F5 components, parts you use

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Parts I used

This is my reference F5 amp , for now.

This is a no thermal compensation, no current limited design, with Toshiba outputs. The resistor compliment is now (from PRP in pic) 1k texas instruments z-foils, 47r z-foils 100K caddock TSF, 1K prp resistor in parallel with 5K pot for setting bias.
The source jfet resistors are 10R caddocks, 50R caddocks for feedback resistors and Mp-930 .5R source resistors for toshibas.

The board is a cviller version 2 board, hacksawed down to fit into smaller chassis. Run ~.750mv bias.
 

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My F5 amp is yet to be completed. And, I don't have any of it here with me to shoot some pics.
However, I'm using a 1 watt PRP JFET Source R and 1/2 watts in the JFET input, Drain, and MOSFET gate stoppers. No temp correction or current limiting as yet. I'm using 5 watt mills MRA-5s at the MOSFET Source Rs and Feedback Rs.
I'm also using a dual pair of Toshiba outputs on The CViller Board.
So far the PSU consists of 1 400VA 2x15 Antek per channel with shotkey diodes (don't remember which ones at the moment) and CRC filter. 5x CDE 10,000uF > 2X .25ohm 50W mills in paralell > 5x CDE 10,000.
I guess that about covers most of the components?
:Pawprint:
 
hey

anything about F5 components

I did ask this question in the other thread, but there was no response..
This thread can be a very valuable resource to already established builders of the F5 - but with the potential danger of being stamped as a sour *** - which I'm certainly not ;) - what about potential new builders....?
All the information is readily available , and a good selection of components out there,too - with one crucial exception - the 2SJ108.....????
 
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There are pics of my F-5 in the pictures thread/sticky. I used the Tech-diy parts kit, very basic, resistors were Panasonic for the larger values, and Dales
for the smaller ones. IRF out puts, Antek transformers.

I'm planning a couple more builds and want to use the Toshiba outputs this time, which I have aquired several sets of, along with matched Jfets. I would like to make this one a little more of a hot rod, so exotic resistors and so forth are what I have my eye on, this one will have no current limiting either. This thread is very timely, efforts appreciated.

Russellc
 
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All the information is readily available , and a good selection of components out there,too - with one crucial exception - the 2SJ108.....????

I neglected to mention, I will use the 74s and 170s as I have several. Rather than the 370s and 108s :Pawprint:

Yes, go with 2SK170's and 2SJ74's. There are still plenty to be had.
I use member BLUES in the states, but Spencer is also a reliable source for these parts. This should be a non-issue.

Tech-diy also offers the kits with the JFET included, and other parts. His service is also excellent. Ships international. I just bought 4 matched sextuplets of IRF's from him.
 
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Hi Tea bag
I have eard very good results /comment for the Z foils.

What are your impression?
Where did you get them?

Tanks
Al

PS. any spares?

These values 1K and 47R were about 10 bucks each for me.
I put them in my DCB1 first and was very impressed.

I put them into the F5 following the PRP, and I got a more detail, and a good tone from it. I've noted that the DCB1 is more prone to noticing resistor changes than the F5, but I can hear a difference between them to. It's quite possible less expensive resistors could bring equally good results, one has to play around with them. Any first build I do, I start with Dale's or PRP's. Both are very good. Some people think resistor mod's are bogus, but I disagree. They certainly change things
 
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With my recently finished build I used a mixture of bulk foils, Vishay VSH; Holco's with heatsinked Caddocks for the source and feedback resistors. The jfets are 74's & 170's with Fairchild mosfets [ thanks Blues & Jackinjay] and cvillers v2 pcb's. I would love to try the Z foils but at 13GBP upwards here in the UK I cough a bit; maybe in the DCB1. I over specced the heatsinks [ UK supplier] as they only reach 40 degrees after several hours of running.
It sure does sound good though.
 
With my recently finished build I used a mixture of bulk foils, Vishay VSH; Holco's with heatsinked Caddocks for the source and feedback resistors. The jfets are 74's & 170's with Fairchild mosfets [ thanks Blues & Jackinjay] and cvillers v2 pcb's. I would love to try the Z foils but at 13GBP upwards here in the UK I cough a bit; maybe in the DCB1. I over specced the heatsinks [ UK supplier] as they only reach 40 degrees after several hours of running.
It sure does sound good though.

Then you are able to crank up the bias up to 2A per device. These MOSFETs are known for reducing their overall THD the higher the bias is.

Regards,
Regi
 
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Tanks Tea Bag

IMO Z foils sound like good part for the gates resistors which 1k ?

Can you say a bit more about sound I got the detail bit but is tone darker / Brighter.

Tanks

Input is 1K, that's what I use there, and a caddock as 100K shunt.
Yes 47Rs are gate resistors. So input path has Z-Foils here.

They are tonally the best resistors/not brighter or darker or rubbery (carbon).
The PRP seemed Darker to me than Takeman resistors used in all the same places.
 
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I used an audio grade 500VA from toroidy.pl. Excellent quality and reasonably priced especially for people in the EU.
Nikon1975 is I believe the only person who has mentioned using an R core transformer in the main F5 thread. Selectronique in France do a 300VA R core for approx 77euros plus shipping; makes them expensive.
 
TB,

I'd initially used the RN60 Dales. Then got turned on th the MRS25 Dales (by Cheffdegaar - the designer of the UGS Preamp and Amp) - they have better temperature coefficients than most. They are 50PPM in the range of the F5 resistors. They are super cheap and very, very good.

Have you tried the Z-foils vs RN60? Have you tried and MRS25s? Maybe it's genetic cheapness, but I find it impossible to buy the Caddock or the Z-foils.



Input is 1K, that's what I use there, and a caddock as 100K shunt.
Yes 47Rs are gate resistors. So input path has Z-Foils here.

They are tonally the best resistors/not brighter or darker or rubbery (carbon).
The PRP seemed Darker to me than Takeman resistors used in all the same places.
 
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