Is anyone building the DIY Pass F-5

sts9fan · « **Reply #40 on:** 18 Sep 2010, 07:54 pm »

I would recommend getting boards from DIYaudio. That way you know they are not "for profit" vultures.

Russellc · « **Reply #41 on:** 22 Sep 2010, 11:23 am »

Quote from: bayman on 13 Sep 2010, 03:09 pm

Hi Chlorofille,

Where did you buy those boards? They look very nice. And what did you pay for them? I´m going to use them on the V-1 open baffle speakers

Thanks Flemming Bay

I think cviller is out of boards. He has given the gerber file to member Variac, who is to run them again and they will appear in the "DIYaudio store" over on DIYaudio.com, where the BA-1 and BA-2 amp boards are.

Russellc

Russellc · « **Reply #42 on:** 2 Oct 2010, 05:12 pm »

Anyone making any headway towards firing up a F-5? Mine still continues to impress.

Russellc

Russellc · « **Reply #43 on:** 29 Oct 2010, 12:21 am »

Throughly broken in now, bias and DC offset are very stable. This amp is fantastic
sounding. If anyone's on the fence, JUMP! Very easy build to boot.

Russellc

jtwrace · « **Reply #44 on:** 29 Oct 2010, 12:23 am »

I had a Pass Alpeph 30. What a great little amp...

1MOR · « **Reply #45 on:** 29 Oct 2010, 01:00 am »

OK, I guess I am up for this!

I have an F5 parts box that keeps getting heavier. Got the case figured out!

Russellc · « **Reply #46 on:** 29 Oct 2010, 02:10 am »

By the way, it appears the DIYAudio forum now has the Cviller F-5 boards back in stock.

Russellc

Russellc · « **Reply #47 on:** 30 Oct 2010, 12:20 am »

Nice parts stash 1MOR! Put that sucker together! As you probably suspect, you have the makings for one of the most impressive amps I've owned, no kidding! I cant wait to see your fireup thread.

Russellc

1MOR · « **Reply #48 on:** 30 Oct 2010, 12:59 am »

Quote from: Russellc on 30 Oct 2010, 12:20 am

Nice parts stash 1MOR! Put that sucker together! As you probably suspect, you have the makings for one of the most impressive amps I've owned, no kidding! I cant wait to see your fireup thread.
Russellc

Sinks are Conrad MF35-151.5 from a GB on diyaudio last year. I stocked up on CViller boards. If you need another set of PD boards let me know, I can help. A "friend" will help with the case aluminum. Still need signal and speaker wiring, will probably go with the Vampire Wire products.

Russellc · « **Reply #49 on:** 30 Oct 2010, 02:08 am »

Quote from: 1MOR on 30 Oct 2010, 12:59 am

Sinks are Conrad MF35-151.5 from a GB on diyaudio last year. I stocked up on CViller boards. If you need another set of PD boards let me know, I can help. A "friend" will help with the case aluminum. Still need signal and speaker wiring, will probably go with the Vampire Wire products.

You have message on AK, I want those boards!

Russellc

Russellc · « **Reply #50 on:** 13 Feb 2011, 12:52 pm »

Thought I would post two things, one the Peter Daniels boards are available again as well as Cviller versions at DIY.

Two, I'm beginning another F-5 build. This one will be a little different. Instead of dual mono, this one will have a single transformer. It will also be a big one, about 500VA. This one will have no current limiting, and will use some fancier resistors. This build will also use the Toshiba mosfets as outputs.

Really, more people should build this amp, boards are available and cheap, parts count is extremely small. Its maybe slightly more difficult than a chip amp, and will quickly fall into your favorite amp slot very quickly. Plus, there is tons of support out there and several well documented builds. I thought I just might document this one right here as an attempt to get a few more into this project. I have boards, fets and the Toshiba outputs gathered up, as well as the power supply boards.

This amp will also use a single power supply, like Nelson's original F-5. Since only one set of caps will be used, I intend to use a little larger and fancier ones instead of the 22,000 uF Panasonics.....but if nothing strikes my fancy, those worked fantastically in my first F-5. Stay tuned, heat sinks and case are to be figured out, and transformer and heat sinks need ordered. I'll likely use Antek and M&M again.

Russellc

avionic · « **Reply #51 on:** 15 Feb 2011, 06:38 am »

"I thought I just might document this one right here as an attempt to get a few more into this project."
I for one would greatly appreciate that. I have been on the fence about building an f5 for some time.

wushuliu · « **Reply #52 on:** 15 Feb 2011, 07:36 am »

Quote from: avionic on 15 Feb 2011, 06:38 am

"I thought I just might document this one right here as an attempt to get a few more into this project."
I for one would greatly appreciate that. I have been on the fence about building an f5 for some time.

Seconded. My big hurdle is the enclosure and drilling/securing the heatsinks, fets, stuff like that. If I could see how that's done I'd feel more open to tackling the F-series...

nodiak · « **Reply #53 on:** 15 Feb 2011, 04:02 pm »

Just to put it out there ... I saved a lot of time and money buying an old Hafler (DH220) for the chassis for my amp project. I know the F5 requires big heatsinks but if the haflers, or some other similar brand, has big enough heatsinks you won't have to drill as much as a new chassis (panel components already drilled, etc). Just make sure of interior space. Just a thought.
Agree on F5 looking like a great amp.

