Nelson Pass F5 build, Part Trois...

rtate said:
Westend, Nelson's PS schematic shows 2 primary windings, however I do think you are right that it makes little difference with AC.
I was just checking :scratch2:

I am planning on starting a thread at some point.
I just wanted to get all the parts in order first :yes:

Thanks for the help.
Click to expand...
No problem, looking forward to your build thread.

Russellc said:
Yet another steps forward to build F-5!:thmbsp:

Russellc
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Soon to be a Dirty Dozen, methinks.:D
 

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Got 'er done!

Just finished up with the top panel and I guess I can call the amp, "done". Instead of getting anything fancy with the faceplate and top panel, I chose to leave the faceplate with a polished look and to drill some ventilation holes in the top and give it a laquer finish.
The faceplate was polished twice because of the remaining scratches mentioned in the previous post. I cut 5/16" off each end of the handles to match the faceplate dimensions.
The top panel was primed and sanded twice, as was the black laquer finish coat. I followed that with two coats of clear-coat. It will pass muster and I can always make another if I get the urge.

The amp is really a treat, something like you encounter only a few times in your life, it's just that good. I'd like to thank Jeff for posting his original build thread and bringing the F5 to our attention. His thread was very clear and I referenced it quite a bit for deciding on what the best way was to layout my components. Tal's thread was also great and his pictures were absolutely the best, showing wiring layout and component locations. Without these two guys, I would have no F5. Thanks to both for leading the way.
 

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Well done Lance. My inspiration came from ejfud's Tim Rawson built F5. Of course I gushed over it and Gary pointed me to the cviller boards on diyaudio.com. The rest, as they say, is history.

My thought was to have two blue LED's on my faceplate too, but I just don't have the gumption to drill the plate. Mine is gold anodized, and I'm uber worried about a sloppy job.
 
Wow, wow I mean wow Lance! That is beautiful. Excellent work.

What did you use to polish the front so nicely?

Glad you like it. Mine just never leaves my system, no matter what speaker I have in their. Yep, it's that good with just about anything.
 
specialidiot said:
Well done Lance. My inspiration came from ejfud's Tim Rawson built F5. Of course I gushed over it and Gary pointed me to the cviller boards on diyaudio.com. The rest, as they say, is history.

My thought was to have two blue LED's on my faceplate too, but I just don't have the gumption to drill the plate. Mine is gold anodized, and I'm uber worried about a sloppy job.
Click to expand...
I think the best way to drill the anodized plate would be to establish the through hole and then chamfer the hole with a larger bit. Any hole you put in it is going to show a slight silver color, in the hole, and, possibly, on the edge. Make it a feature, so to speak. The other way to tackle that would be to use an LED holder that has a small flange to cover the hole:LED holder I have a few of them if you want to do it that way. Lemme know.

ejfud said:
Wow, wow I mean wow Lance! That is beautiful. Excellent work.

What did you use to polish the front so nicely?

Glad you like it. Mine just never leaves my system, no matter what speaker I have in their. Yep, it's that good with just about anything.
Click to expand...
Thanks, Gary, a compliment from a craftsman means a lot. :yes:

The faceplate polish goes like this: wet sand using successively finer grits, 220, 320, 420, 600, 800, 1000, 1500, 2000 (sounds daunting but it is actually pretty painless with a palm sander, spending only a few minutes with each sheet). After sanding I used :Number 7 rubbing compound-first cut, Turtle Wax Polishing Compound-final cut. I applied these with a car buffer. There are better choices of metal polishes, I used the ones I had on hand.

The sound is incredibly sweet. All the adages and reports about the F5 are totally true but it wasn't until I had it hooked up, that I could appreciate the special character of the design. What my couriosity is , now, are all Class A amps this nice or is it just the F5?
 
When you started this thread, I said "great start".

