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F5 v2.0

specialidiot

specialidiot

Break Glass, Smoke Lucky
After building Gary's (ejfud) F5 monoblocks using Toshiba actives, HEXFRED rectifiers, and boutique resistors, it was just a matter of time before I'd build new boards for my F5. With all of my more pressing audio projects out of the way, I set to stuffing a pair of cviller boards.

I'm using Takman carbon composition resistors in most places. The 3 watters are Panasonic, and the 10K is a Vishay which is simply used as a current limiter for the power indicator LED.

Next step is to install the active components. I've learned my lesson to take my time and quadruple check that I have the proper devices in the proper location with proper orientation. Don't ask why. ;)

Here are the two boards with the resistors installed. Not what I've done with the leads of the .47 ohm 3 watts - these are the resistors we measure for bias current. I won't have any problems getting my meter leads to grab.

f5a.jpg
 
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golana said:
I love populating boards. Very soothing. Nice job BTW.
Can we see your nipples?
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You'll have to buy me a drink first - at least.

djnagle said:
Very nice spec. Keep the pix coming.
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ejfud said:
Nice build, nicer picture.

I'm with Dennis, pictures throughout please.
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More pics as things progress. It shouldn't take long. I'm figuring out which actives go where right now but no more close in work for today. My eyes are shot.

Not bad picture for a cell phone huh. Jack should take notice.
 
I found that it was fun to go back and solder from the top side as well, so that both sides look perfect!
 
Got my actives (minus the drivers) and pots installed tonight and I'm done until my thermistors arrive - should be tomorrow or Thursday.

Actually if they don't come tomorrow I can work on replacing the rectifiers with HEXFREDS.

In my search through my F5 parts bin I find that I actually have two stereo sets of Toshiba drivers and outputs!
 
This set of boards go into my F5, but yeah I need to get them over to my cabinet guy so he can machine the panels.

Right now he's busy with wood though.
 
Good looking boards Spec. I've been a tube guy for years but always had a SS amp for backup. I've got no tube amps up and running for the last year so I've been using my Adcom and I got to tell you, that I like the sound. I know there is a difference between tubes and SS but I now feel that it is just that "a difference" not good or bad. All this to say that maybe in the near future, I'd like to give the F5 a shot.
 
D you know I love my tubes but the F5 has a special quality. Before I had my F5 I was running a MC225 in my office. I wanted to try the F5 in here and the McIntosh never made it back. Sold it, in fact.

While my F5 is on the bench for this rework I have an Eico HF-81 running and I am liking it a LOT. Its been fully recapped and Jay rebuilt the phono section.

Still, the convenience of the SS (I left it running for MONTHS) and the sweetness of the F5 - especially with HEXFREDS and Toshibas will mean it will return to my office eventually. I think numbdiver intends to borrow it for a while to see if he wants one.
 
Making some progress tonight.

Hexfreds are swapped in, that was more work than I thought. Toshiba outputs are mounted and wiring is dressed, ready for the transplant patient. Note that I marked the crap out of which output goes where. I will not make that mistake again.

f5c.JPG


Just have to select an LED and I'm ready to go.

f5b.JPG
 
Everything's together and ready for power up - tomorrow. I know if I get going now It'll be daylight before I quit messing with it!

f5d.jpg
 
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Somehow that looks signicantly different from the original, maybe the wiring but for sure, very well done! Ya, it's easier to mark everything and get the solvent out later to take the markings away then frying devices. I am marking everything these days, too much Senior Skid in my head.
 
So if yer done with that one I guess I need to get to work on the Bobbins, huh?


Bobbins = Bob Ribbons. :)
 
westend said:
Somehow that looks signicantly different from the original, maybe the wiring but for sure, very well done! Ya, it's easier to mark everything and get the solvent out later to take the markings away then frying devices. I am marking everything these days, too much Senior Skid in my head.
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Thanks Lance, Really the only thing I did different was that I replaced the speaker output wires to the binding posts, and maybe I dressed it up a bit.

The power supply came up fine, so I'm confident. I just didn't want to keep going any further tonight as there wasn't time for a good warmup to set the idle current anyway.

And I may leave the markings in there for... character? We found a board in our house behind a bathtub wall signed and dated by the original owner in 1937. That was kinda cool.

RayW said:
So if yer done with that one I guess I need to get to work on the Bobbins, huh?


Bobbins = Bob Ribbons. :)
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I like the name!!! Not a huge rush Ray but I'll be itchin' to start yours soon. All the parts are in and I have the heatsinks to deliver to Lance for enclosure fabrication. We just need to decide when to meet up, as he's also in the middle of a speaker build.

You did get the email, right?

I do have a couple of minor projects - tune the input stage of my Allen 60's and relamp my PC2002M. But that's just an evening or two.
 
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