Andy
I just completed the cathode follower amp, and had a great time with the build using a Hammond 272jx for the power transformer. To my knowledge, I followed the very clear plans accurately. It was my first amp project (yes, I know that this isn't recommended for a first build, but I decided to be brave) and I am looking forward to using it!

My problem is when I first went to power it up, the fuse blew. I double checked my wiring for the power transformer and tried again (gray wire - 115v connected). Fuse blew.  I tried powering up without the tubes installed thinking that might help me isolate where a short might be. Fuse blew. I tried reconnecting the power transformer with the black wire - 125v power. Fuse blew. 

I have gone over every connection from step one, double checking all the wiring and feel pretty confident that all is built according to plan. I can't identify any shorts or bad connections.

Can anyone give me some next steps for trouble shooting? Any help is appreciated!
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Robbert
Is the fuse the correct one?  I usually when build stuff i first build the power supply and test that in isolation. This would be a first step, you can check then the high voltages and the filament voltages.

Try to isolate your power supply and check again. If fuse blows now, you know you have a power supply issue. Check the wiring and check the diodes.
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Carson
Have you triple checked the 3rd page in the instructions specific to the Hammond 272jx?  And do you understand how it relates to the last page schematic?  It was a little confusing for me to follow at first

Does your OPT have two heater taps?  Can you post pictures?

This amp is damn near bullet proof and you are going to love it once we get your sorted out...I've built 3 now.
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Andy
Thank you for the input. These are the trouble shooting steps that I am looking for and I appreciate the help! I am taking this on as a learning process so embracing the work of having to figure it out. Here is where I am at now.

Power supply is isolated and still blows a fuse (I have tried fuses 1.0 up to 2.5 amps - plans call for 1.5 amp fuse). The steps I took were to try fuses as I both disconnected the filament side and high voltage side. Fuse blows with both or either side connected. Currently, high voltage side is connected within the power supply, but have isolated the power supply from the rest of the amp by disconnecting power out from the large caps and the filament taps are not connected. After turning on power fuse blows immediately but large capacitors power up to about 110 volts. Just as a diagnostic, I tried the power transformer not connected into the power supply circuitry at all (only AC in, switch and fuse) and the fuse did not blow.

I have checked the resistors. R1 (200K), R2 (100K) and R3 (200K) all read low (R1 and R3- 120K, R2 - 80K) but my understanding is that is because they in the circuit. I took out R1 and it tested fine at 200K). Testing across R1 and R3 in circuit reads 80K.

I have quadruple checked the diode polarity and 3rd page in the instructions for the 272jx. I follow how that relates to the last page schematic, but won't claim to understand the differences between last page and 272jx. What I don't understand is how the center taps on the transformer (red/yellow and green/yellow) impact the circuit, but I have them connected according to instructions, and can identify where in the schematic they fit in. I just can't claim "understanding"!

One question about the capacitors - The capacitor I used for C4 (0.01 MFD 1600v) is rated 1600v DC, but 450VAC.  Could that capacitor have been fried as it is connected on each side to 300VAC so 600V total? Or did I go wrong with the type of film capacitors I used? My C4 is an "AC and Pulse Film Capacitor". My C5 is a "general film capacitor" 0.1 MFD is rated 630VDC and 250VAC.  I went ahead and ordered a new C4 "AC and Pulse Film Capacitor" rated 0.01 MFD 1600VDC 650VAC. But as I write wonder if I went wrong on the type of capacitor? Not being to proud to ask a stupid question - MFD in the plans refers to microfarads NOT millifarads, correct?

Carson - can you clarify OPT? Output transformer? the Power Transformer (272jx) has two heater taps (as I understand) which are the green wires. They are not connected in the photo to isolate the power supply. The Output Transformers are the UBT-1.
IMG_1401.jpg  IMG_1402.jpg  IMG_1404.jpg 
Thank you for any additional trouble shooting steps! Any input is appreciated. 
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