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Transformers [message #10872] Wed, 15 December 2004 20:06 Go to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
It may be 50$ for the power trans on the 5867 pre. I tried many places and that is the lowest acceptable unless you want to try used; such as a dyna which has similar specs. I have considered a better quality trans in liue of boutique caps and such. ICR's and Mouser metal film with radio shack RCA jacks and a trashed line cord and fuse set-up. The chassis is the thing now. And the chokes.

Re: Transformers [message #10874 is a reply to message #10872] Wed, 15 December 2004 21:07 Go to previous messageGo to next message
colinhester is currently offline  colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas
Illuminati (3rd Degree)
I don't think you're going to find a more basic pre around (or meaningful project for that matter.) As Wayne said, this has a good reputation and takes only about an hour to build. I know we had talked about a price of around $100, but that was just a number thrown out.

This is a great project to begin the group build. It's simple and already has a great website devoted to its construction. We can build our own reference section and just see how things evolve.

Not only am I excited about the build, but even if someone decides not to do the construction there is a wealth of knowledge just waiting to be shared floating around these parts. I would be thrilled to hear everyone's opinion on both circuit theory and construction techniques. Like I said before, I'm here to learn.....Colin

Re: Transformers [message #10876 is a reply to message #10874] Thu, 16 December 2004 01:42 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
I am pondering whether to just bite the bullet and purchase a good transformer just for future reference. I feel that the trans is the most important piece and after that it's a crapshoot. Resistors in an amp don't seem to change the sound much and caps, well I am not buying copper lead jupitor beeswax for 126$ apiece; so that leaves ICMW or some other reasonable alternative. The biggest decsision I see is the chassis. And good connectors.

Re: Chassis [message #10879 is a reply to message #10876] Thu, 16 December 2004 02:50 Go to previous messageGo to next message
BillEpstein is currently offline  BillEpstein
Messages: 886
Registered: May 2009
Illuminati (2nd Degree)
If you have a router and a chop saw; if you have just a hand miter saw...............

get a 1x4x6 #2 pine board for $2.46 and a brass plated aluminum (non-magnetic) door kickplate 6x36 for $10. Send the 26" you don't use to the next builder. The kickplate will have holes pre-drilled in it, too. Size the pine to screw the 6" kickplate directly to it or rout a narrow rabbet to accept it then put some "stop" molding where the screws go. You can cut the kickplate with any power saw but sandwich it between sacrificial pieces of plywood to keep metal shards from eyeballs.

After you miter the 4 pieces lay them out edge to edge. Use masking tape to connect them pulling and stretching the tape. 2 pieces on each connection to even the strain. Carefully turn them over to expose the angles and apply PVA or urethane glue to each surface. If you use polyurethane don't forget to dampen the wood, first. Also, it's very runny so apply tape the length of the joint on the outside to keep the glue off the surface.

Now set them on edge, form them into the final box configuration and tape the remaining joint. Place the chassis on some waxed paper to save Wifey's cherry dining room table. It will peel off easily after the glue dries.

Re: Chassis [message #10880 is a reply to message #10879] Thu, 16 December 2004 06:10 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Good idea. Whats the time frame, would you think. The angled cuts and tape, thats how Bottlehead does it.

Re: Chassis [message #10887 is a reply to message #10879] Thu, 16 December 2004 19:15 Go to previous messageGo to next message
GarMan is currently offline  GarMan
Messages: 960
Registered: May 2009
Illuminati (2nd Degree)
Bill, the kickplate is used as the top plate of the wooden chassis, right?

Funny I should read about this tonight. I was just out this afternoon buying material for a chassis for my K-502 amp. Spend $12 for a 8"x10" sheet of 16 gauge stainless steel, polished on one side at the Metal Supermarket and $8 for a piece of 3x1x4 dressed oak. All prices in Cdn. I think the 16 gauge might be overkill. It weighed in a over a pound and half. 18 or 20 gauge would have suffice.

Re: Transformers [message #10891 is a reply to message #10872] Fri, 17 December 2004 20:48 Go to previous messageGo to next message
colinhester is currently offline  colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas
Illuminati (3rd Degree)
Will Hammond's 269EX work for this project? Can one run both heaters off the same 6.3V secondary and the other secondary at 190V? This should be close enoght to the 200V in the hand-drawn schematic. The pice from Angela is $27

Re: Transformers [message #10892 is a reply to message #10891] Sat, 18 December 2004 02:41 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
That is the schematic for the M7 audionote clone. His runs 360v ct. We need some advice on this. I am competant to build from an existing schematic with voltage test points, but I don't yet trust my design or substitution abilities. If you can find one an old dyna would work according to my calculations, and that should be cheap. To be truthfull; crunching the numbers still comes out to about 125$. Thats 60$ for the trans. 20$ for the chassis. 10$ for tubes and sockets 30$ for chokes and Well I geuss another 25$ for parts, although I have a lot in my junk drawer. What do you have for figures?

here is a pic of mine [message #10897 is a reply to message #10872] Sun, 19 December 2004 07:31 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)

this one was very similar to the E-T ForePlay. Building it with 12B4's soon, just as described below.
reggards,
Douglas

Re: here is a pic of mine [message #10898 is a reply to message #10897] Sun, 19 December 2004 10:02 Go to previous messageGo to previous message
Wayne Parham is currently offline  Wayne Parham
Messages: 18787
Registered: January 2001
Illuminati (33rd Degree)
Those are really attractive amps, Douglas. Thanks for posting the photo.

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