Russellc · « **Reply #54 on:** 17 Feb 2011, 04:44 am »

Quote from: wushuliu on 15 Feb 2011, 07:36 am

Seconded. My big hurdle is the enclosure and drilling/securing the heatsinks, fets, stuff like that. If I could see how that's done I'd feel more open to tackling the F-series...

Well, stay tuned. If you want a preview, look at my build "F-5 take four" on AK. The drilling and tapping was my first time, and it went perfectly. This was due in no small part to member Westend's aluminum cutting skills. There are also several other completed builds there as well, and at least 2 current builds going on.

The case construction for a basic amp is very straight forward. The heatsinks form the sides of the amp. The only holes that are threaded are the ones that go into the heat sink. I drilled them by hand with a cordless drill and tapped them with an tap bought from the local hardware store. Very easy to do. The other holes are through holes that a bolt and nut go through. Top and bottom connected to pieces of angle aluminum that run along the bottom and top edge of the heat sinks. They are attached to the heat sink by tapped holes. I used 4-40 for the small stuff, and 10-32 for the larger. The panels were 1/8 inch aluminum.

I think I have a few pics in the gallery here of the F-5 as well, but the AK build shows it from pieces stage all the way to completion. Wush, I know exactly how you feel, I was VERY apprehensive about working with metal, drilling and tapping were alien. I am glad to say it was no big deal at all, of course I had all my pieces cut to size. You'll see, you can do it easily if I can!

Russellc

Russellc · « **Reply #55 on:** 21 Feb 2011, 01:37 am »

OK, having gone through the parts drawer, I've collected 2 pairs of matched Jfets, 2 matched pairs of Toshiba outputs. Since I have them, I'm using the Peter Daniels Boards again, as well as the power supply board. I'm trying to buy some really nice 75 volt 68,000 uF caps, but am having a little pay pal address problem. A little more than twice what the Daniels boards carried on my previous build, but this one will have a single power supply board instead of two, and single transformer, (like the actual First Watt F-5) but a little more capacitance, and the transformer a little larger, 500VA vs 300 VA I believe the original has, or there abouts.

The transformer needs to be ordered, along with RCA jacks, binding posts, standoffs.
Previously I used a kit from Tech-diy, but since I already have the j-fets and mosfets and am eliminating the current limiting circuitry, there are so few parts that I thought I'd try some fancy resistors this time. Also, last time I used the Peter Daniels diode boards, loaded with 16 MUR 3060 30 amp rectifiers. I think with half the power supply (one board instead of two) I think only 8 would be needed, I'll have to check over the schematic. Even with 8, its a lot of holes to be drilled, 8 devices to slip pads under and so forth. That's another change this time, last time I used silpads, which worked fine, but I've bought some mica insulators. At the last min., I may have decided to use the keratherm or what ever that Zhou sold on DIY. they are supposed to have even better heat transfer than mica and goop.

That will leave heatsinks and aluminum for the case and faceplate. Now to decide on some fancy board stuffing resistors. Oh, and the other little devices, I think some of them are eliminated with the deletion of the current limiting circuitry, again I'll have to check Peter's group buy thread where this info was included.

Ok, until next time, and then the pics will start....I assume no one wants to see pics of some boards and bags of fets!

Russellc · « **Reply #56 on:** 23 Feb 2011, 01:45 am »

I'm going to round up the tools needed for chassis building and take pics of them. There are various ways to do things, this is a good way, and an inexpensive way to assemble a aluminum chassis.

russellc

avionic · « **Reply #57 on:** 23 Feb 2011, 06:58 am »

Nice russellc, I have ordered boards from Peter and located and ordered all transistors. Looking for some heat sinks now. Looking forward to this

Russellc · « **Reply #58 on:** 23 Feb 2011, 02:26 pm »

Quote from: avionic on 23 Feb 2011, 06:58 am

Nice russellc, I have ordered boards from Peter and located and ordered all transistors. Looking for some heat sinks now. Looking forward to this

Nice, you will like this one. As you can see from above, I am also using the Daniels boards. His F-5 Group buy (In group buy forum on DIYAudio.com) is a good read, is much shorter than the F-5 thread, and has tons of good info, and suggested grounding and so forth.

I havent tried the others boards, I had such good luck with Peter's boards. The amp is dead silent, even with ear right next to the driver, and this is with horns and high efficiency speakers!

Which output devices are you using? I used IRF on the first build, I think Westend and some others on AK used the Fairchild devices. I'm using the Toshibas this time, Specialidiot and others advised me they helped bring the amp to "another level".

There's the buggaboo about one of the 2 IRF devices not being entirely symetrical with the other, and it can be measured, but the hearing part sounds superb!

A glance at the bank account shows that the tax man was good, so heatsinks and transformer to be ordered shortly.

Avionic, are you going for the basic "amp shape" or have something else in mind? I saw a nice one where the heat sink was on top, laying down fins up. The power supply caps were arrainged along the sides, with the whole thing looking sort of like a tube amp with no tubes....dont know how efficient the sinks are oriented like this however...

Just wondering...

Russellc

Russellc · « **Reply #59 on:** 23 Feb 2011, 02:30 pm »

Also, I'm wanting to use some "fancy" resistors this time, althought the Dale's sounded great.

Russellc