they may produce too much coloration or too laid back sound: experimenting with their size and voltage rating is recommended as that affects sonic signature to some extend as well. If you use BG N caps, never add any additional bypasses.

One might try Rubycons ZA or ZL, but too me they are a bit too clinical and empty bodied, similar with Cerafines.
 
What your opion on the Dale CMF55 ? Any Comparison made to the caddocks ? Where do get the Vishays from ?

Anyhow, I changed my mind again and would like to get 3 additional amp-Boards, so in total that results in 6 Amp Boards and 6 Power-Supply-Boards...money has been send.

Best Regards
 
I just was thinking about usingthe Jensen, but than I came across their current-ratings:

Radial type
Ø D x L [mm]
Idc [A]
35 x 40 3,4
35 x 50 4,1
35 x 70 5,5

So, if one is using only one PSU-Board for the F4, I guess Jensens are not an option.
 
Blitz said:
Hmmm...if you read this, than Tants or Rikens are the answer...anyone tried them in a Transistor-Amp ? I understand that they sound great in a high-voltage-Tube-Amp. Interesting that the Tants shall resolve better than metal film...

Rikens are OK in some parts of the circuit, they tend to sound a bit euphoric, sort of like Nichicons FG. I never liked tantalums in SS though, they sounded dull, without top end extention, midrange was nice though, bass wasn't bad either, IIRC.
 
Blitz said:
I just was thinking about usingthe Jensen, but than I came across their current-ratings:

Radial type
Ø D x L [mm]
Idc [A]
35 x 40 3,4
35 x 50 4,1
35 x 70 5,5

So, if one is using only one PSU-Board for the F4, I guess Jensens are not an option.

You might be right here, I received some comments from a person who was using Jensens in 4 pole configuration and he complained about excessive heat in the caps. He later switched to normal configuration and it worked fine.

I am using it for my F4 amp modules and I left it on over night (no
input or load, just to set the bias) and the Jensen capacitors became
quite hot. Is this normal ? I read in Jensen Capacitors website that due
to their special construction of the capacitors, DC load current passes
through the capacitors. Any heat generated by this DC current must be
taken into account when the capacitor's operating temperature is
calculated.
 
C1-2 and C3-4 working voltages?

I have a final buy sheet (US suppliers) for most all of the F4 parts, but after reading the various threads and references, I still couldn't resolve best choices for C1-C2 220uf coupling caps and the other pair of 220uf's C3-C4.

What should working voltage be in those two spots?

I thought about spending a little more to upgrade the two coupling caps, so was wondering what good choices might be for those (BG, Nichicon, Panasonic or otherwise) as well as the C3-C4 spots?

Tom
 
I'm still working through those last few caps and sourcing mostly to DigiKey among others but will post when complete. I just selected some reasonable cost Panasonic TS-HA 15,000 uf/35v filter caps and Panasonic FM series for the 220uf/50v's. Resistors are nothing special either, so if you want boutique parts feel free to substitute Caddock, etc.

Tom
 
Re: interested in your list

jims said:
Hi Tom

Can you post your list? I am buying parts now, and it would be very helpful to see the suppliers you found.


Thanks

Jims

Here is my draft as of today. I haven't ordered any parts or assembled anything yet, so won't know until it all gets here whether it's all correct. Prices are from website queries, no shipping included. Many possible substitutions too, so just use this as a guide.

Tom
 

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