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PostPosted: 12 May 2010, 20:34 
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Joined: 16 Apr 2010, 16:10
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Despite all the postings about building the Bugle there are very few that show how to build it into a case, and none, so far as I could find, that give the details that a new builder would want. Hence this posting.

I started with Jack Gallagher's kits for the Bugle and power supply. Not only does he supply all the parts, he gives some very good instructions regarding how to wire the power supply to the Bugle. So I recommend you start out by getting and wiring Jack's kits. Note that the resistors on the Bugle are very close together. You need a fine tip 15-25 watt soldering iron and small diameter solder wire to avoid solder bridges. The Radio Shack 64-2051 soldering iron would work fine.

My goals for a case were functional, compact and cheap, rather than elegant. And I wanted just one case rather than two with a cable between them. That dictated a case large enough to allow 3-4” of distance between the Bugle and its power supply, with both oriented to keep the AC farthest away from the audio input, in order to minimize hum and noise.

I made some choices that could be changed. I put the power switch on the back panel to minimize power wiring and attendant hum. I used a power entry module with built in fuse box. (Jack's power supply kit includes a 1/16 amp 5mm x 20mm slo-blo fuse that fits this box.) The module requires a 3-wire IEC power cord (type C13 socket) but makes for easy, very sturdy power wiring. Be careful to get the polarity right – looking at the FRONT of the module with the fuse box down, hot is left, ground middle, neutral right, assuming you have 117 volt power as in the U.S. For the power cord I used an old three-wire PC cord with an IEC connector, so I didn't buy one. If you need to buy one, Mouser carries them.

The power switch includes a red light, redundant with the LED, but pretty. Wiring the switch is not obvious – terminal 1 goes to load (the power supply), terminal 2 to source (the top terminal on the module), terminal 3 to neutral on the module (for the light.) I used quick disconnect terminals for the power entry module and power switch to make it easier to assemble the power wiring before installing into the case. I put an LED on the front panel to show when the unit is on. (The red wire goes to the + hole on the power supply.)

I used gold-plated RCA jacks to minimize corrosion. (The insulating washers prevent grounding the shields of the jacks to the case.) I used audio coax for the I/O wiring to minimize hum and noise. (This might not be necessary, but it was easy to do.) I carefully avoided ground loops by having a one-point audio and power ground to the case, using a lug connected to the ground binding post for the turntable ground.

Installing the PCB's in the case is tricky. I wired as much as I could while the PCB's were still on the bench – power wiring between power supply and Bugle, power wiring from the module to the switch to the power supply (but I waited until installing the unit to connect the quick disconnects.) I soldered the I/O cable to the PCB's, but not to the RCA jacks – these install from the outside of the case, so you have to mount them before soldering the cables to them. For the same reason, don't solder the LED until mounted in the case.

I wanted to make the case look nice by not having mounting screws protrude through the outside of it, so I used adhesive PCB standoffs. Just before installing everything in the case I pushed the standoffs through the holes in the two PCB's, inserted the PCB's down into the case, and carefully pasted the standoffs to the inside of the case in the right locations. The cover is the bottom of the case, so the PCB's are upside down. There is only about 1/8” of clearance between the cover and the power supply heat sink, but it is enough. I spray-painted the case glossy black to fit in with my other equipment.

The attached pictures include the inside of the case, the case back panel, and a full-size drilling template for the back panel.

The inside picture shows the details of the wiring, including the one-point ground using green wire. The two connections to the ground binding post, and through this to the case, come from the ground screw on the Bugle and the ground terminal on the power input module. (The power supply is grounded through the Bugle.) The RCA jacks for input and output line up with the corresponding solder holes on the Bugle, allowing shorter runs of the audio coax. The power supply DC outs line up with the corresponding DC ins on the Bugle. At the top the yellow wire connects +15V to +; the black wire connects GND to -. At the bottom the blue wire connects -15V to -; the black wire connects GND to +. The AC wiring uses red wire for the hot runs and black wire for the neutral runs. On the power supply PCB there is no absolute AC polarity; I soldered the black wires to the back holes and the red ones to the front holes. Note that if you have 117V AC, as in the U.S., you need to connect the AC to the power supply in two places observing relative polarity; Jack's power supply instructions show how to do this, but you don't need to run two sets of wires from the power switch. Just use the parallel solder holes to run extension wires – black wire between the back holes, red wire between the front ones. Also shown are the plastic adhesive standoffs on each corner of the two boards. In use the cover is screwed on and the case flipped over, so we are looking at the bottom of the unit.
Attachment:
inside.jpg

The outside picture shows the RCA jacks, the Ground binding post, the power input module and the switch. The module and switch are oriented to minimize the lengths of power wiring between them. In the picture the switch is in the off position. Not shown is the case cover that is actually on the bottom.
Attachment:
outside.jpg

The picture with the cutting template is 8.5”x11”, and the template itself is exactly 11” wide. Cut the template out and paste it on the back of the chassis using rubber cement. (Make sure to put the correct side up!) It includes (from left to right) input RCA jacks (white is left channel), ground post, output RCA jacks, power input module, and power switch. The five round holes are drilled with the indicated drill sizes. I used a nibbler tool to cut the square openings. Lacking such a tool you could cut these openings by drilling, sawing, or filing. The power input module uses screws; the holes for these aren't shown. Mark and drill them after fitting the module in the opening. The switch is just a press fit, so be careful not to make its opening too big.
Attachment:
chassislayout.png