Now I must say, Great Finnish! ( pun intended ) The rack handles look fantastic! :thmbsp:

just
Scott
 
Awesome work my friend!!!!

enjoy:thmbsp::music:


specialidiot said:
My thought was to have two blue LED's on my faceplate too, but I just don't have the gumption to drill the plate. Mine is gold anodized, and I'm uber worried about a sloppy job.
Click to expand...

I was initially only going to do one because of concerns like yours, but those bright blue LED's are so nice looking in 'stereo' on the front panel that,.... next thing I knew there was, my faceplate clamped down to a drill press me drilling holes thinking to myself "i'm probably going to regret this"
Haven't yet, love those bright blue leds on the front of my f5!
Mine have built in shrouds that allow for a 'little' error.

F5LED008.jpg

Q19P1CXXB24E.JPG


cheers
tal
 
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Can't wait to hear this when I come up after Thanksgiving. That baby looks SWEET! I love the polishing you did on the aluminum.
 
Great job guys!! Beautiful work!

Suggestion when firing it up with the dim-bulb tester. Yes, it steals most voltage as the amp sucks more current, so...as you discovered...you cannot rely on ANY voltage measurement when it is connected. The purpose is simply to confirm that nothing self-destructs.

When you first fire it up (with, say, a 100W bulb as your dim-bulb), you should check the bias on both channels. Confirm that changing the pot changes the bias current on each channel, then turn the bias down to near-minimum! Then you know that it is totally safe to power up the amp and start cranking up the bias to the recommended levels, and don't have to worry about clockwise or counter-clockwise. ;)

Anyway, great job. Wish I had time to tackle such a project.
 
qboneus said:
I was initially only going to do one because of concerns like yours, but those bright blue LED's are so nice looking in 'stereo' on the front panel that,.... next thing I knew there was, my faceplate clamped down to a drill press me drilling holes thinking to myself "i'm probably going to regret this"
Haven't yet, love those bright blue leds on the front of my f5!
Mine have built in shrouds that allow for a 'little' error.
Click to expand...

Tal, any chance you have a source for those LEDs for me?
 
MrIgotNomoney said:
Guys
Good info about the pot orientation, I have got my boards and and I am starting to plan out my build.
The biggest hassle is getting heatsinks and a chassis together, Im thinking to save money the best bet is to build my own chassis. Im still reeling over the cost and shipping for a pair of Conrad heatsinks.
I have a bunch of Nichicon 10000uf@50v I was thinking about using 10k uf and going with a 600va transformer for the ps. anyone using CVillers rectifier boards ?
The small parts and silicon, are pretty reasonable from TechDiy

bob
Click to expand...

I'm using the Daniels boards, including the power supply as well as rectifier boards, which use MUR 30 amp ultra high speed rectifiers. Probably very similar.

russellc
 
The electrical stuff is easy...the case is not. I don't think I could duplicate your's or Westend's efforts there.
 
EchoWars said:
Great job guys!! Beautiful work!

Suggestion when firing it up with the dim-bulb tester. Yes, it steals most voltage as the amp sucks more current, so...as you discovered...you cannot rely on ANY voltage measurement when it is connected. The purpose is simply to confirm that nothing self-destructs.

When you first fire it up (with, say, a 100W bulb as your dim-bulb), you should check the bias on both channels. Confirm that changing the pot changes the bias current on each channel, then turn the bias down to near-minimum! Then you know that it is totally safe to power up the amp and start cranking up the bias to the recommended levels, and don't have to worry about clockwise or counter-clockwise. ;)

Anyway, great job. Wish I had time to tackle such a project.
Click to expand...
Well, you summed up the correct way to bias the amp at start-up better than any of the folk at DIY audio or I could ever hope to. Since my near melt-down, I've done a bit of reading on the trimmers and see that , depending on how they are placed in circuit (pin positions, trace leads, and parallel vs. series), denotes the operation.

