Fuses on Apt Holman preamp

[steelglam]

Anyone know where the fuses are on an Apt Holman preamp? I can't seem to locate them inside the unit, or on the schematic for that matter. My unit no longer turns on, and I think I may have blown one of the fuses.

Thanks in advance for any insight!

 

[cademan]

It could have a fusible link or internal fuse inside the power transformer. Can you post the schematic or at least the power supply section?

 

[steelglam]

The schematic is located here, the first pic being the left side of the schematic and the second being the right side.

http://kenrockwell.com/audio/apt/images/holman-preamplifier/schematic-1.jpg

http://kenrockwell.com/audio/apt/images/holman-preamplifier/schematic-2.jpg

 

[cademan]

It has a fuse! It shows a 1/8 amp slo-blo pigtail fuse just before the power transformer. Should be located near the power transformer or the main line power input somewhere. It shows it's on the schematic.

 

[steelglam]

It has a fuse! It shows a 1/8 amp slo-blo pigtail fuse just before the power transformer. Should be located near the power transformer or the main line power input somewhere. It shows it's on the schematic.

OK, wow. I'll dive back in tomorrow or the next day and see if I can find it in one of those locations. Thanks much!

 

[blhagstrom]

Things are pretty tight around the transformer. It may be hiding a little.

 

[cademan]

Circled in red!

 

[steelglam]

Awesome. Thanks so much guys. I'll let you know the result of my search!

 

[chicks]

Find the green and black wires from the transformer. It's tied to them on one end, and the three switched outlets on the other. Looks mighty tight in that transformer shielding box...

 

[steelglam]

Hi everyone,

Reviving an old thread that I started. I am just getting around to purchasing the fuse for my Apt Holman pre. Would this be an OK replacement for the one that blew:
http://www.amazon.com/Eaton-Bussman...r=8-2&keywords=Slow-Blow+Fuse+1/8+amp+pigtail

1/8 amp = 0.12 amp, correct? The Apt one needs to be 1/8 amp, slow blow, and pigtail.

Let me know.

Thanks.

 

[century tek]

Should work. Hope you bought a few just in case.

 

[steelglam]

I replaced the fuse, and it works now. It was a really tight spot, particularly at the bottom connection, so I had to do some improvising by leaving some of the old lead in place at the bottom and soldering the new lead onto the old one. But it worked!

The "tone defeat" is still giving me problems (cuts out one channel when disengaged), but at least the unit is working otherwise!

Thanks for all of the help!!