Parts list including Mouser Part #
Code:
  Description                  Quantity   Mouser Part #,  Price (each)
Chassis 9"x7"x2"                  1        563-AC-406        $13.80
Chassis Bottom Plate              1        563-BPA-1593      $6.10
Screws for Bottom Plate           4        534-9579          $0.14
Power Entry Module w/ fuse box    1        161-0717-187-E    $2.09
Screws for power entry Module     2        hardware store
Lighted Power Switch              1        540-LRA22H2BBRLN  $1.10
Disconnect terminals (red)        3        159-2251          $0.15
Disconnect terminals (blue)       3        159-6251          $0.12
Panel LED (red)                   1        696-LXH312ID-150  $0.87
Adhesive PCB Stand-offs           8        561-LAD250        $0.49
RCA Jacks (white),                2        502-BPJF03AUX     $2.49
RCA Jacks (red)                   2        502-BPJF02AUX     $2.25
RCA Jack insulating washers,      4        502-S1564         $0.45
RCA Jack insulating washers,      4        502-S2207         $0.50
Ground Binding Post,              1        530-111-2223-001  $2.11
Solder Lug for Binding Post,      1        159-2229          $0.14
Coax for I/O wiring,              1        172-1103          $3.03

Note this is my first post here. Please excuse if the layout is deficient. I couldn't space the parts list neatly.


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PostPosted: 13 May 2010, 12:34 
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Joined: 28 May 2008, 21:53
Posts: 4580
Location: Winnipeg, CANADA
Thanks dnelson40 for sharing your building experience and tips with the Hagerman Bugle phono preamp kit and power supply. Your build looks great.
I cleaned up the BOM a bit to make it more legible.

How do you like the preamp?

Welcome to the forum.
Cheers

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PostPosted: 13 May 2010, 15:03 
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Joined: 16 Apr 2010, 16:10
Posts: 4
In my original post I forgot to say how I like the Bugle. In short, great. Just as all the other posters have said - clear, sweet, and great value. I am using it to rip my classical LP collection to digital, using the Delta 44 breakout box attached to my computer.

Specifically regarding the sound of the Bugle in my enclosure, I seem to have made the right design choices. The Bugle is dead silent at the output. (I wired it for 40dB gain.) My turntable has an on-off switch. With the turntable connected to the Bugle, but off, still dead silent. When I turn on the turntable I can hear a bit of hum through headphones, totally masked by the music, but that originates in the turntable. The turntable ground wire to the enclosure binding post is important. If I disconnect it, hum goes up a lot, maybe by 6 dB. (I'm using a Shure V15-II cartridge in a Technics direct drive turntable.)


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PostPosted: 17 May 2010, 21:30 
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Location: Winnipeg, CANADA
Thanks for sharing you notes! ;)

BTW - here is Alan's build of the Hagerman Bugle Phono Stage with Bugle Power Supply.
Cheers

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PostPosted: 30 Jun 2010, 20:03 
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Joined: 23 Jun 2010, 14:56
Posts: 2
dnelson40:

I have to say THANK YOU! (Sorry for shouting.)

This is an extremely helpful post, and I'm grateful. I've been enjoying the Bugle for awhile with 9-volts, and I've had a power supply built and just sitting on my kitchen counter for maybe two months. I was just overwhelmed with getting all the parts together to make the enclosure.

Now, after forgetting to turn it off, and then having my wife forget twice in one week, I got sick of the whole battery thing and google'd away until I found this here.

Everything worked perfectly (except the $0.14 solder lug) and it sounds great -- it's hard to tell at the moment but I'm feeling that it might sound slightly better with 15v. [The "Solder Lug for Binding Post, 534-915, $0.14" that mouser shipped me turned out to be way too small, but that was a snap to fix with parts I had lying around. It might have been an error on the part of the person packing my order -- who knows?]

It doesn't appear that you post here often, so I'm going to find the post that directed me here, and thank you again there!

Best,

T


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PostPosted: 01 Jul 2010, 12:16 
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Joined: 16 Apr 2010, 16:10
Posts: 4
Dear Tianat,
Thanks for your very kind note. I am glad that everything worked out for you. I tried to make everything clear, so that anyone who wanted to build the case would have an easy time of it. As far as I know, you are the first to build it after me. Did you make any changes to improve it? Why not post a photo or two?

I'm sorry about the solder lug. I just checked, and I did list the wrong part number!! (For some reason I ordered small lugs from Mouser also, and in compiling the parts list I put in the P/N for the small one.) The right one is P/N 159-2229 with a 1/4 " hole to fit the ground binding post.

Maybe our esteemed moderator could edit my post to substitute the right part number. Fixed - 3 July 2010 - GM

All the best,
David


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PostPosted: 07 Jul 2010, 19:23 
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Joined: 23 Jun 2010, 14:56
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dnelson40 wrote:
As far as I know, you are the first to build it after me. Did you make any changes to improve it? Why not post a photo or two?

Will do, and sorry for the delay. I had to wrestle the SLR camera from my wife. I took a photo from each direction to try to show the layout. I really followed your design as closely as I could.

I may experiment with a brush on a dremel to create a more course pattern on the aluminum, or I may paint it.

I'm considering adding a select switch to adjust the loading, but for now it sounds pretty good (to my ears) with my denon DL-160 on a technics sl-1600mk2.

Image

Image

Image

-T


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PostPosted: 07 Jul 2010, 19:41 
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Joined: 16 Apr 2010, 16:10
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T,
Almost eerie how close yours is to mine, except that your chassis is still bright metal. Makes me proud to see that you could duplicate the design from my instructions. Your two turntables look very nice; the one on the left resembles my own Technics turntable.

Well, if anyone else is reading this thread, the moral is: if T. can build it from the original post, you can too!
David


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