EchoWars said:
The electrical stuff is easy...the case is not. I don't think I could duplicate your's or Westend's efforts there.
Click to expand...
May not be a need to duplicate. Maybe we could work out a trade or there are different case models that are surfacing that won't break the bank.

specialidiot said:
thanks a bunch Tal.... I have two 16mm's on the way. I have also built a little amp platform out of mdf and painted it with some rattle can flat black. When I get the lamps going I'll post pictures in my thread.
Click to expand...
He takes the plunge...er...drill :D I'm looking forward to seeing the platform.
 
westend said:
The sound is incredibly sweet. All the adages and reports about the F5 are totally true but it wasn't until I had it hooked up, that I could appreciate the special character of the design. What my couriosity is , now, are all Class A amps this nice or is it just the F5?
Click to expand...

I can't speak for all Class A amps, but the DoZ (Rod Elliott's Death of Zen) that Echowars built for me is as nice as you describe - and easily the best amp I have had in my system.
 
westend said:
OK, here is the bill of materials for my F5 build.

I bought the Tech-DIY kits and there was some problem with the parts being of different values and some were missing. I will try not to duplicate those missing parts in this BOM.

Power entry model:http://search.digikey.com/scripts/D...go&lang=en&site=us&keywords=Q303-nd&x=25&y=15

Transformer:http://www.antekinc.com/details.php?p=75 John Angio was offering a $10 discount by using a coupon code from the F5 thread at diyAudio.

Rectifier bridges:http://search.digikey.com/scripts/D...&lang=en&site=us&keywords=gbpc3502-e4/51gi-nd

NTC Thermistors:http://search.digikey.com/scripts/D...=search_go&lang=en&site=us&keywords=kc006l-nd

Amp and PS board from Cviller group buy at DIYaudio. Nice boards and here is the guide: http://viller.org/audio/2009jan_gbf5/gbf5_guide.pdf It has pics and board layout with the original N Pass circuits. Ordering webpage:http://viller.eu/gb/

Power supply: 8 x http://search.digikey.com/scripts/D..._homepage_link=hp_go_button&KeyWords=p6668-nd
8 x http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P0.47W-3BK-ND
2 x http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P2.2W-3BK-ND

The Tech-diy kits will have some sort of .47 resistor, also, but I used the same Panasonic 3w resistors (above) for the amp boards.

Tech-diy kits:http://tech-diy.com/Store/CloneKits.htm The kits contain all the transistors and resistors for the F5 amp boards. Jack has been sending out a single 50 ohm resistor for the current limiting circuit but I populated the boards with 8 x http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P100W-3BK-ND

I purchased mica insulators, TO-247 from Digikey but the vortex of grunge sent them off to a parallel universe so I purchased these Bergquist Silpads for the Mosfets:http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=BER120-ND

I sourced a 4 place terminal strip at Ratshack for the NTC thermistors, covered with a piece of Craftsman display holder. Worked great. These are placed in series on the transformer primaries to limit in-rush current. RS also supplied fuses and LED's.

Wires: Power runs and speaker leads- 14ga. stranded from Home Depot (largest size that will fit the vias in the Cviller boards, I believe). Input signal-Shielded interconnect twisted pair 24 ga., I had on-hand.

A builder will need some wire management items like tie straps, etc. and some sort of standoffs. I sourced most of this from my local True Value and Home Depot. I used HDPE for the standoff bases. This I had on hand and was purchased at Rockler Woodworking.

Chassis jacks are Vampirewire, as are speaker teminals. I was fortunate to get them on Ebay at a low price.

The heatsinks are the M&M metal sinks:http://www.mmmetals.com/extrusions/drawings/MK62430.JPG

The Chassis: As was posted, the aluminum chassis, I built, using panels and angle from my local supplier. The Amerock faceplate handles are stainless steel, sold at Home Depot.

I hope I ddin't miss out on anything. If anyone building one of these fine amps has a question, feel free to ask. The fact that a Caveman like myself can put one of these together, sounding and looking fairly nice speaks volumes about the ease of construction. Go for it! :yes::banana::thmbsp::music::D
Click to expand...

So, would one need to order TWO tech DIY kits for one amp? Seems like just enough parts for one amp board. :scratch2:
 
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